2021 Recordings

Session Session_Type Science_Section Session_DT Tracking_Num Watch Abs # Title Session_Order Presenter Keywords Authors Institutions Abstract
ADSA Dairy Foods Poster Competition (Graduate) Competitions ADSA Dairy Foods Poster Competition (Graduate) 7/11/2021 0:00 s9700                  
ADSA Dairy Foods Poster Competition (Graduate) Competitions ADSA Dairy Foods Poster Competition (Graduate) 7/11/2021 0:00 t84267 Watch SC109 Determining the types of Bacillus endospores in whey protein concentrate and nonfat dried milk powders. 1 S. Jha endospore mesophile thermophile S. Jha1,2, S. Anand1,2 1Midwest Dairy Foods Research Center, Minneapolis, MN, 2Dairy and Food Science Department, South Dakota State University, Brookings, SD Several spore-forming bacterial species are commonly encountered in dairy powders. These are known to produce thermally resistant endospores. Determining the types of endospores formed by these bacteria could thus be useful in developing control strategies to improve their microbial quality and further application in product development. In the current study, samples of whey protein concentrate (WPC) and nonfat dried milk powder (NFDM) were analyzed for the presence of different types of Bacillus endospores, based on their thermal activation treatments. Twenty-five samples of each of WPC and NFDM were procured from commercial dairy plants. The 11 g of each sample was reconstituted in 99mL of phosphate buffer saline. A 20 mL portion of the respective reconstituted sample was heated at 80°C/12min for regular spores (SP), 100°C/30min for high-heat resistant spores (HHRS), and 106°C/30min for specially thermoresistant spores (STS). After the heat treatment, the samples were cooled to room temperature, and the desired serial dilutions were plated on the tryptic soy agar. The plates were incubated for 24 h at 37°C for mesophiles, and 55°C for thermophiles. The experiments were performed in duplicates and the means were compared using ANOVA. Several spore-forming species were identified based on colony morphology followed by MALDI-TOF. In WPC the samples containing the mesophilic spores were found to be 64% SP, 20% HHRS, and 16% STS. The samples containing thermophilic spores were 73% SP, 14% HHRS, and 13% STS. Similarly, in NFDM the samples containing the mesophilic spores were 95% SP and 5% HHRS. The samples containing thermophilic spores were 60% SP and 40% HHRS. This distribution reveals the higher incidence of SP in the dairy powders that could play a vital role as the powders are intended for reconstitution before use. MALDI-TOF analysis revealed Bacillus licheniformis and Bacillus cereus as the predominant species in WPC and NFDM, respectively. Some other prominent Bacillus species identified were B. pumilus, B. subtilis, and Geobacillus stearothermophilus.
ADSA Dairy Foods Poster Competition (Graduate) Competitions ADSA Dairy Foods Poster Competition (Graduate) 7/11/2021 0:00 t84266 Watch SC110 Influence of sampling intervals on the standard plate counts of milk samples. 2 R. Kalita sampling variability intervals R. Kalita1,2, S. Anand1,2, G. Djira3 1Midwest Dairy Foods Research Center, Minneapolis, MN, 2Dairy and Food Science Department, South Dakota State University, Brookings, SD, 3Department of Mathematics and Statistics, South Dakota State University, Brookings, SD High accuracy in sampling is critical in determining the microbiological quality and safety of milk and dairy products. The issue arises with the lack of a standard approach to lower the variability of sampling results of low count milk (LCM) and high-count milk (HCM). It may occur in extended and multi-processing conditions that are triggered by the heterogeneous and aggregating nature of bacteria. This study focuses on the influence of sampling intervals on the microbial count variability of LCM and HCM samples. For a pilot-scale study, 380 gallons of raw whole milk (<4°C) were spiked with Bacillus licheniformis vegetative cells (4 log cfu/mL) and pasteurized at 72°C/16 s at a 0.5 gpm flow rate for 12 h. Samples (100mL each) were drawn aseptically at intervals 0, 4, 8, and 12 h from each of the raw (HCM) and pasteurized (LCM) sides of the unit operation using commercially available a port-septum-based sampling device with needle insertion. Two continuous composite samples (2-L each) were also collected during the 12 h run in sterilized sampling bags at 2.5mL/min rate and held at < 4°C. Samples were analyzed at each interval for standard plate counts using tryptic soy agar and incubated at 32°C for 48 h. The study was done in duplicates and ANOVA was used to compare the microbial counts. Mean counts for the individual samples at 0, 4, 8, 12 h., and the composite samples at 12 h., were found to be 4.18 ± 0.10, 4.29 ± 0.12, 4.24 ± 0.12, 4.41 ± 0.12, and 4.38 ± 0.13 log cfu/mL for the HCM, and 1.52 ± 0.13, 1.57 ± 0.13, 1.66 ± 0.12, 1.69 ± 0.12, and 1.78 ± 0.10 log cfu/mL for the LCM, respectively. Results showed an increasing trend in the counts for LCM with no significant difference between the intervals (P > 0.1). The microbial counts of samples from various intervals compared with composite samples were also not significantly different (P > 0.1) for both LCM and HCM. Under the conditions of analysis, a single sample of 100 mL volumes at any interval during processing is as effective as composite sampling for estimating the microbial quality of milk under prolonged dairy processing conditions of 12 h.
ADSA Dairy Foods Poster Competition (Graduate) Competitions ADSA Dairy Foods Poster Competition (Graduate) 7/11/2021 0:00 t84254 Watch SC111 A genotypic evaluation of environmental Listeria isolates from a dairy plant. 3 S. Minj genotype phenotypic sequencing S. Minj1,2, N. Singh1,2, S. Anand1,2, J. G. Hernandez3, B. Kraus4 1Midwest Dairy Foods Research Center, Minneapolis, MN, 2Dairy and Food Science Department, South Dakota State University, Brookings, SD, 3Young Brothers Seed Technology Lab, South Dakota State University, Brookings, SD, 4Wells Enterprises Inc, Le Mars, IA Listeria species are ubiquitous in nature. Despite improvements in hygiene protocols, some strains of Listeria can persist for long periods in dairy plant environment and pose a risk of product cross-contamination. A genotypic evaluation of environmental Listeria isolates can thus provide an insight into their significance from a product cross-contamination and safety perspective. In this study, whole-genome sequencing was conducted to determine the genotypic variations and associated phenotypic expressions of 6 Listeria isolates (Listeria innocua 634–2; Listeria innocua 634–34-S-5; Listeria innocua 634–34-S-6; Listeria welshimeri 634–3; Listeria welshimeri 634–253-S-5, and Listeria monocytogenes 315-S-1) obtained from the processing environment of a commercial dairy plant. Genomic DNA was extracted using the Wizard Genomic DNA extraction kit and run through whole-genome sequencing on the Illumina MiSeq platform using V2 chemistry with 2 × 250 paired-end chemistry. The genome was fed into the RAST database to develop the annotations. The results revealed at least 13 types of phenotypic responses related to the genotypic variants of the Listeria isolates. Overall, the genotypic variants differed with the species and within the strains. Some of the common variants and features identified in the isolates were virulence (DNase, phage terminase, tRNA-Arg-ACG), cell signaling (NAG-IIA, NAG-IIB), phage immunity (CRISPR proteins), osmotic stress (CadA), oxidative stress (YRKL), and antibiotic resistance (BaiE, Lde). While L. monocytogenes was positive for all these phenotypic characteristics, L. innocua and L. welshimeri isolates lacked variants for motility (ActA), biofilm formation (AgD), and acid tolerance (AdiA), making them less resilient to environmental stress. Such information about the genes and their role in expressing phenotypic attributes can help create more robust interventions for the control of Listeria in a dairy plant environment.
ADSA Dairy Foods Poster Competition (Graduate) Competitions ADSA Dairy Foods Poster Competition (Graduate) 7/11/2021 0:00 t84132 Watch SC112 A comparison of various methods to measure the insoluble calcium content in cheese. 4 A. V. Swaminathan cheese insoluble calcium A. V. Swaminathan1, J. A. Lucey1,2 1University of Wisconsin–Madison, Madison, WI, 2Wisconsin Center for Dairy Research, Madison, WI The functionality of cheese like low-moisture part-skim (LMPS) Mozzarella is greatly impacted by solubilization of insoluble calcium phosphate during cheese manufacture. Measuring the insoluble calcium content (INSOLCC) in cheese at various points during manufacture would help to predict its functionality. The current method we use to measure INSOLCC in the final cheese involves acid-base titration, but it takes time to perform these titrations (several h), which could be a concern due to rapid pH changes impacting INSOLCC during cheesemaking process. We evaluated a simple water-soluble calcium (WSC) extraction method as an alternative method to quantify INSOLCC. The WSC method involved adding 40 g of water (55°C) to 4 g of curd, homogenizing with a hand-held mixer for 2 min, and centrifuging at 10,000 × g for 10 min. Supernatants were stored before measuring total calcium in soluble phase by ICP. We compared INSOLCC obtained by both WSC and acid-base titrations for commercial string cheeses made by both direct acid (DA) and starter cultures (SC) (n = 3). DA cheese had significantly lower INSOLCC than SC cheese. At 2 d of storage, DA and SC cheeses had an INSOLCC level of approximately 12 and 21 mg Ca/g protein, respectively, as measured by acid-base titration. Slightly higher INSOLCC levels (2–3 mg) were observed with WSC method possibly due to incomplete extraction of all soluble calcium from the curd matrix. We are currently comparing INSOLCC results of these cheeses measured by another method, i.e., cheese aqueous phase (“juice”) using high hydraulic pressure. The cheese juice method does not involve any dilution of cheese so can be considered a good reference method. The cheese juice method results would clarify if our WSC method requires a correction factor. We are also using WSC method to evaluate changes in INSOLCC during manufacture of LMPS Mozzarella. In initial trials, we made experimental LMPS cheese under following cheesemaking conditions: pH of renneting = 6.6, pH of draining = 5.8, and final pH (1 d) = 5.2. The INSOLCC levels were 34, 26, and 20 mg Ca/g protein in the initial milk, curd at draining, and final cheese, respectively.
ADSA Dairy Foods Poster Competition (Graduate) Competitions ADSA Dairy Foods Poster Competition (Graduate) 7/11/2021 0:00 t84130 Watch SC113 Gel structure formation as functions of solids concentration and thermal denaturation in heated yogurt mix. 5 J. S. Myers   E. J. Donald1, J. S. Myers1, K. A. Schmidt1 1Kansas State University, Manhattan, KS Gel formation and quality in yogurt may be manipulated by altering milk solids non fat (MSNF) concentration or varying mix heating temperatures. The strength of yogurt gels is partially due to the interactions of β-Lactoglobulin (β-Lg), α-Lactalbumin (α-La) and κ-casein which aggregate forming complexes with casein micelles typically during mix heating. Dependent upon the temperatures, different associations and bonds form. While β-Lg starts to denature and interact at ~70°C, α-La denatures and interacts at 80°C. When larger aggregates are formed, a firmer texture results. This study focused on yogurt produced from 9 and 12% MSNF heated at 70, 75, or 85°C for 30 min as a means to maximize gel firmness. Mixes were heated to the respective temperature and held for 30 min, cooled, inoculated and incubated at 42°C to pH 4.6 then stored at 4°C. Yogurts were analyzed for textural and rheological properties and syneresis; while mixes were assessed for denaturation, measured by protein fractionation and the fluorescence of advanced Maillard products and soluble tryptophan (FAST) index. The firmest yogurt was made from a 12% MSNF mix heated at 85°C for 30 min (12–85), 310.8 g, while the least firm yogurts were made from 12 to 70, 9–70 and 9–75 mixes, ~144.2 g. Storage and loss moduli showed the 12–85 yogurt to be the most viscous, 283.4 Pa and 93.1 Pa, while 9–70 yogurt was the least viscous, 31.1 Pa and 12.2 Pa, respectively. Unaffected by MSNF, the degree of denaturation was ~53.5% at 85°C, 33.5% at 75°C, and 9.9% at 70°C. However, the FAST index was greatest in 12–85, 54.5, and least in 9–70, 7.7. Syneresis was greatest in 9–85, 7.38%, and least in the 12% MSNF mixes, ~0.46%. Increased MSNF correlates with increased protein content, resulting in additional denaturation and aggregation upon heating, translating to a denser protein gel network. Understanding the relationship between gel formation, MSNF and heating allows for conditions to be optimized to yield yogurts with maximum firmness. Further research to determine how MSNF concentration affects denaturation and aggregation may potentially lead to the production of firmer yogurts.
ADSA Dairy Foods Poster Competition (Graduate) Competitions ADSA Dairy Foods Poster Competition (Graduate) 7/11/2021 0:00 t84129 Watch SC114 Milk phospholipids influence adhesion of bifidobacteria and lactic acid bacteria to human intestinal cells and their inflammatory response. 6 E. Kosmerl probiotics gut microbiota HT29-MTX E. Kosmerl1, J. Ortega-Anaya1, I. García-Cano1, R. Jiménez-Flores1 1The Ohio State University, Columbus, OH Milk phospholipids (MPLs) are highly regarded for their health-promoting properties spanning from neurocognitive functions to modulation of the gut microbiota and more. However, little is understood about their mechanisms and interactions with beneficial bacteria, such as bifidobacteria and lactic acid bacteria (LAB). We hypothesize one mechanism is that MPLs improve the adherence of bifidobacteria and LAB to human intestinal epithelial cells and shift intestinal cell cytokine production toward an anti-inflammatory state. To test this hypothesis, 4 strains (B. lactis BB-12, B. infantis ATCC 15697, L. delbrueckii, L. casei) were selected, diluted to an optical density of 0.1 (600 nm), and incubated in MRS + 0.05% L-cysteine media supplemented with or without 0.5% MPLs at 37°C. These bacteria were then collected during the late exponential growth phase for imaging by TEM, measurement of ζ-potential and adhesion properties, and inflammatory response of HT29-MTX human intestinal cells. The ζ-potential of ATCC 15697 decreased significantly from −17.3 ± 4.6 mV to −24.3 ± 7.0 mV in response to MPLs, and increased adhesion to HT29-MTX cells. Similarly, MPLs shifted the ζ-potential of L. delbrueckii from −12.5 ± 2.9 to −18.0 ± 4.4 mV. Preliminary results also suggest that MPLs increase the adhesion of L. casei to HT29-MTX cells from 8.0% to 13.9%. The bacteria pre-incubated with MPLs were applied to HT29-MTX cells for assessment of cytokine (MCP-1, TNFα, IFNγ and IL-10) expression changes by qPCR. After 3 h incubation, L. delbrueckii had the most observable shift toward an anti-inflammatory state. In the presence of MPLs, L. delbrueckii increased anti-inflammatory IL-10 expression by 2.2-fold and decreased the expression of proinflammatory cytokines MCP-1, TNFα, and IFNγ by 1.37-, 4-, and 50-fold, respectively. Similar trends were observed for both BB-12 and L. casei. Taken together, these results shed light on one mechanism of MPLs in the promotion of human health and suggest MPLs may be able to improve probiotic efficacy.
ADSA Dairy Foods Poster Competition (Graduate) Competitions ADSA Dairy Foods Poster Competition (Graduate) 7/11/2021 0:00 t83975 Watch SC115 Reducing the sugar in school lunch chocolate milk. 7 R. P. Nakamura chocolate milk school lunch sugar reduction R. P. Nakamura1, H. R. M. Keefer1, D. M. Barbano2, M. A. Drake1 1North Carolina State University, Raleigh, NC, 2Cornell University, Ithaca, NY The federal school lunch program mandates caloric and nutrient content of school lunches. This program also requires schools to provide a 240 mL serving of flavored or unflavored skim or 1% fat milk. Chocolate milk remains the most popular milk among school children but added sugar and total calories of chocolate milk are a concern. The current school lunch chocolate milk (SLCM) formulation contains 19.5 g of sugar per serving, which includes 7.5 g of added sucrose. The objective of this study was to evaluate sucrose replacement in SLCM by non-nutritive sweeteners (allulose, mixed sugar syrup (glucose, fructose, allulose), monk fruit, stevia, or sucralose). Power function curves were first generated for each sweetener to determine isosweet taste equivalency to 5.8% (wt/wt) sucrose in water (the sweet taste intensity of SLCM) using magnitude estimation scaling (MES) with a trained panel. Identified isosweet taste concentrations for each sweetener in water were confirmed by paired comparison tests with consumers (n = 40). Subsequently, SLCM with no added sugar (skim milk, cocoa powder, stabilizer) was high temperature short time processed (78C, 26 s) followed by addition of each sweetener, including sucrose at the current SCLM formulation of 7.5 g per 240 mL serving. The SLCM sweetened with sucrose served as the target control. Isosweet taste concentrations for each sweetener in SLCM were confirmed by MES scaling and paired comparison testing as previously described. Chocolate milks with each sweetener at isosweet taste intensity were subjected to descriptive sensory analysis and temporal dominance of sensations profiling (TDS) to characterize other sensory attributes. At isosweet concentrations, SLCM with allulose followed by SLCM with mixed sugar syrup or sucralose had sensory profiles most similar to SLCM with sucrose by both trained panel and TDS. Chocolate milks with monkfruit or stevia had low bitter taste intensities, later sweet taste onset and lower viscosity than SLCM with sucrose. This study establishes a platform for sucrose replacement in SLCM.
ADSA Dairy Foods Poster Competition (Graduate) Competitions ADSA Dairy Foods Poster Competition (Graduate) 7/11/2021 0:00 t83972 Watch SC116 A physicochemical investigation of flux decline in ultrafiltration of acid whey from tvarog production. 8 J. Tarapata acid whey ultrafiltration fouling critical flux J. Tarapata1, J. Zulewska1 1University of Warmia and Mazury, Olsztyn, Poland Due to increasing production of tvarog (acid coagulated cheese), popular in Eastern Europe, there is a need for optimized acid whey processing. The main challenge in protein concentration by means of ultrafiltration (UF) is membrane fouling. Thus, this study aimed to investigate flux decline in UF of rather rarely processed acid whey obtained during tvarog cheese and lactose-free tvarog cheese manufacture. Acid whey (normal (AW-N) and lactose-free (AW-LF)) was ultrafiltered using 20 nm ceramic membrane, at 50±1°C, cross-flow velocity of 4.1 m/s, and transmembrane pressure of 0.3 MPa, as recommended by membrane manufacturer. The average time of whey processing was 180 min. The reference process was UF of sweet whey (SW) conducted under the same conditions. The physicochemical properties of feed, permeate, retentate and 2 foulants streams obtained after UF: foulants located on the membrane surface and inside the pores were investigated. The average (n=3) flux decline was 26±4, 33±1 and 37±1% for SW, AW-LF and AW-N, respectively. The permeation fluxes (77±2 and 92±2 kg/m2h) for AW-LF and AW-N were considerably higher (P < 0.05) than calculated critical value (~64 kg/m2h) indicating protein deposition on membrane surface. SDS-PAGE electrophoresis showed that all major whey proteins were present in stream containing surface foulants. β-lactoglobulin and α-lactalbumin did appear to be the major cause of pore blocking. Dynamic Light Scattering analysis of particle size distribution showed multimodal size distribution in permeate streams shifted toward smaller particle sizes in contrast to unimodal (SW, AW-LF) and bimodal (AW-N) particle size distribution in feed. Higher Ca content in AW-LF and AW-N than in SW (1174a±24 mg/L and 1180a±74 mg/L vs 366b±50 mg/L) contributed to significantly higher Ca content in stream containing internal foulants (6.9a±0.2 mg/L and 3.7b±0.4 mg/L vs 2.2c±0.8 mg/L). The knowledge generated in this study advances the understanding of fouling in UF of polydisperse systems like tvarog acid whey in which diffusive transport is complex and not yet clearly understood.
ADSA Dairy Foods Poster Competition (Graduate) Competitions ADSA Dairy Foods Poster Competition (Graduate) 7/11/2021 0:00 t83858 Watch SC117 Consumer understanding of fluid milk and cheese composition and processing. 9 A. N. Schiano consumer ultrafiltration ultrapasteurization A. N. Schiano1, M. A. Drake1 1North Carolina State University, Raleigh, NC Ultrapasteurized and filtered (ultrafiltered or microfiltered) milk products are becoming common in the United States, but there is concern that consumers may form negative uninformed perceptions of these milks or cheeses made with them. The objective of this study was to explore consumer understanding of milk processing and constituents. We investigated 4 questions: (1) Does the average dairy product consumer (DPC) understand the basic nutrients in fluid milk and cheese? (2) Do they understand the basic processes for fluid milk and cheese? (3) Do different processes impact perception or purchase intent? (4) Does explaining a process change consumer beliefs about and purchase intent for dairy products? Qualitative interviews (n=54) and an online survey (n=1,210) were conducted with DPCs. Data were evaluated by nonparametric and parametric statistical analyses. The average DPC could recall key words related to dairy processing and composition, but was largely unfamiliar with these subjects. Highly educated and older consumers were more likely than other consumers to have a better understanding of dairy composition and nutrition (P < 0.05). Processing-related descriptors (e.g., ultrapasteurized or ultrafiltered) in ingredient statements were generally overlooked on labels; 34% of DPCs read the labels on dairy products. The majority (>80%) of DPCs were unfamiliar with filtered milk, but uninformed perceptions were generally positive. Consumers unfamiliar with processing methods were likely to assume that additional processing methods or terms increased the price of a dairy product (P < 0.05). Purchase intent for fluid milk and cultured dairy products was not impacted when non-conventional processing terms such as ultrafiltered or microfiltered were included in the ingredients statement (P > 0.05). This impact was consistent for fluid milk and Cheddar cheese but not for cottage cheese, suggesting possible product-specific effects. Providing a definition of filtration increased consumer understanding, positive beliefs, and purchase intent for fluid filtered milk and cheese made with it. Educating consumers through on-package labeling or marketing messaging should be investigated for ultrapasteurized or filtered milk products.
ADSA Dairy Foods Poster Competition (Graduate) Competitions ADSA Dairy Foods Poster Competition (Graduate) 7/11/2021 0:00 t83859 Watch SC118 The impact of encapsulation on vitamin premix stability and flavor in ready-to-mix protein beverages. 10 H. R. M. Keefer vitamin premix stability protein beverages H. R. M. Keefer1, M. A. Drake1 1North Carolina State University, Raleigh, NC Vitamin fortification of ready-to-mix (RTM) protein beverages is desirable to many consumers. However, vitamins are unstable and degradation can lead to off-flavors in fortified foods. Encapsulation is used to improve stability and shelf life, but studies have not investigated shelf life of vitamin premixes or potential flavor impacts of these premixes in foods. The objective of this study was to determine encapsulated (EN) and unencapsulated (UNEN) vitamin premix stability at 2 temperatures (21°C and 35°C) and to determine flavor effects on fortified ready-to-mix (RTM) protein beverages. Two vitamin premixes (EN and UNEN, vitamins B1, B2, B3, B5, B7, B9, D, E, and A) were obtained in duplicate lots. The premixes (subsampled into moisture barrier pouches) were stored at 21 and 35°C and sampled monthly through 6 mo. At each time point, fat- and water-soluble vitamin concentrations were documented by UPLC with a photodiode array detector. Additionally, at each time point, premixes were evaluated in vanilla whey protein RTM beverages (15 g protein/240 mL serving) by descriptive sensory analysis. Vitamin degradation and beverage sensory properties were compared using 2-way ANOVA (EN/UNEN × vitamin premix storage temperature) with Fisher’s least significant difference (LSD) for means separation. All vitamins evaluated decreased in concentration with storage time and decreased faster at 35°C compared with 21°C with the highest degradation noted in vitamins A and B1 (P < 0.05). Vitamin loss in encapsulated premixes was slower than that in unencapsulated premixes at both storage temperatures (P < 0.05). A distinct perfumey/carrot flavor was documented by mo 1 in RTM beverages with EN and UNEN stored at 35°C, by mo 2 in RTM beverages with UNEN at 21°C, and by mo 3 in RTM beverages with either premix at both storage temperatures. The perfumey/carroty flavor was attributed to vitamin A degradation. This study demonstrates vitamin premix stability and its role in sensory properties of RTM protein beverages.
ADSA Dairy Foods Poster Competition (Graduate) Competitions ADSA Dairy Foods Poster Competition (Graduate) 7/11/2021 0:00 t83862 Watch SC119 Consumer perception of natural hot pepper cheeses. 11 C. M. Racette hot pepper cheese consumer drivers of liking C. M. Racette1, M. A. Drake1 1North Carolina State University, Raleigh, NC Hot pepper cheese (HPC) is a growing category of flavored natural cheese. With increasing consumer interest in this category, it is important for manufacturers to understand consumer perceptions of HPC. The objective of this study was to evaluate consumer perception of HPC using a combination of quantitative survey methods and consumer evaluation of actual HPCs. An online survey (n = 510) was conducted to understand drivers of purchase for the hot pepper cheese category. Hot pepper cheese consumers answered Maximum Difference (MXD) exercises and an Adaptive Choice Based Conjoint (ACBC) activity focused on hot pepper cheese attributes. Subsequently, natural HPC (n = 6) were manufactured in duplicate with different hot pepper blends with a range of heat/burn intensities and distinct colors. Trained panel profiling and a consumer acceptance test (n = 194 consumers) were applied to the cheeses. Univariate and multivariate statistics were used to evaluate the data. Three clusters of consumers were identified from the survey. Cluster 1 (n = 175) placed value on visual characteristics of HPC, while cluster 2 (n = 152) preferred milder HPCs. Cluster 3 (n = 183) showed the most interest in novel HPCs, such as those made with habanero peppers or white Cheddar cheese. Conceptually, the overall ideal HPC was a Monterey Jack with medium-sized, multicolored pieces of jalapeno peppers and a moderate heat/burn intensity. Heat/burn intensity and type of cheese were the most important attributes in the MXD exercise followed by price and appearance. Trained panelists confirmed that the 6 HPC used for consumer testing had a distinct range (low to high) of heat/burn intensity. Consumer overall liking increased as heat/burn intensity increased to a certain point, indicating consumers have an optimal point for heat/burn in HPCs. Consumers also preferred HPCs with multicolored pepper pieces over those with a singular pepper color, which was consistent with ACBC results. This study demonstrates that most HPC consumers prefer HPCs with higher heat/burn intensity and are also motivated by visual characteristics of HPCs.
ADSA Midwest Branch Young Scholar Presentations Orals ADSA Midwest Branch Young Scholars 7/11/2021 0:00 s9718 Watch                
ADSA Midwest Branch Young Scholar Presentations Orals ADSA Midwest Branch Young Scholars 7/11/2021 0:00 t85386 Watch 496 Elucidating the serotonin-calcium axis. 1 M. Connelly calcium serotonin M. Connelly1 1Affiliation, City, country Dysregulation of calcium (Ca) occurs during the peripartal period due to the rapid and robust increase in Ca demand by the mammary gland. Thus, mammary-derived signals, such as serotonin (5HT), play a role in coordinating responses to this abrupt Ca loss. Serotonin plays a diverse role in maternal circulation and mammary physiology, modulating Ca metabolism and mammary parathyroid hormone-related protein (PTHrP) production. Still, the biology underpinning the 5HT-Ca axis and timing of Ca homeostatic mechanisms in relation to Ca loss remains largely unknown. Therefore, the objective was to elucidate how 5HT modulates Ca metabolism and responds to Ca perturbations as well as delineate timing of Ca feedback in the peripartal cow. The initial aim was to uncover 5HT’s action on Ca by infusing the precursor, 5-hydroxy-L-trytophan (5-HTP). Infusion of 5-HTP elicited a transient hypocalcemia and increased mammary 5HT content and Ca trafficking, resulting in increased milk Ca concentrations. These robust blood Ca changes elicited no response in blood parathyroid hormone but did increase mammary PTHrP mRNA. Next, the 5HT-Ca axis under Ca perturbations was examined. Ca chelation did not alter blood 5HT in early lactation and dry, non-pregnant cows. However, circulating 5HT, mammary 5HT and PTHrP mRNA were increased in early lactation compared to dry, non-pregnant cows, with PTHrP mRNA being robustly upregulated in chelated early lactation cows when compared to all other groups. Moreover, when cows were infused for 24h immediately after parturition with Ca to maintain normocalcemia, blood 5HT was unchanged. However, blood 5HT was increased in cows fed a prepartum negative dietary cation anion difference (-DCAD) diet. Cows fed a -DCAD diet also had higher Ca concentrations in the peripartum period and required less Ca to maintain normocalcemia in the 24h post-partum. Interestingly, an approximate 18h delay in blood Ca changes occurred in both perturbation studies, suggesting Ca homeostatic mechanisms require time to adapt to Ca change. Collectively, this work demonstrates 5HT’s ability to modulate the Ca axis and improve Ca metabolism, while suggesting 5HT may drive Ca, but Ca perturbations do not drive 5HT.
ADSA Midwest Branch Young Scholar Presentations Orals ADSA Midwest Branch Young Scholars 7/11/2021 0:00 t85488 Watch 497 Elucidating the physiological and genomic underpinnings of dairy cow lipid-related metabolic disorders and leveraging farm data streams to predict disorder cases. 2 R. S. Pralle   R. S. Pralle1 1School of Agriculture, University of Wisconisn–Platteville, Platteville, WI Hyperketonemia (HYK) and fatty liver syndrome are thought to be comorbid metabolic disorders related to endogenous lipid metabolism. These lipid-related metabolic disorders (LRMD) have subclinical prevalence of approximately 50% during the first 21 d postpartum. The frequency of LRMD cases and their association with reduced lactation performance, impaired fertility, and greater risk of comorbidities and involuntary culling cause LRMD incidence to be a significant economic burden for the dairy production system. Thus, investigations into the pathophysiology of these LRMD and innovations in the LRMD case identification have tremendous potential for beneficial impact on cow health and dairy profitability with two major hypotheses: 1) LRMD pathology is determined in part by variation in the liver expression of key regulatory genes and metabolic pathways and 2) that data streams available within dairy production systems can be leveraged to identify biological features of HYK and develop convenient, high-throughput HYK prediction tools for diagnosis. After exploring the effects of a ketosis-induction protocol on peripartum cows, we found evidence for liver PNPLA3 protein abundance to regulate peripartum liver triglyceride accumulation. Through whole-transcriptome RNA sequencing of liver samples, we discovered novel divergence in the regulation of immunometabolism was associated with LRMD risk and severity. Genetic epidemiology of a HYK phenotype determined by repetitive blood BHB sampling, identified candidate SNP and inferred genes associated with human metabolic syndrome that contribute to genetic susceptibility to HYK. Finally, using machine learning algorithms we developed prediction equations based on farm data streams as a less invasive and high-throughput option for managing HYK. Future progress in the integration of biological research into dairy herd data collection and development of data-based management tools has tremendous potential to improve dairy husbandry and will provide opportunities for the precision management of LRMD.
ADSA Midwest Branch Young Scholar Presentations Orals ADSA Midwest Branch Young Scholars 7/11/2021 0:00 t85489 Watch 498 Evaluation of alpha-1-acid glycoprotein as a marker of transition cow health, metabolism, and feed intake: A potential diagnostic tool? 3 W. Brown   W. Brown1 1Department of Animal & Dairy Sciences, University of Wisconsin–Madison, Madison, WI Production performance of livestock is dependent upon adequate feed intake to meet metabolic demands, yet activation of the immune system reduces feed intake. Transition dairy cows suffer from inflammatory activation from multiple sources which may contribute to poor intake during this period. While feed intake reduction resulting from inflammation most classically is caused by cytokines, recent evidence has also implicated the acute-phase protein alpha-1-acid glycoprotein (AGP). Using a large dataset, we analyzed plasma AGP in 434 transition dairy cows to determine its association with dry matter intake (DMI), common blood inflammatory and metabolic biomarkers, and transition cow health disorders with an overarching goal of evaluating AGP as a diagnostic tool. The plasma AGP concentration increased after parturition, but there was no evidence of difference from d 3 to d 21 postpartum. There was a strong negative association between AGP and postpartum DMI. Conversely, there were positive associations between AGP and metritis, retained placenta, hyperketonemia and haptoglobin in the postpartum period. Overall diagnostic ability of AGP to predict depressed intake or transition disorders was marginal based on receiver operating characteristic analysis. Nonetheless, the ease of quantifying plasma AGP and the lack of association with common blood metabolic biomarkers suggest it may be a useful tool to evaluate transition status in dairy cows. Further work elucidating mechanisms and contributions of inflammation-induced hypophagia in transition dairy cows is warranted. Additionally, exploration of acute-phase proteins as biomarkers and mediators of hypophagia should also be evaluated.
ADSA Midwest Branch Young Scholar Presentations Orals ADSA Midwest Branch Young Scholars 7/11/2021 0:00 t85490 Watch 499 Effects of rumen-protected methionine supply and body condition prepartum on antioxidant, inflammation, and mechanistic target of rapamycin pathways in adipose tissue during the periparturient period. 4 Y. Liang amino acid oxidative stress periparturient period Y. Liang1, A. S. Alharthi1, R. Bucktrout1, A. A. Elolimy1, V. Lopreiato2, I. Martinez-Cortés3, E. Trevisi2, C. Parys4, J. J. Loor1 1Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana, IL, 2Department of Animal Sciences, Food and Nutrition, Faculty of Agriculture, Food and Environmental Science, Università Cattolica del Sacro Cuore, Piacenza, Italy, 3Agricultural and Animal Production Department, UAM-Xochimilco, Mexico City, Mexico, 4Evonik Nutrition & Care GmbH, Hanau, Germany In non-ruminants, adipose tissue is responsive to AA supply, can utilize them as fuels, or for protein synthesis regulated in part via insulin and mechanistic target of rapamycin (mTOR) signalling. Nuclear factor, erythroid-derived 2-like 2 (NFE2L2, formerly Nrf2) is a key transcription factor controlling cellular oxidative stress in non-ruminants. Our research examined the effects of rumen-protected methionine (RPM) supply or body condition (BCS) prepartum on pathways associated with mTOR and NFE2L2 pathways in subcutaneous adipose tissue (SAT) during the periparturient period. Multiparous Holstein cows were assigned from –28 to 60 d relative to parturition to a basal diet [control; 1.47 Mcal/kg of DM and 15.3% CP prepartum; 1.67 Mcal/kg and 17.7% CP postpartum] or the control plus ethyl-cellulose RPM. The RPM was fed individually at a rate of 0.09% of DMI prepartum and 0.10% postpartum. SAT harvested at -10, 10 and 30 d relative to parturition was used for quantitative PCR and western blotting. Enhanced Met supply led to greater overall mRNA abundance of Gln (SLC38A1), Glu (SLC1A1), L-type AA (Met, Leu, Val, Phe; SLC3A2), and neutral AA (SLC1A5) transporters along with greater gene expression of glutathione (GSH) metabolism-related genes. Furthermore, it upregulated protein abundance of insulin-responsive proteins phosphorylated (p) protein kinase B (p-AKT). A diet × day interaction was observed for mTOR protein abundance due to greater values for RPM cows at 30 d postpartum compared with controls. Additionally, supply of Met resulted in an overall upregulation of protein abundance of glutathione peroxidase 1 (GPX1), GPX3, glutathione S-transferase mu 1 (GSTM1), and glutathione S-transferase alpha 4 (GSTA4) all related to GSH metabolism. There was a diet × time effect for protein abundance of NFE2L2 and its repressor kelch like ECH associated protein 1 due to lower values at 30 d in cows fed Met versus controls. Thus, the data suggest that exogenous Met may play a role in activating GSH metabolism and the anti-oxidant NFE2L2 pathways in SAT. In our BCS studies, compared with cows with normal BCS (NBCS, BCS ≤ 3.17), cows calving at high BCS (HBCS, BCS ≥ 3.5), although HBCS cows had greater overall total protein abundance of NFE2L2 inSAT, ratio of p-NFE2L2-to-total NFE2L2 was lower suggesting a decrease in the activity of this antioxidant system. Overall mRNA abundance of the GSH metabolism-related genes along with protein abundance of GSTM1 were greater in HBCS cows. Overall mRNA abundance of the high-affinity cationic (SLC7A1), proton-coupled (SLC36A1), and sodium-coupled amino acid transporters (SLC38A2) also was greater in HBCS namely due to upregulation in the postpartum phase. Data suggest that increased abundance of mRNA and protein components of the GSH metabolism pathway in SAT of HBCS cows might help alleviate tissue oxidant status. Overall, these responses suggested that mTOR and NFE2L2 pathways in bovine SAT are responsive to nutritional status and BCS prepartum.
ADSA Production MS Poster Competition Competitions ADSA Production MS Poster Competition (Graduate) 7/11/2021 0:00 s9702                  
ADSA Production MS Poster Competition Competitions ADSA Production MS Poster Competition (Graduate) 7/11/2021 0:00 t84606 Watch SC129 Evaluating skim milk as a substrate for the biomanufacturing of value-added ingredients and products. 1 L. Wise lactose ethanol galactose L. Wise1 1Cornell University, Ithaca, NY Recent decreases in skim milk consumption have challenged the dairy industry, with resultant increases in waste and reduction in its use in foods despite its nutritional quality. Repurposing skim milk is therefore crucial to avoid loss and provide alternative uses. For example, valuable products can be derived from fermenting lactose in skim milk. In fact, several yeast species can ferment lactose into ethanol. Alternatively, when lactose is hydrolyzed into glucose and galactose, Brettanomyces yeast can selectively ferment glucose into ethanol, leaving behind galactose, a useful ingredient in snacks, sweeteners, pharmaceuticals and galactooligosaccharides. The goal of this study is to screen parameters for optimal ethanol and galactose yields in skim milk fermentations using Brettanomyces claussenii and Kluyveromyces marxianus, 2 lactose-hydrolyzing yeasts, as well as Saccharomyces cerevisiae and Brettanomyces bruxellensis. A minimum of 5 × 106 cfu/mL of each species was pitched into 2 bottles of skim milk, one treated with lactase, the other without. Triplicate fermentations were run and pH measured continuously. Cell counts and densities were determined on alternate days, and fermentations run until all densities were level for 3 straight days. HPLC samples were drawn at the beginning and end of each replicate to isolate the contents of lactose, glucose, galactose, ethanol and organic acids. Residual galactose levels in B. claussenii were erratic and lower than anticipated. The highest ethanol productions were recorded in K. marxianus and B. claussenii, particularly without lactase, where average final ethanol concentrations approached 2.5%. The variance yielded a P-value < 0.0001, meaning ethanol production differed across species. A Tukey’s test confirmed that ethanol production in B. claussenii and K. marxianus was different from that of the 2 other species. Further research will aim to improve fermentation stability and the sensory properties of the fermented milk, and optimize ethanol and galactose yields using response surface methodology.
ADSA Production MS Poster Competition Competitions ADSA Production MS Poster Competition (Graduate) 7/11/2021 0:00 t84542 Watch SC130 Impact of increasing dietary cottonseed on rumen fermentation, nutrient digestibility, and microbial community composition in continuous culture fermenters. 2 C. Castro bacteria fiber protozoa C. Castro1, N. Baghme1, F. Batistel1 1Utah State University, Logan, UT In this study, we determined the impact of increasing dietary cottonseed (CS) on rumen fermentation, nutrient digestibility, and microbial community composition. The study was conducted as a replicated 4 × 4 Latin square using continuous culture fermenters (n = 8). Treatments were a control diet without CS, and the control diet plus 5, 10, or 15% of CS. The control diet (40 g DM/day) was a 50:50 orchardgrass hay:concentrate fed twice daily. The prokaryotic community was determined by sequencing the V4 region of the 16S rRNA gene, and protozoa were counted. Data were analyzed using a mixed model including the fixed effect of treatment and the random effects of period and fermentor. Linear, quadratic and cubic contrasts were tested. No treatment effect was observed for NDF and starch digestibility as well acetate concentration (P ≥ 0.23). Butyrate and ammoniacal N concentrations increased (Quadratic, P ≤ 0.05), while propionate concentration tended to decrease (Quadratic, P = 0.08) as CS was added. Increasing CS in the diet, decreased protozoa count and relative abundance of archaea (Linear, P = 0.01). Analysis of the phyla abundance showed that 6 phyla were affected by treatments. The most abundant phyla across treatments were the Firmicutes and Bacteroidetes. Firmicutes abundance increased whereas Bacteroidetes decreased with the addition of CS (Linear, P ≤ 0.05). Lachnospiraceae and Prevotellaceae were the most abundant bacteria families in all the samples. No treatment effect was observed for Lachnospiraceae, while Prevotellaceae abundance tended to decrease as CS was added to the diet (Linear, P = 0.07). The 2 most abundant genera across samples were Prevotella and Pseudobutyribrio, and the addition of CS decreased the abundance of both (Linear, P ≤ 0.05). Our preliminary results indicate that increasing levels of CS up to 15% DM diet do not negatively impact fiber and starch digestion in the rumen. Furthermore, the inclusion of CS affected the microbial community composition at different levels.
ADSA Production MS Poster Competition Competitions ADSA Production MS Poster Competition (Graduate) 7/11/2021 0:00 t84301 Watch SC131 Earlier administration of an internal teat sealant in primigravid dairy heifers to prevent intramammary infections at calving. 3 L. R. Larsen mastitis heifer mastitis IMI L. R. Larsen1, P. H. Baker1, K. M. Enger1, L. E. Moraes2, B. D. Enger1 1The Ohio State University, Wooster, OH, 2The Ohio State University, Columbus, OH Intramammary infections (IMI) are common in primigravid dairy heifers and negatively impact future milk production. Bismuth subnitrate-based internal teat sealants (ITS) have been used to prevent prepartum IMI in dairy heifers by creating a physical barrier within the teat, preventing pathogens from entering the gland, though determination of when to administer ITS in heifers has yet to be investigated. The objectives of this study were to determine if infusion of ITS during first gestation reduces the risk of IMI at calving and if administering ITS at different stages of gestation (75 vs 35 d prepartum) differentially affects IMI prevalence at calving. A total of 270 heifers were utilized at a single farm. One-quarter of each heifer was randomly assigned to receive ITS 75 d prepartum (TS75), another quarter of each heifer received ITS 35 d prepartum (TS35), while the remaining 2 quarters served as control quarters (CON). After calving, aseptic colostrum samples were collected from all quarters and were cultured to determine quarter infection status. Data were analyzed using PROC GLIMMIX to yield odds ratios (OR); ITS treatment and quarter location (fore or rear) were included as fixed effects while heifer was a random effect. For major mastitis pathogens, CON quarters were 3.5 times (95% CI: 1.5–8.0) and 3.4 times (95% CI: 1.5–7.8) more likely to be infected at calving than TS75 and TS35 quarters, respectively. For minor mastitis pathogens, CON quarters were 5.2 (95% CI: 3.0–9.2) and 4.9 (95% CI: 2.8–8.7) times more likely to be infected than TS75 and TS35 quarters, respectively. Odds of IMI at calving was not affected by quarter location (P = 0.07) and were similar between TS75 and TS35 quarters for both major (OR = 1.0) and minor (OR = 1.1) mastitis pathogens. Results indicate that ITS administration at either 75 and 35 d prepartum significantly reduced IMI prevalence at calving in primigravid dairy heifers and that there was no disadvantage to earlier ITS application. Farm factors may influence timing of heifer IMI and earlier administration of ITS provides an extended period of protection for the developing gland.
ADSA Production MS Poster Competition Competitions ADSA Production MS Poster Competition (Graduate) 7/11/2021 0:00 t84273 Watch SC132 Effects of treating soybean meal on ruminal fermentation, microbial growth, nutrient digestion, and nitrogen partitioning in a dual-flow continuous culture system. 4 A. Bahman rumen-undegradable protein rumen-degradable protein ruminal ammonia A. Bahman1, H. F. Monteiro1, A. D. Ravelo1, J. Arce-Cordero1, T. S. Winowiski2, A. P. Faciola1 1University of Florida, Gainesville, FL, 2Borregaard USA Inc, Rothschild, WI The objective of this study was to evaluate the effect of 3 different protein supplements on ruminal fermentation, nutrient digestibility, microbial efficiency, and ruminal nitrogen partitioning. The treatments were: a control soybean meal (SBM), the control soybean meal treated with 0.75% amino resin (ARSBM), and the control soybean meal heat-treated (HTSBM). Experimental design was set up as a replicated 3 × 3 Latin square with 6 fermenters in a dual-flow continuous culture system. Treatments were randomly assigned within Latin square for each period. Each fermentor was fed 106 g/d of diet DM equally distributed in 2 feeding times per day at 0800 and 1700. Diets were formulated to contain 16% CP, 30% NDF, and 30% starch across treatments. The experiment consisted of 3 experimental periods, each lasting for 10 d, for a total of 30 d of fermentation. The first 7 d of each period was considered adaptation, and the last 3 d were used for sampling and data collection. On d 8 and 9, samples were collected for pH, volatile fatty acid (VFA), lactate, and NH3-N kinetics. Days 8, 9, and 10, samples were collected for VFA and NH3-N pools, digestibility measurements, and bacterial analysis. Data were analyzed using the GLIMMIX procedure of SAS and significance was declared when P ≤ 0.05. No effects were observed for pH or lactate. Ammonia concentrations were significantly different among treatments. Compared with the control SBM (16.91 mg/dL), both the ARSBM (8.24 mg/dL) and the HTSBM (7.99 mg/dL) had lower NH3-N concentrations, indicating a lower ruminal protein degradation and greater ruminal undegraded protein supply. Our preliminary NH3-N results indicate that the treatment of soybean meal could be effective in increasing ruminal undegraded protein levels in the diet.
ADSA Production PhD Poster Competition Competitions ADSA Production PhD Poster Competition (Graduate) 7/11/2021 0:00 s9704                  
ADSA Production PhD Poster Competition Competitions ADSA Production PhD Poster Competition (Graduate) 7/11/2021 0:00 t84650 Watch SC142 First-lactation milking performance of dairy heifers fed pre- or probiotic diets in the prewean period. 1 P. M. Lucey probiotic prebiotic milkfat P. M. Lucey1, I. Lean2, E. Block3, H. A. Rossow1 1Veterinary Medicine Teaching and Research Center, UC Davis, Tulare, CA, 2Scibus, Camden, NSW, Australia, 3Arm & Hammer Animal and Food Production, Princeton, NJ The focus of the pre-wean period is growth, rumen development and reducing risk of disease. Success during this period can impact a heifer’s survival and performance in the milking herd. The objective of this analysis is to compare the first-lactation 305-d milk, fat, and protein production, age of calving, and survival to the milking herd, between comparable groups of heifers who were randomly assigned to a control (CON), a Bacillus subtilis probiotic (PRO), mannan-oligosaccharide as a prebiotic (PRE), or both agents in combination (SYN). Each supplement was mixed into the milk feed twice daily and fed the entire duration of the pre-wean period. A total of 1,801 Holstein heifer calves at a commercial dairy were randomized into each treatment group at birth. Bodyweight was measured at beginning and end of the pre-wean period and ADG was compared between treatment groups. Fixed linear regression models were created to analyze first-lactation 305-d milk, fat and protein yield in kg. Logistic regression was performed on the odds of survival to the milking herd. Ordinal logistic regression was performed on the age in months at first calving. In 305 d, cows in CON produced 10,911 (± 114) kg milk, 456 (± 5) kg fat, 349 (± 3) kg protein, cows in PRE produced 11,106 (± 120) kg milk, 469 (± 5) kg fat, 357 (± 4) kg protein, cows in PRO produced 11,168 (± 118) kg milk, 468 (±5) kg fat, 359 (± 4) kg protein, cows in SYN produced 11,175 (± 116) kg milk, 473 (± 5) kg fat, 358 (± 4) kg protein. Cows in SYN yielded 15 kg more milk fat than cows in CON (P = 0.03), no other differences in milk production were seen. The proportion of calves that entered the milking herd was 78% (± 2) for CON, 75% (± 2) for PRE, 77% (± 2) for PRO and 79% (± 2) for SYN. No difference in odds of survival or age at calving was seen between treatments. Though many environmental factors impact the adult performance of dairy animals, examining these data on a single site, with homogenously managed dairy cattle, and a pre-wean dietary difference may add information the potential impact of pre-wean diet on future milk production.
ADSA Production PhD Poster Competition Competitions ADSA Production PhD Poster Competition (Graduate) 7/11/2021 0:00 t84347 Watch SC143 Impacts of in utero heat stress on the gastrointestinal morphology of dairy calves. 2 B. D. Davidson immunoglobulin jejunum villi B. D. Davidson1, S. L. Field1, B. Dado-Senn1, M. A. Steele2, G. E. Dahl3, J. Laporta1 1Department of Animal and Dairy Sciences, University of Wisconsin–Madison, Madison, WI, 2Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada, 3Department of Animal Sciences, University of Florida, Gainesville, FL Late-gestation heat stress in dairy cows negatively impacts offspring absorption of immunoglobulin G (IgG) from colostrum. Herein, the objective was to quantify the gastrointestinal tract (GIT) structure of in utero heat-stressed or cooled heifer calves at birth. For the last ~56 d of gestation (THI ≤68), pregnant dams were either heat-stressed (HT, shade; n = 41) or cooled (CL, shade, fans, soakers; n = 41) and gave birth to calves which were in utero heat-stressed (IUHT) and in utero cooled (IUCL), respectively. At birth, calves were weighed, fed 3.78 L of high-quality colostrum within 2 h, and blood was collected at 24 h (n = 15/treatment). Apparent efficiency of absorption (AEA) of IgG was calculated by measuring IgG in fed colostrum and 24 h serum. Within 4.6 ± 2.3 h of birth, a subset of calves was euthanized (n = 8/treatment, no colostrum) to harvest the GIT. Full tract weights (including stomach) were obtained, and a cross-section of jejunum was fixed for 18 h in 10% neutral buffered formalin, dehydrated, and embedded in paraffin. Jejunal morphology was assessed from sectioned tissues stained with Hematoxylin and Eosin. Villi length, width, and crypt depth were measured with Keyence BZ-X800 Analyzer software (n = 20 villi/calf). Data were analyzed using PROC MIXED in SAS, with in utero treatment as a fixed effect. Colostrum IgG concentration fed to calves was not different (136.1 vs. 122.5 ± 13.4 g/L; IUHT vs. IUCL, respectively, P = 0.32), but AEA of IgG was reduced in IUHT relative to IUCL heifers (23.5 vs. 33.3 ± 3.1%. P = 0.004). Weight for the GIT at birth was not different between treatments (1.4 vs. 1.4 ± 0.07 kg, P = 0.98). Villi length (802.4 vs. 796.6 ± 95.5 μm, P = 0.95), villi width (102.9 vs. 112.9 ± 8.1 μm, P = 0.24), and crypt depth (249.5 vs. 235.0 ± 9.6 μm, P = 0.16) from the jejunum were not different between IUHT and IUCL calves. In utero heat stress does not seem to alter the morphology of the jejunum. These results suggest there might be structural differences in other portions of the intestine (i.e., ileum or duodenum) or negative effects at the cellular and molecular level which impact IgG absorption of in utero heat-stressed calves.
ADSA Production PhD Poster Competition Competitions ADSA Production PhD Poster Competition (Graduate) 7/11/2021 0:00 t84247 Watch SC144 Effects of Mg sources and buffer inclusion on high-producing dairy cows` performance. 3 R. R. Lobo DHI MgO Na sesquicarbonate R. R. Lobo1, J. A. Arce-Cordero1, M. N. Marinho1, S. So2, A. Ravelo1, B. C. Agustinho3, J. Vinyard1, M. L. Johnson1, E. Sarmikasoglou1, H. Monteiro1, A. P. Faciola1 1University of Florida, Gainesville, FL, 2Khon Kaen University, Khon Kaen, Thailand, 3University of Idaho, Moscow, ID The objective of this study was to evaluate sources of Mg and buffer inclusion, on high-producing dairy cows’ performance. Sixty Holstein cows (initial milk production of 40.5 kg and 100 DIM) were arranged into blocks according to parity, DIM, and milk production, a total of 15 blocks with 4 animals in each were formed. Animals in each block were assigned into one of 4 treatments: 1) MgO; 2) MgO + Na sesquicarbonate (Na sesq); 3) proprietary mineral formulation (PMF); 4) PMF + Na sesq. During 60 d animals were fed a corn silage-based diet with similar chemical composition (16.3% CP, 26.8% NDF, 31.8% starch, 0.67% Ca, and 0.27% Mg, on a DM basis) in individual Calan-gates and treatments were top-dressed. Animals were milked twice a day and milk samples were collected 2 d a week for 7 weeks on both morning and night milking. The experiment was carried out as a randomized block design with a 2 × 2 factorial arrangement, data were analyzed using the MIXED procedure of SAS, orthogonal contrasts were used to evaluate the effects of Mg source, buffer, and interactions. Partial data are presented in Table 1. Sources of Mg and buffer did not affect milk yield. Interactions were observed on DMI, feed efficiency, and energy-corrected milk; however, neither Mg source nor buffer effects were observed in any of these parameters. In summary, the replacement of MgO by PMF had no major effects on DMI, feed efficiency, and milk yield and composition. Table 1. Effects of source of Mg and buffer (+) on performance of high-producing dairy cows
Parameter MgO MgO+ PMF PMF+ SEM P-value1
DMI, kg day−1 22.0 23.1 23.0 21.2 0.53 0.03 (I)
FE, kg milk kg−1 DMI 1.8 1.6 1.7 1.7 0.05 0.02 (I)
Milk yield, kg day−1 39.8 38.2 38.5 36.9 1.13 NS
ECM, kg−1 kg DMI 1.6 1.5 1.5 1.6 0.04 0.04 (I)
MUN, mg dL−1 12.0 12.4 11.5 11.4 0.38 0.06 (S)
Fat, kg day−1 1.1 1.2 1.1 1.1 0.05 NS
Protein, kg day−1 1.2 1.2 1.2 1.1 0.03 0.09 (S)
Fat, % 3.0 3.2 2.9 3.2 0.13 0.07 (B)
Protein, % 3.1 3.2 3.1 3.2 0.04 0.06 (B)
1P-values of the contrasts of main effects of Mg source (S), buffer (B), and interaction (I). NS = nonsignificant.
ADSA Production PhD Poster Competition Competitions ADSA Production PhD Poster Competition (Graduate) 7/11/2021 0:00 t83912 Watch SC145 Factors impacting pregnancy at first service in lactating cows. 4 F. M. Masia conception rate health issue logistic regression F. M. Masia1,2, M. B. Piccardi1,2, M. G. Molina1,3, M. G. Balzarini1,2, R. L. De la Sota2,4 1Facultad de Ciencias Agropecuarias–UNC, Córdoba, Córdoba, Argentina, 2CONICET, Córdoba, Córdoba, Argentina, 3Instituto de Ciencias Básicas y Aplicadas–UNVM, Villa María, Córdoba, Argentina, 4Facultad de Ciencias Veterinarias–UNLP, La Plata, Buenos Aires, Argentina During the periparturient period, dairy cows experience an increase in the prevalence of metabolic and production-related diseases. These health problems not only cause reductions in milk production and increases in production costs but also reduce the reproductive performance of cows. This study aimed to estimate the relative contribution of factors affecting the likelihood of pregnancy at the first service. We analyzed 66,935 lactations from 20 Argentinian dairies as function of 2 factors: parity season (warm: vs cool) and occurrence of early postpartum diseases (retained placenta 35%, hypocalcemia 3%, displacement of the abomasum 2%, metabolic diseases 36%, and mastitis 24%). Lactations were categorized according to the occurrence of diseases as follows: diseases appearing within 21 DIM, between 22 and 42 DIM, and without any disease. A logistic regression model was adjusted in JMP (v14.2) including parity, season, occurrence of postpartum diseases and their interaction independently for primiparous and multiparous cows. Parity and season affected the pregnancy odd ratio (OR) (P < 0.0001) while their interaction was not significant. Primiparous and multiparous cows without postpartum disease were 1.19 (OR, 95% CI: 1.13–1.26) and 1.23 (OR, 95% CI: 1.17–1.29) times more likely to conceive at the first service than those with a disease event during the first 21 d in lactation, respectively. The odds of pregnancy at first service were not affected by the occurrence of disease between 22 and 42 DIM. Primiparous and multiparous cows that calved during the cool season were 1.68 (OR, 95% CI: 1.59–1.77) and 1.61 (OR, 95% CI: 1.53–1.69) times more likely to become pregnant at first service than those who started in the warm season, respectively. We concluded that in addition to parity season, the occurrence of health events during the first 21 d postpartum impacts the reproductive efficiency at the first service of dairy herds.
ADSA Production PhD Poster Competition Competitions ADSA Production PhD Poster Competition (Graduate) 7/11/2021 0:00 t83419 Watch SC146 White wastewater recovery from dairy industries: Evolution of bacterial ecosystem during treatment by reverse osmosis. 5 S. Alalam white wastewater reverse osmosis metabarcoding S. Alalam1, J. Chamberland1, A. Bérubé1, Y. Pouliot1, S. Labrie1, A. Doyen1 1STELA Dairy Research Center, Institute of Nutrition and Functional Foods (INAF), Department of Food Sciences, Laval University, Quebec, QC, Canada White wastewater (WW) is a dairy effluent, generated during cleaning of equipment, after the first hydraulic flush. Pressure-driven membrane technologies, mainly reverse osmosis (RO), are interesting to recover its valuable dairy components and generate process water. In a sustainability context, different valorization processes were proposed. However treated effluents are generally of lower quality than that required for different water applications, while any study was focused on the microbiological quality of milk by-products. Consequently, the purpose of this study was to characterize the microbial ecosystem and the chemical composition, of WW generated during the cleaning procedure of pasteurizers from 2 Canadian dairy plants, and their subsequent RO retentate and permeate generated at 50°C in recirculation mode. Bacterial ecosystem was performed through a metabarcoding approach coupled to quantitative PCR targeting the 16S ribosomal RNA (rRNA) gene. Results demonstrated that bacterial communities identified in concentrated WW were different depending on their sampling site. The WW of the dairy plant #1 was dominated by psychrotrophic bacteria (Pseudomonas abundance of 51%), but there was no increase of the total number of 16S rRNA genes in the retentate throughout RO. Thermophilic bacteria (Streptococcus abundance of 71%), were the most abundant genus in the initial samples of WW of dairy plant #2. During their recirculation in the RO system, the total number of 16S gene copies in the RO retentate increased significantly (P < 0.05) from 6.9 ± 0.5 log 10/mL to 9.6 ± 0.6 log 10/mL after 20 h. Both RO concentrates showed similar chemical compositions to that of skim milk and could potentially be reused in cheese milk. However, RO should be done at 10°C to avoid the development of thermophilic bacteria. Consequently, considering that RO generates permeate requiring minimal treatments to be recycled in the dairy plant, RO represents an interesting strategy to reduce the environmental impact of dairy effluents.
ADSA Production PhD Poster Competition Competitions ADSA Production PhD Poster Competition (Graduate) 7/11/2021 0:00 t84315 Watch SC147 Synchrotron-based study to determine the inherent molecular structure changes induced by steam pressure times in faba bean seeds. 6 M. Rodríguez synchrotron dairy cattle faba beans M. Rodríguez1, D. Christensen1, R. Newkirk1, Y. Ai1, V. Guevara1, P. Yu1 1University of Saskatchewan, Saskatoon, SK, Canada Synchrotron technology is currently a valuable instrument to examine detailed intrinsic molecular features in a variety of materials including feed ingredients. Heat processing methods commonly used in the feed industry alter the physicochemical structure of feeds, modifying their degradation behavior when fed to livestock animals. Traditional research tools are unable to detect processing induced molecular structure changes associated with nutrient supply. Hence, this study aimed to determine the extent of protein molecular structure modifications related to steam pressure processing times in fava bean seeds. Analyzed samples belong to CDC Snowbird variety heated at 121°C for 0, 30, 60, 90, and 120 min. Seeds were pre-processed into cross-sections (6 μm thickness) and then fixed into BaF2 windows (3 windows/sample) for molecular analyses. This study was performed using the infrared beamline at the Advanced Light Source-ALS (Berkeley, CA) where spectra were collected in the mid-infrared region from 4,000 to 750 cm−1. Molecular data were analyzed using OMNIC 7.3 software and SAS software 9.4 (SAS Institute, Inc., Cary, NC) was used for statistical analysis with significance declared at P < 0.05. Results showed variations in the spectra protein related areas and heights with a lower amide I area (P < 0.01) found at 0 min (47.53 AU, infrared absorbance units) compared with 30 min (54.16 AU) and 120 min (57.01 AU). Amide II area was higher (P = 0.01) at 30 min (24.36 AU) compared with 60 and 90 min (22.06 and 22.16 AU, respectively). The α-helix to β-sheet ratio was higher (P < 0.01) at 0 min (1.09 AU) compared with all heating times (avg. 1.01 AU). Protein molecular structure changes associated with heat processing can be directly identified using synchrotron technology. The increased knowledge in the area of feed molecular structure will benefit the application of precise dairy feeding strategies as we get a better understanding of the close relationship between individual inherent structure characteristics of each feed nutrient and the overall degradation behaviors of feedstuffs when fed to cattle.
ADSA Production PhD Poster Competition Competitions ADSA Production PhD Poster Competition (Graduate) 7/11/2021 0:00 t84349 Watch SC148 Production and temporal plasma metabolite effects of soybean meal versus canola meal fed to dairy cows during the transition period and early lactation. 7 J. Kuehnl canola meal transition period early lactation J. Kuehnl1, K. Kalscheur2 1University of Wisconsin–Madison, Department of Animal and Dairy Science, Madison, WI, 2U.S. Dairy Forage Research Center, USDA-ARS, Madison, WI Replacement of soybean meal (SBM) with canola meal (CM) in diets fed to early-lactation dairy cows increases milk production. Our objective was to determine production and temporal plasma metabolite effects of dairy cows fed isonitrogenous diets formulated with SBM or CM during the transition period and early lactation. Multiparous Holstein cows (n = 79), blocked by calving date, enrolled in a 2 × 2 factorial arrangement of treatments in a randomized complete block design. Cows consumed diets containing SBM or CM as the main protein source from wk −3 to +16 relative to calving. Half of the cows consumed each diet pre- (PRE) and postpartum (POST), with half of each PRE group switching protein source at calving. Milk production, components, DMI, and BW were determined weekly. Plasma was collected twice weekly from the coccygeal artery in wk −3 to +8, composited by cow for each wk, and evaluated using ELISA and enzymatic colorimetry. Data were analyzed using the MIXED procedure of SAS. Fixed effects were wk, prepartum diet, postpartum diet, and all 2- and 3-way interactions. Block was included as a random effect. Cows fed CM increased DMI both PRE and POST compared with cows fed SBM (15.3 vs. 14.5 ± 0.3 kg/d; 26.2 vs. 25.0 ± 0.4 kg/d; P < 0.05). Milk production tended to increase for cows fed POST CM compared with POST SBM (52.8 vs. 50.9 ± 0.7 kg/d; P = 0.09). An interaction between PRE and wk was detected for ECM (P < 0.05) and FCM (P = 0.05). Cows fed POST CM decreased in MUN compared with POST SBM (12.9 vs. 13.7 ± 0.2 mg/dL; P < 0.05). Diet did not affect BW, BW change, feed efficiency, components, plasma insulin, IGF-1, or glucose (P > 0.1). Plasma triiodothyronine decreased both PRE and POST for cows fed CM compared with cows fed SBM (1.38 vs. 1.54 ± 0.03 ng/mL; 1.14 vs. 1.35 ± 0.03 ng/mL; P < 0.01). Plasma growth hormone decreased for cows fed the PRE CM compared with PRE SBM (5,050 vs. 6,230 ± 382 pg/mL; P < 0.05). Altogether, our data demonstrates that the early-lactation dairy cow fed a diet formulated with CM increases production and DMI and alters physiological status.
Animal Behavior and Well-Being: Orals Orals Animal Behavior and Well-Being 7/11/2021 0:00 s9630                  
Animal Behavior and Well-Being: Orals Orals Animal Behavior and Well-Being 7/11/2021 0:00 t84114 Watch 100 Effects of shade and sprinklers on physiological responses of heat stress on grazing dairy cows. 1 C. A. Becker heat stress grazing sprinkler C. A. Becker1, A. R. Woolums1, B. B. Karisch1, M. X. S. Oliveira1, A. E. Stone1 1Mississippi State University, Mississippi State, MS This study was conducted at the Mississippi State University Bearden Dairy Research Center from July 1, 2019 to July 30, 2019. The objective of the study was to monitor effects of heat stress on grazing dairy cows by comparing daily milk yield, reticulorumen temperature (RT; SmaXtec, Graz, Austria), respiration rate (RR), milk fat percent, milk protein percent, somatic cell score (SCS), hygiene score, and body condition score (BCS). Three treatments were studied: shade (portable shade structure), sprinkler (portable polyvinyl chloride pipe sprinkler system), and control (no heat abatement). Each treatment was replicated 3 times (n = 3) with 3 s trimester, lactating cows (2 Holstein and one Jersey) in each pen (27 cows total enrolled in study). Pens were balanced by parity, days in milk, and days in gestation. Ambient temperature and relative humidity were averaged and split into 3 time periods: morning (0000 h to 1159 h), afternoon (1200 h to 1759 h), and evening (1800 h to 2359 h). The MIXED procedure of SAS was used to evaluate the effects of treatment, time of day, and treatment × time of day interaction on milk yield, reticulorumen temperature, and respiration rate. For milk yield, milk fat percent, milk protein percent, somatic cell score, hygiene score, and body condition score treatment, week, and treatment × week effects were evaluated. Pen nested within treatment was used as a random variable to account for pen being the experimental unit. Comparison of effects were conducted using LSMEANS. No significant difference occurred for milk yield between treatments (11.51 ± 0.54 kg/d, 11.35 ± 0.54 kg/d, and 12.82 ± 0.54 kg/d for control, shade, and sprinkler, respectively). However, a significant week effect occurred for milk yield. Sprinkler cows had a significantly lower RR (66.0 ± 6.70 breaths/min) compared with control cows (93.34 ± 6.54 breaths/min). No significant difference in RR occurred between the shade and control groups or the sprinkler and shade groups. A treatment × time of day interaction occurred for RR, RT, milk fat percent, milk protein percent, SCS, and BCS. Hygiene scores were lower for the sprinkler group (1.47 ± 0.16) compared with the shade (2.39 ± 0.16) and control group (2.44 ± 0.16). Providing sprinklers for grazing dairy cows may decrease some of the negative physiological effects associated with heat stress to a greater extent when compared with shade or no heat abatement.
Animal Behavior and Well-Being: Orals Orals Animal Behavior and Well-Being 7/11/2021 0:00 t84483 Watch 101 Salix extract and flunixin meglumine dosage to minimize inflammation after disbudding in dairy calves. 2 K. Sharpe disbudding flunixin meglumine Salix K. Sharpe1, B. Heins1, M. Endres2, H. Phillips2 1West Central Research and Outreach Center, Morris, MN, 2University of Minnesota, St. Paul, MN The objective of the study was to determine the dosage of Salix extract (Mountain Rose Herbs, Eugene OR) from white willow bark that would minimize inflammation in dairy calves during disbudding. Calves were Holstein and crossbred bull calves (n = 25; 4 to 9 wk of age) that were housed in an automatic calf feeder group fed 8 L/d. A randomized crossover design with repeated measures was used for the study. During each of the 2 treatment periods, calves were randomly assigned to 1 of 5 treatment groups: 1) No treatment (CON; n = 5), 2) Flunixin meglumine (FM; 2.2 mg/kg BW; n = 5), 3) low dose of Salix extract (LD; 225 mg/kg BW; n = 5), 4) medium dose of Salix extract (MD; 450 mg/kg BW; n = 5) or 5) high dose of Salix extract (HD; 900 mg/kg BW; n = 5). Flunixin meglumine was administered via venipuncture, and Salix extract was administered orally via a rumen bolus. A 7-d washout period was used to minimize carry-over effects between periods; treatment sequences were orthogonal. Blood samples via venipuncture were collected 5 min before and 1, 2, and 4 h after treatment. The samples were sent to Iowa State University for analysis. Concentration of flunixin meglumine and Salix extract in the blood were determined using HPLC. Inflammation was determined by measuring prostaglandin E2 (PGE2) metabolites in the blood. Dependent variables for analysis were PGE2 and Salix extract concentrations. Independent variables were breed, period, treatment, time, the interaction of period and treatment, and the interaction of time and treatment. Calf body weight was a covariate, and calf within period was a random effect within the model. There were no differences among treatments for Salix extract concentration in blood serum across period and time. The PGE2 concentration was 5,229 pg/mL for CON; 3,393 pg/mL for FM; 5,167 pg/mL for LD; 3,329 pg/mL for MD; and 3,842 pg/mL for HD. Differences were not significant among treatments or period. In summary, Salix extract did not provide reduction in inflammation compared with control for hot iron disbudding in dairy calves.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 s9556                  
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t83505 Watch P100 Individual variation and reproducibility of infrared thermography of the eye and rectal temperature in dairy calves. 1 M. Woodrum Setser precision technology health fever M. Woodrum Setser1, M. Hayes1, M. Cantor1, G. Mazon1, J. H. C. Costa1 1University of Kentucky, Lexington, KY Rectal temperature is the most common proxy for body temperature in dairy calves. However, this process is labor intensive and requires calf handling. Ocular infrared thermography (IRT) is a possible alternative and has shown potential to detect fever but its reliability and reproducibility remains uncertain. This study aimed to measure the reliability and reproducibility of an IRT camera measuring ocular temperature in weaned bull calves (n = 12) age 95 ± 16 d (mean ± SD). Calves were placed and restrained in a chute with an IRT camera placed 1.5m from their eyes and provided a 10 min acclimation period. At the end of the habituation period, rectal temperature (GLA M700 Thermometer, GLA Agriculture Elect., San Luis Obispo, CA) and ocular temperature using an IRT camera (FLIR T540sc, FLIR Systems, Inc. Wilsonville, OR) were measured simultaneously for 5 min per calf (20 ± 6 pictures; mean ± SD). The eye temperatures for each calf was recorded as the maximum temperature found within an oval drawn around the eye using the accompanying image processing software (ResearchIR Max Software, FLIR Systems, Inc. Wilsonville, OR). Mean rectal temperature was greater than ocular temperature (rectal = 39.3 ± 0.30, ocular = 37.6 ± 0.21°C; P ≤ 0.001). Furthermore, the mean difference between the rectal temperature and IR eye temperature across calves was 2.0 ± 0.44°C. The Bland-Altman plot between the rectal and IR ocular temperatures for all calves revealed a negative bias and a positive increased error with magnitude increase for IRT temperature when compared with rectal temperatures. The Pearson correlation between the rectal temperature and ocular IRT temperature across calves was moderate (r = 0.40 P ≤ 0.001). The coefficient of variation for temperatures within individual calf was greater for ocular than it was for the rectal temperature (median % CV [Q1, Q3]; ocular IRT = 1.16 [0.84,2.03], rectal = 0.10 [0,0.13]; P ≤ 0.001). These results suggest that IR imaging was repeatable, but may not serve as proxy for rectal temperature. Future research should determine optimum fever detection thresholds for ocular temperatures measured utilizing IRT.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t83875 Watch P101 Wisconsin farmer-reported management strategies for individually vs. socially reared preweaned calves. 2 F. L. M. Silva survey behavior welfare F. L. M. Silva1, J. Van Os1, C. Winder2, M. Akins1, T. Kohlman3, T. Ollivett4, H. Schlesser3, B. Schley3, S. Stuttgen3, J. Versweyveld3 1Department of Animal and Dairy Sciences, University of Wisconsin–Madison, Madison, WI, 2Department of Population Medicine, University of Guelph, Guelph, ON, Canada, 3Division of Extension, University of Wisconsin–Madison, Madison, WI, 4School of Veterinary Medicine, University of Wisconsin–Madison, Madison, WI Although research has demonstrated many benefits, social housing of pre-weaned dairy calves remains an uncommon farm practice. To characterize calf-rearing practices in Wisconsin, an online survey was distributed to dairy farmers and calf raisers. A total of 201 producers responded, of which 163 (81%) housed their heifer calves only individually and 38 (19%) housed at least some calves socially. Among farms using social housing, 12 (32%) kept their calves only in pairs, 11 (29%) in groups of 2–8, and 15 (39%) in groups of more than 8. Among farms using only individual housing, 10 (6%) kept their calves with no visual contact, 114 (70%) with visual contact, and 39 (24%) with visual and tactile contact. Practices on farms housing their calves individually vs. socially were compared using chi-squared or Wilcoxon tests. Compared with farms raising calves individually, farms with social rearing had more milk-fed calves (median 25 vs. 50, respectively; P = 0.02) and milking cows (200 vs. 400; P = 0.04). The daily milk feeding frequency for 4-week-old calves was greater for farms using social vs. only individual housing (P < 0.0001); 22 (58%) vs. 16 farms (42%) with social housing fed them ≤2 times/d vs. ≥ 3 times/d, and 146 (90%) vs. 17 farms (10%) with only individual housing fed with those respective frequencies. Milk was fed through a nipple more frequently on farms that housed calves socially vs. only individually (P < 0.0001); 28 farms (74%) housing calves socially used nipples vs. 10 farms (26%) which did not, whereas 38 (23%) vs. 125 farms (77%) with only individual housing fed using those respective methods. The amount of milk or milk replacer fed to 4-week-old calves did not differ between farms using social vs. only individual housing (P = 0.40); the most common quantity was 8 L/d on 13 (36%) vs. 54 (34%) of farms raising their calves socially vs. only individually. These results indicated that many Wisconsin farmers housing calves socially also used feeding strategies previously demonstrated to promote calf welfare, such as feeding milk several times daily at a high plane of nutrition, using nipples.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t83886 Watch P102 Effects of airspeed from fans located above freestalls on heat stress and lying time. 3 K. J. Reuscher heat abatement lying behavior K. J. Reuscher1, N. B. Cook2, M. R. Mondaca3, J. M. C. Van Os1 1Department of Animal and Dairy Sciences, University of Wisconsin–Madison, Madison, WI, 2School of Veterinary Medicine, University of Wisconsin–Madison, Madison, WI, 3Honorary Fellow, The Dairyland Initiative, School of Veterinary Medicine, University of Wisconsin–Madison, Madison, WI Our objective was to evaluate how airspeed from variable-speed fans above the resting area affect heat stress and lying time, a key indicator of cow comfort. Lactating Holsteins (n = 8 groups of 16 cows) were exposed to 3 treatments in a replicated crossover design (3 d acclimation, 4 d data collection): control (fans off, 0.4 ± 0.2 m/s, measured 0.5 m above the stall surface to represent cow lying height) vs. 60% (1.7 ± 0.5 m/s) and 100% (2.4 ± 0.8 m/s) fan power. Vaginal temperature (VT) and lying time (LT) were recorded at 1-min intervals with data loggers. Temperature-Humidity Index (THI) in the pens was measured at 5-min intervals. Linear mixed-effects models were used to analyze fixed effects of treatment, maximum daily THI, and their interaction, with a random term for group of cows. There were main effects of treatment and treatment × THI interactions for all dependent variables. Among all treatments, LT differed in a dose-dependent fashion (100% vs. 60% fan power vs. control: 14.3 vs. 14.0 vs. 13.3 h/d, respectively, SEM = 0.17 h/d; P < 0.036). For every 10-unit THI increase, LT in the control decreased 0.4 h/d, whereas both fan treatments showed the opposite pattern (+0.3 and 0.7 h/d in 60% and 100% fan power treatments, respectively; P < 0.046). Maximum daily VT was lower in the 2 fan treatments (39.1°C in both 60% vs. 100% fan power treatments, respectively, SEM = 0.06°C) relative to the control (39.5°C; P < 0.001). For every 10-unit THI increase, VT increased 0.3°C in the control but was stable in both fan treatments (+0.0°C in both 60% vs. 100% fan power treatments; P < 0.019). Milk yield (MY) was higher in the 2 fan treatments (42.7 vs. 43.3 kg/d in 60% vs. 100% fan power treatments, respectively, SEM = 0.4 kg/d) relative to the control (41.4 kg/d, P < 0.001). For every 10-unit THI increase, MY in the control decreased 1.1 kg, whereas both fan treatments showed the opposite pattern (+1.1 vs. 1.9 kg in 60% vs. 100% fan power treatments, respectively; P = 0.011). In conclusion, higher airspeed at cow resting height was effective not only for maintaining vaginal temperature, but also for improving lying time and milk yield in heat stress conditions.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t84033 Watch P103 Effects of hutch ventilation on preference and heat stress in pair-housed dairy calves. 4 K. J. Reuscher heat abatement social housing K. J. Reuscher1, C. S. Yu1, R. Salter1, T. Bresolin1, J. M. C. Van Os1 1Department of Animal and Dairy Sciences, University of Wisconsin–Madison, Madison, WI Our objective was to evaluate the effects of social contact and hutch ventilation on calves’ responses to heat stress. Newly weaned Holstein heifers (n = 25 pairs; 55 ± 1 d of age) were pair housed in adjacent hutches with a shared outdoor area. In each pair of hutches, 1 was ventilated with 2 25.4-cm-diameter windows at the rear base and the rear bedding door propped open; the other had no rear windows and the bedding door was closed. Calves were exposed to 4 treatments for 1 h each (1100–1200 and 1230–1330 h on 2 consecutive d) in a 2 × 2 factorial design in a balanced order: individually or in pairs in the nonventilated or ventilated hutch. Respiration rate (RR) was recorded before and after each exposure. Temperature-Humidity Index (THI) was recorded in both hutches at 5-min intervals. A generalized linear mixed model was used to evaluate the fixed effects of ventilation, number of calves inside the hutch, and their interactions, on THI and change in RR after 1 h; the random effect was pair of calves. To evaluate preference, calves were observed for the subsequent 3 d with time-lapse cameras. The calves’ locations were recorded at 15-min intervals by an observer blinded to hutch ventilation. The proportion of time calves spent in each hutch was averaged within pairs and across the 3 d of observation. A 1-sample t-test was used to evaluate preference for the ventilated hutch, compared with 50% (chance, no preference). After 1 h, RR decreased vs. was unchanged, respectively, when calves were in the ventilated vs. nonventilated hutch (−10.1 vs. +0.3 breaths/min, respectively, SE = 2.0 breaths/min; P < 0.001), regardless of how many calves were inside (no main effect or interaction with number of calves, P ≥ 0.475). Calves preferred the ventilated hutch (72.3 ± 4.3% of the total time inside both hutches, mean ± SE; P < 0.001). This preference was likely driven by calves seeking heat abatement: after calves were inside for 1 h, THI was lower in the ventilated vs. nonventilated hutch (72.7 vs. 78.2 THI units, respectively, SE = 1.7; P > 0.001). In conclusion, newly weaned calves preferred ventilated hutches, which reduced their heat stress in outdoor pair housing.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t84136 Watch P104 Impact of stationary brush quantity on brush use in group-housed dairy heifers. 5 F. S. Baier grooming oral behavior competition F. S. Baier1, A. R. Gimenez1, K. M. Coel1, E. K. Miller-Cushon2, J. R. Dorea1, J. M. C. Van Os1 1University of Wisconsin–Madison, Madison, WI, 2University of Florida, Gainesville, FL Grooming is an important natural behavior for cattle and can be practically facilitated with objects in the environment, such as brushes. Our objective was to evaluate the effect of the number of brushes on brush use and competition in group-housed, weaned dairy heifers naïve to brushes. We predicted providing more brushes would allow for greater use and less competition. Sixty-three Holstein heifers (96 ± 6 d old) were housed in groups of 8 (with the exception of 1 group of 7) in straw-bedded pens with either 2 or 4 stationary brushes (n = 4 groups/treatment). Behavior was recorded continuously for all heifers from video for 6-h time periods on d 1 (0–6 and 18–24 h of exposure) and 6 (120–126 and 138–144 h of exposure). We measured brush oral manipulation (contact with mouth or tongue), grooming (rubbing head, neck, or body), and displacements (physical contact between heifers that stopped brush use); values were averaged at the pen level. Linear models were used to evaluate the effect of brush quantity on brush use and displacements. Pairwise comparisons were performed using a Tukey’s adjustment. Latency to use any brush after entering the pen was 4.0 ± 8.4 min (mean ± SD). All heifers used a brush at least once. Heifers provided access to 4 vs. 2 brushes displayed greater durations of oral manipulation (1.9 ± 0.2 vs. 1.5 ± 0.1 min/6 h, mean ± SE; P = 0.047), grooming (5.6 ± 0.4 vs. 4.0 ± 0.3 min/6 h; P = 0.002), and total brush use (7.5 ± 0.4 vs. 5.4 ± 0.4 min/6 h; P = 0.001). Regardless of treatment, duration of oral manipulation was greater in the initial 6 h of exposure than on d 6 (P ≤ 0.03). However, the greatest brush use for grooming was during the last 6 h of d 6 (P ≤ 0.03). Competition did not differ between treatments (P = 0.54). Overall, more frequent displacements were observed in the first 6 h of exposure on d 1 compared with the corresponding time period on d 6 (P = 0.01). In conclusion, heifers provided with more brushes used them for longer periods of time, suggesting that expression of brush-directed behavior may depend on resource availability.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t84190 Watch P105 Early-life behavior of organic-certified Holstein heifer calves housed in pairs. 6 A. Velasquez-Munoz behavior calves pair housing A. Velasquez-Munoz1, P. Pinedo1 1Colorado State University, Fort Collins, CO The objective was to describe the behavior of Holstein heifer calves during their first days of pair housing. Newborn calves (n = 15 pairs) were monitored from July to August 2020 in a rearing facility in northern CO, USA. Due to management constrains, a control group individually housed was not included. Calves were moved to the rearing facility at 1 d of life, and milk was offered 3 times per day. Calves were housed in pairs sharing 2 polyethylene hutches and a sand bedded front yard (4.50 m2), enclosed by a galvanized welded wire fence. Pairs were video recorded during the first 10 d of life, and behavior was assessed during 1 h before and after each milk feeding (6:30AM, 12:30PM, 7:30PM). Behaviors included resting and active time and time alone or interacting as a pair (inside or outside the hutches). Continuous THI inside the hutches was collected during the study. Data were summarized using SAS and paired t-test was used to assess differences among feeding times within age (Table 1). Calves were less active at noon regardless of age, likely due to higher THI. Over time, calves increased their time spent interacting inside the hutch, especially in the AM and Noon periods. At noon, calves spent > 83% of the time resting and they spent more time alone or in pairs inside the hutch. In conclusion, activity and pair interactions varied depending on time of the day and calf age. Table 1. Percentage of time that calves performed the behaviors of interest for each feeding period at 2, 5, and 9 days of age
Age (d) Activity, %(SD) Pair interaction, %(SD) THI hutchMean (SD)
Resting Active Alone Pair outside Pair inside
2            
 AM 85.2a (3.8) 14.8a (3.8) 78.3a (26.8) 6.6a (12.2) 15.1a (23.14) 60.8 (3.4)
 Noon 89.9a (7.6) 10.1a (7.6) 57.9a (31.4) 0.8a (1.0) 41.3b (31.22) 81.5 (1.6)
 PM 65.4b (12.1) 34.6b (12.1) 55.3a (29.8) 19.2b (17.3) 25.5a (22.7) 69.4 (1.8)
5            
 AM 72.2a (7.2) 27.8a (7.2) 61.3a (27.6) 11.3a (8.1) 27.4a (28.7) 61.2 (2.2)
 Noon 88.2b (10.0) 11.8b (10.0) 55.8a (25.2) 2.3b (3.2) 41.8a (25.0) 80.5 (2.1)
 PM 67.1a (9.8) 32.9a (9.8) 45.9a (31.6) 19.5a (13.6) 34.6a (23.5) 72.1(2.5)
9            
 AM 75.3a (8.2) 24.7a (8.2) 44.7a (30.0) 9.8a (6.6) 45.5a (29.6) 59.3 (3.1)
 Noon 83.4b (12.1) 16.6b (12.1) 42.8a (40.0) 2.4b (3.6) 54.8a (43.7) 81.6 (1.7)
 PM 65.4c (10.5) 34.6a (10.5) 54.3a (17.3) 18.6a (9.2) 27.1b (17.3) 72.2 (0.7)
a–cDifferent letters within column and age indicate statistical differences.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t84207 Watch P106 Peripartum feeding behavior is related with onset of ovarian cyclicity in dairy cows with different dry period lengths. 7 A. T. M. van Knegsel fertility behavior dry period length B. G. C. de Bruijn1, A. Kok1, J. Ma1, A. T. M. van Knegsel1 1Adaptation Physiology Group, Wageningen University & Research, Wageningen, the Netherlands Poor reproductive performance is one of the main factors contributing to culling of dairy cows. Monitoring of feeding behavior can be valuable in early detection of reproductive problems. The objective of the current study was to investigate relations between feeding behavior and onset of luteal activity (OLA) in dairy cows subjected to no (0-d) or a short (30-d) dry period (DP). Feeding behavior was continuously recorded by computerized feeders for 123 dairy cows and analyzed from 4 weeks prepartum to wk 14 of lactation. Cows were randomly subjected to a transition treatment: 0-d DP with a low postpartum dietary energy level (0-d DP LOW) (n = 41), 0-d DP with a standard postpartum dietary energy level (0-d DP STD) (n = 40), or 30-d DP with a standard postpartum dietary energy level (30-d DP STD) (n = 42). Milk progesterone concentration was determined 3 times per week until 100 d in milk (DIM) to assess onset of luteal activity (OLA). Feeding behavior variables were analyzed using mixed models, including fixed effects of OLA class (OLA < 21 or ≥ 21 DIM), transition treatment, parity (2, or > 2), and their interactions. Cow was included as repeated subject. Before calving, visits to the feeder per day were higher in cows with OLA < 21 DIM (OLA < 21) compared with OLA ≥ 21 DIM (OLA ≥ 21), and often interactions with transition treatment were found. During the first 4 weeks postpartum, cows with OLA < 21 had a higher feed intake, meal size, feeding rate, meal duration and more visits per meal and visits per day, but fewer meals per day compared with cows with OLA ≥ 21. During the first 2 d postpartum, cows with OLA < 21 had higher cumulative feed intake, meal size, and more visits per day and visits per meal compared with OLA ≥ 21. In conclusion, the relation between prepartum feeding behavior and OLA was greatly affected by transition treatment, i.e., dry period length and postpartum dietary energy level. Cows with an early OLA had a postpartum feeding behavior that reflected a faster recovery from parturition and better adaptation to a new lactation compared with cows with a later OLA.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t84265 Watch P107 Effects of eliminating head lockup in stalls during transition period in a dairy farm: A case study. 8 J. Piñeiro lockup dairy freestall S. Paudyal1, J. Piñeiro1,2, L. Papinchak1 1Department of Animal Science, Texas A&M University, College Station, TX, 2Texas A&M AgriLife Research and Extension Center, Amarillo, TX Self-locking feed stanchions improve labor efficiency by reducing the amount of time spent handling cattle on dairy farms. However, extended lockup times have been associated with stress and increased total daily standing time, which leads to negative impacts on milk production and health. The objective was to evaluate the association of eliminating stall lockup during the early postpartum period of dairy cows (21 d after parturition) on test-day milk yield, reproductive performance, and health disorders. A retrospective cohort case study was conducted on 400 Holstein cows from a dairy farm in northwest Texas divided into treatment (TRT; n = 200) and control group (CON; n = 200). CON received an average of 2 h per day lockup time during 21 d postpartum whereas TRT animals were not exposed to headlock restraint during this period. Farm records including monthly milk yields, monthly linear somatic cell score (SCS), days in milk to first breeding (DIMFB), days in milk to subsequent pregnancy (DIMPREG), and incidence of mastitis and lameness, were obtained from the farm management software. Herd records were analyzed using SAS ver.9.4. The continuous variables were analyzed using a mixed model using cow as a random effect and the frequencies were analyzed using Chi-squared tests. TRT demonstrated greater milk yield (LSM ± SEM) on second (86.2 ± 1.68 vs. 82.6 ± 1.29; P < 0.05), third (72.9 ± 2.50 vs 67.6 ± 1.19; P = 0.06), and fourth monthly test day (53.9 ± 3.70 vs 45.2 ± 6.20; P = 0.05) compared with CON cows. TRT cows had lower SCS on the third monthly test day (2.6 ± 0.24 vs 3.2 ± 0.11; P = 0.01). TRT cows came to estrus earlier in the lactation as indicated by smaller DIMFB (66.2 ± 3.70 vs 76.8 ± 2.90; P = 0.02) and became pregnant sooner as indicated by smaller PREGDIM (66.9 ± 12.32 vs 112.1 ± 5.50; P < 0.01). Cows in TRT group also had lower incidence of mastitis (3% vs 23%; P < 0.001), and lower incidence of lameness (3% vs 9.5%; P = 0.007). We conclude that eliminating lockup time in early lactation might provide improvements in milk production, health, and reproductive performance of lactating dairy cows.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t84446 Watch P108 Preferences of dairy cattle for supplemental light-emitting diode lighting in the lying area. 9 A. M. Wilson light behavior stall A. M. Wilson1, T. C. Wright2, J. P. Cant1, V. R. Osborne1 1Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada, 2Ontario Ministry of Agriculture, Food and Rural Affairs, Guelph, ON, Canada Supplemental lighting has been used to increase milk yield in dairy cows. Light-emitting diode (LED) lights are highly efficient and are becoming more common on farms. The objective of this experiment was to determine the effect of 3 LED light colors in the stall area on short-term preferences of dairy cows. Second-lactation cows (n = 14; 210.1 ± 35.2 DIM; 35.8 ± 5.1 kg/d) were housed in a pen with unrestricted access to 28 freestalls. The stall platform was separated into 2 sides by an opaque divider. Lights were installed as part of the stall partitions and positioned above cows’ heads when resting. Two combinations of light were tested each period (P1: white light, 3000K vs. no light; P2: white light vs. green-yellow/570 nm light; P3: white light vs. blue/475 nm light). The experiment consisted of 3 periods, each with 3 d of adaptation (no light) followed by 4 d of light treatment where treatments were applied to opposite sides after 2 d. Facility lights were on from 0400 h to 2000 h and supplemental LED lighting was provided from 0400 h to 2400 h. Video data and lying behavior were recorded continuously using cameras and leg-mounted pedometers, respectively. Preference was assessed by the amount of time spent lying down and number of bouts in each treatment. Data were summarized by treatment per block of time (dark, facility+LED lights, LED only) per cow and analyzed by ANOVA with a Tukey’s adjustment (PROC GLIMMIX, SAS v.9.4). Differences between treatments within each period were not significant for lying time (P = 0.98) or number of bouts (P = 0.86). There were no treatment differences between block of time within periods for lying time (P = 0.88) and number of bouts (P = 0.73). Cows spent 2.1 vs. 2.2 ± 0.13 h/block of time lying in white vs. no light, 2.0 vs. 2.0 ± 0.14 h/block of time lying in white vs. green light, and 2.1 vs. 2.1 ± 0.13 h/block of time lying in white vs. blue light. Cows did not avoid lying under white light when also given the option of no light, suggesting that supplemental light in the stall area was not aversive short-term to cows. Additionally, cows did not have a preference between white and green or blue light.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t84471 Watch P109 The effect of heat stress on behavior and milk production of dairy cows. 10 Y. Ma animal behavior dairy cow heat stress Y. Ma1, C. Shen1, K. Yang1, K. Shen1, D. Renaud2, D. Kelton2, T. Duffield2, Q. Dong1 1College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China 712100, 2Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada Heat stress (HS) is reported to affect the standing, feeding, drinking, and lying behavior of dairy cows. This study was to observe and summarize the effect of HS on the behavior and milk production of cows with differing levels of milk production. A self-powering meteorological station was established in a herd of about 1,500 Holstein cows to monitor temperature and humidity, and THI (temperature-humidity index) was calculated. The degree of heat stress was classified into 3 categories according to the daily average THI from 08:00 to 20:00 [no heat stress (NOHS, THI <72), mild heat stress (MIHS, 72 ≤ THI ≤ 79), and moderate heat stress (MOHS, THI >79)]. All cows were divided into 3 groups (high productive group (HG, daily milk yield 40.1 ± 2.0 kg), middle productive group (MG, 85 – 154 DIM, daily milk yield 28.7 ± 1.4 kg), low productive group (LG, 15 – 84 DIM, daily milk yield 23.6 ± 1.2 kg)). According to the change of DIM, the cows flowed between groups. The cows were housed in a freestall equipped with fans, sprinklers and water trough. Feeding time was at 06:00, 13:00, 19:30. Cows were milked 3 times daily (07:00, 13:00, 21:00) in a milking parlor and make milk yield measurements. Changes in feeding, drinking, lying, and standing behavior were monitored visually and the proportion of the 4 behaviors were calculated every hour from 12:00 to 18:00 by manual scanning and tracking under the condition of NOHS and MOHS. A mercury thermometer was used to determine the rectal temperature of cows from 12:00 to 15:00 every day. The influence of HS on rectal temperature and behavior of dairy cows with different productive groups were analyzed by one-way ANOVA test (Tukey test). There was no significant difference in rectal temperature between HG, MG, LG when cows experiencing NOHS, MIHS, and MOHS. Under the influence of MOHS, the feeding proportion of HG and MG increased about 100%, and the standing proportion of HG and MG decreased by 51.06% and 23.33% respectively (P < 0.05), while these 2 behaviors of LG had no significant change. The potential reason may be that the position of the sprinklers is above the feeding stall so the cows want to cool down and eventually eat casually. There was no significant difference in daily milk production between HG, MG, LG under the conditions of NOHS and MIHS. HS can cause different degrees of behavioral changes for dairy cows with different levels of milk production.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t84562 Watch P110 Assessing human-directed behavior in dairy calves reared with varying social contact. 11 S. B. Doyle human-animal interaction social housing nonnutritive oral behavior S. B. Doyle1, E. K. Miller-Cushon1 1University of Florida, Gainesville, FL While social contact for calves has broad effects on behavioral development, influences on human-animal relationships have been minimally studied, despite implications for longer-term calf management and welfare. We characterized human-animal interactions in 2 distinct testing contexts to examine response repeatability, effects of housing, and activity following testing. At birth, calves were randomly assigned to individual housing (IH; n = 6 calves) or pair-housing (PH; n = 6 calves; 1 focal calf/pair). A human approach test was performed in the home pen (wk 3) and within a test arena (wk 4), where a human approached, and then extended their hand, over a 5 min period. We measured latency to contact the human, frequency of human-directed oral behavior, latency to lie down following testing, and assigned a score for human approach (0 = complete avoidance of human, 4 = close proximity and human contact). Latency to contact the human was 60.3 ± 54.0 s (mean ± SD) for the home pen approach test, and 133.3 ± 121.6 s, for the arena test. Human-directed nonnutritive oral behavior occurred in 59% of calves, on average. There was no effect of housing treatment on any approach test outcomes in our preliminary data set (P > 0.2). For the home pen approach test, we found that calves who performed human-directed nonnutritive oral behaviors had reduced latency to lie down following testing (7.4 vs. 16.7 min; SE = 3.26; P = 0.04). Latency to lie down following testing was also negatively associated with approach test score (estimate = −2.79; SE = 1.36; P = 0.04), indicating that calves that approached the human more readily lay down faster following testing, which may reflect reduced disruption in calves that are more comfortable with human interaction. We found no association between the 2 approach tests in latency to approach the human or approach test score (P > 0.4). Overall, these results highlight variability in human-directed behavior between individual calves and testing contexts in response to human approach.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t84563 Watch P111 Effect of pair-housing on calf health, intake, and growth performance. 12 E. E. Lindner social contact feed intake weight gain E. E. Lindner1, K. N. Gingerich1, P. D. Krawczel2, E. K. Miller-Cushon1 1University of Florida, Gainesville, FL, 2University of Helsinki, Helsinki, Finland Dairy calf social housing affects early-life calf behavior and performance, yet less is known about longer-term impacts of social housing. We hypothesized that pair-housed calves would consume more solid feed during the preweaning period compared with individually housed calves, which would translate into a growth benefit, potentially carrying over into the postweaning period. Calves were randomly assigned at birth to either individual (IH; n = 15 calves) or pair pens (PH; n = 10 pairs). Calves received 8 L/d of milk replacer in 2 meals, and were provided ad libitum access to calf starter and water. Calves were mingled between treatments and group-housed (5 ± 1 calves/pen) at 8 wks of age and then regrouped and moved to pens on pasture and followed for 2 mo. We monitored health (days scouring) during the first week of life. Milk and starter intake were measured 5x/wk and body weight was measured weekly until wk 9 of age, and again after 2 mo on pasture. Data were averaged for pair-housed calves, and analyzed in a general linear mixed-effects model, with week as a repeated measure for preweaning data. Duration of scours was not affected by housing (5.7 vs. 3.9 d; IH vs. PH; SE = 0.95; P = 0.16). Milk intake during the first 3 wks of age did not differ (3.4 L/meal; SE = 0.09; P = 0.22), and all calves finished their allotment beyond this time point. Calves housed in pairs tended to consume more starter during the preweaning period (96.1 vs. 62.5 g/calf/d; PH vs. IH; SE = 0.9; P = 0.064) and maintained greater starter intake during weaning (1.1 vs. 0.88 kg/calf/d; PH vs. IH; SE = 0.01; P = 0.05). Preweaning ADG did not differ between treatments (0.59 vs. 0.57; IH vs. PH; SE = 0.03; P = 0.17), and body weight did not differ at the time of postweaning grouping (wk 8; 69.6 kg; SE = 2.6; P = 0.67) or after 2 mo on pasture (120.1 kg; SE = 5.4; P = 0.80). In conclusion, pair-housing supported increased starter intake during the preweaning and weaning period, but we did not observe a longer-term effect on weight gain.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t84575 Watch P112 Association between personality traits and behavior in the home pen in group-housed dairy calves. 13 K. N. Gingerich personality behavior calf social housing K. N. Gingerich1, E. E. Lindner1, E. K. Miller-Cushon1 1University of Florida, Gainesville, FL Given evidence of considerable individual variability in the expression of many behavioral traits, the objective of this study was to evaluate associations between personality and aspects of social behavior, feeding behavior, and interaction with environmental features. Holstein heifer and bull calves (n = 32) were introduced to group pens at 2 weeks of age (8 calves/pen; 7.4 × 16.0 m). Each pen included contained 2 rotating brushes and 2 shelters (3 sided; 1.2m x 1.2m) offering visual seclusion from the rest of the pen. Calves were fed a maximum of 12 L/d of milk replacer (min meal size = 2 L; max meal size = 4.5 L) via an automatic milk feeder. At 4 weeks of age, calves were tested in a series of standardized behavioral tests, including open field, novel object, unfamiliar calf, and unfamiliar human tests. Behavior was recorded continuously for 24 h in the week following behavioral testing to characterize use of the shelters and brushes, and feeding behavior data were obtained from the milk feeder for a 7-d period encompassing this focal day. Four factors were identified from principal component analyses of responses during behavioral tests and were interpreted as “exploratory active,” “inactive avoidant,” “calf-avoidant,” and “human-directed.” Association between these factor scores and behavior were analyzed using linear regression. The “calf avoidant” factor tended to be positively associated with shelter use (P = 0.10), lying duration within the shelter (P = 0.07), and milk intake (P = 0.10), and was negatively associated with frequency of entering an occupied shelter (P = 0.06). The “exploratory active” factor tended to be negatively associated with shelter use (P = 0.10). The “human-directed” factor was positively associated with duration of brush use (P = 0.01). The “inactive avoidant” factor was not associated with any focal behaviors. Our results suggest that personality is associated with behavioral expression in the home pen, including aspects of feeding behavior and use of shelters and rotating brushes, highlight the need for further study of individual differences in livestock behavior.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t84582 Watch P113 Assessment of the associations of management practices during the dry period and activity patterns in dairy cattle. 14 A. A. Barragan dry period farm practices activity patterns A. A. Barragan1, M. Shabloski1, E. Hovingh1, L. da Costa2 1Department of Veterinary and Biomedical Sciences, Penn State University, University Park, PA, 2Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, OH The objective of this study was to assess the associations of dry period management practices and activity patterns (i.e., lying time, number of lying bouts, and lying bout duration) during the 14 d before calving. Heifers and cows from 4 dairy farms (700–2,800 milking cows) located in Pennsylvania were enrolled in this trial. Based on on-farm records, cows that were between 20 and 30 d from expected calving date were fitted with a HOBO accelerometer on the rear right leg. Only animals that had complete activity data for 14 d before the actual calving date were included in the study (heifers, n = 66; cows, n = 70). A 20-question multiple-choice survey was developed to collect farm management practices information (e.g., feed push-up frequency, bedding material used). The data were analyzed using the MIXED procedure of SAS. Heifers and cows that were housed in pens with sand or straw as bedding materials spent more time lying (sand = 815.7 ± 12.01 min/d; straw = 845.61 ± 21.68 min/d; sawdust/recycled manure = 650.30 ± 17.06 min/d), and had more lying bouts (sand = 11.18 ± 0.25 bouts/d; straw = 12.69 ± 0.51 bouts/d; sawdust/recycled manure = 9.45 ± 0.37 bouts/d) and of shorter duration (sand = 75.02 min, 95% CI:56.79–99.13; straw = 66.21 min, 95% CI:56.98–76.93, sawdust/recycled manure = 98.31 min, 95% CI:67.92–142.30) compared with cows that were housed in pens with either sawdust or recycled manure as bedding materials. Furthermore, heifers and cows that were fed 2 times a day spent nearly 3 h less lying down (2 times feeding = 650.36 ± 22.05 min/d; one time feeding = 823.77 ± 13.57 min/d) and tended to have longer lying bouts (2 times feeding = 98.33 min, 95% CI:65.61–147.37; one time feeding = 72.23 min, 95% CI:58.30–89.47) compared with cows that were fed one time a day. The results from this study suggest that farm practices during the dry period may alter cow behavior.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t84600 Watch P114 Temperament and dominance in confined beef cattle: Effect on feeding behavior, intake and performance. 15 V. Fischer beef cattle dominance temperament V. Fischer1, A. F. Bettencourt1, A. T. Machado1, I. D. V. Angelo1, D. G. Adamich1, C. S. Silva1, J. A. Guimarães1, L. S. Garcia1, C. A. K. Ximenes1, A. C. Vieira1, J. U. Tarouco1 1Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil This study aimed to evaluate the relation between temperament and dominance and the effects on the feeding behavior, dry matter intake (DMI) and daily weight gain (ADG) of beef cattle. Two trials were conducted during 70 d (each one), with 20 Angus bulls and 21 Brangus calves, housed in drylots with automatic feeders and drinkers. The social hierarchy of the animals was evaluated at the beginning of the study, classifying them in dominant and subordinate animals based on the sucess rate in agonistic interactions (Dominance Index, DI). The temperament was evaluated at the beggining, middle and end of the trials, as the time spent by animais to exit the squeeze chute and traverse a fixed distance of 1.80 m (ET); also as the composite score (CS) considering the movements, breathing intensity, vocalization and kicking while animal was hold at the scale. Feeding behavior and DMI were assessed using automated feeders. All measurements were averaged per animal, generating one value per bovine. The values of ID and ET were used to classify the animals in classes of dominance (DIT) and temperament (ETT). Means of ET, CS, DI, ingestive behavior, DMI and ADG within trials were submitted to correlation analysis and ANOVA (GLM procedure of SAS), considering the fixed effects of DIT, ETT and their interaction according to a complete randomized design. Dominance did not correlate with temperament in bulls. Reactive bulls (ETT ≤6.2 s) tended (P < 0.10) to have a higher DI. Dominant bulls (DIT >0.49) tended (P < 0.10) to have higher DMI rate. Calm bulls (ETT >6.2 s) tended (P < 0.10) to have fewer visits to the feeder and higher DMI rate, but had larger meal duration (P < 0.05). Dominance was moderately correlated with ET (r = 0.45; P = 0.04), indicating that dominant calves were calmer than subordinates. The DMI rate tended (P < 0.10) to be higher for reactive calves (ETT ≤3.5 s). Neither DIT nor ETT affected DMI and ADG of bulls and calves. The temperament and dominance, despite changing some characteristics of feeding behavior, did not influence DMI and ADG of confined beef cattle with access to automated feeders.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t84609 Watch P115 Attitudes and perspectives of Brazilian dairy farmers regarding the use of automated behavior recording and analysis systems. 16 V. Fischer behavior farmer’s perspectives monitoring technology V. Fischer1, A. C. Vieira1, M. E. A. Canozzi2, L. S. Garcia1, J. T. Morales-Piñeyrúa2 1Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil, 2Instituto Nacional de Investigacion Agropecuaria (INIA), Colonia, Uruguay Automated behavior recording and analysis systems (ABRS) have been developed to help in the farm management. However, the knowledge about attitudes and perspective of farmers and manager staff in relation to technology use and alerts are still scarce. The aim of this study was to investigate the motivations and perspectives of Brazilian dairy farmers who adopted (YABRS) or not (NABRS) the automated system. Thirty-eight farmers were contacted. A semi-structured interview was conducted by telephone, and the answers were transcribed and codified for further descriptive analysis. Farmers were classified in 2 groups, 22 and 16 in the NABRS and the YABRS, respectively. The data were analyzed descriptively and by ANOVA comparing groups of farmers using SAS Studio (SAS Institute, version 3.8, 2016). In both groups, the majority of farmers are less than 40 years old and have superior education level (P > 0.10); 68.7% of the farmers in the YABRS group are in the dairy activity for more than 20 years against 36.3% of the farmers in NABRS (P < 0.05). In NABRS group, 77.2% of the farms are pasture-based systems, while 100% in the YABRS group confined cows. Herds were larger in NABRS commpared with YABRS (P < 0.05), 165.5 ± 139.7 vs 50.6 ± 41.6 cows, respectively. The estrus detection and cow’s health monitoring were the main motives to invest or desire to invest in this technology for both groups but cost is the most important factor that prevents farmers from purchasing monitoring systems. All YABRS famers observed the target cows after receiving a health or estrus alert, but less than 33% give feed back about the alerts to the company, although 75% of YABRS considered it was easy to adapt to the monitoring system and 85% of them claimed to partially trust the alerts. YABRS farmers believe that they can intervene in the evolution of the animals' health status, as the alerts give a window of 3 to 4 d before the onset of clinical signs of diseases, anticipating the start of the treatment and 75% of them stated they improved service and conception rates. All contacted farmers showed interest in health, calving, thermal comfort and especially estrus alerts, but factors as cost, difficult access to internet, impairing access to the system, to the equipment and service’s suppliers, prevent ABRS acquisition or the spread of its use by farmers.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t84623 Watch P116 Evaluation of parity impact on social competition and feed efficiency in lactating cow. 17 F. S. Baier social dynamics grouping strategies F. S. Baier1, M. J. Martin1, S. J. Erb1, G. J. Combs1, K. A. Weigel1, H. M. White1, J. M. C. Van Os1 1University of Wisconsin–Madison, Madison, WI Social order can impact feeding behavior and other feed and production related outcomes in dairy cows. Our objective was to evaluate the impact of parity and grouping on feed efficiency and feed bunk social dynamics. Lactating Holstein cows (29 primiparous, 30 multiparous; 168 ± 22 DIM mid trial, mean ± SD) were housed in a freestall pen with 30 Insentec feeders. Cows were randomly assigned to 1 of 3 treatments (PRIM: 100% primiparous, MULT: 100% multiparous, MIX: 50% primiparous (MIXP), 50% multiparous (MIXM)) with 2 replicates each (10 cows/replicate). Each cow had access to 5 bins. Video was recorded continuously for 6 nonconsecutive h in wk 1 (1 h postmilking, 0450 and 1545 h; 4 h post-feed delivery, 1000 h). Competitive replacements (actor is successful or not in replacing the receiver at the feed bunk) were coded, and the ratio of successful replacements out of total attempts were calculated for each cow (excluding 6 cows uninvolved in replacements). Residual feed intake (RFI) was calculated by regressing DMI on milk energy output, median DIM, metabolic BW, and change in BW, each nested within parity. Linear models with fixed effect of parity within treatment were conducted in R (v. 3.6.3) with planned contrasts between MULT vs. PRIM, MULT vs. MIXM, and PRIM vs. MIXP. However, due to nonnormal data, a Wilcoxon rank sum test was used to evaluate replacements. Cows in MULT were more successful when initiating replacements relative to PRIM (0.96 ± 0.03 vs. 0.76 ± 0.1, mean ± SE; P = 0.02), but no differences in success index were found between multiparous or primiparous cows in same- vs. mixed-parity treatments (MULT vs. MIXM: 0.96 ± 0.03 vs. 0.81 ± 0.1; PRIM vs. MIXP: 0.76 ± 0.1 vs. 0.92 ± 0.1; P ≥ 0.41). Parity within treatment did not impact RFI (PRIM vs. MIXP: −0.11 ± 0.3 vs. 0.24 ± 0.4; MULT vs. MIXM: −0.31 ± 0.3 vs. 0.58 ± 0.4; PRIM vs. MULT: −0.11 ± 0.3 vs. −0.31 ± 0.3; P ≥ 0.48). The potential influence of parity grouping on social dynamics and RFI warrants further investigation.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t84640 Watch P117 Coefficient of variation of daily lying bouts increases at parturition. 18 J. M. Piñeiro parturition prediction behavior J. M. Piñeiro1, B. T. Menichetti2, G. M. Schuenemann2 1Department of Animal Science, Texas A&M AgriLife Extension, Amarillo, TX, 2Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, OH The objective was to assess the effect of parturition on behavior [lying time, steps, lying bouts (LB), LB duration (LBd), standard deviation (SD) of LBd and the coefficient of variation (CV) of LBd]. A total of 1,052 prepartum Holstein cows (401 heifers and 651 cows) from 3 Ohio dairy herds were enrolled in monthly cohorts of 20 to 36 cows 2 weeks before parturition. Individuals animals were fitted with electronic data loggers (IceQube, IceRobotics, Edinburgh, UK) on a rear leg to assess their behavioral activity. Lying time (min/d), number of steps (no./d), number of LB (no./d), LBd (min/d), SD of LBd and the CV of LBd were recorded. Data were analyzed using MIXED procedure of SAS using days relative to calving as repeated measures (SAS Institute Inc., Cary, NC). Cows had decreased lying time (10.6 h/d) the day of parturition compared with each day of the week before calving (over 12 h/d; P < 0.0001). However, heifers had decreased lying time at parturition (8.6 h/d) and day −1 (8.7 h/d) compared with days −7 to −2 (over 9.8 h/d; P < 0.0001) but day −1 and the day of parturition did not differ (P = 0.75). Heifers showed a different behavioral pattern compared with cows with the decrease of lying time starting one day before parturition compared with the decrease observed in cows occurring the day of parturition. Heifers and cows showed significantly increased steps and more LB of shorter duration the day of parturition compared with days −7 to −1 relative to parturition (P < 0.0001). The SD of LBd of cows and heifers at parturition decreased compared with days −7 to −2 (P < 0.0001). However, the CV of LBd increased at parturition compared with each day of the week before calving (P < 0.0001). The CV of LBd duration is standardized by the mean of LBd (CV = SD/mean × 100), and mean LBd decreased at parturition. Therefore, the CV of LB duration best measures the dispersion compared with the SD of LBd to assess the increased variation of LBd before parturition. These findings show that the CV of LBd increases at parturition.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t84676 Watch P118 Predicting pre- and postweaning performance of dairy calves: An investigation using precision technology data. 19 M. C. Cantor growth automated feeder activity M. C. Cantor1, H. W. Neave2, M. M. Woodrum Setser1, J. H. C. Costa1 1Dairy Science Program, University of Kentucky, Lexington, KY, 2Animal Behaviour and Welfare, AgResearch Ltd, Hamilton, New Zealand The early identification of individual traits that are associated with performance in dairy calves is fundamental to tailor management and characterize phenotypes. We aimed to identify if feeding behavior patterns and activity in early life (first 30 d) were associated with total performance (ADG) and total starter intake from birth to 14 d postweaning. Calves (n = 42) wearing a leg accelerometer (IceRobotics, Scotland) were fed from an automated feeder (Förster-Technik, Germany) starting at 3 ± 2 d of age. Calves were weighed at birth and twice weekly on a scale. Calves had an allowance of 10 L/d of milk replacer until d 50 and ad libitum access to starter from another feeder. Calves were step-down weaned off milk from d 50 (50% reduction until d 64, additional 20% reduction until complete weaning at d 70). Calves were followed for 14 d postweaning. Total starter intake and ADG were summarized over the experimental period (d 3 to 87 ± 2 d of age). The automated feeder recorded daily feeding behavior variables: starter intake, milk intake, rewarded and unrewarded visits, and drinking speed. The accelerometer recorded daily activity variables: lying time, lying bouts, total step count, and activity index based on acceleration rate and steps. All feeding behavior and activity variables from pen entry to d 30 were input variables in a Principal Component Analysis, resulting in 3 factors explaining 70% of the variance. In a linear regression, factor 3 (“Feed motivated”: high drinking speed and starter intake) was associated with greater ADG (P < 0.01) and total starter intake over the experiment (P = 0.02). Factor 2 (“Milk driven”: high rewarded and unrewarded visits at milk feeder) was associated with lower total starter intake (P = 0.03) but not with ADG (P = 0.45). Factor 1 (“High activity”: high steps, lying bouts and activity index; low lying time) was not associated with ADG or total starter intake (P > 0.2). These results suggest that feeding behavior patterns during the first 30 d of life are associated with total starter intake and weight gains up to 14 d postweaning; these indexes could serve as a proxy for later calf performance.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t84707 Watch P119 Rumination and activity of cows with metritis treated with chitosan microparticles. 20 J. G. Prim metritis rumination activity J. G. Prim1, E. B. de Oliveira2, A. Veronese1, R. C. Chebel1, K. N. Galvão1 1University of Florida, Gainesville, FL, 2University of California, Davis, CA The objective was to compare the rumination and activity of cows with metritis treated with chitosan microparticles (CM) or ceftiofur crystalline-free acid (CEF). In addition, rumination and activity of cows that cured and did not cure from metritis were also compared. Nulliparous Holstein cows (n = 311) were fitted with an automated monitoring device from −21 to 60 DIM. Cows with metritis (d 0; watery, fetid, pink/brown uterine discharge) were assigned to: CEF (n = 47) – subcutaneous injection of 6.6 mg/kg of CEF on d 0 and 3; CM (n = 45) – intrauterine infusion of 24 g of CM dissolved in 40 mL of distilled water on d 0, 2, and 4; CON (n = 39) – no treatment. Cure was defined as a uterine discharge that was not watery, fetid, pink/brown on d 12. Data were analyzed by ANOVA for repeated measures. Pre- (d −4 to −1) and post- (d 0 to 21) diagnosis data were analyzed separately. Pre-diagnosis, treatment was not associated with rumination or activity. Postdiagnosis, CM (447.3 ± 10.6 min/d) had lower (P ≤ 0.05) rumination than CEF (499.3 ± 9.6 min/d) and CON (491.5 ± 11.3 min/d). There was no difference between CEF and CON. Postdiagnosis, CM (653.4 ± 13.4 arbitrary unit) had (P ≤ 0.05) lower activity than CON (713.4 ± 14.2 arbitrary unit), whereas CEF was intermediate (673.2 ± 12.3 arbitrary unit) and was not different from CON. Cure of metritis was not associated with rumination pre- and post-diagnosis. There were tendencies for an association between cure and activity. Cows that did not cure had lower activity than cows that cured pre-diagnosis (596.3 ± 18.7 vs. 638.8 ± 14.8 arbitrary units; P = 0.07) and post-diagnosis (634.0 ± 13.0 vs. 665.3 ± 10.2 arbitrary units; P = 0.06). In summary, CM decreased rumination and activity compared with CON, which indicates that CM hinders the recovery of cows with metritis. Furthermore, the pattern of activity of cows that did not cure from metritis was different from cows that cured, even before diagnosis, which could potentially be used to predict cure.
Animal Behavior and Well-Being: Posters Posters Animal Behavior and Well-Being 7/11/2021 0:00 t84782 Watch P120 Accuracy of infrared temperatures taken from different anatomical regions on neonatal dairy calves. 21 M. L. Pister infrared thermometer temperature calves M. L. Pister1, K. N. Brost1, C. A. Hayes1, J. K. Drackley1 1University of Illinois, Urbana, IL The objective of this study was to determine if skin temperatures collected via infrared thermometer were comparable to rectal temperatures of neonatal dairy calves. The experiment used 25 calves (4 male, 21 female) enrolled on trial at 4 d of life and observed until 24 d. Calves were housed in individual hutches bedded with straw. Feeding and medical treatments were performed per farm protocol. Rectal and infrared temperatures (IRT) were recorded daily at 0700 h. The anatomical regions used to collect IRT were: neck, rump, and forehead. All IRT measurements were taken from a distance of 30 cm. Infrared temperatures were recorded twice from each anatomical region. Health scores, heart rate (HR), and respiratory rate (RR) were recorded daily. Temperature and relative humidity were recorded hourly by on-site data loggers. Data were analyzed using MIXED and FREQ procedures in SAS. Variables used to determine the accuracy of IRT were: rectal temperature (RT), maximum daily temperature of the environment, maximum daily temperature of the hutch, heat stress (h/d) of the environment, and heat stress (h/d) of the hutch. Heat stress was defined as the hours/day of environmental or in-hutch temperature-humidity index (THI) ≥ 89. Regression analysis demonstrated that RT, maximum environmental temperature, and maximum hutch temperature were significant (P < 0.05) for all anatomical regions. Although significant, the IRT range differed greatly by season (−5.4 to 37.9°C) whereas RT was maintained closely by the calf (36.9 to 39.6°C), causing the correlation to be difficult to use on farm without further analysis. The IRT was correlated (P < 0.05) with RR and RT, maximum environmental temperature, and heat stress (h/d) inside the hutch, demonstrating a relationship between the heat variables and RR. No significant results were observed for HR. Incidence of pyrexia was low and in general, the calves were healthy. To conclude, the infrared thermometers provided statistically significant relationships, but do not reflect RT with the current parameters. Further research is needed on IRT collection methods using health challenged calves.
Animal Health: Orals Orals Animal Health 7/11/2021 0:00 s9631                  
Animal Health: Orals Orals Animal Health 7/11/2021 0:00 t83496 Watch 102 The economic impact of suboptimal mobility in spring-calving, pasture-based dairy herds. 1 A. H. O’Connor lameness grass-based claw disorders A. H. O’Connor1,2, E. A. M. Bokkers2, I. J. M. de Boer2, H. Hogeveen3, R. Sayers1, N. Byrne1, E. Ruelle1, L. Shalloo1 1Teagasc, Animal and Grassland Research and Innovation Center, Moorepark, Fermoy, Co. Cork, Ireland, 2Animal Production Systems group, Department of Animal Science, Wageningen University & Research, the Netherlands, 3Business Economics group, Department of Social Sciences, Wageningen University & Research, the Netherlands, 4Mathematical and Statistical Methods - Biometris, Department of Plant Sciences, Wageningen University & Research, the Netherlands Suboptimal mobility refers to any abnormality to a cow’s gait which causes a deviation from the optimal walking pattern of a cow. So far, the economic consequences of suboptimal mobility has been investigated mainly for non-pasture-based systems. The aim of the current study was to determine the economic consequences, specifically on farm net profit, associated with varying prevalence of suboptimal mobility within spring calving, pasture-based dairy herds. A new submodel was developed (Mobility submodel) predicting mobility scores (on a 4-point, 0–3 scale) was developed and integrated within the existing Pastured Based Herd Dynamic Model (PBHDM). The PBHDM simulates the operation of a spring calving, pasture-based dairy farm with a daily time step. The Mobility submodel predicts claw disorders initially and then the mobility score of each individual cow in the herd. The impact of a cow having suboptimal mobility was also simulated, whereby cows with a mobility score >0 have an increased risk to be culled and cows with a mobility score >1, also have a reduced milk yield. ­­The impact on farm net profit was simulated based on production and reproductive effects of individual animals as well as the associated treatment costs. Several scenarios were simulated based on a varying cow-level value for a genetic predisposition for suboptimal mobility and a varying value representing the herd-level management factors (good, average, poor and very poor) . This ‘good’ herd scenario (with a 3% prevalence of suboptimal mobility) achieved about €4,000 more farm net profit compared with the ‘poor’ herd scenario (with a 47% prevalence of suboptimal mobility) per year, for a 100-cow herd. The decrease (5% compared with the ‘good’ herd) in farm net profit is due to reduced milk yield, increased culling, and treatment costs for mobility issues.
Animal Health: Orals Orals Animal Health 7/11/2021 0:00 t84495 Watch 103 Assessment of the association between week of diagnosis of hyperketonemia and variations in milk characteristics, herd removal, and reproductive performance in dairy cows. 2 Z. Rodriguez hyperketonemia milk performance Z. Rodriguez1, G. Cramer1, E. Shepley1, P. P. C. Ferro1, N. L. Moraes1, M. I. Endres2, L. S. Caixeta1 1Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, 2Department of Animal Science, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN Hyperketonemia (HYK) is commonly diagnosed between 3 and 14 d postpartum in dairy cattle. In this study, we aimed to evaluate whether the week postpartum when HYK is diagnosed is associated with variations in milk yield and composition, herd removal, and reproduction in multiparous cows. Blood samples from multiparous Holstein cows (n = 383) in a single dairy herd in Minnesota were collected at 7 ± 2 and 14 ± 2 d postpartum for the diagnose of HYK (BHB ≥1.2 mmol/L). Milk yield and characteristics (fat, protein, somatic cell count) were obtained for the first 10 mo. of the lactation. Reproductive performance and herd-removal records were obtained from farm management software. Milk yield and characteristics were analyzed using a generalized estimated equation with an exchangeable correlation structure among monthly measurements within individuals. To evaluate pregnancy rate by 150 d and herd removal by 60 d we performed Cox proportional hazard models. Potential confounder variables included BCS, parity, and calving ease. The prevalence of HYK was 22.7% at 7 d and 17.0% at 14 d. Hyperketonemia positive cows (HYK+) in wk 1 (W1) postpartum produced on average 1,067 kg (95% CI: 305, 1,830) less milk during the first 10 mo. than hyperketonemia negative (HYK-) cows. Also, HYK+ in W1 had a higher fat % in milk than HYK- cows (mean = 0.27%, 95% CI: 0.07, 0.46). HYK+ cows in wk 2 (W2) postpartum showed no difference in milk yield (mean = 0.05 kg, 95% CI: −2.48, 2.58) nor milk fat % (mean = 0.14%, 95% CI: −0.07, 0.36) when compared with HYK- cows. The risk of being removed from the herd by 60 d was 3.9 times (95% CI: 1.66, 9.30) higher for HYK+ than HYK- cows in W1, while no difference was observed in W2. The risk of becoming pregnant by 150 d was lower for HYK+ cows in W1 than W2 (HR W1 = 0.70, 95%CI: 0.48, 1.01; HR W2 = 1.09, 95%CI, 0.74, 1.62). Cows diagnosed with HYK during W1 had lower milk yield and milk fat %, higher risk of being removed by 60 DIM and lower risk of becoming pregnant than HYK- cows. These parameters were not affected when HYK+ was diagnosed in WK2.
Animal Health: Orals Orals Animal Health 7/11/2021 0:00 t84020 Watch 104 Relationship between serum metabolites and milk fatty acid with periparturient diseases in Pacific Northwest dairy farms. 3 C. Y. Tsai serum metabolites health status dairy cow C. Y. Tsai1, H. H. Hung1, T. Weber1, Q. Huo2, P. Rezamand1 1Department of Animal and Veterinary Science, University of Idaho, Moscow, ID, 2Department of Chemistry and NanoScience Technology Center, University of Central Florida, Orlando, FL During the periparturient period, dairy cows mobilize stored nutrients to support fetal development and milk production. The objective of this study was to determine the relationship between the serum metabolites in dairy cows and calves, and milk fatty acid composition with the health status of the periparturient cows. Blood samples from periparturient cows were obtained (farm A, n = 645; farm B, n = 559, respectively) on d-21, d-7, d+1, d+7 and d+14 relative to calving. Blood samples of calves were obtained within the first 4 d of life (farm A, n = 429; farm B, n = 428, respectively). Sera were analyzed for α-tocopherol, β-carotene, retinol, haptoglobin (Hpt), β-hydroxybutyrate (BHB), and glucose (calves only). In addition, 115 healthy and mastitic and lameness cows were randomly selected for milk fatty acid composition (gas chromatography) and serum type1/type 2 immunity balance analysis (D2Dx immunity test). The type 1/type 2 immune balance was evaluated by measuring the relative quantity ratio of immunoglobulin G1 and G2 subclasses (IgG1/IgG2). Health records were categorized based on the occurrence of postpartum diseases. Data were analyzed using linear mixed models in SAS with significance declared at P ≤ 0.05. Results showed that cows with pneumonia and lameness had lower serum α-tocopherol and retinol compared with that of healthy cows at postpartum (farm B). Serum Hpt was lower when cows had pneumonia at d +1 (farm A). Greater Hpt was observed with retained placenta (RP) at d +1 and pneumonia (farm B). Serum BHB was greater at d +7 and +14 for cows with lameness and RP (farm B). The D2Dx immunity test score was greater at d +14 for diseased cows corresponding to a decreased relative quantity ratio of IgG1/IgG2. Serum glucose in calves was greater when the calves were born from the RP dams. No significant difference in milk fatty acid composition between diseased and healthy cows was observed. In summary, disease affects the lipid-soluble vitamins status and serum metabolites of periparturient cows, and consequently calves may experience health issues.
Animal Health: Orals Orals Animal Health 7/11/2021 0:00 t84374 Watch 105 Heat stress in transition dairy cows is associated with impaired production, health, and reproduction. 4 P. R. Menta dairy cow heat stress transition period P. R. Menta2, V. S. Machado2, J. M. Piñeiro3, W. W. Thatcher4, J. E. P. Santos4, A. Vieira-Neto1 1Kansas State University, Manhattan, KS, 2Texas Tech University, Lubbock, TX, 3Texas A&M University, College Station, TX, 4University of Florida, Gainesville, FL Objectives were to determine the association between heat stress (HS) exposure during the transition period with production, health, and reproduction in dairy cows during the first 90 d postpartum. Holstein cows (n = 5,722; from 2 California dairies and 3 years) were categorized into groups based on temperature-humidity index (THI) exposure during pre (Pre; −28 to −1 d relative to calving) and early postpartum (Post; 1 to 28 d relative to calving) periods as: TN-TN (mean THI Pre = 57.9 and Post = 63.7), TN-HS (mean THI Pre = 68.2 and Post = 72.0), HS-TN (mean THI Pre = 71.4 and Post = 65.6), and HS-HS (mean THI Pre = 72.2 and Post = 72.7). Data from nulliparous and parous cows were analyzed separately using mixed models. In nulliparous cows, exposure to HS during the Pre and/or Post was associated (P < 0.05) with a 1.7-kg/d reduction in milk yield and 15%-point increase in incidence of metritis compared with TN-TN. Postpartum HS was associated (P < 0.05) with increases of 4.4%-point in incidence of retained placenta and 2.0%-point in incidence of mastitis, but a reduction in 5.3%-point in pregnancy at first AI and an increase in 4.5%-point in pregnancy loss compared with Post TN. In parous cows, exposure to HS during the Pre and/or Post was associated (P < 0.05) with a 2.4-kg/d reduction in milk yield compared with TN-TN. Postpartum HS was associated (P < 0.05) with an increase in 6.3%-point in incidence of metritis and tended to be associated (P = 0.08) with an increase in 1.9%-point in mastitis incidence compared with Post TN. There was an interaction (P = 0.01) between HS exposure Pre and Post and pregnancy per AI, because Post HS was associated with reduced pregnancy in 10.6-% point within Pre TN cows, whereas no difference was found within HS Pre cows. The data suggest that Post HS is associated with performance losses to a greater extent than Pre HS and that nulliparous and parous cows are prompt to losses associated with exposure to HS during the transition period. This data set concurs with results from manipulative experiments that evaluated the loss of milk yield in cows under HS but adds insights to the associations between HS and health and reproduction.
Animal Health: Orals Orals Animal Health 7/11/2021 0:00 t83622 Watch 106 Whole transcriptome-based competing endogenous (ce)RNA network analysis revealed ochratoxin A-induced intestinal tight junction damage through WNT/Ca2+signaling pathway. 5 X. Yang ochratoxin A whole-transcriptome tight junction X. Yang1,2, N. Zheng1,2, Y. N. Gao1,2, J. Q. Wang1,2 1State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, P. R. China, 2Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, P. R. China The harm of ochratoxin A (OTA) to humans and livestock remains a global concern in public health because it is a widespread environment pollutant that has negative effects on both humans and animals in a continuously exposed environment. Recently, the compromised intestinal barrier caused by OTA has aroused widespread concern. The aim of this study was to reveal the underlying mechanism of OTA-induced tight junction (TJ) proteins damage, the important component of intestinal barrier through in vivo whole transcriptome analysis combined with in vitro functional verification. There were 619 differential expression (DE) mRNAs, 71 DE miRNAs, 493 DE lncRNAs and 144 DE circRNA. Bioinformation analysis revealed that regulated TJ protein related mRNA expression (FZD4, WNT5a, Axin2, Cav1, ACTG1 and CCND1) were perturbed, which activated the WNT/Ca2+signaling pathway possibly regulated by some lncRNAs (Zeb1, Stk36, Phkb, Prss23, Inpp5e and Gm28588) and miRNAs (miR-1258-x, mmu-miR-1258–3p, mmu-miR-122–5p, miR-205-z, mmu-miR-1981–5p, mmu-miR-1943–5p and mmu-miR-146b-5p). Competing endogenous RNA (ceRNA) network revealed that lncRNA Zeb1 regulated FZD4 binding with WNT5a to release the Ca2+ by targeting miR-1258-x to reduce the expression of TJ proteins, thus damaging the function of intestinal barrier. As the RT-qPCR results depicted, 16 selected randomly DERNAs were consistent with results by RNA-seq. In vitro Caco-2 cells experiment verified that the increase of Ca2+ level was involved in OTA-induced decreased the expression of TJ proteins. Taken together, these results will help us to find the target of OTA compromise the intestinal barrier, which can provide the basis for preventing the hazard and risk of OTA.
Animal Health: Orals Orals Animal Health 7/11/2021 0:00 t84245 Watch 107 Feeding Saccharomyces cerevisiae fermentation products lessens the severity of a viral-bacterial co-infection in preweaned calves. 6 P. O. McDonald Saccharomyces cerevisiae fermentation products bovine respiratory disease preweaned calves P. O. McDonald1, C. Schill1, T. W. Maina1, B. Samuel1, I. Yoon2, J. L. McGill1 1Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, 2Diamond V, Cedar Rapids, IA Bovine respiratory disease is the leading cause of mortality in preweaned dairy calves and weaned dairy heifers. In prior research, Saccharomyces cerevisiae fermentation products (SCFP; SmartCare and NutriTek; Diamond V) reduced clinical signs and lung pathology following experimental bovine respiratory syncytial virus (BRSV) infection in preweaned dairy calves. The objective of this study was to determine the effect of SCFP supplementation on the outcome of a viral-bacterial co-infection. Twenty-eight, 1–2 d old Holstein-Angus cross calves with adequate passive transfer were enrolled in the study. Calves were assigned to 2 treatment groups (14/group): 1) control, base milk replacer and calf starter; or 2) SCFP treated, milk replacer with 1 g/d SmartCare and calf starter top-dressed with 5 g/d NutriTek. One calf in each group was euthanized during the feeding period, so 13 calves/group were included in the challenge period. Calves were infected with ~104 (Median Tissue Culture Infectious Dose, TCID50) BRSV on d 21, followed 6 d later by intratracheal inoculation with ~107 colony-forming units of Pasteurella multocida (PM, strain P1062). One control calf reached clinical endpoint and was humanely euthanized on d 8 post viral infection. The remaining calves were euthanized on d 10 post infection. Calves receiving SCFP had a tendency toward reduced thoracic ultrasonography scores on d 7 and 10 post infection (P = 0.02 and P = 0.09) and lower lung pathology scores at necropsy (P = 0.06). No differences (P = 0.40) between treatments were observed in lung viral loads; however, BRSV was detected in the lungs of fewer SCFP fed animals compared with controls (5/12 controls vs. 3/13 SCFP). No differences in bacterial lung loads were detected between treatments (P = 0.34). Results from this study suggest that supplementing with SCFP may improve the outcome of a respiratory viral-bacterial co-infection in preweaned calves.
Animal Health: Orals Orals Animal Health 7/11/2021 0:00 t85577 Watch 502 Negatively controlled trial investigating the effect of dry cow therapy on clinical mastitis and culling. 7 S. M. Rowe dry cow therapy mastitis antimicrobial use S. M. Rowe1,2, M. Dziuba3, B. Boyum4, S. Godden2, E. Royster2, L. Caixeta2 1University of Sydney, Camden, Australia, 2University of Minnesota, St. Paul, MN, USA, 3Michigan State University, East Lansing, MI, 4Riverview LLP, Morris, MN We hypothesized that dry cow therapy (DCT) was not necessary in well managed herds, such that the use of an internal teat sealant (ITS) alone would be sufficient to maintain cow health and welfare after dry-off. Therefore, the objective of this negatively controlled clinical trial was to determine the effect of DCT on clinical mastitis and removal from the herd during the dry period and the first 90d of the subsequent lactation. The study was conducted in a commercial dairy herd in South Dakota during June 2020 to January 2021. Dry-off sessions (n = 43) over a 2-mo period were scheduled in advance such that all cows at a given session were dried off either using an internal teat sealant alone (ITS-only, n = 1,108 cows) or a commercial intramammary DCT product containing cloxacillin 500 mg, followed by ITS (ABX+ITS, n = 1,331 cows). Dry-off procedures were conducted by farm workers, with the same staff administering treatments to both treatment groups. Outcomes of interest were clinical mastitis (CM) during 1–90 d in milk (DIM) and removal from the herd between dry-off and 90 DIM. Farm personnel were blinded to the treatment group when collecting outcome data. Hazard ratios (HR) for the effect of the treatment group on these outcomes were estimated using Cox proportional hazards, adjusting for the clustered treatment allocation strategy. Parity, previous clinical mastitis history and dry period length were offered to the models as covariates. Risk of CM during 1–90 DIM was lower in ITS+ABX cows (5.9%), when compared with ITS-only cows (10.8%, HR = 0.53, 95%CI: 0.37–0.76). Risk of removal from the herd during the dry period was slightly lower in ITS+ABX cows (1.1 vs 2.7%, HR = 0.44, 95%CI: 0.23–0.82). Risk of removal from the herd during 1–90 DIM was similar in ITS+ABX (11.1%) and ITS-only cows (11.5%, HR = 1.06, 95%CI: 0.85–1.32). The beneficial effects of DCT were consistently observed across strata of parity, previous clinical mastitis history and dry period length. These findings demonstrate that the cessation of DCT can be detrimental to cow health and welfare.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 s9693                  
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84441 Watch P121 Genetic relationship of Escherichia coli isolated from the reproductive and gastrointestinal tracts of dairy cows pre- and postpartum. 1 K. L. Jones Escherichia coli genetic characterization uterus K. L. Jones1, F. Cunha1, S. J. Jeon2, K. C. Jeong1, Y. Yang3, K. N. Galvão1 1University of Florida, Gainesville, FL, 2Long Island University, Brookville, NY, 3Sun Yat-sen University, Guangzhou, China The objective was to investigate the source of bacterial colonization of the uterus by exploring the genetic relationship among E. coli strains isolated from the recto-anal junction (RAJ) and the reproductive tract (RT) of dairy cows pre- and postpartum. Cows (n = 34) had a swab sample collected from the vulva, vagina, and RAJ every 3 d starting 6 d before expected calving until 9 d postpartum. A blood sample was collected at all time points. A swab sample was collected from the uterus at the same time points postpartum. All samples were cultured aerobically on CHROMagar E. coli selective medium for 24 h at 37°C. Isolates from cows with growth from the vulva and/or vagina in addition to the uterus (n = 8) were used for whole-genome sequencing (WGS). All RAJ samples grew and none of the blood samples grew. A total of 44 isolates were selected for WGS, which was performed using an Illumina MiSeq. PATRIC was used to annotate each genome. The Harvest Suite was used for core genome alignment, SNP identification and phylogenetic tree rendering. Clades with no branching were evaluated for SNPs. Strains were considered clonal isolates if ≤4 SNPs difference between strains. Clonal strains were isolated from individual cows from the RAJ and vulva (1 cow; 1 SNP), the RAJ, vulva and vagina (1 cow; 0 SNP), the vulva and uterus (1 cow; 0 SNP), the vagina and uterus (2 cows; 0 SNP between strains in each cow), and the vulva, vagina, and uterus (1 cow; 0 SNP) postpartum. Clonal strains were also isolated from different cows from the vulva prepartum, and vulva and vagina postpartum (0 SNP between strains), the RAJ prepartum, and vagina and uterus postpartum (max 1 SNPs between strains), the RAJ, vulva and vagina postpartum (max 1 SNPs between strains), and the uterus, vulva and vagina postpartum (max 2 SNP between strains). Finding clonal E. coli strains in the RAJ from the same cow or different cows in the vulva, vagina, and uterus postpartum indicates that the GI is a source of E. coli that can colonize the RT, and that E. coli can be transferred among cows.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t83499 Watch P122 Genes associated with immune function are downregulated in blood-derived neutrophils from periparturient cows. 2 E. Asiamah periparturient neutrophils dairy E. Asiamah1, K. Ekwemalor2, S. Adjei-Fremah2, B. Osei3, M. Work2 1University of Arkansas, Pine Bluff, Pine Bluff, AR, 2North Carolina Agricultural and Technical State University, Greensboro NC, 3Oklahoma Medical Research Facility, Oklahoma City, OK The periparturient period (3 weeks pre-calving and 3 weeks postcalving) is a challenging period for dairy cows in large part due to the dysfunction of their immune system. The compromise in the immune system puts the dairy cow at a higher risk of infections and other diseases. The impairment of neutrophil function plays a crucial role in the immunosuppression of the periparturient dairy cow. Research is emerging to better understand the molecular mechanisms underlying the impaired immune function in dairy cows during the periparturient period. This study aimed at evaluating the global gene expression of blood-derived neutrophils from periparturient cows. Blood was collected from Holstein Friesian periparturient cows (n = 3) at −14 d relative to expected calving date and 7 d relative to the actual calving date. Neutrophils were isolated based on procedures described by Abdelmegeid et al. (2017; Journal of Dairy Science 100:3155–3165). Isolated neutrophils were subsequently used for transcriptional profiling using the Agilent bovine (v2) 4 × 44 K array. Data normalization and statistical analysis were performed using GeneSpring GX software version 13.0. The analysis was carried out using a t-test unpaired statistical method with Benjamini-Hochberg FDR method. Fold changes in gene expression calculated were filtered at a cut-off of ≥ 2 (P < 0.05). The results showed that 249 genes were differentially expressed (FC ≥ 2, P < 0.05.). Eighty-seven genes were downregulated and among the top 20 downregulated genes were genes essential to neutrophil response and immunity. These included PGLYRP1, which is involved in pathogen recognition, and SERPINB4, which is a protein that inhibits neutrophil-derived proteinases to protect tissue damage at inflammatory sites. Additionally, genes associated with cellular adhesion and migration (ADRM1 and THY1) were also significantly downregulated. Concurrently, the pathway analysis also revealed that the TLR, inflammation response, oxidative stress, and MAPK signaling pathways are affected in bovine neutrophils during the periparturient period (P < 0.05). This work sheds some light on the altered gene expression in neutrophils during the periparturient period and the knowledge generated will ultimately be used for the development of novel management strategies to combat immunosuppression and disease susceptibility during this stage in the dairy cow.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84297 Watch P123 Effect of Holstein milk yield genotype on ex vivo innate immune response to lipopolysaccharide and lipoteichoic acid during the periparturient period. 3 A. A. Brink milk yield genotype LPS LTA A. A. Brink1, W. J. Weber1, J. D. Lippolis2, J. B. Cole3, S. M. Godden4, B. A. Crooker1 1Department of Animal Science, University of Minnesota, St. Paul, MN, 2USDA-ARS National Animal Disease Center, Ames, IA, 3USDA-ARS Animal Genomics and Improvement Laboratory, Beltsville, MD, 4Department of Veterinary Population Medicine, University of Minnesota, St. Paul, MN Our objectives were to determine effects of milk yield genotype on innate immune response to ex vivo lipopolysaccharide (LPS) and lipoteichoic acid (LTA) stimulation. Unselected (UH, stable milk yield from 1964, n = 10) and contemporary (CH, n = 11) Holsteins that differ by more than 4,500 kg milk/305 d were fed the same diet ad lib and milked twice daily. Cows were blocked (1/genotype) by parity and expected calving date. Heparinized blood was collected at −14, 7, 28, and 49 DIM, mixed with a low or high dose of LPS (10 and 100 µg LPS/mL blood) or LTA (0.01 and 1.0 µg LTA/mL blood), and incubated for 4 h at 37°C. Plasma concentrations (pg/mL) of IL-6 and IL-1β were quantified by ELISA (Invitrogen, Carlsbad, CA), log-transformed and analyzed by repeated measures using PROC MIXED (SAS) with DIM as the repeated effect. Means differed when P < 0.05. Milk yield was less in UH than CH (29.0 vs. 45.3 kg/d FCM). The response of IL-6 and IL-1β to LPS and LTA were greater (P < 0.01) with the high dose of antigen. The IL-6 response to LPS was greatest (P < 0.01) at d7 and did not differ among other days while the IL-1β response was greatest (P < 0.01) at d-14 and decreased postpartum (2.7, 3.2, 2.8, 2.6 ± 0.14 for IL-6 and 3.8, 3.6, 3.3, 3.3 ± 0.08 for IL-1β on d-14, 7, 28, and 49, respectively). There was a genotype by dose interaction (P < 0.01) for IL-1β response to LPS as the low dose was greater in UH than CH (3.2 vs. 2.9 ± 0.10) but did not differ for the high dose (4.0 vs. 3.9 ± 0.10). The IL-6 response to LTA was greatest (P < 0.01) at d7 and did not differ among other days while the IL-1β response was greatest (P < 0.01) at d-14 and decreased postpartum (2.6, 3.0, 2.8, 2.5 ± 0.14 for IL-6 and 3.5, 3.2, 3.1, 3.0 ± 0.07 for IL-1β on d-14, 7, 28, and 49, respectively). There was a trend (P = 0.07) for IL-6 response to LTA to be greater in UH than CH cows. The UH cows had a greater (P < 0.02) IL-1β response to LTA than the CH cows (3.4 vs. 3.1 ± 0.08). Cytokine profiles demonstrate postpartum alterations in the innate immune response and a more sensitive IL-1β response to both antigens by the UH cows.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84126 Watch P124 Whole-blood transcriptomic signature after 17 and 35 days of feeding OmniGen AF to prepartum Holstein cows. 4 M. Garcia OmniGen dairy cow immunity M. Garcia1, J. Chapman1, B. Humphrey1 1Phibro Animal Health Corporation, Teaneck, NJ OmniGen AF (OG; Phibro Animal Health, Teaneck, NJ) is a feed additive with demonstrated benefit on improving the immunocompetence of stressed dairy cows. This study aimed to identify an early whole-blood transcriptomic signature, focused on immunity, during the first 35 d of feeding OG to prepartum Holstein cows. Sixteen cows (60 d before expected calving date) were randomly assigned to 1 of 2 treatments at dry-off: CTL (no supplementation) or OG (56 g OG/cow/d). Cows were bled at d 17 and 35 after OG feeding began. Isolated whole-blood RNA samples with RNA integrity number >7 (n = 5 per treatment) were submitted for RNA sequencing (Novogene Co., Ltd.). Sequencing libraries were generated using NEBNext UltraTM (NEB, Illumina, USA). Processed reads were mapped to the bovine genome using HISAT2. Differentially expressed genes (DEG, P < 0.05) were identified using DESeq2 R package. Gene ontology (GO) analysis of DEG was performed with clusterProfiler R package, and enriched GO terms with corrected P < 0.05 were deemed significantly different. Cows fed OG had 1,130 and 1,574 DEG at d 17 and d 35, respectively. At d 17, 18 DEG, 17 upregulated, were part of 4 enriched GO terms. Three GO terms were ancestor terms of neutrophil chemotaxis (neutrophil migration, granulocyte chemotaxis, and granulocyte migration). At d 35, 325 DEG, 264 upregulated, were part of 46 enriched GO terms. Two GO terms enriched at d 17 were also enriched at d 35. Noticeable, 10 of the 18 DEG enriching GO terms at d 17 were also part of enriched GO terms at d 35. Furthermore, the other 44 enriched GO terms at d 35 were mostly biological processes involved in innate (e.g., inflammatory response, phagocytosis) and adaptive (e.g., regulation of T-helper 1 type immune response, positive regulation of IFNγ production) immunity. A unique set of genes were identified that are similarly regulated at d 17 and d 35 of OG feeding. These findings confirm that biomarkers of immunity, regulated by OmniGen AF, can be detected as early as 17 d, and are further enhanced after 35 d of initial day of feeding.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84703 Watch P125 Effect of in vivo heat stress on respiration rate, rectal temperature, and blood mononuclear cell function of dairy cows ranked for immune response. 5 S. Cartwright heat stress immune response blood mononuclear cells S. Cartwright1, J. Schmied1, M. McKechnie1, A. Livernois1,2, B. Mallard1,2 1Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada, 2Centre of Genetics of Livestock Improvement, University of Guelph, Guelph, ON, Canada Heat stress (HS) causes disease in dairy cattle. High (H) immune response (IR) dairy cattle have reduced disease, however variations in response to HS have not been evaluated. Therefore, the objective was to evaluate the effect of in vivo HS on respiration rate (RR), rectal temperature (RT), and blood mononuclear cell (BMC) function related to heat shock protein 70 concentration (HSP70 conc) and cell proliferation (CP) in IR phenotyped cattle. Holstein cattle (n = 24), ranked for IR [8 H, 8 average (A), 8 low (L)], based on estimated breeding values, were evaluated. Cattle were HS at the same time on 2 subsequent days (HS1 = 1 HS, HS2 = 2 HS), in the tie-stall wing of the barn, by increasing temperature to 29°C for 4 h. Blood samples were taken pre and post HS1 and HS2. Manual RR and RT and barn temperature (temp) and humidity (hum) were taken pre-HC and every 30 min during HS. Temperature-humidity index (THI) was calculated for each measurement using temp and hum. From blood samples, BMC were obtained to assess HSP70 conc and CP. Repeated-measures models, run in R, evaluated differences in RR and RT and included effects of IR phenotype, THI, parity, pregnancy status and production. General linear models, run in R, evaluated differences in HSP70 conc and CP with similar models. Results showed HIR (THI 76–81 LSM from 43.2 to 55.7 breaths per min (bpm)) had lower RR at higher THI compared with AIR (THI 76–81 LSM from 53.2 to 66.1 bpm) and LIR (THI 76–81 LSM from 50.4 to 73.4 bpm). Differences in RR were observed at THI of 76 (H vs A P = 0.0247, H vs L P = 0.0202), 77 (H vs A P = 0.0419, H vs L P = 0.0453) and 81 (H vs A P = 0.0247, H vs L P = 0.008). No differences in RT was observed. Results also showed HIR had greater HSP70 conc after HS1 (H LSM HS = 12.1 ng/mL SEM = 0.5, A LSM HS1 = 9.2 ng/mL SEM = 0.8, L LSM HS1 = 7.5 ng/mL SEM = 0.5) compared with A (P = 0.0247) and L (P = 0.001) and greater CP after HS1 (H LSM = 3.36 SEM = 0.65, L LSM = 0.99 SEM = 0.3, P = 0.0279) and HS2 (H LSM = 2.83 SEM = 0.62, L LSM = 0.59 SEM = 0.1, P = 0.0425) compared with L. Therefore, results may indicate HIR are more thermotolerant compared with A and L.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84619 Watch P126 Persistent, transient or delayed hypocalcemia in Jersey cows: Associations with metabolites and milk production. 6 A. M. Fillus calcium transition period A. M. Fillus1, C. C. Baccili2, V. Gomes2, R. B. Navarro3, R. Almeida1 1Universidade Federal do Paraná, Curitiba, Paraná, Brazil, 2Universidade de São Paulo, São Paulo, São Paulo, Brazil, 3Capal Cooperativa Agroindustrial, Arapoti, Paraná, Brazil The aim of this study was to determine the types of subclinical hypocalcemia (SCH) and relate it to milk yield (10, 30, and 60 d postpartum) and blood metabolites. Thirty-one primiparous and 85 multiparous Jersey cows were housed in a compost barn with a robotic milking system. Blood samples were collected at 1, 2, 3, and 4 d postpartum to characterize the level of plasma total Ca and diagnose cows with SCH. Primiparous cows were categorized in 4 early postpartum Ca status groups: NC (normocalcemic; > 2.15 mmo/L at 1 and 2 DIM), tSCH (transient; ≤ 2.15 mmo/L at 1 DIM and >2.15 mmol/L at 2 DIM), dSCH (delayed; > 2.15 mmol/L at 1 DIM and ≤2.15 mmol/L at 2 DIM), and pSCH (persistent; ≤ 2.15 mmol/L at 1 and 2 DIM). The plasma Ca thresholds for multiparous were the same described above, but the second blood collection was at 4 DIM. Statistical analyzes were performed by SAS procedures (v.9.4) using the GLM for single measures and MIXED for repeated measures over time. We found 52.6% NC cows (n = 61), 26.7% tSCH (n = 31), 12.1% dSCH (n = 14), and 8.6% pSCH (n = 10). Average milk yield in the first 10 d was greater (P = 0.04) for tSCH than pSCH cows (23.24 vs. 18.96 kg/d, respectively), while NC and dSCH cows showed intermediate yields (21.66 and 20.54 kg/d, respectively). No differences on average milk yield in the first 30 and 60 d were found (P > 0.10) among groups. Haptoglobin concentrations were higher (P < 0.05) for pSCH and dSCH cows than for tSCH ones; 24.5 ± 3.3 and 22.8 ± 2.7 vs. 14.9 ± 2.1 mg/dL, respectively. NEFA concentrations were higher (P < 0.05) for pSCH cows than NC ones; 0.43 ± 0.07 vs. 0.25 ± 0.03 mmol/L, respectively. Bilirubin concentrations were higher (P < 0.01) for pSCH cows than NC ones; 0.33 ± 0.03 vs. 0.17 ± 0.01 µmol/L, respectively. Albumin concentrations were lower (P < 0.05) for pSCH and dSCH cows than for NC ones; 3.14 ± 0.06 and 3.18 ± 0.05 vs. 3.40 ± 0.03 g/L, respectively. No differences were found (P > 0.05) for BHB, AST, cholesterol, and glucose concentrations among groups. In conclusion, transient SCH Jersey cows produce more milk than persistent SCH and their metabolic profile are similar to normocalcemic cows.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84174 Watch P127 Calcium dynamics in blood and milk in dairy cows after calving. 7 T. Aubineau hypocalcemia milk dairy cow T. Aubineau1,2, P. Gaignon3, M. Pocher1,2, R. Guatteo2, A. Boudon3 1GDS Bretagne, Rennes, France, 2BIOEPAR, INRAE, Oniris, Nantes, France, 3PEGASE, INRAE, Agrocampus Ouest, Saint-Gilles, France Routine identification of cows suffering from subclinical hypocalcemia around calving has great significance in dairy cattle to adapt prevention programs. Milk and blood calcium contents may be correlated, as the calcium sensing receptor contributes to the regulation of calcium secretion into milk according to blood calcium level. Milk would be a more convenient sample to identify cows at risk. Thus, our objective was to describe milk calcium (MiCa) dynamics and plasma calcium (PlCa) one during the week after calving and to assess their correlation. Eight primiparous and 12 multiparous Holstein dairy cows, milked twice a day, were submitted to morning daily simultaneous blood and milk sampling from the day of calving to 7 d later. Plasma and milk samples were analyzed for total calcium content by atomic absorption spectrometry. Plasma and milk calcium dynamics were first described using PROC GLIMMIX in SAS, with a generalized linear mixed model with repeated values. Time, parity and the interaction between both were included as fixed effect and cow as random effect. Post hoc tests were then realized to identify sampling times which differ between them. Finally, a Spearman correlation matrix aimed to identify sampling days with best correlations between PlCa and MiCa. PlCa increased from the day of calving to d 7 (time effect, P = 7.10−11), and decreased with parity (P = 0.002). Primiparous and multiparous PlCa dynamics were different (interaction time × parity, P = 0.007), as multiparous had lower PlCa on the day of calving (75 ± 12 mg/L) and the day after (80 ± 12 mg/L), and primiparous had lower PlCa only the day of calving (89 ± 5 mg/L). MiCa was higher in the first 2 d after calving, sharply decreased until d 3 before stabilizing over the following days (time effect, P = 2.10−9). MiCa was not affected by parity and correlations between PlCa and MiCa greatly depended on parity. Higher correlations were observed between PlCa on d 3 and MiCa on d 4 when considering only multiparous cows (r = −0.8, P = 0.002). Our results suggest that milk calcium measurements might be effective to assess blood calcium levels after calving in multiparous dairy cows, but these results remain to be confirmed in broader experimental conditions.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84614 Watch P128 Assessment of prevalence of ketosis in dairy cattle. 8 C. Marquès ketosis prevalence BHB in milk C. Marquès1, S. Calsamiglia1, A. Jubert2, J. Marxuach3, L. Castillejos1 1Servicio de Nutrición y Bienestar Animal, Dpto. Ciencia Animal y de los Alimentos, Universidad Autónoma de Barcelona, Bellaterra, Spain, 2Associació Lletera Interprofessional de Catalunya (ALLIC), Passeig de Cabrils, Barcelona, Spain, 3It Elazos, Barcelona, Spain Ketosis (KET) is a metabolic disorder in which the prevalence of its subclinical form ranges between 6.9 and 43% during the first 2 mo postpartum. The prevalence of ketosis can be monitored by determining β-hydroxybutyrate (BHB) in milk. The objective of this study was to evaluate the prevalence of ketosis using a database of Interprofessional Milk Analysis Laboratory and to study its correlation with other biomarkers. A database of the Interprofessional Milk Analysis Laboratory in Catalonia from 2017 to 2020 containing 84,216 individual cow records collected between 5 to 25 d postpartum was used. Data were obtained by infrared spectrometry (MilkoScan). Prevalence of KET (BHB in milk ≥0.10 mM) was evaluated according to parity and season. Statistical analysis was performed using GLM adjusted by Tukey, correlation, and regression with the SAS program. A significant lower prevalence (P < 0.01) was observed in primiparous cows (15.0%) than in multiparous cows (20.9%). A significant lower risk of KET (P < 0.01) was observed in spring (15.0%), a medium risk in winter (17.1%) and autumn (20.3%), and a higher risk in summer (22.6%). Finally, a correlation of 0.62 was found between BHB and Acetone: BHB = 0.0487 + 0.2617 × Acetone; n = 43,955; Rsq = 0.3894; P < 0.01. No correlation was observed between BHB and fat (%), protein (%), or fat (%) / protein (%) ratio. In conclusion, the prevalence of ketosis is higher in multiparous than in primiparous cows. In summer there is a higher prevalence of ketosis. Acetone in milk could be a good alternative biomarker to BHB in milk.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84150 Watch P129 Association between transition diseases and changes in body condition score of Holstein cows. 9 D. Manriquez body condition score disease transition D. Manriquez1, A. De Vries2, P. Pinedo1 1Colorado State University, Fort Collins, CO, 2University of Florida, Gainesville, FL The objective was to quantify the impact of dystocia (DYS), clinical hypocalcemia (CHC), clinical ketosis (CKT), left displaced abomasum (LDA), and metritis (MET) on the magnitude of body condition score change (ΔBCS) at multiple time periods. Holstein cows (5,894) in one dairy located in CO, USA were enrolled at calving from April 2019 to August 2020 and daily BCS were obtained from an automated camera system (BCSTM, DeLaval Inc.). Disease events were retrieved from DairyComp (VAS, Tulare, CA). Cows were classified in 6 health categories (HLC; Table 1) based on their first disease diagnosed within 21 DIM. Mixed models for repeated measures (SAS Institute Inc., Cary, NC) were used to calculate LSM for BCS (1, 14, 21, and 30 DIM) and ΔBCS by HLC. Models included HLC, parity (1; ≥ 2), DIM, and HLC by DIM interaction. As no significance was established for the interaction HLC by parity, this term was excluded from the models. A total of 531 (9%), 373 (6.3%), 300 (5.1%), 53 (0.9%), and 847 (14.4%) cows were diagnosed with DYS, CHC, CKT, LDA, and MET, respectively. Differences in average BCS among HLC were established only at 1 and 14 DIM (Table 1). The magnitude of the ΔBCS depended on HLC and period in analysis. Overall, small magnitude differences in BCS and ΔBCS were detected among HLC using the automated BCS system. Cows affected by ketosis and LDA evidenced the greatest losses in BCS at 21 and 60 DIM. Table 1. LSM (± SEM) for BCS and ΔBCS measured by an automated camera system among health status categories
Item Dystocia Clinical hypocalcemia Clinical ketosis LDA Metritis Healthy
BCS            
 1 DIM 3.35±0.01a 3.35±0.01ab 3.44±0.01c 3.36± 0.05ab 3.33± 0.07a 3.36±0.003b
 14 3.25±0.05ab 3.24±0.01ab 3.32±0.004b 3.24±0.014ab 3.23±0.013a 3.26±0.007ab
 21 3.15±0.05a 3.12±0.01a 3.19±0.01a 3.10±0.05a 3.12±0.01a 3.16±0.003a
 60 3.05±0.01a 3.02±0.01a 3.00±0.02a 2.91±0.05a 3.01±0.01a 3.10±0.004a
ΔBCS            
DIM difference:            
 21 − 1 −0.19±0.008c −0.24±0.01a −0.24±0.01a −0.25±0.02a −0.22±0.007ab −0.20±0.003bc
 60 − 1 −0.29±0.01b −0.32±0.01b −0.40±0.02a −0.42±0.04a −0.31±0.009b −0.29±0.004b
 60 − 14 −0.19±0.010b −0.20±0.01b −0.30±0.01a −0.31±0.04a −0.20±0.007b −0.19±0.003b
 60 − 21 −0.09±0.011b −0.09±0.01b −0.18±0.01a −0.18±0.03a −0.08±0.005b −0.09±0.003b
a–cDifferent letters within rows indicate significant differences between HLC at the Tukey adjusted P < 0.05.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84166   P130 Effects of dandelion supplements on lactation performance, antioxidative activity, and plasma metabolome in primiparous dairy cows. 10 Y. Li dandelion lactation performance dairy cow Y. Li1, J. Wang1, B. Wang2, J. Liu1, H. Liu1 1College of Animal Sciences, Zhejiang University, Hangzhou, China, 2State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China Dandelion contains various biological phytochemicals that are beneficial to animal health. It is commonly used as a medicinal herb owing to its excellent antibacterial, anti-inflammatory, antiallergy, and antioxidant properties. However, only limited data are available concerning the production performance of dairy cows. In this study, we evaluated the effects of dandelion supplements on lactation performance, plasma antioxidative activity and metabolomics in primiparous dairy cows. A total of 60 mid-lactation Holstein dairy cows (days in milk = 151.72 ± 2.36 d; milk yield = 34.29 ± 0.34 kg/d) were divided into 4 treatment groups randomly, comprising the addition of dandelion at 0, 100, 200, 400 g/d per head. The whole plant part except root was used and composition was detected in the previous study. The experiment lasted for 8 weeks with a 10-d adaptation period. All data were analyzed by the mixed model (SAS 9.2, 2000) and checked for normality by the UNIVARIATE procedure. Results indicated that 200 g/d of dandelion increased the yield of milk and lactose (P ≤ 0.05). The milk somatic cell counts (P ≤ 0.05) were lower in all dandelion groups than that in the control group. The concentrations of glutathione peroxidase (P ≤ 0.05) and superoxide dismutase (P ≤ 0.05) were increased, and malondialdehyde (P = 0.01) was decreased in plasma when cows were fed 200 g/d dandelion. The plasma metabolomics analysis showed that 19 metabolites were upgraded and 4 metabolites were downgraded in the 200 g/d dandelion group. The hub differential metabolites such as ribose, glutamic acid, valine, and phenylalanine were enriched in phenylalanine, tyrosine and tryptophan biosynthesis (P < 0.01, impact = 1), phenylalanine metabolism (P = 0.01, impact = 0.36) and starch and sucrose metabolism (P = 0.20, impact = 0.42). Moreover, correlation analysis showed that plasma ribose, mannose, and glutamic acid were positively related to milk yield. In summary, dandelion supplementation improved lactation performance by elevating the plasma carbohydrate and amino acids metabolomics and antioxidative activity. Supplementation of 200 g/d dandelion is recommended for lactating dairy cows.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t83902 Watch P131 Effect of injectable trace mineral supplementation on peripheral polymorphonuclear leukocyte function, oxidative stress, health, and performance in dairy cows in semi-arid conditions. 11 P. R. Menta trace minerals innate immunity oxidative stress P. R. Menta1, T. Silva1,2, I. Guimaraes1, D. Paiva1, L. Fernandes1, M. L. Celestino1, A. S. Netto2, M. A. Ballou1, V. S. Machado1 1Texas Tech University, Lubbock, TX, 2University of Sao Paulo, Pirassununga, Sao Paulo, Brazil The objective of this study was to evaluate the effect of subcutaneous injections of Cu, Se, Zn, and Mn on peripheral blood neutrophil activity, on polymorphonuclear leukocyte (PMNL) function, concentrations of antioxidant enzymes, and haptoglobin (Hp) in dairy cows during summer months. This study was conducted in 2 dairy farms located in West TX. A total of 923 Holstein multiparous cows were randomly allocated to receive 3 injections of 15 mg/mL of Cu, 5 mg/mL of Se, 60 mg/mL of Zn, and 10 mg/mL of Mn (Multimin 90, Multimin North America, Fort Collins, CO) following the label dose of 1 mL/90.7 kg of body weight at 208 ± 3 and 260 ± 3 d of gestation, and at 35 ± 3 d postpartum (ITMS) or remain untreated (CON). Blood samples were collected at enrollment, and at 3 ± 1, 7 ± 1, 10 ± 1, and 35 ± 3 DIM to evaluate PMNL function; phagocytosis and oxidative burst capacity of neutrophils, and the quantification of the adhesion molecule L-selectin; glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity and thiobarbituric acid reactive substances (TBARS) and Hp. Statistical analysis was undertaken in SAS using logistic regression and mixed linear models. We observed that ITMS decreased the incidence of stillbirth (P = 0.05) and metritis (P = 0.05) compared with CON cows. Innate immunity during the postpartum period was improved in ITMS cows due to increased proportion of PMNL that performed phagocytosis (P < 0.01) and oxidative burst (P < 0.01) and also increased oxidative burst intensity (P = 0.05). The expression of the L-selectin in neutrophils was increased in CON cows compared with ITMS counterparts (P = 0.04). Injectable trace mineral supplementation did not affect the activity of the SOD (P = 0.32) and GPx (P = 0.97) and TBARS (P = 0.56). In contrast, CON tended to present higher serum haptoglobin concentration at 10 d after calving (P = 0.09). In conclusion, ITMS improved innate immunity by increasing neutrophil activity, but it did not influence the oxidative inflammatory status of dairy cows.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84094 Watch P132 Assessing the relationship between the metabolic health index and energetics, inflammation, and milk production in lactating Holstein cows. 12 E. A. Horst inflammation MHI E. A. Horst1, C. Sousa1, L. Rodriguez1 1Innovative Liquids LLC, El Dorado Hills, CA Composite indexes such as the liver functionality, liver activity, and metabolic health index (MHI) have been demonstrated to be effective strategies for depicting the magnitude of inflammation and its potential downstream consequences on health and performance in transition cows. Therefore, objectives of the study were to evaluate changes in milk production, energetics, and inflammation in cows with high or low MHI. Multiparous Holstein cows calving on a commercial dairy were retrospectively categorized into high (positive MHI, mean = 1.74; n = 54) or low (negative MHI, mean = −1.96; n = 48) MHI groups. Blood samples were collected at 7 DIM and submitted to the Texas A&M Veterinary Medical Diagnostic Laboratory for analysis. MHI was calculated using albumin, bilirubin, and cholesterol concentrations according to previously described methods (Askel et al., 2020; J. Dairy Sci. 103, Suppl. 1). Milk yield was recorded daily and samples for composition analysis were obtained weekly. Milk and energy-corrected milk (ECM) yields are presented as an average of the first 4 weeks postpartum. Fixed effects of MHI group were analyzed using the mixed procedure of SAS. Fibrinogen and globulin concentrations were increased (19 and 7%, respectively; P ≤ 0.03) whereas the albumin to globulin ratio was decreased (15%; P < 0.01) in low vs. high MHI cows. Relative to the high MHI group, average milk yield in the first 4 weeks postpartum was decreased (7%; P = 0.03). No treatment differences were observed for ECM yield in the low relative to high MHI group (48 vs. 58 kg, respectively; P > 0.13). Low MHI cows had decreased calcium concentrations (5%; P < 0.01) when compared with the high MHI group. NEFA and BHBA concentrations were increased in low relative to high MHI cows (54 and 48%, respectively; P < 0.01), however, BUN and glucose concentrations did not differ. Relative to the high MHI group, the NEFA to cholesterol ratio increased 2-fold in low MHI cows (P < 0.01). In summary, a more pronounced inflammatory response, decreased milk yield, and increased NEFA and BHBA were observed in low vs. high MHI cows.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84310 Watch P133 Transition Cow Index as a monitor of fresh cow health and performance in Brazilian dairy herds. 13 D. C. Silva health transition period D. C. Silva1, J. K. Poncheki1, J. H. Carneiro1, J. A. Horst2, K. Nordlund3, R. Almeida1 1Universidade Federal do Paraná, Curitiba, Paraná, Brazil, 2Associação Paranaense de Criadores de Bovinos da Raça Holandesa, Curitiba, Paraná, Brazil, 3University of Wisconsin, Madison, WI The objective of this study was to develop and to validate an index to monitor fresh cow health and performance based upon standard milk recording data, known as Transition Cow Index (TCI). Data set from official DHIA Paraná herds, Southern Brazil, had originally 373,458 first monthly test-days (TD) from 2010 to 2019. First-lactation data were excluded and after editions only Holstein data were kept in the final data set, which had 116,264 first TD from 602 herds. Previous cumulative milk yield, DIM in prior lactation (L and Q effects), linear somatic cell score at the last TD of previous lactation, days dry (L and Q effects), lactation number, month of calving, milking frequency and DIM at first TD were the independent variables used in GLIMMIX procedure from SAS to generate an expected milk yield in the first TD after calving. The expected daily production was compared with the production in the first TD after calving, collected between 5 and 45 d, to generate TCI in kg/d. The results from the DHI data indicated that 53% had a positive TCI and 47% a negative TCI and the overall TCI average was −0.0004 kg/d. To validate TCI equation, we had used data from 4 herds which monitored health disorders on 3,326 fresh cows between 2017 and 2019. The GLM procedure from SAS was used to compare the TCI from cows with and without disease. Cows with clinical hypocalcemia (n = 30) had lower (P < 0.01) TCI than healthy cows (n = 3,296); −5.18 vs. +1.05 kg/d, respectively. Cows with retained placenta (n = 156) had lower (P < 0.01) TCI than healthy cows (n = 3,170); −4.82 vs. +1.25 kg/d. Fresh cows with metritis (n = 318) had lower (P < 0.01) TCI than healthy cows (n = 3,008); −1.67 vs. +1.37 kg/d. Animals with displaced abomasum (n = 114) had lower (P < 0.01) TCI than healthy cows (n = 3,212); −10.52 vs. +1.33 kg/d. Cows with clinical mastitis (n = 153) in the first 30 DIM had lower (P < 0.01) TCI than healthy cows (n = 1,996); −0.80 vs. +1.18 kg/d. Fresh cows with 1 disease (n = 655) had lower (P < 0.01) TCI than healthy cows (n = 2,671); −2.75 vs. +2.05 kg/d. Transition Cow Index proved to be an efficient tool for monitoring fresh cow health and performance of dairy herds.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84237 Watch P134 Pattern of rumination time and physical activity captured by an ear-attached sensor around the time of clinical diagnosis of metritis and mastitis in dairy cows. 14 C. Rial dairy cow health rumination C. Rial1, A. L. Laplacette1, M. M. Perez1, C. C. Florentino2, F. Pena-Mosca2, L. Caixeta2, J. O. Giordano1 1Deparment of Animal Science, Cornell University, Ithaca, NY, 2College of Veterinary Medicine, University of Minnesota, St. Paul, MN The objective of this prospective observational study was to characterize the pattern of rumination time (RT), and physical activity (PA) as measured by an automated health monitoring system based on an ear-attached sensor (SmartBow, Zoetis) immediately before, during, and after clinical diagnosis (CD) of metritis (MET) and mastitis (MAST) in lactating dairy cows. Rumination time and PA represented by active time (AT) data were collected from 540 lactating Holstein cows. Clinical health events were monitored daily until 21 DIM. Data were daily summed from −7 to 7 d relative to CD for cows diagnosed with MET (n = 84), MAST (n = 39), and cows without clinical signs of disease (NCD; n = 417). Data for RT and AT were analyzed using ANOVA with repeated measurements. Fixed effects were group (NCD, MET, MAST), time, and their interaction whereas parity and calving season were offered as covariates. Cow was included as a random effect and was the subject of repeated measurement analysis. Compared with NCD, cows in the MET group had reduced (P < 0.05) RT from −7 to 3 d after CD and reduced AT from −7 to 7 d after CD. On the day of CD, RT was 413 ± 13 min/d and AT was 652 ± 17 min/d for the MET group compared with RT of 522 ± 6 min/d and AT of 828 ± 8 min/d for the NCD group. For the comparison of cows in MET and NCD, parity and season of calving affected (P < 0.05) RT and AT. Compared with NCD, cows in the MAST group had reduced (P < 0.05) RT and AT from −2 to 0 d after CD. On the day of CD, RT was 250 ± 18 min/d and AT was 403 ± 24 min/d for the MAST group compared with RT of 536 ± 6 min/d and AT of 839 ± 8 min/d for the NCD group. For the comparison of cows in MAST and NCD, parity and season of calving affected (P < 0.05) RT and tended (P = 0.06) to affect AT. We conclude that rumination time and physical activity monitoring data captured by an ear-attached sensor from an automated health monitoring system might be used to identify cows with metritis and mastitis.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84200 Watch P135 Association of prepartum lying time with colostrum immunoglobulins and cortisol concentrations at calving and milk yield in Holstein dairy cows. 15 B. T. Menichetti lying time consistency immunoglobulins dairy cattle B. T. Menichetti1, A. Garcia-Guerra2, J. Lakritz4, W. P. Weiss3, J. S. Velez5, B. Bothe5, D. Merchan6, G. M. Schuenemann1 1Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, OH, 2Department of Animal Sciences, The Ohio State University, Columbus, OH, 3Department of Animal Sciences, The Ohio State University, Wooster, OH, 4Department of Veterinary Clinical Sciences, The Ohio State University, Columbus, OH, 5Aurora Organic Farms, Boulder, CO, 6ABS Global Inc, DeForest WI The objective was to assess the association of the coefficient of variation of lying time (CV of LT) within 7 d before parturition (dpp) with colostrum immunoglobulin G (IgG), cortisol concentrations at calving and milk yield at first DHIA test in Holstein dairy cows. A prospective cohort study was conducted in 292 Holstein multiparous dairy cows from one large dairy herd in Colorado. All prepartum cows were housed in deep bedded-pack barns with access to outside patio. At 35 ± 3 dpp, a group of 43 to 53 pregnant cows were fitted with an electronic data logger (IceQube, IceRobotics, Edinburgh, UK) to assess their LT. Once calving date was known, the within cow CV of LT was computed by dividing the standard deviation of LT over the mean for the last 7 dpp and reposted as an absolute ratio. Cows were then classified into 1 of 3 groups based on their CV of LT using the 50th (0.13) and 95th (0.24) percentile: < 0.13 (n = 154), from 0.13 to 0.24 (n = 125), and ≥ 0.25 (n = 13). Colostrum samples were collected within 1 h following parturition. Data were analyzed using MIXED or CORR procedures of SAS (SAS Institute Inc., Cary, NC). Mean LT within 7dpp were significantly different among cows with a CV of LT of < 0.13 (720 min/d), 0.13 to 0.24 (657 min/d), and ≥ 0.25 (555 min/d; P < 0.001). The CV of LT within 7 dpp was significantly associated (P < 0.05) with colostrum IgG concentrations at calving and milk yield at first DHIA test but was not associated with colostral cortisol at calving (P = 0.26). Cows with a CV of LT of ≥ 0.25 (116 g/L) within 7 dpp had 43 g/L less colostrum IgG concentrations at calving compared with cows having a CV of LT of < 0.13 (159 g/L) or from 0.13 to 0.24 (157 g/L; P = 0.006). Cows having a CV of LT ≥ 0.25 (31.9 kg/d) within 7 dpp had 5.8 kg/d less milk yield compared with cows having a CV of LT < 0.13 (37.7 kg/d) or from 0.13 to 0.24 (37.6 kg/d; P = 0.03). These findings suggest that prepartum pregnant cows with inconsistent LT within the last 7 dpp, defined as CV of LT ≥ 0.25, was detrimental for colostrum quality at calving and milk yield in early lactation.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t83443 Watch P136 Prophylactic effect of dietary direct-fed Bacillus subtilis C-3102 on incidence of mastitis in dairy cows. 16 T. Marubashi Bacillus subtilis C-3102 direct-fed microbial mastitis H. Aso1,2, M. Urakawa1,2, T. Zhuang1,2, H. Sato3, N. Takada3, N. Ashida4, T. Imabayashi4, N. Otomo4, K. Watanabe1,2, T. Nochi1,2, T. Marubashi5 1Cellular Biology Laboratory, Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi, Japan, 2CFAI, Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi, Japan, 3Miyagi Prefectural Livestock Experiment Station, Osaki, Miyagi, Japan, 4Asahi Biocycle Co. Ltd, Shibuya-ku, Tokyo, Japan, 5Calpis America Inc, Peachtree City, GA The objective was to study the effects of dietary Bacillus subtilis C-3102 (Calsporin; BS) on the incidence of mastitis and on hematological and immunological changes. Holstein dairy cows (control group: 10 head, calving number = 4.3 ± 2.0; BS-fed group: 6 head, calving number = 4.5 ± 1.0) having history of mastitis in their previous lactations were fed a ration comprised of timothy hay and a commercial concentrate without or with BS (3 × 109 cfu/head) 2 times daily for 11 mo (from 1 mo before parturition). The cows with onset of mastitis were diagnosed by the on-site veterinarian’s observation and by the milk quality including its somatic cell count. Plasma concentrations of glucose, urea nitrogen, NEFA, total cholesterol, cortisol, and TBARS were measured monthly. Flow cytometry determined frequencies of peripheral granulocytes, monocytes, B cells, T cell subsets, and dendritic cells (DC). Data were analyzed by nonparametric Mann-Whitney U-test using a statistical software, jSTAT. The number of cows with mastitis onset and the days of medical care required were significantly lower in BS-fed group than those in control group (P < 0.05). The average milk somatic cell count (SCC) in BS-fed group was 4.2 × 104 cells/mL which was significantly lower compared with 5.7 × 106 cells/mL in control group (P < 0.02). After parturition, the plasma total cholesterol rapidly recovered to the original level in BS-fed group, but not in control group. In mid- and late lactation, plasma urea nitrogen, cortisol, and TBARS levels were lower (P < 0.05) in BS-fed group than in control group. The BS-feeding increased (P < 0.05) the proportion of DC, surface marker expression of CD80, and production of cytokines IL-12a and IL-6 in peripheral blood. Results indicate that a ration containing direct-fed BS may reduce the incidence of mastitis by the modulation of immune metabolic functions in dairy cows, with 99.26% reduction in milk SCC that would contribute to increased wholesome milk production in the dairy industry.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t83928 Watch P137 The effects of intramammary ceftiofur hydrochloride and cephapirin benzathine antibiotic treatment at dry-off on peripheral blood mononuclear cell mitochondrial enzyme activity in Holstein cows. 17 T. A. Batchelder mitochondria enzyme cephalosporin T. A. Batchelder1, A. M. Niesen1, H. A. Rossow1 1University of California, Davis, Davis, CA Cephalosporin antibiotics are commonly used at dry-off to treat and prevent intramammary infections. Research in murine and other mammalian cell types has shown that cephalosporin antibiotics can negatively affect mitochondrial respiratory chain activity, which then impacts cellular function. The objective of this study was to evaluate the effects of intramammary cephalosporin (Cefitiofur Hydrochloride; CEFT, and cephapirin benzathine; CEP) antibiotic treatment administered at dry-off on peripheral blood mononuclear cell (PBMC) mitochondrial enzyme activity at 7 d post dry. Thirty-seven Holstein cows from a commercial dairy were enrolled at the time of dry-off and assigned to 1 of 4 treatments: 1) Low SCC control (LCON), 2) High SCC Control (HCON), 3) High SCC CEP (CB), (ToMorrow; Boehringer Ingelheim Vetmedica Inc., St. Joseph, MO), and 4) High SCC CEFT (CH), (Spectramast DC; Zoetis Inc., Kalamazoo, MI). Control treatments received no antibiotics. Low and high SCC cows were defined as <100,000 cells/mL (low), and >200,000 cells/mL (high) at the day of dry-off. Whole blood and milk samples were collected at the time of dry-off and 7 d post dry. Mitochondria were isolated from the PBMC fraction of whole blood. Enzyme activities of citrate synthase (CS), complex I, complex IV, and ATP synthase were performed on crude mitochondrial extracts using kits from Abcam (Cambridge, MA). Data were analyzed using linear mixed models with repeated measures in R (Version 4.0.2). Least squares means CS activity deceased by time within treatment: LCON, 0.588 to 0.325 mOD / min per µg of crude mitochondrial protein ± 0.09 SEM; and CB, 0.614 to 0.299 mOD / min per µg of crude mitochondrial protein ± 0.11 SEM Since changes in CS activity at the end of lactation (dry-off) and at 7 d into the dry period were similar between treatments these data indicate that intramammary infusion of CEFT and CEP administered at dry-off do not affect PBMC mitochondrial enzyme activity. The decrease in CS enzyme activity were similar between treatments and may be associated with the involution of the mammary gland, or indicative of energetic changes with the cessation of lactation.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84635 Watch P138 Randomized clinical trial evaluating effects of an alternative dosing schedule for pegbovigrastim on mammary gland health and milk production. 18 J. L. de Campos dairy pegbovigrastim mastitis J. L. de Campos1, J. Strickland2, J. Gandy2, C. Robison1, L. M. Sordillo2, P. L. Ruegg2 1Department of Animal Science, Michigan State University, East Lansing, MI, 2Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI The objective of this randomized clinical trial was to evaluate effects of an alternative dosing schedule for pegbovigrastim (PEG; Imrestor, Elanco Animal Health) on mammary gland health and milk production. Pregnant late lactation cows were randomly assigned to receive treatment with 15mg of PEG (n = 10 cows) or a sham injection with saline (n = 10) administered 7d before dry-off and on the day of dry-off (DRY). No antimicrobial therapy was administered at DRY. Quarter (QTR) milk samples were collected for bacteriological culture and somatic cell count (SCC) at 8 periods (7 and 2d before DRY, DRY, 7 and 14d after DRY, and 5, 10, and 14d after calving). Daily milk yield in the subsequent lactation were evaluated on 10, 14, 30, 60, and 120 DIM. Chi-squared analysis was used to assess the effect of treatment on incidence of intramammary infection (IMI) and multivariate modeling was used to determine effects of treatment on SCC and milk yield. The incidence of IMI was greater for QTR of cows in the control group as compared with QTR of cows that received treatment (X2 = 6.3; P = 0.006). Compared with cows receiving treatment, the odds of IMI were 7.5 times greater (95% CI:1.5, 36.7) for QTR in the control group. While the overall effect of treatment on SCC was not significant (P = 0.23), significant effects were found for period and the interaction of treatment by period (P < 0.01). As expected based on the mode of action and administration periods, greater Log10 SCC were observed for treated cows 2d before DRY (4.09 control; 4.68 PEG) and at DRY (4.12 control; 4.62 PEG). Significant effects of sampling period (P < 0.001) and an interaction of treatment by sampling period (P = 0.001) were observed for milk yield, and there was an overall tendency for treated cows to have greater milk yield in the subsequent lactation (P = 0.09). Cows in the in the control group produced 45, 48, 52, 52 and 42 kg/cow/d at each sampling period. In contrast, cows in the treatment group produced 48, 51, 62, 58 and 50 kg/cow/d. Cows treated with PEG using an alternative dosing schedule had reduced incidence of IMI during the dry period and increased milk yield in the subsequent lactation.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84462 Watch P139 Intramammary lipopolysaccharide infusion alters the fatty acid profile in blood triacylglycerides and phospholipids of lactating dairy cows. 19 C. Lalonde fatty acid mastitis systemic effect C. Lalonde1, J. Kraft1, R. K. Choudhary1, D. E. Bourne1, E. M. Shangraw2, T. B. McFadden2, F.-Q. Zhao1 1University of Vermont, Burlington, VT, 2University of Missouri, Columbia, MO Mastitis depresses milk yield and reduces milk quality in infected glands, but also has systemic effects that may impair function of noninfected mammary glands. There is much to learn about the impact of these systemic effects on lactation performance and health of the cow. We hypothesized that intramammary endotoxin infusion would affect the blood lipid profile of cows. This study aimed to determine the changes in concentration of fatty acids in blood of dairy cows that receive intramammary infusion of lipopolysaccharide (LPS). Ten multiparous Holstein cows were blocked into pairs by milk yield and somatic cell count. One cow of each pair was assigned to LPS treatment (T) or control (C) group (n = 5). In T cows, one udder half was infused with 50 μg of Escherichia coli LPS (serotype O55:B5) in 10 mL saline into both glands and the contralateral glands received 10 mL saline. C cows received an infusion of 10 mL saline into both glands of one udder half. Blood was collected from the coccygeal at −1h, 3, 6, 12 and 24 h postinfusion. Plasma lipid fractions (cholesterol, free fatty acids, phospholipids and triacylglycerides) were separated by solid-phase extraction, and each fraction was analyzed by gas-liquid chromatography. Statistical significance was determined using a mixed model with Tukey’s test. Principal component analysis revealed that the phospholipid fatty acid profiles of T and C cows clustered together at −1 h and 3 h but diverged at 6 h, 12 h and 24 h postinfusion. Fatty acids in triacylglycerides of T and C cows diverged at 6 h and 12 h. In T vs C cows, there was an increase in concentrations of 18:0 at 6, 12 and 24 h (P < 0.0004) in triacylglycerides and at 12 h (P < 0.0001) in phospholipids, a decrease of 18:2 9c,12c at 6 h (P = 0.0384) and 12 h (P = 0.0004) in triacylglyceride and at 6, 12 and 24 h (P < 0.0001) in phospholipids, and an increase of 22:0 at 12 and 24 h (P = 0.0002) in phospholipids. These findings showed that intramammary LPS results in changes in the fatty acid profiles of plasma triacylglycerides and phospholipids, indicating a systemic effect on lipid metabolism.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t83968 Watch P140 Changes in phospholipids in milk produced by dairy cows with clinical or subclinical mastitis in the first 21 days postpartum. 20 H. K. Peterson phospholipids mastitis milk H. K. Peterson1, J. E. Williams1, S. P. Couvillion2, T. Kelley1, C. D. Nicora2, K. E. Mostoller2, B. M. Webb-Robertson2, E. S. Nakayasu2, T. O. Metz2, E. L. Peterson3, M. K. McGuire4, M. A. McGuire1 1Department of Animal, Veterinary, and Food Sciences, University of Idaho, Moscow, ID, 2Pacific Northwest National Laboratory, Richland, WA, 3Peterson Dairy, Filer, ID, 4Margaret Ritchie School of Family and Consumer Sciences, University of Idaho, Moscow, ID Mastitis is inflammation of the mammary gland frequently caused by bacteria and triggering an immune response that may impact different classes of milk phospholipids (PL), including phosphatidylcholines (PC) and phosphatidylethanolamines (PE). PC and PE are the most abundant PL of animal cell membranes, and PE is the primary PL in bacterial cell membranes. As such, characterizing levels of PC and PE in milk may be useful biological markers of mastitis. The objective of this study was to quantify and compare PC and PE in milk produced by healthy cows and those with clinical or subclinical mastitis. Quarter milk samples (n = 112) were collected from clinical (SCC >400,000 cells/mL and abnormalities), subclinical (SCC >200,000 cells/mL and no abnormalities), and healthy animals (SCC <200,000 cells/mL) on 4 Idaho dairies in the first 21 d postpartum. We performed untargeted lipidomics using liquid chromatography coupled with tandem mass spectrometry and data were analyzed using a generalized linear mixed-effects model with health group (clinical, subclinical, healthy) and day postpartum (0–1 d, ≥5 d) as independent variables and cow nested within dairy as a random variable. Changes were considered significant with P-value <0.0001. We found no differences in PC or PE levels in milk produced by subclinical vs healthy quarters in either time postpartum; and no differences in PC or PE levels in milk produced by clinical vs healthy quarters at 0–1 d. However, at ≥5 d postpartum, levels of PE (18:1/19:0), PE (17:0/18:0), and PE (18:1/0:0) were lower and levels of PC (18:0/22:5), PC (18:1/20:4); PC (16:0/22:5), PC (16:0/O-16:0), PC (18:0/18:2); PC (18:1/18:1), and PC (18:0/20:4) were higher in clinical vs healthy quarters. Higher levels of PC in milk of cows with clinical mastitis may be due to immune cell migration into the udder. Lower levels of PE in milk of cows with clinical mastitis may be related to changes in bacterial community membership associated with mastitis. These results could be useful for monitoring udder health. Funding provided by the National Institutes of Health grant number 1R01HD092297–01A1.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t83947 Watch P142 Comparison of cow-side tests to predict individual cow quarter SCC. 21 L. A. Jacobsen mastitis RT-10 iPhone DeLaval Cell Counter L. A. Jacobsen1, A. M. Niesen1, H. A. Rossow1 1University of California, Davis, Davis, CA Intramammary infections, such as mastitis, are an extensive problem in the dairy industry as this disease can increase treatment and labor costs, decrease milk production and affect milk quality. Cow-side tests that predict SCC could be used to make more informed dry cow therapy decisions in individual quarters. However, there are very few studies that have examined the performance of these tests using the same individual cow quarter samples under the same conditions across multiple herds. This study compares the ability of the California Mastitis Test (Dairy Research Product, Inc., IN), the DeLaval Cell Counter (DCC; DeLaval, Graiguecullen, Carlow), the RT-10 iPhone meter (Dairy Quality Inc., Newmarket, Canada), a pH meter (Hanna Instruments, RI), an electrical conductivity meter (OHAUS, NJ), a dual laser infrared temperature thermometer (Klein Tools, IL), and the Porta Check Quick Test (PC; PortaCheck, NJ) to predict SCC in individual quarters compared with a gold standard, the Chem-Spec 150 (DHIA; Bentley Instruments, MN) at Tulare County Dairy Herd Improvement Association. This study enrolled 80 cows from 2 dairy herds (40 cows per herd). Milk samples were collected on all 4 quarters of the cows at the time of dry-off. The SCC were measured in well mixed milk samples using each cow-side test and by DHIA within 4 h of being collected. The SCC predicted by meters were regressed on DHIA and dairy using PROC GLM (SAS Institute, 2021, v. 9.4). Dairy was not significant. The RT-10 iPhone meter and DCC predicted DHIA quarter SCC the best (R2 = 0.93, R2 = 0.73, respectively), followed by PC (R2 = 0.67). These results indicate that the RT-10 iPhone meter, DCC meter, and PC have the ability to predict individual quarter SCC and could be used to identify individual mammary quarters to treat, potentially reducing antibiotic use at dry-off.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84215 Watch P143 Interactions of candidate gene expression and in vitro infection with Streptococcus uberis in bovine mammary epithelial cells. 22 H. Malcomson mastitis gene expression Streptococcus uberis H. Malcomson1, E. Shepherd1, G. Pighetti1 1University of Tennessee, Department of Animal Science, Knoxville TN Streptococcus uberis can internalize into mammary epithelial cells (MECs) and evade intracellular degradation to cause clinical and chronic mastitis. Our objective was to investigate interactions between Strep. uberis and MEC function relative to RAB4A (Ras-related protein RAB-4a), HECTD4 (HECTD Domain E3 Ubiquitin Protein Ligase 4), and PSAP (Prosaposin coding gene) whose SNP were associated with in vivo infection phenotypes and are involved with intracellular trafficking and degradation. A common MEC-line (MACT) was inoculated with Strep. uberis strains isolated from a chronic (UT888 cfu = 2.15 × 107) or acute (UT366 cfu = 1.19 × 108) mastitis case. Gene expression, MACT viability and intracellular survival of bacteria at 0, 3, 9, and 27 h postinoculation were evaluated with a mixed model ANOVA using SAS 9.4 (Cary, NC). The model included fixed effects of infection status, time, and their interactions, random effect of time, and covariate of Strep. uberis dose. Cell viability was over 80% (SD = 3.1). Internalization of UT888 in MACT (n = 5) was lower than UT366 (n = 1). Both peaked at 3 h, with ~95% and 100% reductions at 9 h and 27 h. Both HECTD4 and RAB4A gene expression hint at an interaction between infection status and time (P = 0.12 and 0.18, respectively). HECTD4 dropped to 0.3 - 0.7 at 3 and 9 h postinfection relative to 0 h regardless of infection status. Only the infected cells rebounded to pre-infection levels by 27 h. RAB4a stayed stagnant in control cells until increasing to 1.6 at 27 h. Infected cells RAB4A gene expression peaked at 4.2 in 9 h, and dropped to 2.0 at 27 h. Only PSAP gene expression increased consistently within infected cells (P = 0.01) where it slightly increased at 3 h, doubled at 9 h, and doubled again at 27 h to 5.7 relative to time 0. Control cells only increased to a max of 1.45. Additional replicate experiments are required, but early experiments suggest changes in candidate gene expression after infection and suggest MECs modify intracellular trafficking and degradation pathways in response to Strep. uberis.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84272 Watch P144 Risk factors associated with intramammary infections in primiparous dairy cows in organic herds. 23 L. Fernandes mastitis organic risk factors L. Fernandes1, M. L. Celestino1, P. R. Menta1, T. H. Silva1,2, D. Paiva1, T. L. Ribeiro1, L. S. Caixeta3, N. R. Noyes3, V. S. Machado1 1Texas Tech University, Lubbock, TX, 2School of Animal Science and Food Engineering, University of Sao Paulo, Pirassununga, Sao Paulo, Brazil, 3University of Minnesota, St. Paul, MN Our objective was to identify risk factors associated with intramammary infections (IMI) during the first wk of lactation in primiparous dairy cows in organic herds and evaluate their association with SCC linear scores (LS) and milk yield in early lactation. A total of 240 nulliparous cows from 2 organic dairy herds located in NM and TX were enrolled 6 wks before expected day of parturition. Risk factors considered were presence of udder edema (UE), teat edema, milk leakage (ML), and poor udder hygiene at 6, 4, 2, 1 wks before calving and within the first wk of lactation, BCS at enrollment and within the first wk of lactation, age in days at calving, gestation length, dystocia, stillbirth, and if cow gave birth to a female singleton calf. A composite milk sample was collected within the first wk of lactation for microbiological analysis, and cows with a bacterial growth in the milk sample were considered as having IMI. A total of 29 cows were excluded from the analysis due to contaminated samples or loss to follow-up. The association between risk factors and IMI was assessed through a logistic regression model using SAS. Variables retained in the logistic regression model were offered to 2 general linear models accounting for repeated measures to evaluate the association of risk factors with milk yield and LS. Milk leakage at first wk postpartum increased the odds of IMI at 3.42 times (P < 0.01), while UE at one wk before calving tended to increase the odds of IMI (OR = 1.86, P = 0.09). Cows with prepartum BCS ≥3.75 were at 3.12 greater odds of IMI than cows with BCS = 3.25 – 3.5 (P < 0.01), but the odds of IMI were not different between cows with BCS ≤3.0 and BCS = 3.25 – 3.5 (P = 0.15). Cows with ML during the first wk of lactation had increased LS (P = 0.01) and lower milk production in the second month of lactation (P = 0.05), while UE diagnosed at one wk prepartum tended to be associated with greater LS (P = 0.09). In conclusion, ML within the first wk of lactation and high BCS 6 wks before calving were associated with IMI, with ML also being associated with greater LS and lower milk production within the first 2 mo postpartum.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84681 Watch P145 Characterization of clinical mastitis on Southern Brazilian dairy herds by severity score. 24 S. T. Guerra bovine mastitis pathological agents S. T. Guerra1, M. Poczynek2, G. C. Aguiar2, L. L. Damasceno1, C. D. Neufeldt1, L. Goltz1, H. P. Janssen1, E. M. Ribas1, G. F. M. Leão1, R. Almeida2 1Negócios Leite, Castrolanda Cooperativa Agroindustrial, Castro, Paraná, Brazil, 2Universidade Federal do Paraná, Curitiba, Paraná, Brazil The goal of this study was to evaluate the distribution of mastitis-causing agents among the levels of clinical mastitis severity. Data from 387 cases of mastitis evaluated in a on-farm culture system based on colorimetric qualitative method were used. Twelve herds in Southern Brazil were monitored from August 2020 to February 2021. Mastitis cases were classified in 3 categories: mild when only the milk was abnormal (n = 133), moderate when abnormal milk was accompanied by swelling of mammary gland (n = 216), and severe when cow exhibited systemic signs of illness (n = 38). Data were evaluated using the FREQ, GLM, and GLIMMIX procedures of SAS (v.9.4). The occurrence of agents differed among mastitis levels. Gram-negative bacteria were most frequent in severe cases, while the gram-positive group were most frequent in the mild and moderate ones. Escherichia coli, Klebsiella spp., and the sum of Streptococcus agalactiae and Streptococcus dysgalactiae were most frequent in severe cases. In the moderate cases, Staphylococcus non-aureus was the most important agent, and the major agents in the mild cases were Streptococcus uberis and non-aureus Staphylococcus. Table 1. Distribution of etiology of milk samples from clinical mastitis cases occurring in cows on Southern Brazilian dairy herds by severity score
Microbiologicaldiagnosis Mild Moderate Severe P-value
n % n % n %
Gram-positive              
 Enterococcus spp. 1 0.8 3 1.4 0 0.0 0.92
 Lactococcus lactis 1 0.8 2 0.9 0 0.0 0.87
 Staphylococcus aureus 3 2.5 13 6.1 2 5.7 0.10
 Staphylococcus non-aureus 32 26.9a 41 19.4b 5 14.2b <0.01
 Streptococcus uberis 35 29.5a 37 17.7b 2 5.8c <0.01
 S. agalactiae/dysgalactiae 13 10.9c 39 18.5a 5 14.2b <0.01
 Other gram-positive              
  3 2.5b 15 7.1a 3 8.7a <0.05
Gram-negative              
 Escherichia coli 18 15.1c 39 18.6b 9 25.7a <0.01
 Klebsiella spp. 8 6.8b 9 4.2b 5 14.2a <0.01
 Pseudomonas 0 0.0 1 0.6 0 0.0 0.96
 Serratia 1 0.8 0 0.0 1 2.9 0.77
 Other gram-negative 2 1.7 4 1.8 0 0.0 0.70
Yeast              
 Prototheca spp. 2 1.7 8 3.7 3 8.6 0.12
Total 119 100 211 100 35 100  
The sum of agents was higher than the number of positive cultures due to the possibility of growth of more than one agent per culture.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84364 Watch P146 Investigating the use of a 7% iodine tincture based umbilical dip as a preventive management practice for umbilical infections in neonatal calves. 25 M. Van Camp navel morbidity omphalitis M. Van Camp1, C. Winder1, D. Gomez2, T. Duffield1, D. Renaud1 1Department of Population Medicine, University of Guelph, Guelph, ON, Canada, 2Department of Clinical Studies, University of Guelph, Guelph, ON, Canada The objective of this randomized clinical trial was to evaluate the efficacy of 7% iodine tincture based umbilical dip as a preventive method to reduce the incidence of umbilical infections in dairy calves, as compared with no treatment. Five dairy farms in southern Ontario were visited bi-weekly from September 2020 through March 2021where Holstein calves were randomly assigned at birth to receive either a 7% iodine tincture based umbilical dip (n = 128) or no treatment (n = 126). The umbilical dip was administered a single time by the producer shortly after birth. During researchers’ first visit with each newborn calf, record of treatment group, birth difficulty, gestation length, colostrum administration, time of birth, calving pen cleanliness, and the dam ID were collected via a calving form. The calf’s body weight, health score including an umbilical assessment, and a blood sample (serum total protein) were also captured at the first visit. Calves were then health scored bi-weekly using a standardized scoring system which evaluated fecal consistency score and respiratory score. Umbilical infections were defined as enlarged navel with pain, heat or malodorous discharge. Serum total protein and birth weight did not differ significantly between treatment groups. In the umbilical dip group, 25 (19.5%) calves developed umbilical infections and 27 (21.4%) developed umbilical infections in the control group. A mixed logistic model showed no effect of treatment group (P = 0.70), however calves born in dirtier calving pens had a tendency for increased odds of infection (OR = 2.5, 95% CI: 1.0 to 6.3, P = 0.06) compared with those born in cleaner pens. Farm had a significant impact on the risk of developing an umbilical infection (ICC = 0.09). These findings suggest that administering a single dose of 7% iodine tincture dip to the umbilicus around the time of birth may not be sufficient at preventing umbilical infections. Conversely, farm level management factors including calving pen cleanliness appear to be more influential on risk of disease.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84181 Watch P147 Supplementing preweaned dairy calves with smectite improves serum IgG concentration, and reduces mortality and antimicrobial treatments. 26 A. Correa preweaned calves smectite antimicrobial A. Correa1, A. Valldecabres1, M. Abreu1,2, N. Silva-Del-Río1 1Veterinary Medicine Teaching and Research Centre, Tulare, CA, 2Universidade Federal de Viçosa, Department of Animal Science, Viçosa, MG, Brazil Our aim was to evaluate the health effects of supplementing preweaned dairy calves with smectite. A total of 200 newborn calves (Holstein, n = 88; Jersey, n = 112) were sequentially assigned to control (CON; force-fed 50 mL of water; n = 100) or smectite [SME; force-fed 2.5 g of smectite (calcium montmorillonite bentonite clay, Redmond Inc., UT) and 50 mL of water; n = 100] at 1 d of age. Calves received treatments 2 h before the afternoon milk feeding for the first 10 d of age. Health evaluations (fecal consistency, signs of respiratory disease, and milk refusals) were performed by researchers daily from 1 to 20 d. Mortality and antimicrobial treatments administered by farm personnel were recorded until 20 d of age. Jugular blood samples (SME, n = 21; CON, n = 23) were collected at 1, 4, 8, 12, and 16 d for IgG determination and at 1 and 8 d for trace serum minerals determination. Statistical analyses were performed in SAS. Risk of health events, antimicrobial treatments, and mortality were analyzed using log binomial regression. Linear regression models were used to evaluate serum IgG and trace serum minerals concentration. Compared with CON, SME calves tended to have a 63% lower risk of mortality (P = 0.09) and a 45% lower risk for antimicrobial treatments (P = 0.04). Health events recorded by researchers were similar for SME and CON calves. Compared with CON, SME calves had higher serum IgG at 4 d (23.4 vs. 19.3 g/L; P = 0.07) and at 8 d (22.1 vs. 15.9 g/L; P = 0.01). However, after treatments ended, IgG were similar for SME and CON at 12 and 16 d Serum concentrations of Ca (P = 0.03), Mg (P = 0.02), Na (P = 0.01) were higher for SME compared with CON calves; P (P = 0.06), and Zn (P = 0.08) were higher for SME compared with CON calves. The positive effects of SME on mortality, antimicrobial treatments, and serum IgG of preweaned dairy calves warrant future research.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84476 Watch P148 The effect of fish and canola oil on body weight, dry matter intake, serum haptoglobin and protectin on Holstein dairy calves. 27 P. Melendez n-3 fatty acids calves diseases P. Melendez1,2, C. Roeschmann3, A. Baudo1, S. Tao1, J. Bernard1, P. Pinedo4, F. Farcey1, A. Kalantari1, M. Coarsey1, Y.-Y. Mosley1, H. Naikare1 1University of Georgia, Tifton, GA, 2Texas Tech University, Amarillo, TX, 3University of Chile, Santiago, Chile, 4Colorado State University, Fort Collins, CO The aim was to assess the effect of a commercial fish oil product as a source of N-3 fatty acids, compared with canola oil on body weight (BW), dry matter intake (DMI), serum haptoglobin and protectin CD59 in Holstein calves. The study was conducted at the Dairy Research Center, University of Georgia Tifton Campus. Between September and November 2019, 30 calves were randomly assigned by sex at birth to 2 groups. Calves were fed a milk replacer (26% CP, 20% fat, 12.5% solution) at rate of 2 L AM and 2 L PM during wk 1. Then, 3 L AM and 3 L PM between wk 2 and 7, and 3 L AM during wk 8. Starter and water were offered from d 3 until weaning. A group received 30 mL of canola oil 98% pure (CAN) and another received 60 g of a fish oil-based product providing 30 g of fish oil (FO), daily, at the AM feeding until weaning. Products were mixed with the milk solution in the feeding bucket. At 7, 14, 21, 28, 35, 42, 49 and 56 d of age a blood sample, and BW were taken. DMI was assessed daily (MR + Starter). In serum sample, haptoglobin, as an indicator of an inflammation process, and protectin as an indicator of inflammation resolution was measured through ELISA commercial kits. BW, DMI, haptoglobin and protectin were analyzed by ANOVA for repeated measures. There was higher haptoglobin concentration in the CAN than the FO at d 7 (P ≤ 0.1), and 14 (P ≤ 0.05), but lower at d 49 (P ≤ 0.1; Table 1). There was higher protectin concentration in the FO than the CAN at d 14 (P ≤ 0.1), but lower at d 28 (P ≤ 0.1), 35 (P ≤ 0.05), and 49 (P ≤ 0.05). DMI was higher at d 42, 49, and 56 for FO than CAN (P ≤ 0.05). There was a trend for higher weaning weight in FO than CAN (65.4 vs 61.9 kg). It is concluded that FO improved slightly DMI and weaning weight of dairy calves, perhaps due to better health and immunological status. Table 1.
Day Haptoglobin (ng/mL) Protectin CD59 (ng/mL) BW (kg) DMI (g)
CAN FO CAN FO CAN FO CAN FO
1 36.1 36.5
7 622.4 465.4** 49.1 50.1 39.3 39.4 359.8 376.5
14 410.5 212.8* 37.3 44.8** 38.7 40.1 362.9 369.6
21 365.0 357.6 44.0 41.2 40.9 41.4 439.0 426.0
28 295.7 314.3 48.8 40.8** 43.7 45.5 490.6 555.8
35 155.4 187.0 50.3 40.3* 48.9 50.2 738.7 791.4
42 203.5 159.9 41.5 39.4 53.4 55.5 971.9 1,072.0*
49 520.6 735.4** 45.5 33.0* 56.4 59.1 1,354.9 1,481.6*
56 53.8 91.7 41.7 39.9 61.9 65.4** 2,005.3 2,130.3*
LSM are reported. *P ≤ 0.05, **P ≤ 0.1: Differences within parameter and day between treatment groups.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84162 Watch P149 Evaluation of a probiotic program on prevention of diarrhea in organic-certified Holstein heifer calves. 28 A. Velasquez-Munoz calf diarrhea probiotic A. Velasquez-Munoz1, N. Meza-Correa2, D. Manriquez1, P. Pinedo1 1Colorado State University, Fort Collins, CO, 2Universidad Tecnologica de Pereira, Manizales, Colombia The objective was to evaluate the effect of a 2-steps probiotic program (Establish Calfbel, Perdue AgriBusiness LLC) on diarrhea incidence in preweaned Holstein heifer calves. A randomized clinical trial was completed from July to October 2020 in one calf rearing facility in CO, USA. Calves were housed in pairs sharing 2 polyethylene hutches and a sand bedded front yard (4.50 m2), enclosed by a galvanized welded wire fence. A total of 116 pairs of calves were enrolled at birth (control [CTR] = 58; treatment [TRT] = 58) and followed until weaning (65 ± 1 d). Treatment consisted of 2 formulations of a bacterial-based probiotic to be added into colostrum (F1) and milk (F2). Treatment calves received 2 g of F1 added into each colostrum feeding and 1 g of F2 added into milk at the morning feeding 3 times per week up to weaning. Calves were weighted at birth and moved to the rearing facility, housed in pairs sharing the same treatment. Serum total protein (STP) was measured at age 3 ± 1d and a complete health assessment was performed 3 times per week. Calves were weighted at weaning and temperature-humidity index (THI) was calculated for the whole study period. Statistical analyses were performed in SAS. Time to event analysis was used to evaluate time to the first diarrhea event and recovery time. Poisson regression was used to evaluate the total number of diarrhea events. Logistic regression was used to calculate the odds of culling and ANOVA was used for comparison of continuous outcomes (STP, average daily gain [ADG]). Calves were continuously exposed to heat stress in the day hours (July to September, mean (±SE) THI = 75 ± 0.44 units). No treatment difference was observed in STP (P = 0.06). At least 1 calf in each pair presented diarrhea during the study period and no differences were determined in the median time to a first diarrhea event (CTR [10d], TRT [11d]; P = 0.78), or in the median time to recovery from diarrhea (CTR [5d], TRT [7d]; P = 0.1). Likewise, treatment was not associated with the number of diarrhea events (P = 0.28), ADG (P = 0.67), or the odds of culling (P = 0.73). In conclusion, the probiotic program was tested in challenging environmental conditions and it did not impact the incidence of diarrhea in preweaned heifer calves.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84809 Watch P150 Histological and ultrasound analysis of Holstein calf mammary gland development. 29 A. Vang mammary gland Holstein calf A. Vang1, T. Bresolin1, W. Frizzarini1, J. Campolina1, G. Rosa1, L. Hernandez1, J. Dorea1 1University of Wisconsin–Madison, Madison, WI Although the bovine mammary gland is an important focus area in bovine research, not many studies focus on development in the period between weaning and the first gestation. Milk production is highly dependent on the development of the mammary epithelium, which occurs during this time. Because of this, longitudinal histological mammary gland analysis is needed to better understand growth and development, as well as the effects of environmental factors such as diet. Holstein calves were pair-fed on high (HI; n = 15) and low (LOW; n = 15) nutrition diets for 8 weeks. The LOW diet contained 0.45 kg of milk replacer per day with 22% crude protein and 15% fat, whereas the HI diet contained 1.12 kg of milk replacer with 27% crude protein and 20% fat. Starter was available at 7 d and weaning began on d 42. The starter amount given to the LOW diet calves were based on the amounts the paired HI diet calves consumed. Mammary gland ultrasound images were taken twice weekly. Mammary gland biopsies were performed at 8 weeks on 15 of the 30 calves, and slides were prepared using hematoxylin and eosin stain for 8 calves. The parenchyma (PAR) tissue of 1,414 ultrasound mammary gland images were manually segmented, and the parenchyma area was extracted. Images were analyzed using Matlab 2021b and statistical analysis was conducted using a mixed model including the fixed effect of time (16 time points), diet (HI and LOW) the interaction time × diet, and birth weight, and the random effect of animal. At time point 1 and 2 of wk 8, animals receiving HI diet presented PAR area of 56 and 81 mm2 compared with 46 and 58 mm2 (P < 0.05). There was no statistical difference in PAR circularity, but the PAR perimeter and maximum length was greater for HI diets (10.1 and 290 mm, respectively) compared with LOW (8.5 and 243 mm, respectively) at wk 8 (time point 2). The average number of ducts for HI and LOW diet was 8.2 and 6.6 ducts, respectively. The number of ducts is purely descriptive in this preliminary study. These results come from a pilot study with only 30 calves, and we were only able to biopsy enough tissue for H&E slides from 8 of those calves. Our preliminary data suggests that features extracted from ultrasound mammary gland images can be a powerful tool to monitor the development of parenchymal tissue in preweaned dairy calves.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84160 Watch P151 Factors associated with body weight of young dairy calves at arrival to veal facilities. 30 C. Rot transport age health C. Rot1, K. Creutzinger1, H. Goetz1, A. Bajus1, M. Conboy1, J. Morrison1, C. Winder1, D. Renaud1 1Department of Population Medicine, University of Guelph, Guelph, ON, Canada Body weight at arrival to veal facilities (BWA) of surplus dairy calves has been demonstrated to be a significant predictor of morbidity and mortality; however, factors influencing BWA have not been well explored. The objective of this study was to determine factors associated with BWA of young dairy calves upon arrival to a veal facility. Calves were enrolled at birth on 4 dairy farms in southern Ontario, Canada and followed until immediately after transportation. Dairy farms were visited daily before transport to record calving difficulty, birthweight, health status, and serum total protein at 24 h after birth. On the day of transport, calves were randomly assigned to 1 of 3 transportation groups: 6, 12, or 16 h of time in transit. Age on the day of transport was recorded and BWA was measured immediately at arrival to the veal facility following transport. A mixed linear regression model was constructed to identify the effect of exposure variables on BWA. Statistical significance was declared at P ≤ 0.05. A total of 60 male and female dairy calves were enrolled. The mean (±SD) birthweight and BWA were 46.27 ± 6.91 kg and 46.85 ± 6.56 kg, respectively, and age on the day of transport ranged from 2 to 22 d. In the final model, birthweight and age at transport were significant. Specifically, for every 1 kg increase in birthweight, there was a 0.86 kg increase in BWA (95% CI: 0.76–0.95; P = 0.001). With respect to calf age on the day of transport, calves that were 5 to 9 d, 10 to 12 d, and ≥13 d at transport were 2.46 kg (95% CI: 0.68–4.23; P = 0.007), 5.94 kg (95% CI: 4.12–7.76; P = 0.001), and 5.93 kg (CI: 4.11–7.75; P = 0.001) heavier, respectively, than calves that were <5 d of age. Interestingly, health status of the calves before transport and duration of transport were not associated with BWA. The initial results of this study suggest that birthweight and age at transport have a significant effect on calf BWA.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84243 Watch P152 Characterizing the literature about transportation of young dairy calves: A scoping review. 31 H. Goetz bull calf veal industry H. Goetz1, C. Winder1, K. Creutzinger1, T. Uyama1, J. Dunn1, D. Kelton1, D. Renaud1 1Department of Population Medicine, University of Guelph, Guelph, ON, Canada Transportation is a stressful event for cattle due to handling, commingling, deprivation of food and water, and fluctuating temperatures. Calves are particularly susceptible to these stressors as their physiological and immune systems are still developing. However, there has been no formal synthesis of published studies evaluating transportation of calves. The aim of this scoping review is to characterize the literature about transportation of young dairy calves. This review targeted descriptive and analytic studies examining transport of calves, including how the impact of transport has been evaluated, and identify knowledge gaps. Eight databases were searched for relevant articles with eligible studies being primary research articles investigating transportation of calves of any sex, younger than 60 d of age or weighing less than 100 kg. Two reviewers independently screened the title and abstracts of 6,862 articles with 351 eligible for full text screening. Of these 351 articles, 54 examined transportation of young calves and had data extracted. The majority of studies did not report where they were completed (n = 23), but of those which reported location, many were conducted in the USA (n = 5), Australia (n = 3), Japan (n = 3), and New Zealand (n = 3). Studies most frequently described transport of male calves (n = 19), while others included a mixture (n = 13), females (n = 2), or did not report the sex (n = 17). Common variables collected included time in transit (n = 15), distance of transportation (n = 8), vehicle-related factors (n = 6), and age at time of transportation (n = 5). Outcome measures described in these articles varied greatly with blood parameters most frequently assessed (n = 29), followed by behavioral parameters (n = 16), health scoring (n = 11), weight (n = 7), mortality (n = 7), and morbidity (n = 4). A diverse range of risk factors and outcomes were evaluated in the studies included in this scoping review, making it difficult to compare findings. Further research should focus on consistent and clear reporting of the impact of transportation on young calves and development of a core outcome set for calf transport studies.
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t84731 Watch P153 Early detection of anaplasmosis in dairy calves using activity and rumination data from commercial devices. 32 L. G. R. Pereira artificial intelligence machine learning thick fever V. A. Teixeira1, A. M. Q. Lana1, G. M. Souza2, T. R. Tomich3, T. Bresolin4, J. P. P. Rodrigues5, L. C. Gonçalves1, S. G. Coelho1, L. D. Ferreira1, J. A. G. Silveira1, M. M. Campos2, E. J. Facury Filho1, L. G. R. Pereira2,4, J. R. R. Dorea4 1Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil, 2Universidade Federal de Lavras, Lavras, MG, Brazil, 3Brazilian Agricultural Research Corporation-Embrapa Dairy Cattle, Juiz de Fora, MG, Brazil, 4Department of Animal and Dairy Sciences, University of Wisconsin, Madiosn, WI, 5Faculty of Animal Science, Federal University of the Southern and Southeastern Pará, Xinguara, PA, Brazil The annual losses caused by anaplasmosis in cattle are approximately 300 and 800 million dollars for USA and Latin America, respectively. The use of wearable devices to monitor animal behavior could be a powerful tool to early predict diseases, as anaplasmosis. The objective of this study was to compare the predictive ability of Recurrent Neural Network to detect anaplasmosis on day zero (0d, The lowest packed cell volume - PCV value, 14 ± 1.8% was used to assume that the animals were sick against 32 ± 2.4% for healthy animals) or 3 d in advance (−3d), based on rumination (RUM) and activity (ACT) data retrieved from 2 devices: collar (Heatime HR) and ear tag (eSense Flex). Fourteen Holstein female dairy heifer calves (119 ± 15 d old) were fitted with both devices (21 d before challenge) and were challenged with 2 × 107 erythrocytes infected with UFMG1 strain (GenBank no. EU676176) isolated from A. marginale. A 7-d sequence was randomly selected from a time window varying from −50 to −15d before d0. This time-series was used to classify a healthy pattern (sequence of days that does not result in a positive case: Anaplasmosis). The sick time-series consisted of a sequence of days that resulted in a positive case (from −7 to 0d) or a sequence of days that ended 3 d before a positive case (−10 to −3d). A Long Short-term Memory was used as a predictive approach to detect sick events and was implemented in Keras R package. To validate the trained algorithms, a leave-one-animal-out cross-validation was implemented. The accuracy (ACC), sensitivity (SEN), and specificity (SPE) for predictions at 0d were similar for collar and ear tag (100%) using ACT data. The predictions based on ACT for −3d in the advance decrease 21% (ear tag) and 29% (collar) the ACC compared with 0d models. When RUM data were used, the ACC, SEN, and SPE were lower compared with ACT data. RNN models based on RUM or ACT data from wearable sensors can be used to detect anaplasmosis in dairy calves. For predictions in advance, the models based on RUM had the best performance compared with ACT. The models based on data from ear tag had better performance compared with collar. Table 1. Models performance to predict anaplasmosis
Item Accuracy Sensitivity Specificity
ACT      
 Ear tag (0 d) 100 100 100
 Collar (0 d) 100 100 100
 Ear tag (−3 d) 79 71 86
 Collar (−3 d) 71 57 86
RUM      
 Ear tag (0 d) 96 93 100
 Collar (0 d) 93 86 100
 Ear tag (−3 d) 86 79 93
 Collar (−3 d) 82 79 86
Animal Health: Posters Posters Animal Health 7/11/2021 0:00 t83481 Watch P154 Impacts of Clostridia populations on dairy cows observed on a Wisconsin dairy. 33 V. G. Bretl   V. G. Bretl1, J. S. Thompson1, R. F. Teal1, A. H. Smith1, T. G. Rehberger1 1Arm & Hammer Animal and Food Production, Waukesha, WI Clostridium is a gram-positive, spore-forming, obligate anaerobe that is commonly found in the gastrointestinal tract and feed of dairy cows. C. perfringens type A has been associated with enteric diseases such as hemorrhagic bowel syndrome in ruminants. These types of Clostridium challenges are often acute and occur rapidly. The objective of this experiment was to better understand the variation and impact of clostridia populations on the performance of dairy cows. Clostridia populations were observed in fecal samples from 11 dairy cows on a single farm, daily, for a 3-week period. Total mixed ration (TMR) in front of each cow and fermented feeds were collected daily to identify incoming clostridia loads. Clostridia was enumerated from fecal samples on tryptose sulfite cycloserine (TSC) agar, incubated at 37°C for 24 h, isolates were picked, and DNA was isolated. Clostridium spp. mPCR was used to specifically identify C. perfringens, C. beijerinckii, P. bifermentans, and C. butyricum. Milk production and SCR monitoring was used to gain performance data including daily and rumination activity, measurements were collected for 4 weeks, each day of the experiment and the week after. Total clostridia counts ranged from 74 to 1,800 cfu/g in fecal samples and 32 to 990 cfu/g in feed samples. The average clostridia levels increased during each week of this observation in both fecal (300, 390, 590 cfu/g) and feed samples (160, 240 and 510 cfu/g). Clostridia loads in the TMR samples increased comparing wk 1 to both wk 2 and 3 (P < 0.05) and trended higher in the fecal samples, comparing wk 1 to 3 (P = 0.07). The source of haylage changed during the second and third week of observation. During the first 2 weeks the average level of clostridia in the haylage was 350 cfu/g which increased to 600 cfu/g during wk 3. Average milk weight/day decreased each week (158.0, 156.6, 153.6 and 146.5 lbs) with wk 1 and 2 being significantly different than wk 4 (P < 0.05). General activity and rumination were not significantly different across the weeks. These results could provide insight on how the level of clostridia might impact the performance of dairy cows.
Breeding and Genetics: Orals Orals Breeding and Genetics 7/11/2021 0:00 s9632                  
Breeding and Genetics: Orals Orals Breeding and Genetics 7/11/2021 0:00 t84709 Watch 108 Response to ad libitum milk allowance by crossbred dairy and dairy-beef calves in an automated feeding system. 1 S. C. Arens automated feeder crossbreeding milk allowance S. C. Arens1, B. J. Heins1, M. M. Schutz1 1University of Minnesota, St. Paul, MN The objective of this study was to determine growth and milk consumption traits of Pure Holstein, ProCROSS, Grazecross, and Limousin crossbred dairy and beef calves fed alternative milk allowances in an automated group feeding system. The study was conducted at the University of Minnesota West Central Research and Outreach Center, Morris, MN. Sixteen Holstein, 24 ProCROSS, 6 Grazecross, and 22 Limousin crossbred heifers, and 23 Limousin crossbred bulls were randomly assigned to one of 2 treatments from September 2019 to June 2020. Calves were introduced to the Holm & Laue HL 100 calf feeder (Holm & Laue GmbH & Co KG, Westerronfeld, Germany) at 5 d. Treatments were 8 L/d (8L) or ad libitum (AL) milk allowance. Calves were weaned from the automated feeder at 56 d. Data were analyzed using PROC MIXED of SAS. Independent variables for analyses were fixed effects of birthweight, season of birth, breed group, treatment group and breed group by treatment interaction. Limousin crossbred bull calves had the greatest (1.1 kg/d, P < 0.01) average daily gain (ADG) and Holstein heifer calves had the least (0.96 kg/d) ADG. Calves fed AL had a greater (P < 0.01) ADG than calves fed 8L (1.13 kg/d versus 0.88 kg/d, respectively). Limousin crossbred bull calves (101.6 kg) had the heaviest (P < 0.01) weaning weight and Holstein heifer calves (98.1 kg) had the lightest weaning weight. Weaning weight was also heavier (P < 0.01) for AL calves compared with the 8L calves (107.4 kg versus 91.4 kg, respectively). Grazecross calves (1,427 mL/min) had the fastest drinking speed (P < 0.01) and Holstein heifer calves (1,193 mL/min) had the slowest drinking speed. The calves fed 8L had faster drinking speed (1,476 mL/min, P < 0.01) than calves fed AL (1,106 mL/min). Limousin crossbred heifer calves had the least milk cost ($151.66, P < 0.01) and ProCROSS heifer calves had the greatest milk cost ($181.32). As expected, AL calves had larger milk cost ($193.66, P < 0.01) than the 8L calves ($138.82). The results from this study show advantages to feeding calves 8L or AL with an automated feeding system depending on breed.
Breeding and Genetics: Orals Orals Breeding and Genetics 7/11/2021 0:00 t84699 Watch 109 Identification of genomic regions associated with dry matter intake, energy-corrected milk, and metabolic body weight in 2 stages of lactation using whole-genome sequence data. 2 K. Houlahan feed efficiency GWAS whole-genome sequence K. Houlahan1, T. C. S. Chud1, F. Miglior1,2, P. Stothard3, G. A. Oliveira Jr.1, F. S. Schenkel1, C. F. Baes1,4 1Centre for Genetic Improvement of Livestock, University of Guelph, Guelph, ON, Canada, 2Lactanet, Guelph, ON, Canada, 3Faculty of Agricultural, Life and Environmental Science, University of Alberta, Edmonton, AB, Canada, 4Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, BE, Switzerland Feed efficiency is an important aspect of dairy cattle productivity. Animals that consume less feed while producing the same amount of milk have the potential to reduce costs without reducing production. The physiology of lactation must be taken into account when selecting for improved feed efficiency. Peak lactation occurs 6 to 8 weeks after calving and coincides with a period of negative energy balance; in early lactation, cows use more energy than they can consume. This requires body store mobilization to meet their energy demands. It is therefore important to consider a feed efficiency related trait as 2 traits, the first before the peak of lactation (calving to 8 weeks of lactation) and the second after the peak of lactation (9 to 43 weeks of lactation). A genome-wide association study was performed using imputed whole-genome sequence to better understand the genomic architecture of traits that underlie common measures of feed efficiency. Deregressed estimated breeding values of 1,163 Holstein cows for dry matter intake, energy-corrected milk, and metabolic body weight at 2 time periods of the lactation were used as pseudo-phenotypes. Tag SNP were selected based on linkage disequilibrium to deal with collinearity. Significant tag SNP (P < 0.01E-06) on BTA 7, 10, 11, 14, 15, 19, 22, 23, and 25 were found for dry matter intake, energy-corrected milk, and metabolic body weight pre-peak lactation and post-peak lactation. Functional analyses of the candidate genes and QTL were also subsequently performed. Candidate genes found in more than 2 traits were ARSB, OTX1, MSI2, MYO1D, and LDLRAD3. The results show promise for attaining a better understanding of the genomic markers associated with traits that underlie common measures of feed efficiency in dairy cattle.
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 s9573                  
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 t84805 Watch P155 Machine learning algorithms for prediction of insemination outcome in historical data of Holstein cattle. 1 L. Alcantara machine learning classification insemination outcome L. Alcantara1, D. Tulpan1, C. Baes1,2, F. Schenkel1 1Centre for Genetic Improvement of Livestock, University of Guelph, Guelph, ON, Canada, 2Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, Switzerland Dairy cattle fertility is a long-standing concern in the dairy industry given its huge financial impact. Knowing the insemination outcome is key to investigate what factors might have an effect on fertility at breeding. Therefore, this study aimed to classify insemination outcome in historical data of Holstein cattle as open, pregnant, or aborted using machine learning algorithms. Data (Lactanet, Guelph) consisted of on-farm insemination records (2015–2020) and their corresponding fertility records used for genetic evaluations. Final data set contained 54,048 records from 20,484 animals (parity 0 to 11). Pairwise combinations of sums and differences between features were used to construct new features, e.g., difference between calving and insemination date. Linear discriminant analysis, k-nearest neighbors, decision tree (DT), Naïve Bayes, random forest (RF), AdaBoost, and support vector machine were used. A stratified 10-fold cross-validation was performed 5 times on 70% of the data. Accuracy of models ranged from 0.93 (DT) to 0.96 (RF). Hyperparameter optimization of DT produced the best model in overall accuracy (0.97), precision (0.96), sensitivity (0.97), and Matthews Correlation Coefficient (0.93). Tree depth was set to 4 to avoid overfitting. Choosing Gini impurity over information gain as the criteria to measure the quality of splits helped increase precision of abortion predictions by 10% (0.71). However, regardless of the criteria, sensitivity was low (0.10) when classifying abortions. Having more abortion records (2.3%) is expected to improve its prediction. The binary feature “date of insemination equal to last insemination date reported” was found to be the most important. As conception is delayed and calving interval lengthens due to unsuccessful services, cows spend a significant portion of their lactations at low production levels. Therefore, the proposed classification model will have a positive impact on the dairy industry by enabling researchers to accurately predict insemination outcome from historical data and better understand the underlying mechanisms of fertility.
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 t84745 Watch P156 Preliminary analysis for the genetic evaluation of leukosis in Canadian dairy cattle. 2 R. Bongers leukosis BLV genetics R. Bongers1, F. Miglior1, C. Lynch1, H. Oliveira1, N. van Staaveren1, C. F. Baes1,2 1Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada, 2Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, Switzerland Enhanced disease resistance is an important goal in dairy breeding. One of the major global diseases in cattle is enzootic bovine leukosis. This chronic disease is caused by bovine leukemia virus (BLV) and is spread through the transmission of infected lymphocytes. Clinical leukosis takes approximately 5 years to manifest and results in persistent lymphocytosis in 30% of cases and fatal malignant lymphoma in 5% of cases. Before these symptoms developing, infected animals can display a lower immune response, decreased fertility and milk production, and experience adverse effects on welfare, thus, making the economic impact challenging to quantify. Infection with BLV is not preventable through vaccination and is currently not treatable, however; breeding for resistance against leukosis is a potential method to mitigate these negative effects. To do so, a clear understanding of leukosis in the Canadian dairy population is paramount. The objective of this analysis was to understand the frequency of leukosis in Canadian herds and assess the potential for genetic improvement of this trait. Data on 122,111 milk ELISA test records for leukosis, from 101,183 cows on 988 farms across Canada, between 2007 and 2021 were investigated. Of these farms, 855 had at least one positive case of leukosis. A total of 37,657 (30.8%) cows tested positive for leukosis, 78,588 (64.4%) tested negative, and 6,868 (5.6%) were suspect. The average prevalence in infected herds was 51.5% (±27.5%). The relatively high prevalence of leukosis highlights the importance of this disease in the Canadian population. Descriptive statistics show that the incorporation of leukosis data into a national genetic resilience evaluation is a necessary step and could benefit the industry while improving the health and welfare of Canadian dairy cattle. Further steps will be performed to estimate genetic parameters and genetic and phenotypic correlations between leukosis and other traits. This study will lay the foundation for the inclusion of leukosis resistance into a new index for resilience.
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 t84725 Watch P157 Characterization of copy number variants identified in Canadian Holstein dairy cattle using genotype array data. 3 H. R. Oliveira copy number variations (CNVs) PennCNV structural variants H. R. Oliveira1, T. C. S. Chud1, G. A. Oliveira Júnior1, C. F. Baes1,2, F. S. Schenkel1 1Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada, 2Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, Switzerland Genomic breeding values (GEBVs) predicted based solely on single-nucleotide polymorphism (SNP) markers may represent only a part of the true breeding values (TBVs) of animals. To increase the correlation between GEBVs and TBVs, copy number variations (CNVs) might be useful, as they can capture part of the genetic variation not accounted for by SNPs. In brief, CNVs are deletions or duplications of DNA segments that can affect gene structure and dosage. The objective of this study was to characterize CNVs identified in Canadian Holstein dairy cattle using medium-density genotype array data. A total of 5,211 animals were genotyped using the GGP Bovine 100K array, and the corresponding intensity signal files (containing the log R ratio and B allele frequency; LRR and BAF, respectively) were provided. The detection of CNVs was performed using the PennCNV software. To reduce false-positive results, the LRR values were corrected for genomic waves based on the guanine-cytosine content of the genomic regions 500Kb upstream and downstream of each SNP. After the CNV detection, quality control was performed to remove CNVs with less than 3 SNPs, LRR standard deviation above 0.30, BAF drift above 0.01, and wave factor above 0.05. In total, 14,451 deletions and 13,001 duplications were detected. Of the deletions, 10,809 (74.8%) and 3,642 (25.2%) were heterozygous and homozygous copies, respectively. Of the duplications, 11,768 (90.5%) and 1,233 (9.5%) were heterozygous and homozygous copies, respectively. These CNVs will be validated using other genotype arrays and sequence data to provide high-confidence CNV regions. Further studies will investigate the functional impact of CNVs on several economically important traits for the Canadian dairy industry and evaluate the performance of genomic predictions incorporating both SNPs and CNV.
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 t84694 Watch P158 Contrast of immune cell lineage, hair, dam, and pooled colostrum genotypes in a newborn calf. 4 T. Muratori calf genotype T cell T. Muratori1, T. Ott1, A. Shabtay2, M. Cohen-Zinder2, E. Lipkin3, C. Dechow1 1Penn State University, University Park, PA, 2Newe Ya’ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel, 3The Hebrew University of Jerusalem, Israel Immune cells in a newborn calf could be produced by the calf, maternally derived, or absorbed from colostrum which has implications for genotyping and telomere length determination. Our objective was to contrast immune cell genotypes from a day-old calf with genotypes from a hair sample, dam hair sample, and colostrum that was pooled from multiple cows before feeding. Polymorphonuclear cells (PMN) were separated from peripheral blood mononuclear cells (PBMC) over a Ficoll gradient. The PBMC were separated by flow cytometry into T-cell, B-cell, and monocyte populations, and samples were genotyped for 139,376 SNP. We assumed the calf hair sample was the true genotype and tested for differences in frequencies of the number of called heterozygous and homozygous loci with chi-squared tests. The call rate for calf genotypes ranged from 96.2% for T-cell to 98.6% for hair and PMN. Cell lineage genotypes mostly returned high concordance with the assumed true genotype, with 2, 37, 56, and 656 mismatches of hair genotype with PMN, B-cell, monocyte, and T-cells, respectively. Calf heterozygosity was higher for the T-cell genotype (33.9%) than for the other cell types (33%), and only the T-cell genotype was different from the hair genotype (P < 0.05). The colostrum sample also had a low call rate (78.3%) and a high degree of heterozygosity (65.4%). Analysis of the 656 nonconcordant T-cell genotypes indicated that 82 matched the dam, 147 matched colostrum, and 105 matched both. Of the 322 that matched neither, 70 had no colostrum genotype. For the remaining 252, 241 were instances where the T-cell genotype was heterozygous, and the dam and colostrum genotypes were homozygous for opposite SNP. Dam and colostrum derived cells contribute to building passive immunity, and T-cell genotypes suggested some degree of DNA contamination with elevated non-call rate, heterozygosity, and mismatches with the true genotype. Nevertheless, immune cells isolated from a newborn calf’s blood provided largely accurate genotypes.
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 t84693 Watch P159 The Resilient Dairy Genome Project: A project overview. 5 N. van Staaveren resilience dairy genomics N. van Staaveren1, F. Schenkel1, E. Goddard2, G. Kistemaker3, M. De Pauw4, R. Cerri5, M. A. Sirard6, P. Stothard4, C. F. Baes1,7 1Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada, 2Department of Resource Economics and Environmental Sociology, University of Alberta, Edmonton, AB, Canada, 3Lactanet, Guelph, ON, Canada, 4Department of Agriculture, Food & Nutritional Science, University of Alberta, Edmonton, AB, Canada, 5Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada, 6Département des Sciences Animals, Faculté des Sciences de l’agriculture et de l’alimentation, Université Laval, Quebec, QB, Canada, 7Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, Switzerland Dairy farming is one of Canada’s most important and dynamic industries. The global demand for dairy products is set to expand further, however, at the same time, the dairy industry is facing several emerging issues related to human and animal health, environmental impacts, sustainability, and social acceptability. The Resilient Dairy Genome Project (RDGP) is a large-scale collaboration between various international research and industry partners, which aims to integrate genomic approaches to enhance dairy cattle resilience. We define dairy cow resilience as the capacity of the animal to adapt rapidly to changing environmental conditions, without compromising its productivity, health or fertility, while becoming more resource-efficient and reducing its environmental burden. This project will develop and collect phenotypes in the key areas of ‘closer-to-biology’ fertility (e.g., estrous expression and embryo survival), enhanced disease resistance (e.g., fertility disorders, Johne’s disease, leukosis, and calf health), and environmental efficiency (e.g., feed efficiency and methane emissions). We will evaluate the genomic and environmental relationships between both novel and existing traits using multigenerational analyses and epigenetic information. Our goal is to integrate these traits into a new resilience index, which can be incorporated in the Canadian dairy cattle genomic evaluation program. Furthermore, we will investigate producers, market, and public perspectives to optimize traits for maximizing resilience and societal acceptance. This strong foundation together with close collaboration with end-users will ensure rapid and meaningful translation and implementation of project results. We would like to acknowledge the support and funding from all the partners involved in the RDGP project through the Large Scale Applied Research Project program from Genome Canada and Genome Alberta.
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 t84691 Watch P160 Estimates of genetic parameters for total lactational health costs in US organic Holstein cows. 6 L. C. Hardie health costs genomics organic L. C. Hardie1, I. W. Haagen1, B. J. Heins2, C. D. Dechow1 1Pennsylvania State University, University Park, PA, 2University of Minnesota, St Paul, MN The objective of this study was to estimate genetic parameters for total lactational health costs (TCOSTS) in US organic Holstein cows. Health records were collected from 39,347 lactations from 19,249 Holstein cows on 16 USDA certified organic farms from across the United States. A subset of producers provided costs for a case of each of the following health issues (median cost): mastitis ($19.48), milk fever ($21.17), ketosis ($26.91), retained placenta ($28.14), displaced abomasum ($250.00), lameness ($16.81), cystic ovaries ($4.74), respiratory disease ($39.91), death ($80.37), and digestive issues ($19.57). Costs reflected veterinary, on-farm treatment, and labor costs but not discarded milk because of the absence of antibiotic usage in concert with feeding nonsaleable milk to calves. New cases were assigned after meeting a minimum threshold of days based on producer-reported days per treatment. Total lactational health cost was calculated by summing across each health issue the product of the median cost and number of cases. Stayability through a given lactation (1 = stayed, 0 = otherwise) was included as a threshold trait with TCOSTS in a bivariate animal model to mitigate potential impacts of selection bias. Animal relationships were established by combining genotypes on 2,347 cows with breed representation of at least 87.5% Holstein and a minimum of 4-generation pedigree in which phenotyped animals were required to have a known Holstein sire and no other identified breeds in the lineage. The model included the fixed effects of herd and lactation and the random effects of herd-year-season of birth (stayability), herd-year-season of calving (TCOSTS), animal, and permanent environment. For TCOSTS, heritability was 0.017 ± 0.003 and repeatability was 0.058 ± 0.008. The genetic correlation between stayability and TCOSTS was −0.49 ± 0.14. The most significant genetic correlations were approximated between TCOSTS with the following nationally evaluated traits: productive life (−0.76), cow livability (−0.61), heifer livability (−0.56), displaced abomasum (−0.52), net merit dollars (−0.51), and mastitis (−0.50). In conclusion, genetic selection for reduced cow health costs is possible among organic cows and afforded by current national genetic evaluations for cow health, longevity, and profitability traits.
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 t84668 Watch P161 Phenotypic parameters for Johne’s disease in Canadian dairy cattle. 7 C. Lynch Johne’s disease health C. Lynch1, H. R. Oliviera1, F. Miglior1,2, F. S. Schenkel1, C. F. Baes1,3 1Centre for Genetic Improvement of Livestock, University of Guelph, Guelph, ON, Canada, 2Lactanet, Guelph, ON, Canada, 3Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, Switzerland Johne’s disease (JD) is an enteric infection caused by Mycobacterium paratuberculosis (MAP), which is often transmitted to calves through the ingestion of contaminated feces or via consumption of colostrum or milk from an infected cow. However, clinical signs of JD (i.e., diarrhea, weight loss and eventual death) are not generally expressed until 3 to 5 years postexposure. There is no cure for JD, and currently there are no available vaccines. Consequently, control JD must be achieved through management practices and genetic selection. Addressing this issue through genetic selection has the major advantage that effects are permanent and cumulative over generations. Several studies have reported genetic variability for resistance to MAP infection, indicating that genetic selection for JD can be performed. As part of a larger project aiming to add JD to genetic evaluations in Canadian dairy cattle, this study provides the groundwork by describing the current situation of JD on Canadian farms. Data were provided by Lactanet Canada and included records on 405,569 milk ELISA tests, which measure the amount of MAP-specific antibody as optical density values. These records were collected from 313,005 cows raised in 3,120 herds distributed across Canada, recorded between 2007 and 2021. From these records, 8,210 (2.0%) were classified as positive, 395,338 (97.5%) were negative, while 2,021 (0.5%) were suspect. In total, 1,146 (36.7%) herds had at least one positive test, while the overall herd median infection rate among positive herds was 3.5%, with a median absolute deviation of 3.05, and a range between 0.3% and 100% of total animals within herds. This highlights the potentially widespread impact of JD and the importance of addressing JD through genetic selection. The descriptive statistics produced in this study will be used to help optimally fit JD into a novel resiliency index for use in national genetic evaluations in Canada.
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 t84531 Watch P162 Genetic correlations among milk yield, electric conductivity, and flow in Holstein cattle in a robotic milking system in Santiago de Querétaro, México. 8 N. L. Cornejo García heritability correlation Holstein N. L. Cornejo García1, M. D. Aguilar1, J. L. Romano Muñoz2, F. J. Ruíz López2, G. J. Cantó Alarcón1, S. V. Eduardo1 1Facultad de Ciencias Naturales - UAQ, Santiago de Querétaro, Querétaro, México, 2Centro Nacional de Investigación Disciplinaria en Fisiología y Mejoramiento Animal - INIFAP, Colón, Querétaro, México The goal of the study was the estimation of variance components and genetic correlations for milk production (MP), mean milk flow (MFm), maximum milk flow (MFx) and electrical conductivity (EC) in a robotic milking system and its comparison with parameters calculated in other milking systems. A total of 174 lactations (complete and incomplete subjects) of 110 primiparous and multiparous Holstein cows, with a total of 42,006 observations (2–3 per day), from 2017 to 2020 were analyzed. Multitrait animal model was used, where the fixed effects were test day, days in milk and lactation number, while as random effects animal and permanent environment were included. To estimate heritability, the restricted maximum likelihood algorithm was used to calculate the additive genetic variance components of the animal, the permanent environment and the residual. The heritability estimated for MP (0.62) was significantly higher than those estimated for MFm (0.44), MFx (0.33) and EC (0.28). Genetic correlations for MP were negative and large with MFm (−0.6117) and MFx (−0.7666), while for the EC trait (−0.1669) was considerably lower. Instead, the estimated genetic correlations for MFx were positive and large for MFm (0.7422) and EC (0.5351) and moderate for MFm and EC (0.3546). These results show that higher yields are attained in slower flow cows and suggest the possibility of including only some of the traits in a genetic improvement program. Given the negative correlation between EC and MP, the positive one with flow traits, and the reported relationship between EC and udder health, EC should be used in improvement programs along with milk yield; however, it is important to increase the number of evaluated animals to obtain more accurate results.
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 t84512 Watch P163 The association between calf birth weight and postcalving cow performance in dairy cows. 9 T. Condon calf birth weight multiparous milk T. Condon1, C. Murphy2, R. D. Slater2, S. Ring3, D. P. Berry1 1Animal and Grassland Research and Innovation Center, Cork, Ireland, 2Munster Technology University, Cork, Ireland, 3Irish Cattle Breeding Federation, Cork, Ireland The objective of the present study was to quantify the association between calf birth weight and its dam’s subsequent performance. A total of 11,112 lactation records with no recorded dystocia at calving from 4,350 spring-calving cows were used. Holstein-Friesian represented the main breed of cow with the remainder comprising Jersey, Norwegian Reds or Montbeliarde (or some combination of such). The association between a series of cow performance metrics (milk and fertility performance, body weight and body condition score) (dependent variables) and calf birth weight (independent variable) was determined using linear mixed models. Nuisance factors included in all models were calf sex, cow live-weight between 100 and 200 d of lactation relative to the mean cow weight per parity, heterosis coefficient of the cow and calf separately, previous dry period length, an interaction between parity (1, 2, 3+) and calf weight, an interaction between parity and age at calving relative to the median age at calving per parity, breed proportion of the dam, and contemporary group of herd-year-season-treatment; cow was included as a random effect in all the models. Mean birth weight was 36.2 kg with a standard deviation of 6.8 kg. Total 60 and 305-d milk yield was 60.35 and 189.5 kg more, respectively in multiparous cows that had heavier calves compared with those that had average weighed calves. Concentrations of milk fat and protein were also significantly increased in multiparous cows that had heavier calves. There was no significant effect of calf birth weight on pregnancy rates to first service and throughout the 12-wk breeding season, but clinical mastitis increased in multiparous cows that had heavier calves. The adoption of new management methods and breeding strategies like the inclusion of calf birth weight in future breeding programs will help maximize performance metrics of dairy cows, ensuring the long-term sustainability of the agricultural sector.
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 t84229 Watch P164 Connecting cattle and human traits using genome-wide association study statistics. 10 V. Iqbal genome-wide association studies V. Iqbal1, L. Ma1 1University of Maryland, College Park, MD Genome-wide association studies (GWAS) are used to reveal insights into the genetic basis of complex traits by identifying associations between genetic variations and traits. Using data from existing human and cattle GWAS and orthologous genes across species, we extracted GWAS summary statistics for 58 human traits and 43 cattle traits. The objective of this study was to find the pairwise correlations between cattle and human traits based on GWAS statistics. First, we calculated the z-score for each SNP for both human and cattle traits. Then, we found the gene level z-score statistic by calculating the mean z-score for all the SNPs inside of each gene for each trait. Additionally, we repeated the analysis using a different method, (tTs) to create gene-level P-value statistics that are less than a cut-off value (0.05). After creating all the gene level z-scores and gene-level P-value statistics for each trait, we did a pairwise correlation analysis for all the cattle to cattle traits, human to human traits, and finally human to cattle traits to investigate the genetic correlation of traits within and between species. There were several cattle production traits highly correlated with one another, several human disease traits correlated with each other, and a few cattle and human traits correlated. By using gene-level statistics and GWAS statistics we can further our knowledge of complex traits across species and help future GWAS research to pinpoint genetic variations underlying these traits.
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 t84090 Watch P165 Identification of long noncoding RNA in Bos taurus calf rumen before and after weaning. 11 A. Marceau lncRNA rumen RNA-seq A. Marceau1, R. Baldwin2, C. Li2, G. Liu2, L. Ma1 1Department of Animal and Avian Sciences, University of Maryland, College Park, MD, 2Animal Genomics and Improvement Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Agricultural Research Service, Agricultural Research ServiceDA, Beltsville, MD Although it has long been known that genes produce gene products, recent technological advancements have revealed that this is likely not always the case. Noncoding regions of the genome can also influence gene products; and a subcategory of these noncoding regions includes long noncoding RNAs (lncRNA) which lack an open reading frame and exceed 200 base pairs in length. This study aims to identify RNA transcripts that meet the long noncoding RNA criteria, and identify lncRNA transcripts that are differentially expressed before and after Bos taurus calves are weaned. Rumen development, which is triggered by weaning and requires changes to the gene expression profile, is crucial for healthy calf development and, when done successfully, leads to a healthy digestive system for the growing animal. To identify these transcripts, tissue samples were taken from 6 Bos taurus calf rumens before and after weaning. These samples were sequenced, and the resulting transcripts were filtered based on size, coding potential, sequence homology, and known protein domains. A Student t-test was then used to identify those transcripts that were differentially expressed at a statistically significant level. Beginning with over 21 million reads per sample, filtering steps lead to the identification of 2,026 and 2,074 long noncoding transcripts in Bos taurus rumen tissue before and after weaning, respectively. 2,025 transcripts were shared in both tissue conditions, 30 transcripts were found only in preweaning tissues, 78 transcripts were found only in postweaning tissues, and 336 transcripts were differentially expressed at a significant level between tissue conditions. These results suggest some connection between long noncoding RNA and rumen development in response to calf weaning, in both what is transcribed and at what levels. These relationships should be further investigated to uncover the specific roles these lncRNA transcripts are playing in rumen development.
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 t83667 Watch P166 Identifying genetic variants and pathways influencing twinning rate in North American Holstein cattle. 12 B. M. Lett twin folliculogenesis genomic prediction B. M. Lett1, B. W. Kirkpatrick1 1University of Wisconsin–Madison, Madison, WI Multiple birth in dairy cattle is a detrimental trait both economically for producers and animal health. Genetics of twinning is complex and has led to several quantitative trait loci regions being associated with increased twinning. To identify variants associated with this trait, calving records from 2 time periods were used to estimate twinning rate for Holstein bulls. Multiple analyses were conducted and compared including genome-wide association studies, genomic prediction, and gene set enrichment analysis for pathway detection. While pathway analysis did not yield a congruent pathway between data sets, genome-wide association analysis across data sets and methods showed 2 strong candidate regions on BTA11. Neither region overlaps with previously identified quantitative trait loci regions for twinning or ovulation rate in cattle. The strongest associated SNPs were upstream from 2 candidate genes LHCGR and FSHR which are involved in folliculogenesis. Using high-density genotype data, the most significant SNP in a combined analysis across data sets had a P-value of 1.9082 × 10−9. Genomic prediction showed a moderate correlation accuracy (0.4263) when predicting genomic breeding values for bulls with estimates from calving records from 2010 to 2016. Additionally, 5-fold cross-validation genomic prediction in the 2 data sets showed moderate accuracy (0.3816 older calving records and 0.5628 newer calving records). Future analysis of the region on BTA11 and the relation of the candidate genes could improve this accuracy.
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 t83643 Watch P167 EPIHAP: A computing tool for genomic estimation and prediction using global epistasis effects and haplotype effects. 13 Z. Liang epistasis haplotype genomic prediction Z. Liang1, D. Prakapenka1, Y. Da1 1Department of Animal Science, University of Minnesota, Saint Paul, MN Epistasis effects are interaction effects and haplotype effects may contain locally high order epistasis effects. To facilitate research on these effects, we developed EPIHAP computing program to integrate global epistasis effects and haplotype effects for genomic estimation and prediction. The full mixed model implemented by EPIHAP includes SNP additive (A) and dominance (D) effects, 3 pairwise epistasis effects (A × A, A × D, D × D), 4 third-order epistasis effects (A × A × A, A × A × D, A × D × D, D × D × D), and haplotype additive effects, for a total of 10 types of genetic effects. All or any or a combination of the 10 effects may be included in the mixed model. Limited tests showed that fourth-order epistasis effects virtually had no contribution to the phenotypic variance but generated considerable computing difficulty. Consequently, epistasis effects higher than the third order are not implemented by EPIHAP. For genomic estimation, EPIHAP estimates variance components and heritability for each type of genetic effect using genomic restricted maximum likelihood estimation (GREML). For genomic prediction, EPIHAP calculates genomic best linear unbiased prediction (GBLUP) and reliability for each type of genetic values, and for the total genetic values as summation of all types of genetic values in the prediction model at the end of GREML iterations. In addition, the epistasis heritability for each SNP pair can be calculated for A × A, A × D and D × D as a user option. This step is extremely demanding for memory space. We developed a triangular memory storage technique that eliminated this memory requirement. Estimates for additive and dominance heritabilities of each SNP and for haplotype additive heritability of haplotype blocks are also available. These heritability estimates can be used for identifying SNPs, SNP pairs and haplotype blocks with high heritability estimates. With the many capabilities under highly complex models for genomic estimation and prediction, the EPIHAP program offers a computing capability to investigate and utilize complex genetic mechanisms.
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 t83594 Watch P168 Genomic heritability and prediction accuracy of additive and nonadditive effects for daughter pregnancy rate in crossbred dairy cows. 14 Z. Liang heterosis genomic prediction heritability Z. Liang1, D. Prakapenka1, P. VanRaden2, Y. Da1 1Department of Animal Science, University of Minnesota, Saint Paul, MN, 2Animal Genomics and Improvement LaboratoryDA/ARS, Beltsville, MD Genomic heritability and prediction accuracy of epistasis effects for daughter pregnancy rate (DPR) were evaluated using 79,294 SNPs and 9,565 crossbred dairy cows. Heritability was estimated under the model with SNP additive effects (A), SNP dominance effects (D), and second and third order epistasis effects of A × A, A × D, D × D, A × A × A, A × A × D, A × D × D and D × D × D. Heritability estimate was 0.162 for additive effects, 0.283 for dominance effects, 0.555 for A × A effects, and zero or nearly zero for A × D, D × D and the third-order epistasis effects. Genomic prediction included all SNP and epistasis effects with heritability greater than one percent, resulting in the prediction model with A, D and A × A effects only. Prediction accuracy as correlation between the genomic best linear unbiased prediction and the phenotypic values from a 10-fold validation study for each model was 0.268 for A-model, 0.363 for D-model, 0.438 for A × A, 0.446 for A+D, 0.455 for A+(A × A), 0.467 for D+(A × A), and 0.475 for A+D+(A × A). Relative to the A-model, the D-model increased the prediction accuracy by 35.6%, A × A by 63.6%, A+D by 66.4%, A+(A × A) by 69.8%, D+(A × A) by 74.3%, and A+D+(A × A) by 77.2%. The heritability estimates and prediction accuracies showed that A × A effects were the largest contributor to DPR heterosis, followed by dominance and additive effects. The high additive heritability (0.16) in crossbred dairy cows relative to the low additive heritability in Holstein cows (0.025 according to our own estimate) indicated that a larger collection of favorable alleles from different breeds in crossbreds than in purebreds was part of the genetic mechanism underlying DPR heterosis. The total heritability was almost 100%, indicating likely overestimates somewhere for unknown reasons. However, the prediction accuracies did support the conclusion that A × A effects were the largest contributor to DPR heterosis, followed by dominance and additive effects, and that prediction accuracy of DPR can be high in crossbred dairy cows. Combined with dominance and A × A effects, the results in this study support our GWAS finding in a separate study that genome-wide additive and nonadditive effects were the genetic mechanism of reproductive heterosis.
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 t83593 Watch P169 Genetic mechanisms of reproductive heterosis in crossbred dairy cows involve genome-wide additive and nonadditive effects. 15 D. Prakapenka heterosis GWAS genetic mechanism D. Prakapenka1, Z. Liang1, P. VanRaden2, J. Jiang4, L. Ma3, J. Garbe5, C. Maltecca4, P. Hansen6, Y. Da1 1Department of Animal Science, University of Minnesota, Saint Paul, MN, 2Animal Genomics and Improvement LaboratoryDA/ARS, Beltsville, MD, 3Department of Animal and Avian Sciences, University of Maryland, College Park, MD, 4Department of Animal Science, North Carolina State University, Raleigh, NC, 5Genomics Center, University of Minnesota, Minneapolis, MN, 6Department of Animal Sciences, University of Florida, Gainesville, FL Reproduction is one of the biological processes with strong heterosis in crossbred dairy cows. To identify the genetic mechanism for reproductive heterosis, we conducted a genome-wide association study for daughter pregnancy rate (DPR) using 79,294 SNPs and 9,565 crossbred dairy cows. Using a significance level of log(1/p) = 8 with the Bonferroni correction, the number of significant SNP effects was 16,449 for additive effects and 10,449 for dominance effects. This compares to only 112 additive and 2 dominance effects for DPR from a large-scale Holstein GWAS. The most significant additive effect had a log(1/p) of 53, whereas the most significant dominance effect had a log(1/p) of 203; 481 dominance effects had log(1/p) > 53. For pairwise epistasis effects, the cut-off significance level with the Bonferroni correction was log(1/p) = 12. This study only focused on the top 50,000 pairwise effects with minimal log(1/p) value of 29. Of these 50,000 effects, 50.2% were A × A effects, 37.6% A × D and D × A, and 12.2% D × D. Epistasis effects were 30% intra-chromosome and 70% inter-chromosome effects. Of the A × A effects, 82% were inter-chromosome and 18% were intra-chromosome effects. These results indicated that the genetic mechanism of reproductive heterosis involved both additive and nonadditive effects, and inter-chromosome A × A effects had a major role in reproductive heterosis. The large number of significant additive effects indicated a larger collection of favorable alleles for DPR in crossbred cows than in purebred Holsteins in comparison with previous GWAS results for Holsteins. The large numbers of significant dominance and epistasis effects indicated a major role of nonadditive effects underlying reproductive heterosis in crossbred dairy cows. The intra-chromosome and inter-chromosome epistasis effects as well as the significant additive and dominance effects involved all chromosomes, indicating that the entire genome contributed to reproductive heterosis.
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 t83592 Watch P170 Genomic heritability and prediction accuracy of epistasis effects for production and fertility traits in US Holstein cattle. 16 Z. Liang epistasis genomic prediction Holstein Z. Liang1, D. Prakapenka1, Y. Da1 1Department of Animal Science, University of Minnesota, Saint Paul, MN Genomic heritability and prediction accuracy of epistasis effects were evaluated using 60,671 SNPs and 22,009 first-lactation Holstein cows for 5 production traits and 3 fertility traits, milk yield (MY), fat yield (FY), protein yield (PY), fat percentage (FPC), protein percentage (PPC), daughter pregnancy rate (DPR), cow conception rate (CCR), and heifer conception rate (HCR). Heritability was estimated for SNP additive effects (A), SNP dominance effects (D), and second and third-order epistasis effects. The additive heritability was 0.28 for MY, 0.24 for FY, 0.21 for PY, 0.51 for FPC, 0.56 for PPC, 0.025 for DPR, 0.038 for CCR, and 0.006 for HCR. Dominance heritability was 0.037 for MY, 0.035 for FY, 0.04 for PY, 0.016 for HCR, and was negligible the other traits. The A × A heritability estimate was 0.14 for MY, 0.16 for FY, 0.18 for PY, 0.08 for FPC, 0.07 for PPC, 0.19 for DPR, 0.07 for CCR and 0.08 for HCR. Other than HCR, A × D, D × D and third-order effects had low heritability estimates of 0–0.03. For HCR, epistasis heritability estimate was 0.10 for A × D, 0.03 for D × D, 0.10 for A × A × A, 0.04 for A × A × D, 0.02 for A × D × D, and 0.01 for D × D × D. These heritability estimates indicated that HCR had the most complex genetic mechanism among all 8 traits. For genomic prediction accuracy, the A+D model increased the accuracy over the A-model by 7.9% (0.047 vs 0.043) for HCR, 1.16% for MY, 1% for FY, and 1.49% for PY, and had negligible accuracy increases for FPC, PPC, DPR and CCR. The 3 fertility traits benefited most from epistasis effects for prediction accuracy, with accuracy increase of 38.1% (0.065 vs 0.047) for HCR, 13.3% (0.153 vs 0.135) for DPR, and 2.7% (0.112 vs. 0.109) for CCR over the best SNP model. The production traits had little accuracy increase due to epistasis, 0.8% (0.477 vs 0.473) for MY, 1.5% (0.454 vs 0.447) for FY, 1.8% (0.445 vs 0.438) for PY, 0.3% (0.640 vs 0.638) for FPC and 0.2% (0.688 vs 0.687) for PPC. These results showed epistasis effects could result in substantial increases in the accuracy of genomic prediction for the 3 fertility traits and dominance should also be considered for HCR.
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 t83591 Watch P171 Genome-wide association study of epistasis effects associated with production and fertility traits in US Holstein cattle. 17 D. Prakapenka epistasis GWAS Holstein D. Prakapenka1, Z. Liang1, J. Jiang2, L. Ma3, Y. Da1 1Department of Animal Science, University of Minnesota, Saint Paul, MN, 2Department of Animal Science, North Carolina State University, Raleigh, NC, 3Department of Animal and Avian Sciences, University of Maryland, College Park, MD Genome-wide association study (GWAS) using 60,671 SNPs and 294,079 first-lactation Holstein cows was conducted for testing pairwise epistasis effects of 5 production traits and 3 fertility traits, milk yield (MY), fat yield (FY), protein yield (PY), fat percentage (FPC), protein percentage (PPC), daughter pregnancy rate (DPR), cow conception rate (CCR), and heifer conception rate (HCR). For each SNP pair, 4 types of epistasis effects were tested, additive × additive (A × A), additive × dominance (A × D), dominance × additive (D × A), and dominance × dominance effects. The results showed that A × A effects were the main epistasis effects except CCR and HCR, for which A × D and D × A were the main epitasis effects (43% for CCR and 45% for HCR). The 5 production traits each had strong intra-chromosome epistasis effects, particularly FPC and MY. Intra-chromosome epistasis effects were the primary epistasis effects for FPC, PPC and MY, whereas FY and PY involved both intra- and inter-chromosome epistasis effects. The 3 fertility traits lacked intra-chromosome epistasis effects, but a Chr05 region with the PKP2 gene had the most significant epistasis effects for DPR. Among the 50,000 most significant pairwise epistasis effects of each trait, the percentage of inter-chromosome epistasis effects was 6% for FPC, 12% for PPC, 22% for MY, 45% for FY, 53% for PY, 87% for DPR, 94% for CCR, and 96% for HCR. Majority of the inter-chromosome epistasis effects of FPC across all chromosomes involved a Chr14 region containing DGAT1, indicating potential regulatory role of this Chr14 region affecting all chromosomes for FPC. The largest percentages of A × D and D × A effects as well as inter-chromosome epistasis effects of HCR indicated that HCR had the most complex genetic mechanism among all 8 traits. The epistasis results provided new understanding about the genetic mechanism underlying production and fertility traits in Holstein cattle and provided evidence for the need to consider epistasis effects in genomic prediction for the 3 fertility traits.
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 t83497 Watch P172 Chromosomal partitioning of genetic parameters in Canadian Holstein bulls. 18 G. Oliveira Junior dairy cattle genomics time trend G. Oliveira Junior1, M. Spehar2, B. Perez3, I. Pocrnic5, L. Lara5, F. Schenkel1, C. Baes1,4, G. Gorjanc5 1Centre for Genetic Improvement of Livestock, University of Guelph, Guelph, ON, Canada, 2Croatian Agricultural Agency, Zagreb, Croatia, 3University of Sao Paulo, Pirassununga, SP, Brazil, 4Institute of Genetics, University of Bern, Bern, Switzerland, 5University of Edinburgh, Edinburgh, Scotland Understanding genetic correlations among traits is important for multitrait evaluation and breeding. In this study, we partition correlations among dairy traits by chromosomes in Canadian Holstein cattle. The data comprised 9,204 progeny-tested bulls genotyped with the Illumina BovineSNP50K array. De-regressed EBV of fat yield (FY), age at first service (AFS), calving to first service (CTFS), and body condition score (BCS) were analyzed. We first estimated allele substitution effects of SNP markers with a multivariate marker model (Ridge Regression) under Bayesian approach. We then used these MCMC samples to obtain posterior distributions of breeding values, which were used to obtain samples from a posterior distribution of genetic (co)variances and correlations among the analyzed traits. We partitioned these posterior genetic (co)variances in genic, within- and between-chromosome linkage disequilibrium (co)variance contribution. This partitioning step was also performed over time to observe each component's trends. Overall correlations based on allele substitution effects ranged from −0.31 (AFS-BCS) to 0.49 (AFS-CTFS), and correlations of breeding values were between −0.71 (AFS-BCS) and 0.81 (AFS-CTFS). All the time trends, except FY (genetic variance), had a regression slope different than zero, suggesting that the (co)variance components have changed over time. The genetic variances were greatly influenced by genic and between-chromosome linkage disequilibrium components, with the latter contributing to the most of genetic correlations. The relationship between the number of SNP and the proportion of additive genetic variance attributed to each chromosome was close to linear, suggesting a polygenic structure of the traits, where, given an evenly spaced SNP chip, the bigger the chromosome, the bigger its influence on genetic variance. Fat yield was the exception to this pattern, with BTA 14 standing out the regression line.
Breeding and Genetics: Posters Posters Breeding and Genetics 7/11/2021 0:00 t83482 Watch P173 Identifying loci associated with foot warts and sole ulcers in Holstein cattle. 19 E. Lai foot warts sole ulcers GWAS E. Lai1, A. L. Danner1, T. R. Famula1, A. M. Oberbauer1 1Department of Animal Science, University of California, Davis, Davis, CA Lameness is the second most prevalent disease in dairy cattle and is commonly caused by foot warts (FW) and sole ulcers (SU). Foot warts are infectious lesions, whereas SU noninfectious lesions resulting from compromised horn production. Genomic selection against these claw lesions requires the identification of loci associated with susceptibility. To detect susceptibility loci, a genome-wide association study (GWAS) was performed using SNP genotypes from the high-density SNP array (777K SNPs) and case/control phenotypes for FW (controls n = 129, FW n = 85) and SU (controls n = 102, SU n = 152). GWAS was performed using linear mixed model (LMM) and random forest (RF) approaches, and effect sizes of top SNPs were estimated using Bayesian regression. For the LMM GWAS, the number of effective SNPs (NES) was calculated as the number of SNPs that were not in linkage disequilibrium and used as the denominator to define Bonferroni-corrected thresholds of significance (P ≤ 0.05/NES) and suggestive significance (P ≤ 0.2/NES). Top SNPs identified in the GWAS were in or near genes that were functionally relevant to claw lesion etiology. The FW LMM and RF GWAS both identified regions of association on Bos taurus autosome (BTA) 1 and 2, and one of the regions on BTA2 contained candidate genes related to immune function. The LMM GWAS for SU revealed an associated region on BTA 8 containing genes related to wound healing, skin lesions, bone growth and mineralization, adipose tissue, and keratinization. Furthermore, the region on BTA8 included a SNP previously associated with SU susceptibility. The RF GWAS for SU was overfitted, suggesting that the SNP effects were very small and prevented detection of susceptibility loci using this approach. For both FW and SU, the estimated effect sizes of top SNPs were small, reinforcing that the environment plays a nontrivial role in susceptibility and the remaining genetic component is likely governed by many loci. Larger sample sizes are necessary to identify small effect loci amidst a strong environmental effect.
Dairy Foods: Orals Orals Dairy Foods 7/11/2021 0:00 s9633                  
Dairy Foods: Orals Orals Dairy Foods 7/11/2021 0:00 t83631 Watch 110 Lactoferrin could alleviate liver injury caused by Maillard reaction products with furan ring through regulating necroptosis pathway. 1 F. Linlin lactoferrin furosine 5-hydroxymethylfurfural (5-HMF) F. Linlin1,2, L. Huiying1,2, Y. Qianqian1,2, W. Jiaqi1,2, Z. Nan1,2 1State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, P. R. China, 2Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, P. R. China The Maillard reaction (MR) is common during heat processing of food, especially dairy processing, diverse Maillard reaction products (MRPs) are generated during early, middle and late stage of MR, including N(ε)-2-furoylmethyl-l-lysine (furosine), pyrraline and 5-hydroxymethylfurfural (5-HMF). Moreover, there are accumulating evidences showing that the consumption of MRPs might lead to multiple diseases, such as cataract, diabetes, degenerative diseases, atherosclerosis, chronic renal failure, etc. We constructed HL-7702 cell (a normal hepatic cell line) model and ICR mouse model, and investigated the toxic effects of furosine, pyralline and 5-HMF on cell viability in vitro, as well as on liver function and liver pathological state in vivo. Additionally, the effects of lactoferrin in alleviating liver injury, as well as regulating necroptosis pathway, were evaluated. First, the contents of MRPs in milk powder samples were detected by UHPLC, and results showed that the content of furosine, 5-HMF and pyralline was 1 401.40 ± 76.70 mg/kg, 1.20 ± 0.15 mg/kg and 0.86 ± 0.097 mg/kg, respectively. The 3 MRPs were further proved to significantly inhibit HL-7702 cells viability in vitro, and 100 mg/L LF (selected by CCK8) could alleviate the damage. To further explore the related mechanisms of LF protective effects, we constructed acute toxicity model using ICR mice. The hematoxylin-eosin (HE) staining of liver tissue in ICR mice showed that the 3 MRPs (0.10 g/kg b.w.) caused occasional cytomorphosis and slight edema in some areas in the liver tissue, and lactoferrin (0.25 g/kg b.w.) showed protective effects in these damages. Meanwhile, the levels of necroptosis pathway related RIPK1, RIPK3, MLKL and p-MLKL, as well as inflammatory factors TNF-α and IL-1β, both in hepatic cells and liver tissue were detected by Western blotting. Results showed that RIPK1, RIPK3, p-MLKL, TNF-α and IL-1β were significantly upregulated by MRPs compared with the control (P < 0.05), meanwhile significantly downregulated by lactoferrin (P < 0.05). All these results indicated that lactoferrin could protect liver injury caused by MRPs with furan ring structure, which mainly through activated RIPK1/RIPK3/p-MLKL necroptosis pathway and downstream inflammatory reaction.
Dairy Foods: Orals Orals Dairy Foods 7/11/2021 0:00 t83632 Watch 111 The combination of lactoferrin and linolenic acid inhibits colorectal tumor growth through activating AMPK/JNK-related apoptosis pathway. 2 F. Linlin lactoferrin oleic acid DHA F. Linlin1,2, L. Huiying1,2, Y. Qianqian1,2, W. Jiaqi1,2, Z. Nan1,2 1State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, P. R. China, 2Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, P. R. China Colorectal cancer is a common cause of death with few available therapeutic strategies, and the preventive complexes in adjunctive therapy are urgently needed. Increasing evidences have shown that natural ingredients, including lactoferrin, oleic acid, docosahexaenoic acid (DHA) and linolenic acid, possess anti-inflammatory and antitumor activities. However, investigations and comparisons of their combinations in colorectal tumor model have not been reported, and the mechanism is still unrevealed. In the study, we examined the viability, migration, invasion and apoptosis of HT29 cells to choose the proper doses of these components and to select the effective combination in vitro. BALB/c nude mice bearing colorectal tumor were used to explore the role of selected combination in inhibiting tumor development in vivo. Additionally, metabonomic detection was performed to screen out the specific changed metabolites and related pathway. The results demonstrated that lactoferrin at 6.35 × 10–5 M, oleic acid at 1.77 × 10–4 M, DHA at 1.80 × 10–4 M, and linolenic acid at 1.52 × 10–4 M significantly inhibited the viabilities of HT29 cells (P < 0.05). The combination of lactoferrin (6.35 × 10–5 M) + linolenic acid (1.52 × 10–4 M) exhibited the strongest activity in inhibiting the migration and invasion of HT29 cells in vivo and suppressing tumor development in vitro (P < 0.05). Furthermore, the lactoferrin + linolenic acid combination activated p-AMPK and p-JNK, thereby inducing apoptosis of HT29 cells (P < 0.05). The present study was the first to show that lactoferrin + linolenic acid combination inhibited HT29 tumor formation by activating AMPK/JNK related pathway.
Dairy Foods: Orals Orals Dairy Foods 7/11/2021 0:00 t83636 Watch 112 Anti-inflammatory actions of acetate, propionate, and butyrate on fetal mouse jejunum cultures ex vivo and immature small intestinal cells in vitro. 3 S. N. Huang SCFA inflammation of immature small intestine inflammatory cytokines S. N. Huang1,2, Y. N. Gao1,2, Z. W. Wang1,2, X. Yang1,2, J. Q. Wang1,2, N. Zheng1,2 1State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, P. R. China, 2Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, P. R. China Necrotizing enterocolitis (NEC) is an intestinal disease that frequently occurs in premature infants. Presently, there is no effectual therapy for NEC. Therefore, the key to reduce the incidence rate of NEC is to take effective intervention measures as early as possible. Short-chain fatty acids (SCFAs) (acetate, propionate and butyrate) are produced by intestinal microbial fermentation. SCFAs could also be obtained directly from bovine milk, which is rich in SCFAs (about 10% of milk fat). SCFAs has been reported to play anti-inflammatory actions in mature intestinal cells. However, little studies focus on their roles in immature small intestine. Here, we evaluated the anti-inflammatory actions of SCFAs ex vivo with ICR fetal mouse jejunum cultures, and explored the potential anti-inflammatory regulators through RNA-seq, and then verified them in vitro with human fetal small intestinal epithelial FHs 74 Int cells. In this study, we found that acetate, propionate, and butyrate decreased IL-1β-induced production of CXCL2 ex vivo and IL-8 and IL-6 in vitro significantly (P < 0.05). Furthermore, the inhibitors of NF-κB p65, JNK1/2, and ERK1/2 pathways, which selected from RNA-seq and depressed by SCFAs, also significantly decreased IL-8 and IL-6 productions induced by IL-1β (P < 0.05). Consequently, our results implied that acetate, propionate, and butyrate ameliorated the fetal small intestine inflammatory response induced by IL-1β through inhibiting ERK1/2 pathway, NF-κB p65, JNK1/2, and ERK1/2 pathways, or NF-κB p65 and ERK1/2 pathways, respectively. Therefore, these findings showed that SCFAs were beneficial for treatment of NEC.
Dairy Foods: Orals Orals Dairy Foods: Dairy Products 7/11/2021 0:00 t83627 Watch 113 Aflatoxin B1 and aflatoxin M1 induce compromised intestinal integrity through clathrin-mediated endocytosis. 4 Y. N. Gao aflatoxin B1 aflatoxin M1 intestinal epithelial barrier Y. N. Gao1,2, X. Y. Bao1,2, J. Q. Wang1,2, N. Zheng1,2 1State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, P. R. China, 2Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, P. R. China Aflatoxin M1 (AFM1) could be present in the milk of dairy cows and human nursing mothers and in mammals that consume a diet containing aflatoxin B1 (AFB1). High AFM1 occurrence and contamination levels in milk samples were reported. With the growing diversity and complexity of diet, humans could be exposed to AFB1 and AFM1 through daily consumption of contaminated agricultural products, milk, and dairy products. The intestine represents the first barrier against external contaminants; however, evidence about the combined effect of AFB1 and AFM1 on intestinal integrity is lacking. To fill this knowledge gap, we determined the changes of intestinal barrier integrity of mice and differentiated Caco-2 cells treated with individual AFB1, AFM1 and the combination of both mycotoxins (AFB1+AFM1). In vivo, the results showed that the serum biochemical parameters related to intestinal barrier function, ratio of villus height/crypt depth and distribution pattern of tight junctions were significantly affected in mice exposed to 0.3 mg/kg b.w. AFB1 and 3.0 mg/kg b.w. AFM1. In vitro results on differentiated Caco-2 cells showed that both toxins provoked a decrease in cell viability determining by CCK-8 assay. AFB1 caused a significant (P < 0.05) decrease of 10% in cell viability at 1 μg/mL, whereas AFM1 treatment led to a similar decrease in cell viability at 4 μg/mL. Permeability measurement on FITC-dextran through determining the intensity of fluorescence showed that AFB1 at 0.5–1 μg/mL and AFM1 at 8 μg/mL were found to exert negative effects (P < 0.05) on paracellular resistance. Furthermore, 4 μg/mL AFM1 aggravated AFB1-induced compromised intestinal barrier, as demonstrated by the significant (P < 0.05) downregulation of tight junction proteins and their redistribution, particularly internalization. Adding the inhibitor chlorpromazine illustrated that clathrin-mediated endocytosis partially contributed to the compromised intestinal integrity. Synergistic and additive effects were the predominant interactions, suggesting that a combined consumption of commodities contaminated by several mycotoxins could lead to a higher risk of adverse effects than consumption of commodities contaminated by only one mycotoxin.
Dairy Foods: Orals Orals Dairy Foods: Processing 7/11/2021 0:00 t83628 Watch 114 Effect of different thermal processes of bovine milk on the gut microbiota composition of rat. 5 H. G. Yang bovine milk thermal processing gut microbiota H. G. Yang1,2, H. Y. Li1, Q. Q. Yao1, N. Zheng1, J. Q. Wang1 1Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, P. R. China, 2Sericultural & Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, P. R. China While thermal processing can eliminate potential pathogens in raw milk, it can also cause complex physicochemical changes such as Maillard reactions (MR) including isomerization, denaturation, etc. During these reactions, natural components are modified in structure or concentration, while new products are generated. In this study, we conducted a rat feeding model to investigate whether milk, treated with different thermal processing conditions, can modulate the gut microbiota composition. Three types of solid diet were produced, which was mainly made from pasteurized (P; 75°C/15 s), ultra-heat-treated (UHT; 135°C/4 s) and in-canned (C; 120°C/15 min) bovine milk, respectively. Thirty male Wistar rats (4-week old) were randomly divided into 3 groups (n = 10 per group, one rat per cage), and the rats had free access to diet and water. In the following experimental period, fresh feces samples were collected once each week (4 weeks, totally), and DNA was extracted immediately. The V3-V4 region of the 16S rRNA gene was amplified, and the data from high-throughput sequencing was mapped to a reference database. Sequence similarity more than 97% was regarded as one OTU (operational taxonomic units). Based on this, the abundance of each level (kingdom, phylum, class, order, family, genus) in every sample was calculated, respectively. ANOVA and Tukey's pairwise comparisons were conducted to test statistical difference between groups in each level, and significance was defined as P < 0.05. At phylum level, it was shown that the P group had a significantly higher abundance ratio of Firmicutes/Bacteroides compared with the other 2 groups. Furthermore, lefse analysis (LDA Effect Size) revealed that the predominant bacteria species from the P group were Ruminococcus, Adlercreutzia, and Dehalobacterium, while Desulfovibrio was relatively enriched in UHT milk feeding, and content of Proteobacteria markedly increased in the C group. Considering rising Proteobacteria was reported to be related to many diseases or intestinal disorders in previous studies, it might be a signal implying that over-heated milk had potential adverse effect on human health. To sum up, this study demonstrated that different thermal processed milk could alter the intestinal microbiota diversity, suggesting more attention to the temperature/time of dairy production is needed.
Dairy Foods: Orals Orals Dairy Foods: Microbiology 7/11/2021 0:00 t83634 Watch 115 Alkaline phosphatase inhibits Cronobacter sakazakii LPS-induced liver injury by regulating miR146a expression. 6 H. M. Wu lipopolysaccharide alkaline phosphatase acute liver injury H. M. Wu1,2, H. Y. Li1,2, N. Zheng1,2, J. Q. Wang1,2 1State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, P. R. China, 2Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, P. R. China Cronobacter sakazakii is a foodborne pathogen, which can cause a variety of diseases and even life-threatening infections in infants, with a mortality rate of 40% to 80%. Lipopolysaccharide (LPS) is a potential virulence factor of Cronobacter sakazakii. After milk powder sterilization, LPS can remain in dairy products and pose a threat to infant health. Alkaline phosphatase (ALP) is a natural enzyme in all raw milk. ALP enzyme is used as a safety indicator of pasteurized milk because its thermal stability is greater than that of pathogens that may exist in milk. ALP can reduce the toxicity of lipopolysaccharide in enteritis and nephritis models, and can effectively treat or prevent sepsis, early pregnancy defects, enteritis, alcoholic liver, acute kidney injury and other diseases. However, the mechanism of oral ALP protecting liver tissue from LPS stimulation is still unclear. In this study, the acute liver injury model induced by Cronobacter sakazakii LPS (200µg/kg) was constructed in vivo, to verify the protective mechanism of ALP (200 U/kg) on mice liver. Next, ELISA, quantitative reverse transcription PCR (RT-qPCR) and Western blotting were used to detect the levels of inflammatory factors at protein level and RNA level, to confirm the inflammation in liver tissue caused by LPS. This study found that oral ALP does not cause liver damage and can effectively prevent the immune response triggered by LPS. Oral ALP can significantly reduce the concentration of LPS in blood (P < 0.05). In LPS stimulated mice, the expression of mir146a in the liver of ALP mice was increased, while the expression of TNF-α/IL-1β/NF-κB was significantly decreased (P < 0.05). At the same time, we found that ALP decreased the expression of TNF-α/IL-1β/NF-κB, which was related to the increase of mir146a. In conclusion, ALP can reduce the degree of liver inflammation by upregulating mir146a levels in liver tissues and hepatocytes and inhibiting the expression of TNF-α/IL-1β/NF-κB.
Dairy Foods: Orals Orals Dairy Foods: Microbiology 7/11/2021 0:00 t83635 Watch 116 The effect of therapeutic administration of β-lactam antibiotics to mastitic cows on the bacterial community and antibiotic resistance patterns in milk. 7 L. Dong dairy cow mastitis cephalosporins milk microbiome L. Dong1,2, L. Meng1,2, H. M. Liu1,2, H. M. Wu1,2, N. Zheng1,2, J. Q. Wang1,2 1State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, P. R. China, 2Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, P. R. China Dairy cows with mastitis are frequently treated with antibiotics. The potential effect of antibiotics on the milk microbiome is still not clear. Therefore, the objective of this research was to investigate the effect of 2 commonly used cephalosporins on the milk microbiota of dairy cows and the antibiotic resistance genes in the milk. The milk samples were collected from 7 dairy cows at the period before medication (d 0), medication (d 1, 2, 3), withdrawal period (d 4, 6, 8) and the period after withdrawal (d 9, 11, 13, 15). 16S rRNA sequencing was applied to explore the microbiota changes, and antibiotic resistance patterns were investigated by qPCR. The microbiota richness and diversity in each sample were calculated using the Chao 1 (richness), Shannon and Simpson (diversity) index. The cephalosporins treatment significantly lowered the Simpson diversity value at the period of withdrawal (P < 0.05). Members of the Enterobacter genera were the most affected bacteria associated with mastitis (P < 0.05). Meanwhile, antibiotic resistance genes in the milk were also influenced by antibiotic treatment. The cephalosporins treatment raised the proportion of blaTEM in milk samples at the period of withdrawal (P < 0.05). Therefore, the treatment of cephalosporins led to significant change in the milk microbiota and increase of β-lactam resistance gene in the milk at the time of withdrawal period.
Dairy Foods: Orals Orals Dairy Foods: Microbiology 7/11/2021 0:00 t84394 Watch 117 A study of environmental Listeria isolates from a dairy plant reveals a relationship of their genotypic variability with phenotypic expression and biofilm formation on clay brick floors. 8 N. Singh Listeria environmental biofilm N. Singh1,2, S. Anand1,2, J. L. G. Gonzalez Hernandez3, B. Kraus4 1Midwest Dairy Foods Research Center, South Dakota State University, Brookings, SD, 2Dairy and Food Science Department, South Dakota State University, Brookings, SD, 3Young Brothers Seed Technology Lab, South Dakota State University, Brookings, SD, 4Wells Enterprises Inc, Le Mars, IA Listeria forms resilient biofilms in dairy plants. Three environmental Listeria isolates: L. monocytogenes (Lm), L. innocua (Li), and L. welshimeri (Lw), were compared for their cell surface properties, and biofilm formation on clay brick floors. For estimating cell attachment and biofilm formation, floor chips (1x1cm2) were immersed in sterile distilled water, containing 6 log cfu/mL of individual isolate, and held for 1h and 48 h at 22.4°C in a shaker incubator. The attached cells were retrieved using 3M sponge sticks and plated on brain heart infusion agar. Three trials were conducted, with samples drawn in triplicates, and the means were compared by ANOVA. For genetic analysis, the genomes were assembled using CLC Genomics Workbench. The water contact angle of clay brick chips, measured by Sessile drop device, was less than 90° (43.3 ± 0.78), indicating it to be hydrophilic and thus supporting Listeria attachment. The Lm and Lw resulted in a greater attachment than Li, also supported by their respective hydrophobicity values (20.13%, 21.15%, and 13.88%), as determined by hexadecane method. The zeta potential values, determined by Zeta sizer, were comparable (−15.8 mV, −16.2 mV, and −15.5 mv, respectively). The adhesion potential of isolates, as log counts, showed variability (Lm 2.91 ± 0.16, Li 2.73 ± 0.04 and Lw 2.89 ± 0.40) that exhibited itself in the biofilm formation: Lm (2.50 ± 0.14/cm2), Li (2.72 ± 0.26 /cm2), and Lw (3.32 ± 0.18/cm2). The presence of genes related to capsular glycan, cell wall/ capsular LTP, biotin biosynthesis, and carbohydrate metabolism, associated with amino sugars such as chitin, were correlated with biofilm formation of the 3 isolates. Whereas in the case of Lw, the presence of N- acetylglucosamine biosynthesis gene (NAG) was also detected. It is anticipated that biotin, chitin, and LTP genes might help the organism to colonize and NAG, when expressed, might interfere with biofilm formation resulting in sporadic presence of Lw as compared with Lm and Li. The study provides evidence that the initial attachment of Listeria species to floor surface is critical for biofilm formation.
Dairy Foods: Orals Orals Dairy Foods: Microbiology 7/11/2021 0:00 t84806 Watch 118 The use of protective lactic acid bacteria adjunct cultures to decrease the incidence of gas defects in aged Cheddar cheese. 9 R. Crompton late gas defects lactic acid bacteria adjunct culture R. Crompton1, T. S. Oberg1, D. J. McMahon1 1Utah State University, Logan, UT Late gas formation in Cheddar cheese, expressed as splits and cracks, continues to be a problem in the dairy industry, causing a negative economic impact on dairy manufacturers due to consumer dislike and downgrading of products. The phenomenon of CO2 production in cheese is caused by heterofermentative non-starter lactic acid bacteria (HFNSLAB) which metabolize the residual hexose sugars in aging cheese. The aim of this research was to use galactose positive, lactose negative lactic acid bacteria as adjunct cultures to reduce gas production in aged cheese challenged with known HFNSLAB. Four cultures were selected for use, 2 commercially available and 2 from the Utah State University (USU) culture collection. Separate Cheddar cheese vats were produced at USU and inoculated with either Lacticaseibacillus rhamnosus, Pediococcus acidolactici, Lacticaseibacillus paracasei and Latilactobacillus curvatus at a level of 105 cfu/mL into the milk the same time as the starter culture. A control vat was made with no added adjunct. The cheese was pressed, refrigerated overnight then ground using a 3mm grinding head. Two 10-pound batches of the ground cheese were then inoculated with one of the following challenge cultures: Limosilactobacillus fermentum, Levilactobacillus brevis, Lentilactobacillus parabuchneri, and Paucilactobacillus wasatchensis, at a level of 104 cfu/g. Two 10-pound batches were not inoculated as a control. The inoculated ground cheese was pressed, cut into 7 one-pound blocks and vacuum sealed. Samples were prepared in quadruplicate. Gas production in the cheese were determined every week for 16 weeks by measuring the height of the gas in the vacuum bags with a ruler. Results showed that samples inoculated with Lev. brevis had profuse gas production, but there was a reduction in gas levels in samples treated with P. acidolactili, Lat. curvatus compared with the other samples. Samples treated with Lcb. rhamnosis showed a reduction in gas compared with control when challenged with Len. parabuchneri and Plb. wasatchensis. These results show the potential of adjunct cultures to reduce late gas formation in Cheddar cheese.
Dairy Foods: Orals Orals Dairy Foods: Chemistry 7/11/2021 0:00 t83461 Watch 119 New insights into the creaming reaction in a model processed cheese system. 10 A. H. Vollmer creaming reaction transmission electron microscopy rheology A. H. Vollmer1, N. N. Youssef1, I. Kieferle2, U. Kulozik2 1Utah State University, Department of Nutrition, Dietetics, and Food Sciences, Logan, UT, 2Technical University of Munich, Chair of Food and Bioprocess Engineering, TUM School of Life Sciences Weihenstephan, Freising, Germany A change in the apparent viscosity of processed cheese during the cooking step has been reported repeatedly in the scientific literature and is commonly referred to as ‘creaming’ or ‘creaming reaction’. Creaming is technically important as it affects the texture and functional properties of the final product. Some creaming is desirable, but over-creaming is not. Handling of an over-creamed product is not only more difficult during manufacturing, but the final product will also show texture defects. While the creaming phenomenon is principally known, its underlying mechanism is still not clear. A basic model has been proposed which describes the reaction as primarily protein-based through the restructuring of casein. Since the viscosity profile can change drastically with process and compositional parameters, it becomes apparent that the current model is not painting the complete picture. High-resolution transmission electron microscopy (TEM) was employed to gain a better understanding of how the protein network changes and possibly interacts with the fat phase during prolonged cooking times (up to 410 min at 90°C with constant shear at 7.93 rpm) in a model processed cheese system consisting of micellar casein concentrate powder, sunflower oil, water, and a mixture of melting salts. Ingredients were pre-mixed, transferred to the pre-heated geometry of a rheometer, continuously stirred under heat, and samples for TEM were taken after a cool-down period at pre-determined times which corresponded to characteristic points in the viscosity profile. Each time point was sampled twice for a total of 12 independent runs. Results reveal an extraordinary complexity of novel ultrastructural changes of the protein network which also clearly interacts with the fat phase, a continuous emulsification of the fat phase and a progressive separation of protein components within the matrix. Taken together, these results shed new light on the complex structure formation processes that take place during the creaming reaction. The knowledge gained here is an essential prerequisite for targeted structural design of this versatile dairy product.
Dairy Foods: Orals Orals Dairy Foods: Chemistry 7/11/2021 0:00 t84230 Watch 120 Pasture and non-pasture-based feeding systems influence aroma-active compounds in raw bovine milk. 11 K. N. Kilcawley pasture milk aroma H. J. Clarke1,2, M. G. O’Sullivan2, J. P. Kerry2, K. N. Kilcawley1 1Teagasc Food Research Centre, Moorepark, Fermoy, Cork, Ireland, 2University College Cork, Cork, Ireland Aroma-active compounds in raw bovine milk produced from cows fed perennial ryegrass (Lolium perenne L.; GRS) or cows fed total mixed ration (mixture of grass silage, maize silage and concentrates; TMR) were identified by sorptive extraction (Hi-Sorb) coupled with gas-chromatography-olfactometry. Five trained panelists evaluated each sample in duplicate including aroma extract dilution analysis. Over 108 volatile organic compounds (VOC) were identified in raw GRS and TMR milk, 15 of which were found to be significantly (P = 0.001) different using the Independent Samples t-Test, thus, highlighting that feeding system influences the VOC profile of raw bovine milk. Moreover, using olfactometry, 34 VOC were found to be aroma active in raw GRS milk and 36 in raw TMR milk, therefore ~30% of the VOC in raw milk influence sensory perception. The odor profile of raw GRS milk was dominated by methanethiol, furfural, benzaldehyde, 1-octen-3-ol, phenylethyl alcohol and maltol which correlated with ‘cheesy’, ‘nutty’, ‘sweet’, and ‘green’ aromas. Raw TMR milk had a much different aroma profile dominated by furfural, 2,5-dimethylpyrazine/2,3-dimethylpyrazine, 2-pentylfuran, benzaldehyde, 1-octen-3-ol, p-cresol/2-pyrrolidinone and 3/4-ethylphenol which correlated with ‘roasted’, ‘smokey’, ‘animal’, and ‘pungent’ odors. While the intensities varied, numerous compounds contributed to the aroma profile of both raw GRS and TMR milk. Raw TMR milk had a higher overall odor intensity which could be due to the diverse source components in the TMR feed as well as direct inhalation of volatiles due to the reduced air circulation from being housed indoors. This is the first study to identify individual aroma-active VOC in raw bovine milk that differ due to feeding system and that are impacting on sensory perception. This further highlights the significance of pasture-based dairy systems in quality milk production.
Dairy Foods: Orals Orals Dairy Foods 7/11/2021 0:00 t84141 Watch 121 Emulsions stabilized by whey protein aggregates: Impact of particle structure on the oil-water interfacial characteristics and emulsion stability. 12 A. Christenson emulsions aggregates rheology A. Christenson1, H. Zheng1 1North Carolina State University, Raleigh, NC Emulsions stabilized by whey protein aggregates (WPAs) are of interest in food research for their improved stability and functionality. Amphiphilic aggregates or Janus particles (JPs) can be formed by aggregation of whey proteins into various structures. Three WPAs, including fractal (FA) and spherical aggregates (SA) and microgels (WPM) have been manufactured by heating WPI dispersions (5 and 10%, wt/wt) at 80, 85 and 90°C, respectively. However, the o/w emulsification mechanism of JPs is not fully understood. In this study we investigated the impact of structural nature of WPI-JPs on emulsion droplet surface excess concentration (Γ, mg/m2), which measured 26.7, 1.4 and 0.7 mg/m2, respectively, suggesting mono- and multilayer protein films. Data were analyzed using one-way ANOVA with Tukey’s HSD test. Aggregate morphology was confirmed by TEM. Surface hydrophobicity significantly (P < 0.05) increased when converting native WPI to JPs; WPI < WPM < FA < SA, and Z-average diameters of JPs for WPM, SA and FA were 1,020, 4560 and 174 nm, respectively. SA had the most negative zeta potential (−77mV). Oil-in-water emulsions (0.8% protein wt/vol, 20% fat vol/vol) were stabilized by each JP and WPI (control) and droplet size measured (via laser diffraction) at d 0 and 10 to determine stability against coalescence, measuring 13.3, 7.3, 10.8 and 13.6%, respectively. Emulsion stability was not significantly different (P > 0.05) between JPs and WPI.
Dairy Foods: Posters Posters Dairy Foods 7/11/2021 0:00 s9578                  
Dairy Foods: Posters Posters Dairy Foods: Cheese 7/11/2021 0:00 t84696 Watch P174 Utilization of lactose-6-phosphate as an alternative to disodium phosphate for process cheese manufacture. 1 K. A. Alsaleem processed cheese lactose-6-phosphate emulsifying salts K. A. Alsaleem1,2, A. R. A. Hammam1, L. E. Metzger1 1South Dakota State University, Brookings, SD, 2Food Science and Human Nutrition Department, Qassim University, Buraydah, Saudi Arabia Process cheese (PC) is a dairy product prepared by blending dairy and nondairy ingredients then heating the blend with agitation to produce a homogeneous product with an extended shelf life. Emulsifying salts (ES) have a critical effect on the emulsification characteristics of casein by sequestering the calcium from the calcium-paracaseinate phosphate complex in natural cheese. Lactose-6-phosphate (LP) is an organic compound produced from lactose that has the potential to function as ES. The objective of this study was to develop a process to produce PC with LP instead of disodium phosphate (DSP). LP was prepared by mixing 1 mol of a-lactose with 0.5 mol of sodium cyclo-triphosphate. The pH of the solution was adjusted using sodium hydroxide to get a pH of 12. The solution was stirred for 3 d at room temperature, and then it was concentrated to 52% total solids (TS). The ingredients in PC formulations were Cheddar cheese, butter, water, milk permeate, and LP (2, 2.4, 2.8, 3.2, 4, 5, and 6%) that were formulated to contain 17% protein, 25% fat, 56% TS, and 2% salt. PC with 2.0% DSP was also produced as a control. The PC was prepared by mixing all ingredients in a kitchenaid. A 25 g of the mixture was cooked in the rapid visco analyzer for 3 min at 95°C with 1,000 rpm for the first 2 min and 160 rpm for the last min. The PC was analyzed for TS, pH, cooked viscosity, hardness, melted diameter, and melting temperature. The experiment was repeated 3 times using different batches of LP. No significant differences (P > 0.05) were detected in the TS of PC; however, the pH of PC made with LP (5.6–5.7) was lower than control (5.8). The cooked viscosity increased (P < 0.05) from 818 to 2,060 cP as the percentage of LP increased from 2 to 6%, while it was 660 cP in control. The hardness of PC made with LP was not different (P > 0.05) compared with control. The melted diameter decreased (P < 0.05) from 43 mm in control to 29 mm in 6% LP, while the melting temperature of PC increased (P < 0.05) from 37.7°C in control to 59.0°C in 6% LP. We conclude that LP can be utilized as a substitute for DSP in PC manufacture.
Dairy Foods: Posters Posters Dairy Foods: Cheese 7/11/2021 0:00 t84284 Watch P175 Textural properties of acid-set Queso Blanco cheese made with microfiltered milk products. 2 K. J. Blake acid-set cheese Queso Blanco micellar casein concentrate K. J. Blake1, M. R. Sainani1, K. A. Schmidt1 1Kansas State University, Manhattan, KS As the demand for native whey protein ingredients continues to rise outside of the dairy industry, microfiltered milk products like micellar casein concentrate (MCC) are becoming increasingly accessible for cheese production. This increase in microfiltered milk and milk products could cause potential issues within the acid-set cheese industry, as whey proteins are often included within the cheese protein matrix. Thus, this research investigated the impact on the textural properties of acid-set cheese produced with MCC using Queso Blanco as a model system. Three trials were completed where cheesemilk was standardized to a 1.2:1 casein to fat ratio using rehydrated milk protein concentrate 80 (MPC), milk protein isolate 90 (MPI) or MCC. Data were analyzed with univariate ANOVA methodology (P < 0.05) and significant means differentiated with Bonferroni comparisons (P < 0.05). Proximate analysis results showed that cheeses exhibited similar moisture (51.18%) and fat (15.13%) contents, but the cheeses made from MPC and MPI had a greater protein (27.05%) content compared with the MCC cheese (25.49%) likely due to the lower whey protein content in MCC. Cheese texture was assessed under 50% strain with a standard double-bite texture profile analysis (TPA) at 10, 30, 50, 70 and 90 d of cheese age. TPA results for springiness, cohesiveness and chewiness differed at 10 d compared with the other days. Cheeses differed in TPA hardness and resilience, although neither attribute was impacted by time. TPA resilience, springiness and cohesiveness showed differences between the MCC cheese vs. the MPC or MPI cheeses, whereas hardness and chewiness differed among the MPC, MPI and MCC cheeses. A trained descriptive panel assessed cheeses at 30 and 70 d in a monadic sequential design on a standard 15-point line scale. No significant differences were found in organoleptic textural properties over time. These results suggest that removing whey proteins via microfiltration before producing acid-set cheese would not cause noticeable texture differences for consumers; however, there could be implications when converting the cheese to reduced formats like shreds or crumbles.
Dairy Foods: Posters Posters Dairy Foods: Cheese 7/11/2021 0:00 t84395 Watch P176 Effect of fat, moisture, storage temperature, and time on shreddability of mozzarella cheese and their relation to other textural properties. 3 G. Rathod mozzarella cheese shreddability cheese texture G. Rathod1, S. Sutariya2, R. Kumar2, P. Upreti3, J. Amamcharla1 1Kansas State Univerisity, Manhattan, KS, 2Agropur, Appleton, WI, 3Nestlé Development Centre, Solon, OH Mozzarella cheese (MC) is one of the popular cheeses available in different forms such as ball, loaves, and shreds. Shredded form is more convenient for consumers. It is important to understand the effect of fat content and also variations in storage temperature and age on the shreddability of MC. As per the experimental design, 3 batches of MC (pH-5.14 to 5.46) with different fat content (3 levels; average - 45.5, 40.8, and 29.1%) were procured directly from a commercial supplier and stored at 2 different temperatures (35 and 40°F) and evaluated in terms of shreddability, texture profile analysis (TPA), and wire cutting after storing for 2 and 3 weeks. Shreddability was analyzed using a cheese grating rig (A/GR) on a horizontal friction system base assembly (A/HFS) with coarse grater insert on the texture analyzer. MC (8 × 6 × 4.5 cm3) was grated for 3 cycles by applying 1.8 kg dead weight. Shreddability parameters such as stiction force and work of grating were extracted from force-time curve. After every cycle, the cheese shreds were collected and weighed in grams. Stiction force for MC samples ranged from 6.43 to 32.25 N and work of grating ranged from 59.20 to 159.42 N·s. The weight of shreds was in the range of 1.93 to 5.54 g. Fat content of MC had a significant (P < 0.05) effect on stiction force, work of grating, and weight of shreds. Storage temperature had significant (P < 0.05) effect on the weight of shreds. Storage time had significant (P < 0.05) effect on stiction force and work of grating. It was observed that the stiction force and work of grating were positively correlated with the area and peak force extracted from wire cutting force-time curve and negatively correlated with weight of shreds. Similarly, TPA parameters such as hardness and cohesiveness were positively correlated with stiction force and work of grating, and negatively correlated with weight of shreds. It can be concluded that shredding was mostly affected by fat content followed by storage time, and least affected by storage temperature.
Dairy Foods: Posters Posters Dairy Foods: Cheese 7/11/2021 0:00 t83573 Watch P177 The effect of whey protein as a fat replacer on the physicochemical, microbiological, textural properties of Mozzarella cheese 4 D. Zhang mozzarella cheese dairy lactic acid D. Zhang1, N. P. Shah1 1Hong Kong University, Hong Kong, China The influence of 2 whey protein-based fat replacers, CH-4560 (FR1) and YO-8075 (FR2), on physicochemical, textural and functional characteristics of low-fat Mozzarella cheeses (LFC, 12.5% fat) using starter culture consisting of Streptococcus thermophilus (ST) strain 1275, Lactobacillus delbrueckii ssp. bulgaricus (LB) strain 859 and with or without Lactobacillus casei strain 290 were studied after 0, 7, 14, 21 and 28 d of storage at 4°C. CH-4560 and YO-8075 were microparticulate whey protein and were added directly into cheese milk at a rate of 0.5 g whey protein concentrates per 100 mL milk. The color of Mozzarella cheeses was closely linked to their composition and storage time, especially moisture and fat content. LFC was darker in color and had lower cheese yield (9.24%), and higher protein content (19.87%), and lactose (0.298%) and galactose (0.156%) as compared with other cheeses (P < 0.05). The yield of Mozzarella cheese increased to 10.82% and 10.66, respectively, when FR1 or FR2 was added. The average protein, fat and moisture content of whey protein-containing Mozzarella cheese were 18.3%, 10.58% and 60.98%, respectively. The pH value of Mozzarella cheese increased slightly after an initial decrease (P < 0.05) with LFC had the highest pH value (pH = 5.74), while FR2 containing Mozzarella cheese was the lowest (pH = 5.50). Serum expulsion in low-fat Mozzarella cheeses decreased significantly when supplied with whey protein due to the great water-holding capacity and high viscosity of whey protein concentrates. The addition of whey protein improved the textural characteristics (softer and stickier texture) of low-fat Mozzarella cheeses (P < 0.05). In addition, whey protein-containing cheese showed better pizza bake performance with more complete shred melt, less scorching and lower browning on the cheese surface. The grated cheese was placed horizontally in a glass tube, heating to 110°C for 10 min, then the meltability of the cheese was taken by the length of the melted cheese minus the length of the cheese before heating. The meltability of low-fat control cheeses increased by 3.33 mm to a maximum distance of 69.00 mm after 28 d of storage. Overall, adding whey protein as a fat replacer improved the pizza bake, texture, lightness and meltability of LFC, showing its potential as a fat replacer in dairy products.
Dairy Foods: Posters Posters Dairy Foods: Chemistry 7/11/2021 0:00 t83981 Watch P178 Evaluation of fatty acid profiles of domestic and imported varieties of cow, goat and sheep milk cheeses stored under different treatment regimens. 5 Y. W. Park cow goat sheep cheeses fatty acid composition storage Y. W. Park1, R. Paswan1 1Fort Valley State University, Fort Valley, GA Fatty acid profiles of cheeses are dependent on those of the original cheese milk. Goat milk contains significantly higher short and medium-chain fatty acids (MCT) (C4:0 - C14:0) than cow milk does. Caprine milk fat also has a unique characteristic of lower lauric:capric acid (C12:C10) ratio than bovine milk (0.46 vs. 1.16), which may affect flavor characteristics of 2 species milk cheeses. The objective of this study was to evaluate fatty acid profiles of 3 different species milk cheeses, including goat milk Gouda (GMG), cow milk Gouda (CMG), cow milk Cheddar (CMC), cow milk Monterey Jack (CMMJ) and sheep milk Manchego (SMM) cheeses, stored under 2 temperatures (4°C and −18°C) and 5 storage periods (0, 1, 2, 4 and 6 mon). Fats were extracted from all the experimental cheeses, and fatty acid methyl esters were derivatized and extracted in hexane solutions for fatty acid analysis. Fatty acid profiles of all experimental cheeses were quantified using a gas chromatograph (GC- 2010 Plus; Shimadzu Scientific, Canby, Oregon, USA), equipped with a fused silica capillary column (100 m x 0.25 mm x 0.2 μm film thickness), flame ionization detector and AOC-20s auto sampler. Results showed that the level of C18:0 was highest, followed by C16:0, C18:1, C14:0, C8:00 acids among all tested fatty acids in CMG. However, GMG and SMM had significantly (P < 0.01) higher levels of the corresponding fatty acids compared with those of CMG. With respect to C12:C10 ratio, CMG, GMG and SMM cheeses showed 0.68, 1.49, 0.85, respectively, indicating the commercial GMG had higher ratio than CMG, which revealed somewhat different ratio reported in the previous studies. ANOVA showed that the main factors, cheese type (CT) and storage period (SP) had significant effects on all fatty acid concentrations, whereas storage temperature (ST) had minimal influence on fatty acid contents. The 2-way interactions of CT × SP were significant (P < 0.01), while CT × ST and SP × ST effects were not significant for most of fatty acids. It was concluded that fatty acid contents of all varieties of commercial cow, goat and sheep milk cheeses were significantly affected by cheese type, storage temperature and periods.
Dairy Foods: Posters Posters Dairy Foods: Dairy Products 7/11/2021 0:00 t83980 Watch P179 Comparison of lipolytic and proteolytic patterns of commercial cow, goat and sheep milk cheeses during 6 months of refrigerated and frozen storage. 6 R. Paswan three-species cheeses lipolysis proteolysis R. Paswan1, A. Singh1, Y. W. Park1 1Fort Valley State University, Fort Valley, GA Cheese quality is highly affected by lipolysis and proteolysis, where levels of free fatty acids, volatile compounds, peptides, amino acids and organic acids tend to be elevated in cheeses during storage and marketing. Commercial Gouda cheeses from cow milk (CMG) and goat milk (GMG), and an imported sheep milk Manchego cheese (SMM) as third species semi-hard reference cheese were purchased at a local retail outlet. Upon purchasing, the 3 types of cheeses were subdivided into equal portions and subjected to 2 temperatures (4°C and −18°C) and 5 storage period (0, 1, 2, 4 and 6 mon) treatments. All the experimental cheese samples were evaluated for basic nutrient contents, pH, acid degree value (ADV) and water-soluble nitrogen (WSN) contents. The experimental design was replicated twice, and data were analyzed using 2-way ANOVA. Results showed that mean protein, fat, ash and moisture contents (%) for CMG, GMG and SMM at 4°C storage were: 24.7, 24.1, 23.1; 25.7, 25.6, 29.4; 3.72, 3.51, 3.78; 42.7, 36.1, 31.8, respectively, indicating moisture content of GMG was lower (P < 0.05) than CMG, while all other basic nutrients were similar in both species cheeses. SMM contained even lower moisture than GMG. The respective ADV values of CMG, GMG and SMM at 4°C for 0, 2 and 6 mon storage were: 0.67, 0.71, 0.78; 1.25, 1.28, 2.03; 1.11, 1.25, 1.79, suggesting that significant lipolysis occurred in all cheeses as storage period advanced, but some ADV increases were not consistent in all cheeses. The pH changes in the 3 species cheeses throughout 6 mon storage period were also significant with some variations. In proteolytic patterns of CMG, GMG and SMM, all 3 cheeses showed increases in WSN with extended storage time, where the elevations of WSN in frozen cheeses were lower than at 4°C stored samples. The lower ADVs were also observed in frozen samples compared with the refrigerated ones, suggesting that less lipolysis occurred in the frozen samples than refrigerated chesses for the same storage period. It was concluded that lipolytic and proteolytic patterns of the commercial cow, goat and sheep milk cheeses were significantly (P < 0.05) influenced by storage temperature and period treatments.
Dairy Foods: Posters Posters Dairy Foods: Cheese 7/11/2021 0:00 t83472   P180 Chemical and microbiological properties of traditional Egyptian cheeses. 7 S. Awad Karish cheese soft white cheese Ras cheese S. Awad1, A. Ibrahium1 1Faculty of Agriculture, Alexandria University, Alexandria, Egypt The National Food Safety Agency of Egypt (NFSA) was established by law number 1/2017 as an independent authority. NFSA started auditing food industries to ensure that food is produced under good conditions to meet the standards of food composition, safety and hygiene. NFSA does not cover all food sectors in Egypt until now, especially small sectors. About 80% of traditional Egyptian cheeses are produced by small sectors. This research was aimed to determine the chemical composition and undesirable microorganisms in traditional Egyptian cheeses that were produced in small sectors to assist cheesemakers in improving their products and meet the Egyptian Standards for chemical composition and microbiological quality. Forty samples of Karish cheese, 50 samples of soft white cheese, and 40 samples of Ras cheese were analyzed for chemical and microbiological properties. All analyses were carried out using ISO methods in accredited laboratory (ISO 17025/2017). Egyptian standards (ES) recommended that the moisture content should not exceed 62% and 58% in fresh and ripened soft cheeses respectively. Moisture was higher in 28% of soft cheese samples. Salt was higher in 7%, and protein content was lower in 10% of traditional white soft cheese samples. ES recommended that the salt should not exceed 9% and protein not less than 10%. In Karish cheese (low-fat cheese), moisture contents above the recommended levels were seen in 36% of samples and 68% of samples had a high level of fat in the dry matter, ES recommended the moisture should not exceed 75%, and fat in the dry matter not exceed 10%. Most of Ras cheese samples were within the Standard, there were only 2 samples of Ras cheese that contained more moisture, as the moisture should not exceed 40% in Ras cheese. Microbiological analysis of the cheese samples showed that only one Karish sample was Staphylococci-coagulase positive. The coliform count in the Ras cheese ranged from <1 to 5.20 log cfu/g with an average of 1.70 log cfu/g. Anaerobic spore-forming bacteria (Clostridium spp.) were found in 29 of the 40 Ras cheese samples. All the Egyptian cheese samples had higher numbers of yeasts and mold. All cheese samples were free of Listeria monocytogenes. The results obtained from this work will be used to develop specific procedures of risk management along with the traditional Egyptian cheeses production chain, as well as to establish a production procedure to produce high-quality cheese within Egyptian Standards.
Dairy Foods: Posters Posters Dairy Foods: Cheese 7/11/2021 0:00 t84669 Watch P181 Bacterial isolation and identification from Appenzeller swiss cheese surface with antibacterial and antifungal activities. 8 R. D. Melendrez-Alvarez antagonism activity inhibition metabolites R. D. Melendrez-Alvarez1, I. Garcia-Cano1, A. C. Mayta-Apaza1, J. Ortega-Anaya1, R. Jiménez-Flores1 1The Ohio State University, Columbus, OH Analysis of the bacterial diversity in fermented foods is the first step in studying their microbial ecology, which can be influenced by the packaging conditions, moisture, ripening time, and other environmental factors. Fermented dairy foods such as cheese harbor a rich diversity of microorganisms with growth-specific requirements. Moreover, some of these microorganisms in fermented foods are known to secrete antibacterial (AB) and antifungal (AF) components that play a role in controlling pathogens and spoilage bacteria. The present study evaluated the AB and AF activities of isolated bacteria from the surface of an Appenzeller Swiss Cheese, including the bacterial identification using conventional and 16S rRNA methods and the metagenomic analysis because it presented non-mold development during a long time of storage. Phase 1: Phenotyping isolation yielded the primary result of the identification of 33 strains. Phase 2: The results from the 16S rRNA sequence, at a genus and species level, showed a relative abundance dominated by Staphylococcus; the results match with the taxonomic metagenome sequencing analysis showing 49.70% of abundance in the original sample of this genus, specifically of S. equorum, 37.5% of uncultured bacterium, 6.3% of Brachybacterium ginsengisoli, 4.5% of Brevibacterium sp., and 2% of others. Phase 3: Focuses on testing AB and AF activity performed in agar plates. Our results show that 4 strains had inhibition against Aspergillus fumigatus, 2 strains against Bacillus amyloliquefaciens, Listeria innocua, and A. fumigatus, and the last 2 showed activity against L. innocua. These results have led us to hypothesize that an antagonistic effect (inhibition halo) observed could be attributed to chitinase, protease, and volatile organic compounds production (butan-1-ol and 3-methylbutan-1-ol); these are common extracellular metabolites from Staphylococcus. Future work will be assessing the isolated collection against Penicillium, which commonly affects the cheese industry. Also, the nature of the metabolites with AB and AF activities must be identified.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t84557 Watch P182 Evaluation of lactose oxidase as an inhibitor of Listeria monocytogenes in a laboratory-scale fresh cheese model. 9 B. Flynn Listeria cheese lactose oxidase B. Flynn1, D. deRiancho1, M. Lawton1, S. Alcaine1 1Cornell University, Ithaca, NY Listeria monocytogenes is a ubiquitous pathogen that can cause morbidity and mortality in the elderly, immune compromised, and fetuses of pregnant women. The intrinsic properties of fresh cheese—high aW, low salt content, and near-neutral pH—make it susceptible to L. monocytogenes contamination at various points in production. The aim of this study was to investigate the effect of lactose oxidase (LO), a naturally derived enzyme, on inhibition of L. monocytogenes growth in fresh cheese during various points of the production process. Lab-scale queso fresco was produced and inoculated with L. monocytogenes at final concentrations of 1 log cfu/mL and 1 cfu/100 mL through inoculation of the milk during the cheese make. Lactose oxidase was incorporated into the milk at final concentrations of 0.12 and 0.6 g/L. A positive control inoculated with L. monocytogenes and no lactose oxidase treatment and an uninoculated negative control were included. Cheeses were incubated at 6°C and enumerated for microbial counts on Modified Oxford Agar on d 0, 1, 2, 4, 7, 14, 21 and 28. Each experiment was performed in triplicate and an ANOVA and Tukey’s Honest Significant Difference test were used individually for each time point to compare log differences in Listeria counts between the treatments and positive control. The higher inoculum exhibited significant differences (P < 0.05) between the 2 treatments and positive control by day 1 of storage and lasted through the entire trial. By day 28, the positive control grew to above 7 log cfu/g while the 2 treatments fell below the limit of detection (LOD) of 1.3 log cfu/g. With the lower inoculum, significant differences between the positive control and the treatment groups were also found by day 1 of storage. The positive control grew to above 7 log cfu/mL and the treatment groups fell below the LOD by day 21 and continued through day 28 of storage. These results suggest that LO is an effective inhibitor of L. monocytogenes in a lab-scale fresh cheese model. Different applications of LO will be explored to investigate its efficacy in different L. monocytogenes contamination scenarios.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t84541 Watch P183 Long production days without intermittent cleaning and sanitation events alter the final microbial composition of aged Cheddar cheese. 10 J. Johnson cheese quality microbiome J. Johnson1, C. Curtin1, J. Waite-Cusic1 1Oregon State University, Corvallis, OR The use of continuous production schedules in modern cheese manufacturing (>18 h without intermittent cleaning and sanitation) can create circumstances which support the growth and accumulation of microorganisms in the cheese production environment. This phenomenon has been observed at several stages of cheese production, including within the pasteurizer, in milk storage and transportation vessels, and more recently in the draining-matting conveyor (DMC) at an industrial Cheddar cheese manufacturer. Selover et al. (2021) demonstrated that coliforms growing on the surfaces of DMC belts were a primary source of intermittent coliform contamination in fresh Cheddar cheese. The current study aimed to continue this work by examining changes in microbial communities in aged Cheddar cheese produced at the start or end of the production day in the same cheesemaking facility. Our hypothesis was that cheeses produced at the end of the day would contain greater concentrations of nonstarter bacteria associated with the cheese production environment. Microbial communities in aged Cheddar cheese, produced at the start and end of 30 production days (nstart = 30, nend = 30), were investigated using 16S rRNA metabarcoding and by plating on selective growth media (MRS, M17, m-Enterococcus, and MacConkey agars). Microbiome analysis revealed that cheeses produced at the end of the production day had significantly greater concentrations of 3 sequence variants (SVs), identified as Streptococcus thermophilus (2 SVs) and Streptococcaceae (1 SV) (upper-tailed t-test with Bonferroni correction, a = 0.0045). Comparing these sequences to those previously observed on the DMC belt surfaces revealed that both S. thermophilus SVs observed in the cheese were present at high relative sequence abundance on the belt surfaces at the end of the production day. These findings provide strong evidence that nonstarter bacteria contributing to microbial time-of-day differences in the aged cheese were the result of microbial growth in the food production environment, thus supporting our hypothesis. In addition, cheeses produced at the end of the day were found to have significantly greater moisture content, as compared with those produced at the start of the day (2-sample t-test, a = 0.05), therefore indicating that time-of-day differences can have direct consequences for cheese quality.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t84411   P184 Comparison of starter and nonstarter lactic acid bacteria of 15 aged Cheddar cheeses from different regions using next-generation sequencing. 11 S. L. Overbeck cheese starter culture nonstarter lactic acid bacteria S. L. Overbeck1, T. S. Oberg1, C. J. Oberg2,1, M. Lefevre1, D. J. McMahon1 1Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan, UT, 2Department of Microbiology, Weber State University, Ogden, UT The objective of this research was to test whether there were regional difference in the bacterial community in aged Cheddar cheeses. Retail packs of cheese were purchased that had been manufactured in different USA states or in Ireland or Australia. DNA was extracted followed by PCR using primers that amplify 460 bp in the V4 region of 16S rRNA. The DNA was sequenced and data processed using QIIME 2 software with raw sequence data demultiplexed, joined, and quality filtered followed by denoising using DADA2 and Deblur. Amplicon sequence variants (ASVs) were aligned and phylogenic trees created. For all cheeses, the microbiota was dominated by starter lactic acid bacteria (SLAB) at ~98% relative abundance (RA). The samples clustered into 2 major groups separated by SLAB with one cluster being dominated by Streptococcus thermophilus (52 to 99% RA) along with Lactococcus lactis while the other cluster was dominated by Lc. lactis at > 95% RA. Among the lactococci, using DADA2 provided more ASVs than that obtained using Deblur although the majority of lactococci still had the same ASV. This suggests that in all of the lactococcal cheeses the strains being used have a common sequence in their 16S rRNA with other traits, such as phage-hardening, not producing difference in this region. Streptococcus thermophilus is added to starter cultures for Cheddar cheese to shorten the manufacturing time. For cheeses in which Lc. lactis was the dominant SLAB, there was a subcluster in which a lactobacilli adjunct had presumably been added. Using Deblur or DADA2 produced similar results for lactobacilli with DADA2 yielding a few more operational taxonomic units. The commonly occurring nonstarter lactobacilli, Lactocaseibacillus casei, Lactocaseibacillus paracasei, Lactocaseibacillus rhamnosus, Lactiplantibacillus plantarum and Latilactobacillus curvatus, were present in some of the cheeses but not all. Other heterofermentative lactobacilli such as Lentilactobacillus kefiri, Lentilactobacillus buchneii, Paucilactobacillus wasatchensis and Secundilactobacillus malfermentans were also present. Differences in microbiome of the cheese appeared dependent on the individual manufacturer’s choice of starter and adjunct cultures as well as the plant environment that provides a source for lactobacilli as well as very low levels of non-lactic acid bacteria in the cheese.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t84642   P185 Selective media for the isolation of Paucilactobacillus wasatchensis. 12 C. Wahlstrom lactic acid bacteria nonstarter lactic acid bacteria (NSLAB) media C. Wahlstrom1, M. Domek1, M. Culumber1, D. McMahon2, C. Oberg1 1Weber State University, Ogden, UT, 2Utah State University, Logan, UT The obligate heterofermentative bacteria Paucilactobacillus wasatchensis has been shown to cause late gas blowing in aged cheeses, which results in defects such as splitting and crumbling of the cheese block. The ability to quickly and accurately isolate Plb. wasatchensis, especially when it is present at low concentrations compared with other bacteria in a cheese sample, could be beneficial to the dairy industry. However, the current protocol for isolating Plb. wasatchensis is time intensive and imprecise. The goal of this study was to accurately detect Plb. wasatchensis when as few as 103 cfu/g are present within 72 h, as well as to inhibit competing starter lactic acid bacteria (SLAB) and nonstarter lactic acid bacteria (NSLAB) with one media. Testing was conducted using 24 well plates in a Tecan Infinite 2000 plate reader, in which 7 SLAB and NSLAB strains were tested in triplicate along with Plb. wasatchensis WDC04. Each well was filled with carbohydrate-restricted MRS (CR-MRS) broth containing 1% ribose, 2% Oxyrase and 0.01% 2-deoxyglucose, a glucose analog. Results showed that under these conditions Plb. wasatchensis WDC04 could complete its logarithmic growth phase in 28 h while the glycolysis inhibitor, 2-deoxyglucose, limited growth of the 7 SLAB and NSLAB strains. Growth of SLAB and NSLAB strains tested were significanly reduced as compared with WDC04 growth when 01% 2-deoxyglucose was added to the CR-MRS broth (t-test, P < 0.05%). Lacticaseibacillus casei and Lacticaseibacillus paracasei, 2 common NSLAB strains, showed the greatest level of inhibition between MRS broth (OD600 1.28) and CR-MRS+2-deoxyglucose (OD600 0.60 and 0.54, respectively) after 28 h. Results for the incorporation of 2-deoxyglucose into CR-MRS agar as a selective plating media for Plb. wasatchensis shows promise. This method could be used to determine the presence of Plb. wasatchensis in cheese when it is low concentrations (103 cfu/g) versus the high concentration of SLAB (108 cfu/g) that obscure its detection with current isolation techniques.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t84540   P186 Paucilactobacillus wasatchensis WCD04 biofilm formation and adherence to stainless steel. 13 L. Mejias lactic acid bacteria biofilm exopolysaccharide L. Mejias1, M. Culumber1, C. Oberg1, D. McMahon2 1Weber State University, Ogden, UT, 2Utah State University, Logan, UT Paucilactobacillus wasatchsensis WCD04 is a nonstarter lactic acid bacteria (NSLAB) that can cause gas production during cheese aging. This NSLAB is thought to be an environmental contaminant, but its reservoir is unknown. Since Plb. wasatchensis does not survive pasteurization, its persistence in cheese manufacturing could be the result of post-pasteurization contamination due to biofilm formation on processing equipment. We investigated the physiological conditions in which Plb. wasatchsensis reaches optimal growth for biofilm formation on stainless steel. Biofilms were grown on sterilized stainless steel washers (5.92 cm2) in the wells of sterile, 24-well polystyrene culture plates. Washers were added to 2 mL of MRS supplemented with 1% ribose (MRS+R) broth amended independently for each experiment. Wells were inoculated with either 10 or 100 mL of a 4 d Plb. wasatchensis WDC04 culture. Variables tested were pH (4, 5, 6 or 7), galactose concentration (0.5%,1%, or 2%), lactose (1% or 2%), glucose (1% or 2%), and oxyrase (1%) in triplicate. Biofilms developed for 7 d at 30°C. Washers were aseptically removed and rinsed with sterile DW to remove planktonic cells. Attached biofilm was removed by vortexing in sterile saline for 1 min. The solution was serially diluted and plated in triplicate on MRS+R agar, then incubated at 30°C for 5 d. Biofilm growth was not detected at pH 4 and 7. Biofilm formation was observed minimally at pH 5.0 but the greatest in MRS+R broth (pH 6.0) with 2% galactose (6.8 × 104 cfu/cm2). Similar growth was observed in MRS+R broth (pH 6.0) with 1% lactose (5.2 × 104 cfu/cm2). Cell recovery was the greatest overall (5.8 × 106 cfu/cm2) in MRS+R broth (pH 6.0) with 1% oxyrase (t-test, P > 0.05). Low-oxygen conditions appear to increase Plb. wasatchensis exopolysaccharide synthesis. Understanding optimal growth conditions for biofilm formation will provide opportunities to test methods for the prevention or removal of Plb. wasatchensis biofilms that may occur in dairy processing facilities.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t84654   P187 Gluconate metabolism by Paucilactobacillus wasatchensis is another risk factor for late gas production in aging cheese. 14 K. Sorensen lactic acid bacteria gluconate cheese K. Sorensen1, C. Oberg1, T. Oberg2, M. Domek1, M. Culumber1, D. McMahon2 1Weber State University, Ogden, UT, 2Utah State University, Logan, UT Paucilactobacillus wasatchensis, a nonstarter lactic acid bacterium, can cause late gas production, and splits and cracks in aging cheese when it metabolizes a 6-carbon sugar, particularly galactose, in cheese to a 5-carbon sugar, resulting in the release of CO2. Previous studies have not explained late gas production in aging cheese when galactose is not present. Based on the genome sequence of Lb. wasatchensis WDC04, genes for potential metabolic pathways were mapped using Knowledgebase Predictive Biology software (KBase). Modeling predicted Plb. wasatchensis WDC04 could metabolize gluconate. Gluconate contains 6 carbons and Plb. wasatchensis WDC04 contains genes to decarboxylate it to ribose-5-P and CO2 using phosphogluconate dehydrogenase. This study’s purpose was to determine if sodium gluconate, often added to cheese to reduce calcium lactate crystal formation, could result in gas production when metabolized by Plb. wasatchensis. Carbohydrate-restricted MRS (CR-MRS) was mixed with varying ratios of ribose, sodium gluconate and/or D-galactose (1% total sugar content) in triplicate. Oxyrase (1.8%) was also added to create an anaerobic environment in the CR-MRS tubes similar to aging cheese. Tubes were inoculated with a 4-d culture of Plb. wasatchensis WDCO4, incubated at 30°C and results recorded over 8 d. Gas production was measured by determining gas volume in Durham tubes in the CR-MRS tubes. Of the 10 ratios used, gas was produced in 6 with the highest gas production resulting from 1% sodium gluconate with no added ribose or galactose followed by the ratio of 0.3% ribose/0.7% gluconate (1% total sugar concentration). Assuming other strains of Plb. wasatchensis have the same genes for metabolizing gluconate and producing CO2 gas, adding sodium gluconate during manufacture of Cheddar cheese is another risk factor for growth of Plb. wasatchensis during cheese aging and subsequent unwanted gas production resulting in the formation of splits and cracks in cheese.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t84661   P188 Depletion of galactose by galactose-positive lactose-negative protective cultures prevents gas formation by Paucilactobacillus wasatchensis in a model gas production test. 15 D. McMahon lactic acid bacteria cheese gas production D. McMahon2, C. Oberg1, I. Green2, J. Broadbent2, R. Thunell2 1Weber State University, Ogden, UT, 2Utah State University, Logan, UT Gas production by obligatory heterofermentative lactobacilli such as Paucilactobacillus wasatchensis is a sporadic problem in Cheddar cheese and can cause slits and cracks in the cheese. Growth and gas production by Plb. wasatchensisis not as rapid as in facultative heterofermentative lactobacilli which makes observation of gas production difficult to observe on a consistent basis. Our objective was to develop a model system that could be used as a gas production test. This test would account for co-utilization of galactose with ribose during exponential growth of Plb. wasatchensis, and then test if galactose could be removed by using a galactose-utilizing adjunct culture to prevent gas formation. Paucilactobacillus wasatchensis WDC04 was inoculated into carbohydrate-restricted MRS broth containing various ratios of ribose and galactose with growth monitored during incubation at 23°C. Gas production was detected using a Durham tube inverted on a 6-cm long capillary tube to increase the volume from which gas could be captured. Gas production was sporadic except when 105 cfu/mL of Plb. wasatchensis WDC04 was inoculated into broth containing 0.3% ribose and 0.7% galactose, incubated at 23°C, then gas bubbles were observed in 8 out of 9 replicates. This was designated as gas production broth and used for further testing. Gas production was observed after 8 d incubation by which time galactose levels had decreased to 0.15%. It was presumed that ribose was exhausted before this and the cells switch to using galactose for energy. When either of 3 lactose-negative galactose-positive cultures (Pediococcus acidilactici 23F, Lacticaseibacillus casei UW4 or Lactobacillus helveticus 7995) was inoculated along with Plb. wasatchensis WDC04 into the gas production broth, all of the galactose was depleted within 4 d with no gas production observed. Such protective cultures have the potential for preventing unwanted gas production in cheese. The gas production test has application in the study of CO2 production by other obligatory heterofermentative lactobacilli.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t84551 Watch P189 Metabolic profiling of Lactilactobacillus curvatus WSU1 for antimicrobial metabolites. 16 D. Leatham lactic acid bacteria metabolites cheese D. Leatham1, T. Oberg2, R. Ward2, C. Oberg1, D. McMahon2 1Weber State University, Ogden, UT, 2Utah State University, Logan, UT Lactilactobacillus curvatus is a common nonstarter lactic acid bacteria (NSLAB) in cheese. If L. curvatus is induced to produce antimicrobial compounds it would be important to the food industry, since it could be used to inhibit pathogens and/or spoilage organisms in cheese. Using the L. curvatus WSU1 genome, bioinformatics analysis revealed possible genes for a metabolic pathway which utilized lactic acid to produce propanol and propionic acid, 2 antimicrobial compounds. Among these genes were 3 encoding for the enzyme diol dehydratase. This enzyme is present in Limosilactobacillus reuteri, a NSLAB that can utilize glycerol to produce 3-hydroxypropionic acid and 3-hydroxypropionaldehyde (reuterin), 2 antimicrobials. It is hypothesized that L. curvatus could also produce these compounds. Since these metabolic processes are anaerobic, cultures were grown in septum-sealed medicine bottles with the headspace purged using 95% N2/5% CO2. Cultures were grown in carbohydrate-restricted MRS media containing either lactate, 1,2-propanediol, hydroxyacetate, acetate, or glycerol at an 80 mM concentration in triplicate. They were grown in duplicates with half containing B12 because diol dehydratase is B12-dependent. A GC analysis was done to test for the presence of 3-hydroxypropionaldehyde, propionic acid, propanol, and 3-hydroxypropionic acid at d 0, 1 and 7. GC measured presence or absence of specific products based on identification standards, but peaks were not quantified. Peaks had to be detected in all 3 replicates for product confirmation. GC results show that L. curvatus WSU1 cannot produce propionate from lactate but can produce propionate when given 1,2-propanediol. This indicates the genome is lacking the gene to convert lactate to lactaldehyde, but does have functioning genes to convert 1,2-propanediol to propionate. When grown on glycerol, small amounts of 3-hydroxyproprionate were produced, indicating either fermentation conditions were not ideal for the pathway or the diol dehydratase had less affinity for glycerol than for 1,2-propanediol. These results indicate the potential for L. curvatus WSU1 to be used as a bioprotective adjunct in dairy fermentations.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t83531 Watch P190 Screening of a food-grade antimicrobial from Lactococcus species of raw milk origin, and optimization of the antimicrobial activity. 17 A. Ichinomiya Lactococcus lactis ssp. lactis nisin optimization A. Ichinomiya1, S. Anand1, R. Nauth1, V. Mistry1 1Dairy and Food Science, South Dakota State University, Brookings, SD Antimicrobials produced by Lactococcus species of milk origin are valuable as natural inhibitors against food spoilage and pathogenic microorganisms. An example is nisin, which has diverse food preservation applications. This study was performed to isolate and identify Lactococcus species from raw milk having antimicrobial activity against selected food spoilage organisms, with the potential to optimize conditions for improved antimicrobial production. During the initial screening, lactic acid bacteria were isolated on MRS agar from 47 raw milk samples from the University dairy farm. Based on colony morphologies on the selective medium, Gram staining, and catalase test, 5 isolates were selected, and screened for antimicrobial activity using agar well assay technique. All the isolates were observed to secrete antimicrobial compounds, active against a test strains Micrococcus luteus (ATCC 10240) and Lactococcus lactis ssp. cremoris (ATCC 19257). The diameter of clear zone around the well of 5 isolates corresponded to an antimicrobial activity of 48.90, 265.41, 213.15, 371.95, and 505.00 IU/mL respectively. Two larger isolates, N40615 and N50615 (P < 0.05), were chosen for further experiments but N50615 produced less antimicrobial activity against Lactococcus lactis ssp. cremoris (ATCC 19257). As a result, N40615 was selected for further studies. On the evaluations for identification and characterization, the inhibitory substance was not identified to be either hydrogen peroxide or bacteriophage. As the inhibitory activity was inactivated by α-chymotrypsin, proteinase, and trypsin, it was concluded that the isolate produced nisin-like antimicrobial activity. N40615 in autoclaved skim milk medium heat treated at 85°C for 15 min supplemented with 0.50% peptone, 0.25% yeast extract, and 0.3% dipotassium phosphate (W/W), without pH control, had 1,571.0 IU mL−1 of antimicrobial activity, and the one with pH control, had 3,896.7 IU/mL of antimicrobial activity (P < 0.05). This nisin-like bacteriocin is inhibitory to salad dressing spoilage organisms such as Lactobacillus brevis (ATCC 367), Lactobacillus buchneri (ATCC11305), and Lactobacillus plantarum (ATCC 8014). In conclusion, the results demonstrated that the antimicrobial activity of the isolated culture N40615 from raw milk was comparable to that of nisin in Nisaplin.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t83415 Watch P191 Use of acid whey and bovine colostrum as potential sources of antimicrobial compounds. 18 D. Rocha-Mendoza acid whey Lactobacillus rhamnosus antimicrobial activity I. Garcia-Cano1, A. Krentz1, S. Badiger1, D. Rocha-Mendoza1, E. Kosmerl1, R. Jiménez-Flores1 1The Ohio State University, Columbus, OH Acid whey (AW) is a by-product generated from dairy processing that the industry has long struggled to use in an economically and environmentally sustainable application. Due to its high biological oxygen demand, AW cannot be easily disposed of into the environment. However, AW contains valuable proteins such as lactoferrin that has antimicrobial activity. Lactoferrin is also a component in bovine colostrum. The objective of this study is to utilize AW as a culture media, in combination with colostrum and Lacticaseibacillus rhamnosus (Lbrh) to generate proteins with antimicrobial activity against Escherichia coli and Listeria innocua. Seven fermentations were performed with different combinations of AW, colostrum, and Lbrh to determine the optimal mixture that produces the highest antibacterial activity. After 48 h fermentation, each batch was centrifuged to remove bacteria cells. The supernatant was ultrafiltered using a 10- and 3-kDa cut-off membranes. The minimum inhibitory concentration (MIC) against E. coli and L. innocua was determined by agar diffusion. The bioavailability and cytotoxicity of 10- and 3-kDa samples were evaluated over Caco-2 cell line. The results from the agar diffusions indicate that antimicrobial activity was observed in 3 of the 7 fermentations. The specific activity of AL (AW + Lbrh) and ACL (AW + colostrum + Lbrh) were 4 times greater than ML (MRS media + Lbrh). The MIC for ACL 10-kDa was 200 and 300 mg/mL against L. innocua and E. coli, respectively. ACL 3-kDa had a MIC of 100 mg/ml against both strains and a zone of inhibition 2.5 times greater than ACL 10-kDa. ACL 10- and 3-kDa samples did not have an effect over Caco-2 cell line, as they showed low cytotoxic effect and the viability of the cells was not compromised, indicating no damage to model intestinal epithelial cells. Acid whey in combination of bovine colostrum can be used as potential sources for low molecular weight proteins with high antimicrobial activity that can provide future uses of a natural preservative from underutilized dairy by-product
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t83564 Watch P192 Antibacterial activity produced by Bacillus velezensis GF 610 against common milk spores. 19 I. Garcia-Cano peptidoglycan hydrolases Bacillus velezensis GF 610 Bacillus subtilis spores X. Liu1, I. Garcia-Cano1, D. Rocha-Mendoza1, R. Jiménez-Flores1, A. Yousef1 1Department of Food Science and Technology, The Ohio State University, Columbus, OH Spoilage due to contamination of spores in milk and dairy products represents a great challenge for the dairy industry, in particular to the milk powder producers. Peptidoglycan hydrolases (PGHs) are a new generation of antimicrobials, which show promise to inhibit sporulated microorganisms. PGHs with different molecular weights (90, 50, 34 and 30 kDa) produced during growth of B. subtilis have been reported. In previous studies, 48 strains of Bacillus spp. produced extracellular antimicrobials compounds; however, identities of the antibacterial compounds were unknown. The aim of this work was to find the strain with highest antibacterial activity and identify the nature of the protein responsible for this activity. The bacteria were grown in tryptic soy broth and harvested by centrifugation at the end of the logarithmic phase. Such as a first approach Micrococcus lysodeikticus and Bacillus subtilis cells were used as a substrate to evaluate the antibacterial activity by agar diffusion, turbidimetric and zymogram techniques. The zymogram assay allowed us to detect the bands responsible of the antibacterial activity. LC-MS/MS was used for the protein identification. Thirty of the 48 Bacillus strains showed lytic activity against M. lysodeikticus. From the 30 positive strains, B. velezensis GF 610 showed the highest activity, resulting in a 76.9% turbidity reduction. Zymogram analysis of the culture supernatant of this strain revealed 2 lytic bands around 30- and 16-kDa. In the 30 kDa band, a PGH sequence was identified by LC-MS/MS. No PGH was detected in the 16 kDa band. Both bands retained partial activities after heating at 90°C for 30 min. B. velezensis GF 610 showed effective bactericidal activity during the germination and propagation of B. subtilis spores isolated from powdered milk, within the tested 10 h. The lytic bands against germinated B. subtilis spores were identical to those detected against M. lysodeikticus by the zymogram. This study screened a strong PGH-producer, B. velezensis GF 610, and revealed that its PGH may be a potential candidate to control B. subtilis spores in milk. Further experiments using Bacillus licheniformis and Bacillus pumilus that are the predominant spore species in milk powder, will be conducted. As well, biochemical characterization of the antibacterial protein will be carried out
Dairy Foods: Posters Posters Dairy Foods 7/11/2021 0:00 t84591 Watch P193 Characterization of the fermentation and sensory profiles of novel yeast-fermented acid whey beverages. 20 S. Luo acid whey novel fermented beverage S. Luo1, D. deRiancho1, T. Demarsh1, S. Alcaine1 1Cornell University, Ithaca, NY Acid whey, a substantial by-product of dairy processing, has become a major sustainability obstacle due to a lack of safe and reliable disposal pathways. This study proposes a solution to this issue by transforming yogurt acid whey (YAW) into potentially palatable and marketable beverages through yeast fermentation. In this study, 5 prototypes were developed and fermented by Kluyveromyces marxianus, Brettanomyces bruxellensis, Brettanomyces claussenii, Saccharomyces cerevisiae (strain: Hornindal kveik), and IOC Be Fruits (IOCBF) S. cerevisiae yeasts. Their fermentation profiles were characterized by changes in density, pH, and concentrations of cells and organic acids. The prototypes were also evaluated on 26 sensory attributes, which were generated through a focus group of 14 participants. Analysis of variance and Tukey’s test were used to compare the differences in sensory ratings. While S. cerevisiae (IOCBF) exhibited the fastest fermentation (8 d) and B. claussenii the slowest (21 d), K. marxianus and S. cerevisiae (Hornindal kveik) exhibited similar fermentation rates; finishing on d 20. The change in pH was similar for all 5 strains (from around 4.45 to between 4.25 and 4.31). Cell concentrations remained stable throughout the fermentation for all 5 strains (at around 6 log cfu/mL) except in the case of S. cerevisiae (Hornindal kveik), which ultimately decreased by 1.6 log cfu/mL. B. bruxellensis was the only strain unable to utilize all of the sugars in the substrate, with residual galactose remaining after fermentation. While both S. cerevisiae (IOCBF)- and B. claussenii-fermented samples were characterized by a fruity apple aroma, the former also had a significant lactic acid/dairy (P = 0.01) and yeasty aroma (P = 0.04). A chemical (petrol/gasoline) aroma was perceived in samples fermented by B. bruxellensis (P = 0.01) and K. marxianus. A poorly aged/rancid cheese aroma also resulted from B. bruxellensis fermentation. In terms of appearance and mouthfeel, the S. cerevisiae (IOCBF)-fermented sample was rated the cloudiest (P < 0.01), with the heaviest body. This study provides a toolkit for product development in a potential dairy-based category of fermented alcoholic beverages, which can increase revenue for the dairy industry by upcycling the common waste product YAW.
Dairy Foods: Posters Posters Dairy Foods 7/11/2021 0:00 t84078 Watch P194 Production and sensory properties of fermented milk by Lactobacillus reuteri J1. 21 Y. Jiang fermented milk Lactobacillus reuteri sensory properties Y. Zhang1, J. Zhao1, H. Zheng2, C. Man1, Y. Jiang1 1Key Laboratory of Dairy Science, Ministry of Education, Department of Food Science, Northeast Agricultural University, Harbin, Heilongjiang, China, 2Department of Food Bioprocessing and Nutrition Sciences, Southeast Dairy Foods Research Center, North Carolina State University, Raleigh, NC Lactic acid bacteria are widely used in fermented dairy products, which not only enhance the flavor, but also improve the functional quality. Some of Lactobacillus reuteri with great functional properties and fermentation characteristics have caught significant interests. L. reuteri J1 as culture starter in milk matrix was studied in this work. After 3 h in artificial gastric juice and 8 h in artificial intestinal juice, the survival rate of the strain (dilution coating method) was 89.98% and 79.95%, respectively. It showed an excellent tolerance in simulated gastrointestinal juices. Adhesion rate is one of the important indicators for the development and application of lactic acid bacteria. In addition, higher viable counts of L. reuteri could improve the nutritional value of fermented milk. High adhesion and viable counts could be the feature points of concern. Caco-2 cells were co-incubated with L. reuteri J1 for 2 h, results showed that it had a great capacity of adhesion with 7.56 log cfu/mL. The viable count was >7.87 log cfu/mL in the milk system. The fermentation process using L. reuteri J1 was optimized. Water-holding capacity, viable count, sensory characteristics and antioxidant capacity were tested for the fermented dairy food samples. Results were expressed as mean ± standard deviation, and statistical significance was determined at P < 0.05. Results showed that the optimum inoculation rate was 4% (wt/wt) at 37°C for 24 h, and the end point pH was 4.85. We also used Streptococcus thermophilus and Lactobacillus bulgaricus to ferment milk as the control sample. Under these conditions, the final viable cell count of L. reuteri reached to >1 × 109 cfu/mL and the water-holding capacity significantly increased (P < 0.05) compared with the control sample. The antioxidant capacity of fermented milk was significantly enhanced (P < 0.05) by fermenting with L. reuteri J1, the scavenging rates of OH and DPPH were 91.38% and 90.32%, respectively. Viscosity and gel firmness were measured as textural sensory attribute indicators and the results were 1,472.59 cps, 46.51 g, respectively. The viscosity and gel firmness were all significantly increased (P < 0.05) compared with the control sample. The results of this study suggested that L. reuteri J1 possessed a prospect to be applied in fermented dairy foods. It provides a practical insight of using L. reuteri J1 as a culture to develop a novel functional fermented milk.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t84021 Watch P195 Optimization of protoplast formation for the probiotic Lactobacillus acidophilus. 22 R. Page probiotic protoplast R. Page1, K. Aryana1 1Louisiana State University, Baton Rouge, LA Transformation of specific Lactobacillus acidophilus, a known probiotic, strains into protoplast are not known or fully explored. The aim of this study was to determine the optimal temperature, incubation time, and buffer molarity when using an optimized concentration of lysozyme for the formation of protoplast. Freeze-dried L. acidophilus cells were suspended in 20 mM of HEPES buffer (pH 7) at different sucrose osmotic conditions of 1, 1.5, or 2 M to yield a 108 cell concentration. Reagents and cell suspension before enzyme addition were incubated at either 37°C or 22°C for 10 min. After lysozyme (125 µg/mL) addition the cell suspensions were incubated for 30 min, 1 h, or 2 h at 37°C. Three fields (3 replicates) were studied by phase-contrast microscopy. Cell wall digestion were seen in all treatments after 30mins of incubation at 37°C at a fixed lysozyme concentration of 125 µg/mL. Cell lysis and aggregation of L. acidophilus cells increased as incubation time increased. Increasing molarity had no significant effect on protoplast production and produced the highest yield of protoplast for all treatments after 30 min. Cells suspended in 2 M HEPES buffer were observed to yield a higher % of protoplasts and reduced cell lysis when incubated for 2 h compared with the cells treated with 1 and 1.5 ML. acidophilus cell suspension, lysozyme and buffer solutions adjusted to 37°C before incubation displayed a higher yield of protoplast after 2 h compared with solutions adjusted to 22°C. A lysozyme concentration of 125 µg/mL incubated at 37°C for 30 min was sufficient in producing a high yield (> = 90%) of protoplast. A 2-way ANOVA was preformed to determine differences in treatments. A P-value <0.05 was noted as significantly different. Buffer molarity and temperature both had significant effects on protoplast yield when incubated for 2 h.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t84742 Watch P196 Paenibacillus odorifer spoilage of fluid milk products and the potential impact of rework practices. 23 J. Waite-Cusic rework spoilage Paenibacillus odorifer C. Rush1, S. Burroughs1, J. Johnson1, L. Meunier-Goddik1, J. Waite-Cusic1 1Oregon State University, Corvallis, OR Rework is a common practice in the dairy industry as a way to help minimize waste while recovering cost from products that might otherwise be unsaleable. However, the quality implications of reworking dairy products have not been investigated and processors have speculated that these practices could contribute to an increase in premature spoilage due to microbial activity causing flavor defects. Paenibacillus odorifer, a psychrotrophic spore-former, has been observed to cause flavor defects (“solventy,” “rubbery,” “athletic tape”) in both fluid and chocolate milk before the end of shelf life. The objective of this study was to characterize spoilage defects, determine growth rates, and sporulation status of P. odorifer strains in fluid and chocolate milk to support model development to predict spoilage rates of reworked products. Commercial UHT-pasteurized fluid milk and chocolate milk samples were independently inoculated with 4 strains of P. odorifer isolated from pasteurized fluid milk (n = 2) and chocolate milk (n = 2) to achieve an initial cell density of 1–2 log cfu/mL. Samples were stored at 4°C and 7°C and aerobic plate counts, and organoleptic observations (visual, aroma) were determined throughout a 21-d shelf life. Aroma deviations were confirmed across all 4 strains on d 15 for fluid milk (6.6–6.8 log cfu/mL) and on d 10 for chocolate milk (5.8–6.1 log cfu/mL) at 4°C and d 6 for both fluid milk (6.3–7.1 log cfu/mL) and chocolate milk (6.4–7.2 log cfu/mL) at 7°C. Gram stains confirmed no sporulation in milk through the shelf life. Plate count data were fit to a 3-phase linear model to ascertain growth parameters for each strain. Strain-specific growth rates ranged from 0.65 to 0.82 log cfu/mL/day and increased to 0.90–0.94 log cfu/mL/day in chocolate milk at 4°C. At 7°C, the growth rates in fluid milk increased to 1.4–2.2 log cfu/mL/day and 1.9–2.2 log cfu/mL/day in fluid and chocolate milk, respectively. Next steps will be to develop and conduct a Monte Carlo simulation to predict the impact of various rework practices on product shelf life.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t84783 Watch P197 Microbiological comparisons between milk sock filters and raw milk. 24 B. Riesgaard raw milk milk sock filter bacteria B. Riesgaard1, A. Torres1, J. Johnson1, C. Rush1, Z. Atamer1,2, J. Waite-Cusic1 1Oregon State University, Corvallis, OR, 2University of Hohenheim, Stuttgart, Germany Dairies use milk sock filters to capture large debris (hay, soil, clots), before passage through the cooling heat exchanger, on the way to the bulk milk tank. Milk leaves the udder at 38°C and travels through the milk sock filter at warm temperatures that can support microbial growth. According to the Pasteurized Milk Ordinance, milk sock filters should be changed after each milking session or once every 24 h in continuous milking operations. The objective of this study was to characterize and compare the microbial diversity and load of milk sock filters and raw milk on a single dairy farm. Samples were collected from the Oregon State University Dairy (~80 milking head) after the morning and evening milkings for 5 d. Microbial populations on milk filters (n = 10) and in raw milk (n = 10) were characterized by 16S metabarcoding and enumerated by standard plating methods on tryptic soy agar (TSA), MacConkey (MAC) agar, and MRS agar. Plates were enumerated after 48 h of incubation at 30°C (MRS, hypoxic chamber) or 37°C (TSA, MAC). The accumulation of material on milk sock filters were visualized by scanning electron microscopy. After 2 h of use, milk sock filters harbored loads of 7.4 log cfu/g aerobic plate count (APC), 5.9 log cfu/g lactic acid bacteria (LAB), and 5.3 log cfu/g coliforms. These cell densities were significantly higher than the bulk raw milk (APC: 3.9 log cfu/mL, LAB: 3.0 log cfu/mL, coliforms: 2.5 log cfu/mL). Species richness (α diversity) was significantly lower on milk sock filters (300 ± 115 sequence variants (SVs)) compared with bulk milk (507 ± 73 SVs). Acinetobacter SV680, Peptostreptococcaceae SV3537, and Brumimicrobium SV2017 were present at significantly higher relative sequence abundance in raw milk. None of the individual SVs were consistently responsible for increased bacterial loads in milk sock filters. Increased bacterial loads on milk sock filters demonstrate the ability of the filter to capture bacteria. Further studies will evaluate whether extended milking sessions (up to 8 h) would support the growth of these captured bacteria and if these long periods of use may have a negative impact on raw milk quality.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t83414 Watch P198 Determination of an effective sanitizing procedure for Listeria innocua in personal protective equipment used in dairy facilities. 25 K. A. Nieto   K. A. Nieto1, L. Sabillón1,2, B. Martínez1,2, J. Stratton1,2, A. Bianchini1,2 1Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE, 2Food Processing Center, University of Nebraska-Lincoln, Lincoln, NE Listeria monocytogenes can survive and grow under wet environmental conditions often encountered in dairy processing facilities. The source of microbial contamination may include employees and their personal protective equipment (PPE), which often contact product and food contact surfaces. This study investigates the effectiveness of chlorine, quaternary ammonia, and peroxyacetic acid (PAA) in reducing Listeria innocua contamination from different types of gloves, aprons, and boots. The PPE was inoculated with a 2-strain cocktail of Listeria innocua that was suspended in either PBS or skim milk to determine the potential effect of organic matter. A linear mixed model with a randomized complete block design was performed to determine the best sanitation protocol and the effect of organic matter at P ≤ 0.05 using SAS software (SAS 9.4). With PBS, results showed 2.08 to 4.60 log cfu/in2 reduction on the different types of aprons, with the PAA-based sanitizer being the most effective. Different kinds of gloves showed a similar average reduction (2.15 – 4.16 log cfu/in2). In comparison, boots showed a 1.00 – 1.70 log cfu/in2 reduction. With skim milk as the carrier of contamination, the sanitizers achieved less than 1.00 log cfu/in2 reduction on the aprons, showing no significant differences in effectiveness among them. Similarly, reduction levels of 0.5 to 0.8 and 0.7–1.0 log cfu/in2 were observed on the different gloves and boots, respectively. Overall, the different sanitizers' antimicrobial activity was diminished in the presence of organic matter. This highlights the negative impact of organic matter in sanitizer effectiveness and the need to include cleaning steps to achieve the desired reduction in the bacterial population. Additionally, an extensive cleaning protocol that included cleaners, mechanical action, followed by chlorine sanitizer was evaluated. This cleaning regimen achieved a ≥3-log cfu/in2 reductions on the different types of PPE. This study highlights the importance of detergent choice and use of scrubbing as essential steps to reduce and control Listeria from PPE
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t83983 Watch P199 Evaluation of the transmission of Listeria innocua from personal protective equipment (PPE) to the plant environment and food products. 26 K. A. Nieto   K. A. Nieto1, B. Martínez1, J. Stratton1,2, A. Bianchini1,2 1Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE, 2Food Processing Center, University of Nebraska-Lincoln, Lincoln, NE Listeria monocytogenes is a foodborne pathogen that can grow and survive in the dairy processing environment. Employees and their personal protective equipment (PPE) are potential vectors of this organism during production. The objective of this study was to evaluate Listeria innocua transference from PPE to food products (cheeses), and dairy processing plant surfaces (cutting boards, stainless steel, and dairy brick floors). A total of 5 combinations of PPE and surfaces of interest were selected. PPE was inoculated using either Phosphate Buffered Solution (PBS) or skim milk as the carrier for L. innocua. A repeated-measures linear mixed model with a randomized complete block design was used to determine the significance of Listeria innocua transmission from each PPE to the surface of interest while considering organic matter effect (P < 0.05). Transmission mediated by gloves and aprons were tested using a texture analyzer to apply a constant force (2.942 N) and time (5 s) mimicking one contact transfer. Additionally, boots inoculated with L. innocua were used to assess bacterial transmission to floors. In general, contamination carried by organic matter led to a higher transfer of Listeria innocua from PPE to tested surfaces than when PBS was used (P < 0.05). With PBS, consecutive touches from gloves to food products led to a decline in transfer; however, Listeria populations were never eliminated. With skim milk, no transfer decline was observed in the different combinations of PPE and surfaces. When different combinations of PPE-surfaces were evaluated and skim milk was the carrier of contamination, on average, gloves transferred 5.33 log cfu/in2L. innocua to queso fresco, followed by 4.28 log cfu/in2 to Cheddar cheese. A 4.01, 2.66, and 2.61 logs cfu/in2 average transmission was observed from gloves to cutting board, aprons to stainless steel, and boots to dairy tiles. In general, bacterial transference from PPE to food contact surfaces and food products was higher than those observed between PPE and non-food contact surfaces, emphasizing the risk associated with the potential cross-contamination of the final product.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t83982 Watch P200 Developing an affordable hyperspectral imaging system for rapid identification of Listeria monocytogenes and Escherichia coli O157:H7 in dairy products. 27 P. Unger identification hyperspectral imaging pathogens P. Unger1, A. Sekhon1, M. Michael1 1Washington State University, Pullman, WA With the increased concerns about food safety and defense, hyperspectral imaging (HSI) can serve as a potential novel technology for rapid and reliable identification method for pathogenic bacteria. The development of an affordable HSI system using a compound microscope and HSI camera offers the possibility for other researchers to explore this technology. The objective of this study was to develop and evaluate the efficacy of an affordable HSI system to identify single and mixed strains of foodborne pathogens in dairy products. This study was designed as a randomized complete block design with 3 replications. Three strains of Listeria monocytogenes and Escherichia coli O157:H7 were evaluated either as single or mixed strains with the HSI system in growth media and selected dairy products (whole milk, cottage and Cheddar cheeses). Freshly prepared single or mixed strains of respective pathogens or inoculated dairy products were streaked on selective media (PALCAM and or Sorbitol MacConkey agar) for isolation. An isolated colony was selected and mixed with 1-mL of HPLC water, vortexed for 1-min, and spread over a microscope slide. Images were captured at 2,000X magnification on the built HSI system at wavelengths of 400 nm to 1,100 nm with 5 nm band intervals. For each image, 3-cells were selected as regions of interest (ROIs) to obtain hyperspectral signatures of respective bacteria. Cells were classified by their hyperspectral signatures as either L. monocytogenes or E. coli O157:H7 using K-nearest neighbor (KNN) and cross-validation technique in R software. With the implementation of KNN (k = 3), classification accuracies of 58.97% and 61.53% were obtained for E. coli O157:H7 and L. monocytogenes, respectively. This preliminary work on the affordable HSI system shows great promise for the rapid identification of foodborne pathogens in a variety of dairy food matrices.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t84795 Watch P201 Need for environmental monitoring programs in small dairy plants based on initial screening of Listeria spp. and monocytogenes. 28 T. T. Lott Listeria dairy foods T. T. Lott1, R. D. Ralyea1, S. E. Roof1, A. S. Harrand1, A. D. Zuber Gianforte1, K. Ospina1, A. Trmcic1, N. Martin1, M. Wiedmann1 1Cornell University, Ithaca, NY Food safety incidences linked to dairy products represent a significant risk for the dairy industry. For example, in 2017 Vulto Creamery, a small dairy facility in Walton, New York, was identified as the likely source of an outbreak of listeriosis affecting 8 people in 4 states. As Listeria monocytogenes is the bacterium most likely to cause severe foodborne disease outbreaks linked to dairy products, the goal of this project is to develop and implement improved practices to control L. monocytogenes in 3 fluid milk, 3 ice cream, and 3 cheese processing facilities in New York State. To evaluate the potential Listeria presence in the plant environment, an initial screening was performed at each plant. The screen involved collecting 40 – 100 sponge samples at each facility with approximately 40%, 50%, and 10% of samples collected in environmental zones 2, 3, and 4, respectively. Samples were enriched in buffered Listeria enrichment broth (BLEB) at 30°C and plated on differential and selective media [L. monocytogenes plating medium (LMPM) and Modified Oxford Agar (MOX)]. Plates were then evaluated for presumptive Listeria spp. and L. mono growth. All 7 plants had samples presumptively positive for Listeria spp. or both Listeria spp. and L. monocytogenes; Listeria spp. positivity rates ranged from 4 to 50%, while L. monocytogenes positivity rates ranged from 0 to 8%. The initial results highlight the importance of this project as it is essential to reduce the potential for negative publicity linked to dairy, which could void the positive impact of other efforts to promote dairy consumption.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t84804   P202 Fluid milk spoilage associated Paenibacillus spp. sporulation methods assessment and novel method development. 29 S. J. Reichler Paenibacillus spore inoculation S. J. Reichler1, N. H. Martin1, M. Wiedmann1 1Cornell University, Ithaca, NY Spore-forming bacterial genera, including Paenibacillus spp., survive high-temperature, short-time fluid milk pasteurization. Their endospores germinate and proliferate as vegetative cells over refrigerated shelf life, causing spoilage. Though Paenibacillus spp. are one of the most common gram-positive bacterial contaminants of pasteurized fluid milk, present in up to 95% of containers without gram-negative contamination, little is known about their biological requirements and optimal conditions for sporulation. This presents a challenge, as accurate experimental modeling of Paenibacillus spp. fluid milk contamination requires endospores rather than vegetative cells for inoculation. We compiled and tested previously reported techniques for laboratory production of Paenibacillus endospores using isolates of 3 well-characterized spp. commonly found in fluid milk: P. amylolyticus, P. odorifer, and P. peoriae. We measured sporulation success qualitatively by phase-contrast microscopy and quantitatively by spore pasteurization and plating. Surface plating on AK Agar #2 and MYPGP agar produced viable endospores of P. amylolyticus and P. peoriae but failed for P. odorifer. We found identical results for Schaeffer’s Glucose broth. A chance observation of P. odorifer-inoculated refrigerated fluid milk revealed the presence of endospores, suggesting milk as an alternative medium for sporulation of this challenging sp. We experimentally optimized the yield of P. odorifer endospores in fluid milk using a Taguchi design to minimize the number of necessary experimental replicates. Briefly, incubation temperature, butterfat, citrate content, and milk dilution were assessed at 3 levels each in combinations determined by an orthogonal array for 3 P. odorifer isolates, with percentage spore yields measured by plating on nonselective media before and after spore pasteurization. The resulting set of optimized sporulation conditions for P. odorifer (32°C incubation of undiluted skim milk containing 0.8% wt/vol sodium citrate) allowed for >75% sporulation for some isolates. Using this method, P. odorifer endospores can be produced for further experiments, necessary for advancing our knowledge of this important species.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t84800   P203 A gentle fluid milk bacterial cell isolation and purification procedure allowing for further applications, including light microscopy. 30 S. J. Reichler spore isolation stain S. J. Reichler1, N. H. Martin1, M. Wiedmann1 1Cornell University, Ithaca, NY Attempts to centrifugally purify bacterial cells from milk for further applications, such basic microscopy, are stymied by the presence of butterfat and protein. Spore-forming bacteria preferentially separate into the butterfat upon centrifugation and are lost when this layer is discarded. Unacceptable quantities of casein partition into the centrifugal pellet in many spoiled samples. Both residual butterfat and precipitated casein confound the results of differential staining techniques and interfere with phase-contrast microscopy of the resuspended cells. We developed a brief and relatively simple process for centrifugal separation of bacterial cells from butterfat and protein in fluid milk, while maintaining the physical integrity of both vegetative cells and endospores. The process begins by treating the milk with a sodium citrate solution to solubilize precipitated casein. The milk is then vigorously shaken to force bacterial cells associated with the butterfat into the aqueous phase. The butterfat is physically removed from the sample after centrifugation, and any remaining is rinsed away using a mild detergent. We verified that this method produces cell suspensions pure enough for accurate phase-contrast microscopy of unstained wet mounts and brightfield microscopy of Gram-stained smears. We confirmed the viability of these suspensions by plating onto Brain Heart Infusion agar. This technique has several potential applications, including isolation of bacterial endospores grown in fluid milk medium for further experimentation. Gram staining of purified cell suspensions may also serve as a rapid preliminary diagnostic technique for fluid milk bacterial spoilage events, with several advantages over existing methods. Unlike the direct microscopic bacterial count technique, no harsh solvents are necessary, concentration of the cells allows for improved microscopic visualization, and differential staining allows for some level of insight into the nature of the spoilage event. Unlike automated bacterial enumeration instruments, such as the BactoScan, no costly and specialized equipment is required.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t83977 Watch P204 Survival and thermal resistance of Salmonella in dry and hydrated milk powders during storage period of 6 months. 31 A. S. Sekhon D- and z-values low water activity Salmonella A. S. Sekhon1, A. Singh1, P. Unger1, Y. Yang1, M. Babb1, M. Michael1 1Washington State University, Pullman, WA Foodborne pathogens such as Salmonella can endure dry environments of milk powders for extended periods due to increased adaptability at low water activity (aw) and proliferate when powders are hydrated. This study compared the survivability and thermal resistance of a 5-serovar Salmonella cocktail in dry and hydrated nonfat dry milk (NFDM) and whole milk powder (WMP) stored for 180 d at ambient temperature (~25°C). This study was designed as 2 factorial (storage day and milk powder type) randomized complete block design with 3 replications as blocks. Milk powders were spray inoculated with 5-serovar Salmonella cocktail and dried back to original pre-inoculation aw. The D-values of Salmonella in inoculated NFDM and WMP were determined periodically (every 30 d, starting from d 1). Milk powders were also individually hydrated on each analysis day to determine D- and z-values of Salmonella in hydrated milk powders. The D-values were determined using thermal-death-time disks and hot-water baths at 80, 85 and 90°C for milk powders, and 59, 62 and 65°C for hydrated milk powders. The D- and z-values of Salmonella at specific temperatures within dry or hydrated milk powders during the storage period were compared at P ≤ 0.05 using 2-way ANOVA and Tukey’s test. The D-values of Salmonella in WMP on d 1 were 18.9, 9.9 and 4.4 min at 80, 85 and 90°C, respectively, which increased to 29.4, 13.6 and 6.5 min at 80, 85 and 90°C, respectively, on d 180. Whereas D-values of Salmonellain NFDM on d 1 were 17.9, 9.2 and 4.4 min at 80, 85 and 90°C, respectively, and stayed similar during the storage. The D-values of Salmonella in hydrated milk powders remained similar throughout the storage. The overall z-value of Salmonella in NFDM and WMP was 16.3°C, whereas in hydrated NFDM and WMP, the overall z-value was 6.4°C.
Dairy Foods: Posters Posters Dairy Foods 7/11/2021 0:00 t83887 Watch P205 Effect of extended storage on the survivability and thermal resistance of Listeria monocytogenes in dry milk powders. 32 Y. Yang D-values z-values survivability Y. Yang1, A. Sekhon1, A. Singh1, P. Unger1, M. Babb1, M. Michael1 1Wasghinton State University, Pullman, WA Listeria monocytogenes (LM) has unique ability to survive in the low water activity (aw) foods such as milk powders for prolonged time periods and can multiply quickly when hydrated. LM can also result in severe diseases like meningitis and even premature death of unborn children. The objective of this study was to determine survivability and thermal resistance (D- and z-values) of LM in nonfat dry milk (NFDM) and whole milk powder (WMP) during storage of 180 d. This study was designed as 2 factorial (storage and powder type) randomized complete block design with 3 replications. Milk powders were inoculated with 3-strain cocktail of LM and dried back to original aw levels, and D- and z-values were determined every 30th day, starting on day one. Five grams of respective samples were transferred into thermal-death-time (TDT) disks, sealed, and placed in water baths set at 75, 80, and 85°C for both powders. The samples were heat treated for intervals of 10, 5, and 2.5 min at 75, 80, and 85°C, respectively and transferred immediately to an ice water bath. The samples were enumerated using injury-recovery media, and D- and z-values were calculated. Two-way ANOVA and Tukey’s test at P = 0.05 were used for statistical analysis. D-values of LM in NFDM for day 1 were 13.1, 6.0, and 4.0 min at 75, 80, and 85°C, respectively. Whereas D-values of LM in WMP for day 1 were 12.0, 6.3, and 3.3 min at 75, 80, and 85°C, respectively. The main effect (storage day) was significant for D75°C and D80°C values of LM and no significant effect was observed for milk powder type, and milk powder type × storage day. Overall, the D75°C and D80°C values of LM increased in milk powders. However, at 85°C, the D-value of LM were similar for milk powders. In addition, the z-values of LM in milk powders were also found to be similar (18.85°C on d 1) during the storage period. The LM population decreased by 2.1and 2.2 log cfu/g in NFDM and WMP, respectively, after 180 d of storage. D- and z-values from this study will provide basic information about the effect of storage time and milk powder type on heat resistance of LM in the milk powders.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t84357 Watch P206 Determination of thermal inactivation parameters of Listeria monocytogenes in dry and hydrated milk powders. 33 M. Michael   Y. Yang1, A. Sekhon1, A. Singh1, P. Unger1, M. Babb1, M. Michael1 1Washington State University, Pullman, WA Although not commonly studied, Listeria monocytogenes (LM) can survive and pose food safety health risks in low water activity (aw) foods such as milk powders. Thermal processing technologies are one of the commonly used methods used to inactivate foodborne pathogens in the dairy industry. Determination of thermal inactivation parameters is crucial in developing an effective pasteurization protocol. This study aimed to determine the thermal resistance (D- and z-values) of LM in dry and hydrated nonfat dry milk (NFDM) and whole milk powder (WMP). This study was designed as a randomized complete block design with 3 replications as blocks. Respective milk powders were inoculated with a 3-strain LM cocktail and dried to their original aw levels. The dry powders were then subjected to heat treatment using thermal-death-time disks in a hot water bath at 75, 80, and 85°C. The hydrated (13% total solids) NFDM and WMP were also subjected to heat treatment at 54, 57, and 60°C at predetermined time intervals within the range of 0 to 40 min. The surviving microbial population of LM in the dry and hydrated milk powders was enumerated using injury-recovery media: Brain Heart Infusion (BHI) agar, overlaid with PALCAM agar. The data were analyzed using one-way ANOVA, and Tukey’s test was used to determine significant differences among the mean values at P ≤ 0.05 using Minitab19. The D-values of LM were 13.1, 6.0, and 4.0 min in dry NFDM, and 12.0, 6.3, and 3.3 min in WMP at 75, 80, and 85°C respectively. The D-values in hydrated NFDM were 9.7, 3.2, and 1.0 min and that of the hydrated WMP were 8.6, 3.4, and 1.0 min in hydrated WMP at 54, 57, and 60°C, respectively. The average z-value of LM determined in NFDM was 19.6°C and 17.8°C in WMP. In the hydrated milk powders, the z-value of LM in NFDM and WMP were 6.1 and 6.3°C, respectively. Statistically, there were no significant differences between the D- and z-values of Listeria monocytogenes within the dry and hydrated milk powders. D and z-values from this research can be used to develop a thermal kill step protocol on Listeria monocytogenes in milk powders.
Dairy Foods: Posters Posters Dairy Foods 7/11/2021 0:00 t84505 Watch P207 Comparison of the decimal log-reductions of Salmonella Senftenberg with other Salmonella serovars in nonfat milk and powder. 34 A. Singh Salmonella nonfat dry milk (NFDM) powder A. S. Sekhon1, A. Singh1, M. Michael1 1Washington State University, Pullman, WA Foodborne pathogens such as Salmonella can survive in dry environments of nonfat dry milk (NFDM) for prolonged time periods and multiply when hydrated. It is well established that Salmonella Senftenberg is the most heat tolerant Salmonella serovar in high moisture foods; however, the scientific literature in low moisture foods, especially NFDM, is scarce. Therefore, this study was performed to determine whether Salmonella Senftenberg is the most heat tolerant Salmonella serovar in NFDM among the 5 common foodborne illness-causing Salmonella serovars studied. This study was designed as completely randomized with 3 replications. Five serovars of Salmonella used in this study were Enteritidis, Montevideo, Newport, Senftenberg, and Typhimurium. The NFDM was inoculated with individual serovars of Salmonella and dried back to original pre-inoculation water activity levels. The inoculated NFDM was hydrated at 13% (wt/vol) total solids just before the heat treatments. The inoculated powders (5g) or hydrated powders (5mL) for individual Salmonella serovars were transferred into thermal-death-time disks, sealed, and placed in hot-water baths set at 80 and 90°C for NFDM, and 59 and 65°C for hydrated NFDM. The samples were held for 0 to 60 min at respective temperatures and transferred to ice-water baths at pre-determined time intervals. The samples were enumerated using injury-recovery medium, and the average log reductions for the individual serovars were calculated. The average log reductions of individual serovars at specific temperatures within dry or hydrated NDM were compared using one-way ANOVA and Tukey's test at α = 0.05. As expected, Salmonella Senftenberg was found to be most heat resistant in hydrated NFDM at 59 and 65°C; however, Salmonella Montevideo and Salmonella Typhimurium were found to be most heat resistant in NFDM at 80 and 90°C, respectively. The heat resistance of the Salmonella serovars is found to be different in NFDM and hydrated NFDM. The results confirm that Salmonella Senftenberg is not the most heat resistant serovar in NFDM, and should not be used as the sole serovar for thermal inactivation studies of low moisture dairy powders, but should be used in a Salmonella cocktail of several heat resistant serovars.
Dairy Foods: Posters Posters Dairy Foods: Chemistry 7/11/2021 0:00 t83996 Watch P208 Infrared spectroscopy as a screening tool for grass-fed status of Canadian dairy herds. 35 M. Bahadi grass-fed milk FTIR spectroscopy chemometrics M. Bahadi1,2, D. Warner2, R. Lacroix2, D. E. Santschi2 1Department of Animal Science, McGill University, Sainte-Anne-de-Bellevue, QC, Canada, 2Lactanet, Sainte-Anne-de-Bellevue, QC, Canada Dairy farmers in Canada who produce grass-fed milk need to prove their adherence to the stipulations of grass-fed standard by determining the ratio of linoleic acid (LA) to α-linolenic acid (ALA) throughout the year. Determination of this ratio by gas chromatography (GC) is time consuming and expensive. The objective of this pilot project was to evaluate the potential of Fourier transform infrared (FTIR) spectroscopy in screening for LA:ALA ratio as an affordable alternative to the GC analysis. Monthly milk samples were collected from bulk tanks of 12 grass-fed farms and silos of 6 milk processing facilities in Québec in 2019 and 2020. The effective total number of samples was 174. GC was used to determine LA:ALA ratio and 75 milk fatty acids including omega 6 (n-6), omega 3 (n-3), and odd and branched-chain fatty acids (OBCFA). Principal component analysis was applied to the GC results. Scores projected on principal component 1 (PC1) revealed a tendency of separation between grass-fed and silo samples. PC1 correlation loadings revealed an inverse relationship between n-6 on one hand, and n-3 and OBCFA on the other. These results confirmed that grass-fed milk can be differentiated from conventional one by the fatty acids profile. A partial least squares (PLS) regression model was built using milk spectra collected in 2019. The calibration set consisted of spectra of 11 grass-fed and 5 silo samples (average LA:ALA ± SD of 2.64 ± 1.302; range of 0.79–4.77). The model was cross-validated using a leave-one-out approach and the external validation set consisted of 76 grass-fed samples. The root mean square error of calibration, cross-validation (RMSECV), and prediction (RMSEP) were 0.46, 0.56 and 0.51, respectively. The RMSEP was acceptable according to the Canadian grass-fed standard and the close values of the 3 measurements of error indicated that the model was stable. The RMSECV was significantly different (P = 0.003) from the RMSECVs of 100 permutations of the LA:ALA PLS model. We concluded that FTIR spectroscopy has the potential to be used as a screening tool for LA:ALA ratio to monitor the grass-fed status of dairy herds.
Dairy Foods: Posters Posters Dairy Foods: Dairy Products 7/11/2021 0:00 t83740 Watch P209 Feasibility of mid-infrared and visible/near-infrared spectroscopy to authenticate organic bulk milk. 36 A. Costa infrared spectroscopy organic production PCA C. L. Manuelian1, V. Vigolo1, A. Costa1, M. De Marchi1 1University of Padova, Legnaro, Padova, Italy It is important to have fast, inexpensive and nondestructive methods, such as infrared spectroscopy, to verify the declarations on the labeling of those products in which certain characteristics represent a premium in the sale price. Thus, we aimed to evaluate the feasibility of mid-infrared (MIR; 5,012–925 cm−1) and Vis/near-infrared (Vis/NIR; 400–2,500 nm) spectroscopy to discriminate organic from conventional cow milk. Bulk milk samples (n = 225) from 24 farms (Organic = 12; Conventional = 12) located in the same area, mainly raising Italian Friesian cows, and similar management conditions, except for spending a period of time in the pasture when organic, were collected from September 2019 to August 2020. Chemical composition of the lactation total mixed ration was similar between groups. The MIR and Vis/NIR spectrum of each sample were collected, and a principal components analysis (PCA) and a partial least square discriminant analysis (PLS-DA) were done with R software. For the PLS-DA, records were split into a train set (75% records) and a test set (25% records), and only wavelengths with VIP >1 were retained. Results from PCA showed that PC1 and PC2 explained 64.3% and 93.2% of the variance with MIR and Vis/NIR spectra, respectively. However, the PCA plot showed the overlapping of both populations. The PLS-DA showed several MIR regions contributing to the model (1 ≤ VIP ≤ 3.5). Vis region contributed more to the Vis/NIR model (1 ≤ VIP ≤ 3.0), but few VIP peaks (≤1.4) in the NIR region were observed. Despite only milk protein content differed (P = 0.04) between groups, those MIR and NIR regions are linked to lactose, fat and protein content. Results from the PLS-DA revealed an accuracy of the model of 70.2% and 71.7%, for MIR and Vis/NIR, respectively, in the test set. In conclusion, both infrared-regions performed similarly, and the moderate accuracy of the PLS-DA could be related to the similarity of the selected farms between both categories (e.g., breed and total mixed ration composition). It would be interesting to incorporate other parameters such as the fat or protein profile of the milk to improve the models.
Dairy Foods: Posters Posters Dairy Foods: Dairy Products 7/11/2021 0:00 t84027 Watch P210 Influence of incorporation of whey protein isolates on the physicochemical, rheological, and microstructural properties of nonfat yogurt. 37 M. A. Hashim yogurt whey protein isolate rheological properties M. A. Hashim1,2, L. A. Nadotchii1, A. Prockora1, M. Muradova1 1ITMO University, Saint Petersburg, Russia, 2Agricultural Research Center, Giza, Egypt Consumers give a significant awareness for healthy, naturally functional food products with clean labels and less added ingredients and external hydrocolloids. Nowadays, the demand for low and nonfat products has increased because of the problems related to obesity, diabetes and cardiovascular diseases. So, significant attention has been given to the production of low and nonfat dairy products. This study’s objective was to explore the potential of whey protein isolate (WPI) to improve the quality of nonfat yogurt made by reconstituted skim milk and in the presence of full-fat and nonfat yogurts as controls. Yogurt mixes were formulated using a skim milk powder as a milk base enriched with WPI up to 6% protein content. The replacement percentage of skim milk powder by WPI in the yogurt mixes was between 3 and 9%. Nonfat and full-fat set-style yogurts (6.0 ± 0.1% protein, 15 ± 1.0% solids) were made from skim milk and whole milk, respectively. The texture, microstructure, the rheological properties (storage modulus, loss modulus, apparent viscosity) and sensory properties of the yogurt samples were analyzed in comparison with full-fat (3.0% fat, wt/wt) and nonfat (0% fat, wt/wt) yogurts. The rheological parameters were measured using a rheometer (RN 4.1, RHEOTEST Medingen GmbH, Germany). The texture was analyzed by domestic texture analyzer “Structurometre ST2,” and the maximum force required to penetrate the gel was taken as a measure of the relative gel strength. The microstructure was assessed by scanning electron microscopy. The yogurt samples were evaluated by a trained panelist familiar with sensory evaluation techniques. The average and standard error were carried out for 3 replicates using an SPSS computer program. The incorporation of WPI improved the water-holding capacity of the nonfat yogurt and the rheological properties. The nonfat yogurt incorporated with 7% WPI had comparable sensory and textural characteristics to the full-fat yogurt. The firmness of yogurt samples significantly decreased by increasing the addition of WPI. The SEM micrographs showed that the addition of WPI improved the microstructure of nonfat yogurt samples by adding WPI. So, WPI can be used as a fat replacer to develop nonfat yogurt with desired features. WPI might be a natural and economical ingredient for producing nonfat fermented dairy food products.
Dairy Foods: Posters Posters Dairy Foods: Dairy Products 7/11/2021 0:00 t84289 Watch P211 Synergistic and antagonistic ingredient interactions as a sugar reduction strategy. 38 A. Riak sensory synergy cross-modal interactions A. Riak1, R. Roberts1, J. Hayes1, G. Ziegler1, H. Hopfer1 1The Pennsylvania State University, University Park, PA Approaches to combating childhood obesity include food product reformulation to decrease added sugar while maintaining product acceptability. This research is testing for perceived synergistic and antagonistic ingredient interactions between sucrose, vanillin, and cocoa powder in chocolate milk, which is the most popular flavor in the National School Lunch Program. The objectives of this study were to (i) evaluate response-surface intensities of sucrose, vanillin, and cocoa powder mixtures while assessing optimization in chocolate milk (ii) determine the presence of synergistic, additive, and antagonistic ingredient interactions using the isobole method, and (iii) measure formulation acceptability. One hundred thirty-six adults evaluated 10 of the 22 samples in a counterbalanced, incomplete block design for the response-surface and isobole findings. Final regression models were then used to create tri-variable contour plots with the Ternary package in R. The evaluation of the contour plots highlighted the large contributions of sucrose-vanillin and sucrose-cocoa interactions to sweetness, bitterness, and chocolate flavor intensities on 100-point intensity scales. Of the 5 samples evaluated with the isobole method for both sweetness and bitterness, samples with 2.33% sucrose, 0.033% vanillin, and 0.67% cocoa, as well as samples with 4.67% sucrose, 0.017% vanillin, and 0.83% cocoa (%wt/wt) both had interaction index values below 0.9 and above 1.1 that illustrated sweetness synergy and bitterness antagonism, respectively. For both the adult (n = 142) and child (n = 61) acceptability tests utilizing 9-point hedonic scales, a mixed-effects ANOVA model (P < 0.05) was used to determine statistically significant differences in overall acceptability scores of the evaluated samples. Results from this indicated that samples with sucrose concentrations of 4.67% and 9.00% were liked significantly more than samples with 2.33% sucrose. These results could assist chocolate milk retailers in formulating products that decrease added sugar content while maintaining consumer acceptability.
Dairy Foods: Posters Posters Dairy Foods: Chemistry 7/11/2021 0:00 t84400 Watch P212 Understanding casein-whey protein interactions in acid gels of fibrillated model milk protein concentrate using Förster resonance energy transfer (FRET) microscopy. 39 G. Rathod Förster resonance energy transfer (FRET) casein-whey proteins interactions fibrillated model MPC G. Rathod1, D. Boyle1, J. Amamcharla1 1Kansas State Univerisity, Manhattan, KS Förster resonance energy transfer (FRET) is a widely used technique to study interactions between 2 molecules and it is based on the non-radiative (dipole-dipole) energy transfer from a donor fluorescent dye to an acceptor fluorescent dye only when they are in close proximity (<10 nm). The objective of this study was to use the FRET technique to understand the interactions between caseins and whey proteins during acid gelation. So, 2 lots of micellar casein concentrate (MCC) and milk whey protein isolate (mWPI) were obtained from commercial sources. Proteins in MCC were labeled with the donor dye ATTO-488 NHS ester and proteins in mWPI were labeled with the acceptor dye ATTO 532-NHS ester. The labeled MCC and mWPI dispersions were mixed accordingly to prepare control model milk protein concentrate (C-MPC) and fibrillated model MPC (F-MPC). F-MPC was prepared by mixing MCC (8% protein) with fibrillated mWPI (2% protein) in equal proportions, resulting in a 5% protein dispersion. Similarly, C-MPC was obtained by mixing MCC with mWPI. The resulted C-MPC and F-MPC contained 5% protein with a casein-to-whey proteins ratio similar to milk. The protein dispersions were heated to 90°C for 10 min, cooled to 30°C, and acidified to pH 4.6 with glucono-δ-lactone to form acid gels. Acid gels were viewed using a confocal laser scanning microscope and the images were analyzed using ImageJ software and FRET analyzer plugin where bleed through analysis gave a Pearson r-value of more than 0.95 indicating that FRET interactions are highly significant (P < 0.05) in both MPCs during gelation. From the FRET index images, F-MPC showed 61% white area, indicating strong molecular interactions within the Förster radius. On the other hand, C-MPC showed only 4.3% white area. The results show very strong interactions between caseins and fibrils while moderate and uniform interactions in C-MPC gels. The gel strength and other rheological properties of acid gels are strongly influenced by casein and whey protein interactions. FRET analysis can be a useful tool to understand protein interactions at a molecular level.
Dairy Foods: Posters Posters Dairy Foods 7/11/2021 0:00 t84283 Watch P213 Switchable solvents: A novel extraction method for milk phospholipids. 40 K. Rathnakumar phospholipids dairy by-products CyNMe2 K. Rathnakumar1, S. I. M. Monteagudo2 1South Dakota State University, Brookings, SD, 2New Mexico State University, New Mexico, NM Phospholipids (PLs) found in dairy products are of great interest due to their health and nutritional benefits associated with their consumption. Dairy by-products represent a potential source of PLs, which make them an attractive feedstock for value-added opportunities of milk phospholipids. Currently, the extraction of PLs from streams of by-products result in overall low efficiencies, and it involves subsequent solvent separation and lipid recovery. The research work focuses on the extraction of milk phospholipids from by-product streams with a tertiary amine (N, N-dimethyl cyclohexylamine, CyNMe2) as a switchable hydrophilicity solvent. This solvent can be reversibly switched between a hydrophobic and hydrophilic form by simply bubbling or removing CO2. Different dairy by-products streams, including buttermilk (BM), β-serum (BS), concentrated buttermilk (CBM), and raw cream (RC) was used to evaluate the feasibility of CyNMe2. The extraction efficiency of CyNMe2 ranged from 0.33 to 99%, depending on the type of by-product. Remarkably, CyNMe2 extracted up to 99% of the PLs directly from buttermilk (BM). The extraction of PLs from BS was further studied using ultrasound before CyNMe2 extraction. Overall, higher acoustic intensity before CyNMe2 extraction recovered 69.07 ± 0.11% of PLs, 10 times higher than the samples without ultrasound pretreatment. The recovered fraction of PLs mainly comprised phosphatidylinositol (32%), phosphatidylethanolamine (30%), and sphingomyelin (37%). The effect of the extraction temperature(25, 40, and 60°C), time (3, 10, and 18h) and solvent ratio (3/1,10/1, and 18/1 mL) was also studied. The highest yield obtained was 29.29 ± 0.06% of PLs at 60°C, at minimized solvent ratio and time (3/1 mL and 3 h). All experiments were carried out in 3 replicates and statistically analyzed using Tukey's test. Insights into the extraction mechanism of the CyNMe2 was studied through various analytical measurements, such as analysis of protein profile, particle size, zeta-potential, and microstructure such as confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). CyNMe2 seems to disrupt the protein-membrane through ion pair formation, releasing the PLs into the aqueous medium. Therefore, CyNMe2 shows to be an effective way to concentrate PLs from by-products.
Dairy Foods: Posters Posters Dairy Foods: Cheese 7/11/2021 0:00 t84072   P214 The effect of different heat treatment conditions on functional properties of polymerized liquid whey proteins. 41 T. Fang whey proteins J. Wang1, T. Fang1 1Jilin University, Changchun, Jilin, China Fresh sweet whey was pasteurized (60°C for 30min) and pre-filtered using a screen mesh. The treated whey was subjected to microfiltration (MF, 0.1um, at 45°C for 1h). MF whey was treated by ultrafiltration using a 10 kDa cut-off membrane to 25-fold. The UF treated whey was electrodialyzed (ED) to remove 90% of salt and the final protein content of the liquid whey protein (LWP) was ~8.0%. Polymerized liquid whey protein (PLWP) was prepared by heating. Influence of heating temperature, heating time, and pH on turbidity, solubility, zeta-potential, free sulfhydryl group, surface hydrophobicity, emulsifying properties, and degree of polymerization of PLWP was studied. There were significant differences (P < 0.05) in surface hydrophobicity, zeta-potential, free sulfhydryl group on the surface, turbidity and emulsifying properties between LWP and PLWP. The absolute value of zeta-potential of PLWP increased in range of pH 7.0–9.0, and higher than LWP (>20MV). The free sulfhydryl group of PLWP was significantly higher (P < 0.05) than LWP (4.15µmol/g). The SDS-PAGE confirms the formation of polymers with large molecular weight by heating. The a-lactalbumin (a-LA) and β-lactoglobulin (β-LG) of PLWP were determined by HPLC and the degree of polymerization was calculated. The polymerization degree of LWP increased up to 85.89% with increasing heating temperature and time. The denaturation degree of a-LA with PLWP were more than 70% at 70°C, while that of β-LG increased with pH (7.0–9.0), but there was no significant difference (P > 0.05) in the denaturation degree at pH 7.0–7.5. The results of rheological properties of PLWP showed that the flow curves of all the PLWP with different heating conditions were suitable for the Sisko model, and all flow indices of PLWP were less than 1. The viscosity of PLWP was significantly higher (P < 0.05) than LWP. The apparent viscosity of PLWP increased with the temperature from 70 to 90°C at pH 7.0. All experimental analyses were carried out in triplicates. The significant differences of data between samples and control were calculated using Version SPSS11.5. The significance level was set at P < 0.05. One-way ANOVA was employed to find the significant differences. The PLWP (75°C for 20min at pH7.0) can be used as a thickening agent in the preparation of yogurt and it may be used as a natural and functional ingredient for formulation of milk based fermented foods.
Dairy Foods: Posters Posters Dairy Foods: Processing 7/11/2021 0:00 t84584 Watch P215 Production of milk fat globule membrane-enriched ingredient derived from acid whey as potential healthful ingredient. 42 M. Chrusciel milk fat globule membrane acid whey membrane filtration M. Chrusciel1, J. Ortega-Anaya1, R. Jiménez-Flores1 1The Ohio State University, Columbus, OH Milk fat globule membrane (MFGM) containing milk phospholipids (MPL) have recently been shown to have potential health benefits such as neuronal health and development, as well as gut function, skin health, and cancer-fighting properties. Acid whey, the by-product from the manufacturing of acid-based cheeses and yogurts, is generally regarded as containing little nutrition value due to its low pH and high-water and mineral content. However, this by-product is a valuable source of MFGM and other components when processed. In this study, acid whey was treated by membrane filtration to produce a retentate rich in MFGM, and finally spray dried to create a shelf stable powder ingredient with potential use in foods with health benefits. Fresh acid whey was ultrafiltered though a 50 kDa lab-scale membrane system in triplicate, and further treated with tri-sodium citrate and diluted ammonium hydroxide (for pH adjustment at low temperature) combined with ultrafiltration/diafiltration to remove whey proteins. The final fraction was spray dried to produce an ingredient with a total average of 4.5% of MPL measured by high-performance liquid chromatography (HPLC). Moreover, the analysis of individual classes of MPL showed a composition of 4.2 µg/mg of PI, 2.8 µg/mg of PS, 10.2 µg/mg PE, 13.1 µg/mg of PC and 15.0 µg/mg of SM. In addition, we were able to significantly reduce the content of caseins and whey proteins to a maximum of 20% of total protein in dry basis, identified by SDS-PAGE-fluorescence analysis. Migration to a pilot-plant scale is currently being conducted to calculate yields for potential industrial application. The ability to transform acid whey into a nutrient rich, functional powder ingredient in an economical and efficient way will have industrial and commercial applications as a high-value, healthful product.
Dairy Foods: Posters Posters Dairy Foods 7/11/2021 0:00 t84344 Watch P216 Biofilm formation in the milk sampling devices as a result of prolonged use in a dairy processing facility. 43 R. Kalita biofilm sampling device R. Kalita1,2, S. Anand1,2 1Midwest Dairy Foods Research Center, Minneapolis, MN, 2Dairy and Food Science Department, South Dakota State University, Brookings, SD During prolonged processing of milk, adhesion of bacteria cause biofilm formation in the dairy equipment surfaces. This leads to cross-contamination and shedding of bacteria in processed milk affecting the safety and quality of the milk products. The objective of this study was to determine the extent of biofilm formation in the milk sampling devices used in the dairy industry. To represent a higher incidence of Bacillus licheniformis, raw whole milk (at 4°C) was spiked with vegetative cells of B. licheniformis (4 log cfu/mL) and pasteurized for 12 h, uninterruptedly at 72°C/16 s. Commercial port-septum type of sampling devices was fitted in a pilot-scale pasteurization unit at the points of raw milk-in and pasteurized milk-out. Raw and pasteurized milk samples were drawn aseptically at different intervals of processing to examine the bacterial levels. After 12 h run, attached bacterial cells in the different parts of the sampling ports were swabbed using quick swabs and aerobic plate count was performed using tryptic soy agar with incubation at 32°C for 48 h. Selected isolates from the sampling devices were identified using MALDI-TOF. The experiment was conducted in duplicates and data were compared using ANOVA. The sampling device on the raw side found to experience higher bacterial attachment and biofilm growth (2.12 ± 0.12 log cfu/cm2) compared with pasteurized side (1.14 ± 0.03 log cfu/cm2), indicating a higher attachment potential in the raw side sampling device. A significant difference (P < 0.05) was observed between the biofilm counts in the sampling devices from raw and pasteurized sides. MALDI-TOF revealed B. licheniformis to be the predominant species in the sampling port biofilms on the pasteurized side. However, B. licheniformis, Staphylococcus sp., E. coli, and Strep. uberis were identified in the biofilms of the sampling port on the raw side. The results demonstrated that the prolonged usage may prompt biofilm formation in the sampling devices. This suggests that replacing the septum-based sampling device after a certain interval or processing of milk within a shorter period could help to prevent biofilm formation.
Dairy Foods: Posters Posters Dairy Foods: Processing 7/11/2021 0:00 t84312 Watch P217 Effect of common dairy clean-in-place protocols on the surface roughness of stainless steel surfaces. 44 T. Almalki surface roughness biofilm T. Almalki1,2, S. Anand1,2 1Midwest Dairy Food Research Center, Minneapolis, MN, 2Dairy and Food Science Department, South Dakota State University, Brookings, SD Thermoduric spore formers survive heat treatments and lead to the formation of contact surface biofilms. These biofilms are difficult to clean and cause cross-contamination of milk and dairy products during milk processing. When bacteria aggregate on the surfaces, they form resilient biofilms over time that need to be removed and washed by applying harsh CIP chemicals. These typical cleaning and disinfection protocols in dairy plants are vital in ensuring good quality products. It is hypothesized that repeated use of CIP chemicals would alter the surface roughness of native, welded, and polished SS 316 surfaces and support biofilm formation differently. The present study is focused on evaluating the role of repeated CIP process on surface properties and understanding the relationship between surface roughness and biofilm formation. Plate heat exchanger CIP protocol was followed to clean the SS 316 coupons (2X2 cm2) for 10 consecutive cycles after forming biofilms using Geobacillus stearothermophilus. The selected organism was spiked into sterile skim milk samples at 6.0 log cfu/mL. After every CIP cycle, the biofilm counts were taken using standard microbiological techniques. Scanning electron micrographs were also taken to visually observe the developed biofilms. Laser scanning microscope images were taken to observe surface roughness changes pre-and post-CIP treatment. The replicate data from 3 trials for the chosen organism were analyzed and means were compared using Keyence VK Analyzer software. The surfaces roughness measurements (Ra) of pre-CIP treatment of native, welded, and polished surfaces were 0.6µm, 2.06 µm, and 1.01 µm respectively, and the measurements of post-CIP first cycle were 2.3 µm, 6.7 µm, and 2.9 µm after the first cycle. whereas the post tenth-cycle measurements were 3.8 µm, 19.2 and 4.8 µm respectively. These results demonstrate obvious changes in surface roughness after exposure to CIP chemical solutions, highest being on weldments. These observations agree with our hypothesis that repeated exposure to CIP cleaning cycles alters surface roughness and may cause cross-contamination in dairy products processing due to increased biofilm formation.
Dairy Foods: Posters Posters Dairy Foods: Processing 7/11/2021 0:00 t83868   P218 Effect of plate-and-frame filtration temperature on the functionality of milk protein concentrate. 45 A. Mishra milk protein concentrate plate-and-frame filtration functional properties A. Mishra1, A. R. Hammam1, V. Sunkesula1, L. E. Metzger1 1South Dakota State University, Brookings, SD A high level of solids in feed material saves cost of energy in spray drying. In our related research, we determined that plate-and-frame filtration (PF) system could be efficient in concentrating milk protein concentrate (MPC) when processed at elevated temperature. In this study, the functionality of concentrated MPC produced using PF system was compared with the feed; an MPC80 obtained from the ultrafiltration of skim milk. Feed containing 20% total solids and about 80% total protein based on solids was concentrated in PF system fitted with flat sheet membranes having 3.3m2 surface area with a 10 kDa molecular weight cut-off for 3 replications. Three different PF treatments such as PF at 22°C (PF22), PF at 50°C for medium solids (PF50MS), and PF at 50°C for high solids (PF50HS) were performed. For PF22 and PF50HS treatments, filtration was continued until the transmembrane pressure difference become 900 kPa whereas for PF50MS treatment, retentate was drawn when the level of solids achieved nearly 30%. Feed and PF retentates were spray dried to get MPC powder and their functional properties were evaluated. Reconstituted MPC showed a pseudoplastic behavior and best fitted with the Herschel-Bulkley model where consistency index was decreased, and flow behavior index was increased for the high-temperature PF treatments. Rennet coagulation time was longer for the high-temperature PF treatments and required CaCl2 ~0.25% for timely coagulation. Wetting time was increased whereas dissolution capacity and heat coagulation time were decreased for the powders from high temperature PF when compared with PF22 and feed. High-temperature PF did not impact emulsion formation but improved the emulsion stability. Foaming capacity was increased with increasing protein in the powder however, their stability was similar for all treatments. The level of whey protein reduced slightly at high-temperature PF on which the amount of denatured protein was also higher. This study determined that temperature optimization is important for concentrating MPC in the PF system to maintain the functional properties.
Dairy Foods: Posters Posters Dairy Foods: Microbiology 7/11/2021 0:00 t84172 Watch P219 Fermentation of whey permeate using Brettanomyces claussenii: Creating opportunities to develop value-added products. 46 V. K. Rivera Flores whey permeate valorization galactose ethanol V. K. Rivera Flores1, T. A. DeMarsh1, S. D. Alcaine1 1Cornell University, Ithaca, NY Whey permeate has various functional benefits that have driven its use as an additive in many foods. However, no current application explores potential valorization that would enable better utilization of this once considered by-product. Through an innovative value-added approach, the lactose present in whey permeate can be hydrolyzed into galactose and glucose, which can then be strategically converted to ethanol through fermentation. If galactose remained unmodified, it could confer low-glycemic attributes and potential health benefits, to thus create low-alcoholic beverages from whey permeate with added functionality. Previous research from our group has shown that such approach is feasible. Under anaerobic conditions, Brettanomyces claussenii can selectively ferment glucose into ethanol from hydrolyzed lactose, leaving the galactose intact. This creates an opportunity to explore whey permeate fermentation to produce value-added products. Hence, the aim of this research is to optimize whey permeate fermentation by B. claussenii to maximize ethanol and galactose production, using surface response methodology. For this purpose, 5 fermentation factors were studied for their impact on ethanol and galactose yield: temperature (20–40°C), substrate concentration (5–15% TS), enzyme/substrate ratio (0–40 IU/ g lactose), inoculation level (6–8 log cfu/mL), and time (6–30 d). Anaerobic fermentations were carried out in 200 mL of substrate, and a quadratic model was built for each response to allow for optimization. Results showed that all factors were significant in the synthesis of both products. The predictive models for ethanol and galactose achieved coefficients of determination (r2) of 92% and 95%, respectively. With optimized concentrations of 4.6% vol/vol for ethanol, and 70.8 g/L for galactose. These results demonstrate that it is possible to adjust multiple fermentation parameters to maximize ethanol and galactose production from whey permeate. Moreover, they open possibilities for the design of biomanufacturing processes to develop functional beverages that would appeal to health-conscious consumers.
Dairy Foods: Posters Posters Dairy Foods: Processing 7/11/2021 0:00 t84028 Watch P220 Model fermentation of dairy effluents by Brettanomyces claussenii with lactose cleavage to create a value-added product. 47 K. Jencarelli fermentation lactose acetic acid K. Jencarelli1, M. R. Lawton1, S. D. Alcaine1 1Cornell University, Ithaca, NY Disposal of dairy by-products such as acid whey is a burden on manufacturers due to high biological oxygen demand. In an effort to upcycle dairy effluents, residual sugars can be recovered. While approximately 70% of adults are lactose intolerant, lactose can be cleaved into its monomers, glucose and galactose, and sold as valuable and digestible simple sugars for other processes. Glucose can also be fermented by Brettanomyces claussenii into acetic acid, a key ingredient in consumer goods such as kombucha and vinegar, while retaining galactose for sugar collection. The objective of this study was to evaluate sugar utilization and time for acetic acid production in an aerobic fermentation by B. claussenii as an effort to upcycle dairy effluents. A 30-d aerobic fermentation was run in synthetic media (YNB, pH 4.4, 4% lactose) to emulate acid whey. Flasks inoculated with B. claussenii at a concentration of 3 × 106 cfu/mL were treated with lactase to cleave lactose into its monomers. The flasks were incubated at 30°C (200 RPM) and 65% relative humidity to control for evaporation. Samples were taken every other day, plated for cell enumeration and analyzed with HPLC for lactose, glucose, galactose, ethanol and acetic acid. ANOVA and Tukey’s test were run to determine significant differences in sugars, acetic acid, and ethanol across fermentation time. By d 2, the lactase cleaved all of the lactose, resulting in an approximate 2% glucose and 2% galactose sugar source. Glucose was used quickly by the yeast, with complete utilization by d 2. Contrary to previous research, once glucose was depleted, B. claussenii utilized galactose, finishing the sugar source and completing the fermentation by d 6. Significant acetic acid production began on d 4 and reached an average concentration of 8.54 g/L by d 6 and maintained these levels for the 30-d period. Future research will be conducted to further investigate galactose utilization by B. claussenii and optimize production of acetic acid and galactose from various milk substrates via a factor screen and response surface methodology.
Dairy Foods: Posters Posters Dairy Foods: Processing 7/11/2021 0:00 t84101 Watch P221 Optimizing lactose fermentations with Brettanomyces claussenii for production of value-added goods from dairy by-products. 48 M. R. Lawton acid whey acetic acid fermentation M. R. Lawton1, K. G. Jencarelli1, S. D. Alcaine1 1Cornell University, Ithaca, NY Functional beverages such as kombucha are popular among consumers for their health benefits. Production involves the use of alternative microorganisms such as acetic acid bacteria and non-Saccharomyces yeasts to produce health-promoting compounds. One such yeast, Brettanomyces claussenii, has the ability to aerobically ferment lactose and produce acetic acid. This microorganism opens opportunities to produce acetic acid containing beverages from dairy by-products where lactose is the main sugar, such as acid whey. The objective of this study is to optimize acetic acid production from lactose using B. claussenii. Several strains of B. claussenii were screened for their ability to ferment lactose to acetic acid. Yeast Nitrogen Base (YNB) with 4% lactose at pH 4.0 was used as synthetic medium. Flasks of YNB, inoculated with each strain to a concentration of 3 × 106 cfu/mL, were incubated at 30°C (200 rpm) for 14 d. Uninoculated YNB was used as a negative control. Samples taken at day 0, 7, and 14 were analyzed for acetic acid and lactose via HPLC. The experiment was repeated 3 times and samples were analyzed in duplicate. Analysis of variance and Tukey’s test were used to determine significant differences in lactose and acetic acid content between strains on day 14. Strains Y-1414 and OYL-201 achieved highest acetic acid production, 7.31 ± 0.36 and 7.38 ± 0.22 g/L respectively. The lab strain (OYL-201) was used to further investigate the time necessary for acetic acid production. Fermentations were set up as previously stated in YNB (4% lactose) buffered at pH 4.4 to mimic acid whey conditions. Samples for the same analyses were taken every 2 d for 30 d. Levels of acetic acid were compared at each time point with ANOVA and Tukey’s test. The results indicate significant acetic acid production began by day 4 (5.27 ± 1.31 g/L), achieved the maximum and plateaued by day 6 (9.28 ± 0.778 g/L). This information will be used in further experiments to optimize acetic acid production through a screening of significant fermentation factors using fractional factorial and response surface methods.
Extension Education: Posters Posters Extension Education 7/11/2021 0:00 s9692                  
Extension Education: Posters Posters Extension Education 7/11/2021 0:00 t84729 Watch P222 Exploring intragroup variation as feeding management tool. 1 J. P. A. Rezende precision nutrition milk composition TMR auditing J. P. A. Rezende1, V. S. V. Dutra1, V. A. Oliveira1, P Machado2, M. A. C. Danes1 1University of Lavras, Lavras, MG, Brazil, 2Instituto Clínica do Leite, Piracicaba, SP, Brazil The importance of individual cow data to better characterize feeding groups when formulating diets is well known. We hypothesized that the variation within group can also be used in feeding management. Individual milk yield and composition, days in milk (DIM), body weight (BW), group dry matter intake (DMI) and diet particle size distribution, using a 3-screen particle separator in 5 points along the bunker were collected every 2 weeks for 6 mo from the high group of a 60 lactating cows dairy farm. Average values and coefficient of variation (CV) were calculated for all variables and an initial exploratory correlation analysis was run using PROC CORR of SAS 9.3. The group evaluated had on average 18 multiparous cows, with 152 DIM and 660 kg BW, producing 27 kg/d of milk, with 3.5% fat, 3.0% crude protein and 13.7 mg/dL milk urea nitrogen (MUN). The average diet proportion retained in top, middle and bottom screen were 8.2%, 41.7% and 50.1%, respectively. Group DMI was negatively correlated with CVs of BW (r = −0.65; P = 0.05) and DIM (r = −0.60; P = 0.05), demonstrating the negative effect of group heterogeneity on intake. Another interesting observation was the correlation between the CV of milk fat content and the CV of the top (r = 0.80; P < 0.01) and bottom (r = 0.74; P < 0.01) screens, unveiling a potential use of individual milk composition as feeding management tools, such as TMR audit. However, it is important to notice that these correlations were achieved after the removal of all observation with somatic cells count (SCC) greater than one million. When the complete data set was used, these correlations were no significant. The reason for that is not clear, since SCC and the CV of SCC did not significant correlate with any of the variables. The MUN negatively correlated with the CV of the bottom screen (r = −0.73; P = 0.01) and the CV of MUN negatively correlated with the CV of the top screen (r = −0.66; P = 0.03), demonstrating that the mixing quality can also affect MUN. This initial evaluation revealed that intragroup variation, calculated from individual milk composition, should be further explored as feeding management tool.
Extension Education: Posters Posters Extension Education 7/11/2021 0:00 t84570 Watch P223 Dairy producers’ perspective: Health and economic implications of the COVID-19 pandemic. 2 N. Silva-del-Rio COVID-19 dairy producer safety N. Silva-del-Rio1, J. Wenz2, F. C. Ferreira1, M. Chahine3, J. Dalton4, M. de Haro Marti5, M. Rovai6, M. B. Abreu1,7 1University of California–Davis, Tulare, CA, 2Washington State University, College of Veterinary, Pullman, WA, 3University of Idaho, Twin Falls Research and Extension Center, Twin Falls, ID, 4University of Idaho, Caldwell Research and Extension Center, Caldwell, ID, 5University of Idaho Extension Gooding County, Gooding, Gooding, ID, 6South Dakota State University, Dairy and Food Science Department, Brookings, SD, 7Universidade Federal de Viçosa, Department of Animal Science, Viçosa, MG, Brazil The aim of this study was to describe dairy producers’ perspectives on the health and economic implications of COVID-19 at the onset of the pandemic. Dairy producers were reached by an anonymous online survey circulated nation-wide via university and allied industry media outlets (Apr-20) and by mail [CA, ID, SD (Jun-Jul-2020), WA (Sep-20)]. Responses (n = 309) were received online (28%) and by mail (CA, 35%; ID, 16%; SD, 11%; WA, 9%) from herds with <100 (n = 45), 100 - 499 (n = 93), 500 - 1999 (n = 91) and ≥2000 (n = 70) cows. Respondents reported they had COVID-19 cases [suspected (4%); confirmed (8%)] at their premises. Regarding safety, overall producers were concerned about the health of their families (83% < 1,000 cows; 72% ≥ 1,000 cows) and their employees (56% < 1,000 cows; 88% ≥ 1,000 cows). COVID-19 information was obtained through television (38%), family and friends (26%), and social media (21%). Producers perceived that their employees were somewhat or very concerned (71%) with the pandemic; training was intended (4%) or provided (75%) in English (26%), Spanish (19%), or both (55%). The focus of training was: how to remain healthy at work (90%), at home (60%), what to do if a worker gets sick (77%), and to provide sick leave information (53%). Producers did not always offer training, and the reasons were: not necessary (38%), insufficient information available (17%), uncertainty about best approach (17%), or had no time (6%). Control measures implemented were: frequent hand-washing and sanitizer use (78%), social distancing (59%), prevention of employee gatherings (57%), limiting on-farm visitors (54%), and providing face masks (45%). The economic impact of COVID-19 concerned most dairy producers (82%); the greatest fears were being forced to reduce production, limit of the availability of goods, and lack of services. Dairy producers (76%) replied they had adequate information to develop COVID-19 emergency plans, and they had (30%) or were working (24%) on a plan. Results from this survey highlight the health and economic concerns of dairy producers during the COVID-19 pandemic and the mitigation efforts adopted.
Extension Education: Posters Posters Extension Education 7/11/2021 0:00 t83525 Watch P224 Udder dissections give dairy employees a better understanding of milk production. 3 M. Rovai dairy farms udder dissection dairy workers M. Rovai1, M. E. de Haro Martí2, M. Chahine3 1Dairy and Food Science Department, South Dakota State University, Brookings, SD, 2University of Idaho Extension, Gooding, ID, 3Animal, Veterinary and Food Sciences Department, University of Idaho, Twin Falls, ID Milk provides the major source of income on dairy farms and high-quality milk is the goal at every stage of the dairy operation. Employees are constantly asked to perform milking procedures correctly and consistently to achieve and maintain maximum milk quantity and quality. However, before performing the regular milking tasks, one needs to understand the function and structure of the mammary gland. It is known that hands-on activities enhance students’ interest and retention. The objective of the project was to assess knowledge gains following a 3-h udder dissection workshop. The training consisted of a PowerPoint presentation followed by an interactive hands-on session. The workshop explained: 1) the importance of understanding the main mammary gland physiology functions related to milk quality; 2) the importance of each step of the milking procedures; and 3) key recommendations about mastitis prevention related to the anatomical udder structure. A total of 18 dairy employees from 20 dairies representing 120,000 cows in Idaho participated in the training session. Participants were administered an exam consisting of 9 written questions before and immediately following the training. Exam scores were compared in SAS 9.4 (SAS Institute Inc., Cary, NC) using a paired t-test. Results indicate that the training had an effect (P < 0.0001) on dairy workers’ knowledge as indicated by the increase in average exam score from 2.13 ± 0.42 to 5.50 ± 0.38. Feedback indicated participants highly valued the hands-on experience and preferred it to traditional classroom settings. Giving dairy employees the chance to see a real udder inside and out will likely give them a different insight when they go back and milk the cows. The chance to get a different view of the udder also gives a better understanding of how mastitis can affect the animal. The knowledge originating from an udder dissection along with the classroom session may lead to a better understanding of the milking process and better milk quality by understanding the key anatomical features of the mammary gland.
Extension Education: Posters Posters Extension Education 7/11/2021 0:00 t83521 Watch P225 Assessing dairy employees’ mental health status in South Dakota: Workplace. 4 L. Guifarro dairy workers stress factors focus group L. Guifarro1, L. Stallones2, J. Rosecrance3, M. Rovai1 1Dairy and Food Science Department, South Dakota State University, Brookings, SD, 2Psychology Department, Colorado State University, Fort Collins, CO, 3Environmental & Radiological Health Sciences Department, Colorado State University, Fort Collins, CO The dairy industry’s dynamics are changing, trending toward a larger number of cows on a single farm with more hired employees. While the majority of the US dairy farm workforce is Latino, little is known about the causes of distress in this group. One of the primary challenges Latino dairy workers face is finding a balance between building a better future and their ability to integrate within their new culture. The quality of milk production is directly related to the well-being of dairy farm employees, and stress can have a negative impact on both employees and the farm. Behavior and health assessments can help to identify anxiety and stress caused by various sources. This study aimed to gather information on the main causes of behavioral stress in dairy farm employees along the I-29 corridor (South Dakota) and evaluate how it affects their work performance and job satisfaction. Six focus groups (FG) of 1 h each in Spanish were conducted with workers (n = 50; 88% male) from México, Guatemala, and other Latino countries (54%, 30%, and 16%, respectively). Transcriptions of the FG were analyzed and coded line by line for each quotation by using ATLAS.TI software (Scientific Software Development GmbH). Over 38 factors contributing to overall stress and job satisfaction at the workplace were identified and grouped as: 1. Work schedule; 2. Cattle handling; 3. Equipment failures; 4. Lack of teamwork; 5. Pressure at the workplace; 6. Interruptions at work; 7. Perception of the workload; 8. Extended shifts; 9. Weather seasons; and 10. Lack of communication skills in English. This project revealed areas of stress for the dairy employees that we were not aware of and needs further consideration. The FG results provided valuable insight that can be used to create better management strategies in the future to help dairy workers to cope with stress and learn how to mitigate stress at work in a healthy manner. Based on the information gathered, a tri-fold brochure was developed with basic knowledge covering stress causes and ways to reduce it. Supported by HICAHS Community-Initiated Grant Program (Colorado State University).
Extension Education: Posters Posters Extension Education 7/11/2021 0:00 t83460 Watch P226 Use of energy drinks, alcohol, and tobacco by dairy farm employees. 5 L. Guifarro dairy farms energy drinks employee health L. Guifarro1, M. Rovai1 1Dairy and Food Science Department, South Dakota State University, Brookings, SD Working on dairy farms may include long work shifts, long workweeks, exposure to extreme weather, high physical demands, and interruption of circadian rhythms. These factors may drive employees to find ways to keep themselves alert and productive. Because of that, energy drinks, tobacco, and alcohol use commonly co-occur in dairy farm employees. Energy drinks are nonalcoholic beverages containing stimulant compounds such as caffeine, which is marketed to reduce fatigue and improve physical/mental performance. Although frequent use of these beverages has been linked to negative health consequences, farmworkers may not be aware of that. This study aimed to determine the use of energy drinks, alcohol, and tobacco by South Dakota dairy farm employees. A personal interview was done with 70 employees from 4 farms. Participants were 76% male (women: 28 ± 1.7 and men: 34 ± 1.6 years old). The majority of workers were Mexican (46%) and Guatemalan (44%). Descriptive analysis was done using PROC FREQ of SAS v9.4. Thirty-nine percent (85% males) consumed energy drinks regularly (43% Monster and Red Bull beverages), whereas 40% (79% males) did not drink energy drinks at all. Only 21% consumed them in the past. The use of energy drinks was increased during wintertime and claimed to increase body temperature. Forty-nine percent (42% males) consumed alcohol after work on a daily basis and at social gatherings, whereas 40% have never consumed it. Nineteen percent currently smoked (only males), and 20% were former smokers (79% males). No sleep aid substances were used, and 6% of the male participants used pain killer drugs sporadically due to headaches, colds, or lack of sleep. Coffee and water were not frequently consumed. Energy drinks use at work and alcohol at home may impact employee’s well-being and increase their risk for future health issues. Measuring the energy drinks consumption and alcohol use is the first step toward understanding its use and risks. A socio-culturally responsive workshop curriculum for farmworkers is needed. This approach is powerful in making meaningful connections between their cultures, languages, current living situation, and life experiences. Study supported by HICAHS (Colorado State University).
Extension Education: Posters Posters Extension Education 7/11/2021 0:00 t83559 Watch P227 Assessing dairy employees’ mental health status in South Dakota: Family and community. 6 L. Guifarro stress factors dairy workers focus group L. Guifarro1, L. Stallones2, J. Rosecrance3, M. Rovai1 1Dairy and Food Science Department, South Dakota State University, Brookings, SD, 2Psychology Department, Colorado State University, Fort Collins, CO, 3Environmental & Radiological Health Sciences Department, Colorado State University, Fort Collins, CO Large-scale dairy farming in SD has become of great importance. Most of the dairy workers are Latinos searching for better life opportunities and personal growth. The new life choice, the lack of a close family circle and friends, and the hardship of adaptation to a new community may be associated with distress and low performance at the workplace. The study aim was to gather information on the stress factors related to family and community in dairy workers and assess how it affects their home and neighborhood conditions. Six focus groups (FG) of 1 h each in Spanish were conducted with workers (n = 50; 88% male) from México, Guatemala, and other Latino countries (54%, 30%, and 16%, respectively). Open-ended questions related to stress-causing factors in their current home, home countries, and community were used. Additionally, participants shared different practices used to manage stress. Sessions were video and audio-recorded. Verbatim transcriptions were analyzed and coded for each quotation using ATLAS.TI software (Scientific Software Development GmbH). Around 35 and 31 factors were identified as stress related to family and community, respectively. Factors were grouped as (A) Family: 1. Lack of communication with family back home; 2. Inability to attend to family concerns in their home country; 3. Family estrangement due to longer distances; and 4. Less time shared with family due to job schedule; and (B) Community: 1. Language barrier; 2. Long-distance to grocery shopping; 3. Cultural differences; 4. Weather variations; 5. High-cost healthcare services; and 6. Lack of social support. The results showed that workers are more likely to be distressed due to their current life situation and working circumstances (e.g., culture differences, lack of family support, English barrier). Over time, stress may contribute to health problems like depression or anxiety. Therefore, the importance of employees’ well-being is essential in achieving consistent and successful production performance levels. Based on the results, a tri-fold brochure was designed with basic knowledge covering stress causes and ways to reduce it based on their sharing ways to reduce stress. Instructional workshops for workers designed to promote behavioral stress awareness and strategies to better manage and cope with their specific stressors are needed. Supported by HICAHS Community-Initiated Grant Program (Colorado State University).
Extension Education: Posters Posters Extension Education 7/11/2021 0:00 t84040 Watch P228 Idaho DHIA supervisor job satisfaction and interest in testing more cows. 7 J. C. Dalton dairy DHIA supervisor survey J. C. Dalton1 1University of Idaho, Animal, Veterinary and Food Sciences Department, Caldwell Research and Extension Center, Caldwell, ID Idaho lactating cow inventory was 635,000 on January 1, 2020, up 21,000 animals from January 1, 2019. Twenty-three independent Idaho DHIA supervisors tested, on average, 289,693 and 300,943 cows per month in 2019 and 2020, respectively. To determine Idaho DHIA supervisor job satisfaction and interest in testing more cows, a survey was conducted in 2 consecutive years. Supervisors (2019: n = 14; 2020: n = 11) in attendance at the 2019 and 2020 Annual Idaho DHIA Supervisor Conference were asked questions regarding length of time working as a supervisor, job satisfaction, number of cows tested per week, number of hours worked per week, and interest in testing more cows. For the years 2019 and 2020, respectively, 65% and 55% of supervisors reported being on the job more than 10 years. When asked how satisfied they were with their job as a DHIA supervisor, the majority responded that they were very satisfied (65% and 82% for 2019 and 2020, respectively). Results showed that 79% and 73% of supervisors (for 2019 and 2020, respectively) tested more than 2000 cows per week, while 69% and 60% of supervisors (for 2019 and 2020, respectively) reported working greater than 40 h per week. When asked if they were interested in testing more cows, 86% and 82% of supervisors responded yes, for 2019 and 2020, respectively. In 2020 63% of supervisors responded they felt respected by dairy personnel, managers, owners, and veterinarians. Survey results provide evidence the majority of Idaho DHIA supervisors are very satisfied with their job and are interested in testing more cows. Idaho, in 2006, was ranked the fourth-largest milk producing state in the United States, with an inventory of 500,000 lactating dairy cows. In 2020, Idaho was the third-largest milk producing state in the United States and had 635,000 cows. With continued dairy industry growth and only 23 DHIA supervisors in Idaho, it is apparent that opportunities exist for current and future supervisors interested in testing cows.
Forages and Pastures: Orals Orals Forages and Pastures 7/11/2021 0:00 s9634                  
Forages and Pastures: Orals Orals Forages and Pastures 7/11/2021 0:00 t84026 Watch 122 Yeast population and dry matter losses of sugarcane silage inoculated with Lactobacillus buchneri. 1 G. B. Neto Lactobacillus buchneri silage losses yeast G. B. Neto1, A. W. P. Freitas1, R. B. Botelho3, C. A. Rosa4, J. P. Sampaio5 1Animal Science Institute of Department of Agriculture and Food Supply, Ribeirão Preto, São Paulo, Brazil, 2Animal Science Institute of Department of Agriculture and Food Supply, Ribeirão Preto, São Paulo, Brazil, 3AnimaDepartment of Agriculture and Food Supply, Ribeirão Preto, São Paulo, Brazil, 4Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, São Paulo, 5Universidade Nova de Lisboa, Lisboa, Portugal Sugarcane has limitations to the ensiling process due to fermentation of sugars and organic acids by yeasts, producing alcohol and gas. The present study was performed to investigate the yeast population and dry matter losses of sugarcane silage inoculated with Lactobacillus buchneri (2.5 × 10−10 cfu g−1). The sugarcane (Saccharum officinarum L.) cultivar IAC-SP93–3046 (28.3° Brix, 36%DM) was chopped and sprayed with inoculant solution and ensiled in plastic buckets with a volume of 20 L, provided with Bunsen valves. Silos were weighed after filling and at the end of ensiling period to assess gravimetric DM losses (DML), gas losses (GL) and effluent losses (EL). The silos were opened after 114 d and the DML were calculated, according to the equation: DML = (FMs – FMo) × 100 / FMs, in which: DML = dry matter losses (% of DM); FMs = weight of forage mass at sealing; FMo = weight of forage mass at opening. The EL were calculated, according to the equation: EL = EW × 1000 / FF, in which: EL = effluent losses (kg/t of fresh forage), EW = effluent weight and FF = fresh forage. Yeast counts were done in silage water extract (25 g silage and 225 mL deionized water, blended for 4 min) sequentially diluted and plated in Petrifilm YM 3M, 48h at 30°C. The data were submitted to one-way analysis (GLM procedure in SAS) and means were compared by Tukey test (P < 0.05). The high density of the silos led to subestimation of effluent losses as it was not removed from the silos during ensiling. The additive was capable of reducing yeast counts and dry matter losses during fermentation of sugarcane silage (Table 1). Table 1. Losses of sugarcane silage inoculated with Lactobacillus buchneri
 Item Control L. buchneri SEM P-value
Density, kg m3 881 885 16.391 0.815
pH (0 h) 3.13 2.90 0.081 0.024
pH (2 4h) 3.31 3.03 0.072 0.008
DM (%) initial 36.47 36.81 1.616 0.022
DM (%) final 28.14 32.90 0.400 0.358
DM losses, (%DM) 32.26 19.68 5.260 0.042
Gas losses, (%DM) 16.21 10.10 2.533 0.041
EL, kg t−1 64.06 64.42 5.280 0.936
Brix 15.53 20.70 2.714 0.080
Yeast (0 h), log cfu g−1 4.79 2.95 0.986 <0.001
Yeast (24 h), log cfu g−1 6.00 4.47 0.212 0.391
Forages and Pastures: Posters Posters Forages and Pastures 7/11/2021 0:00 s9580                  
Forages and Pastures: Posters Posters Forages and Pastures 7/11/2021 0:00 t83508   P229 Effect of growing degree-days and dry matter at harvest of whole-plant corn silage on total-tract neutral detergent fiber digestibility. 1 E. Giugge total-tract neutral detergent fiber digestibility (TTNDFD) corn silage fiber E. Giugge1, J. L. Monge2, F. Bargo3 1Grupo Chiavassa, Carlos Pellegrini, Santa Fe, Argentina, 2Universidad Nacional Villa María, Villa María, Córdoba, Argentina, 3Universidad de Buenos Aires, Capital Federal, Argentina In whole-plant corn silage (WPS), fiber content and fiber digestibility depend on hybrids, cycle length, and growing and soil conditions during the growing season. The variable to define silage harvesting time is the dry matter at harvest (DMatH), also if DMatH is combined with the growing degree-days (GDD) we could define fiber content and digestibility. The aim of this study was to analyze the effect of DMatH and GDD in fiber content and fiber digestibility of the WPS. We registered at a commercial dairy farm in Argentina (Chiavassa Dairy Farm; −32°02′60″ S, −61°47′59″ W) the GDD since planting to harvest time and DMatH during silage harvest and sampled 144 silo-bags (61 flint and 82 semident hybrid types) for 3 years (2017, 2018 and 2019). Before filling each silo-bag and during the silage harvest, each wagon was weighed before loading the material into the bag. Every 2 h, silage DMatH was determined with 200 g whole-plant corn chopped sample dried for 2 h in forced air oven at 135°C. GDD was calculated using the daily average temperature (registered by wireless Vantage Pro 2 weather station in the farm) minus basal temperature 10°C. After 90 d, one sample was collected manually and composed from 3 sampled points from the side of each silo-bag. The samples were analyzed by NIRS (Rock River Lab Inc.) for aNDF, ADF, lLignin (Lig), total-tract neutral detergent fiber digestibility (TTNDFD) and acid detergent indigestible crude protein (ADICP). We ran partial correlation (InfoStat, 2017) keeping year and hybrid type as fixed variables. TTNDFD was negatively correlated (P < 0.05) with GDD (r = −0.56), DMatH (r = −0.31), Lig (r = −0.482) and ADICP (r = −0.46). TTNDFD was positively correlated (P < 0.05) with aFDN (r = 0.19). ADICP (as a result of the conservation processes) was positively correlated with Lig (r = 0.35). We concluded for these ranges of GDD (1,357–1,666°C) and DMatH (34–52%) that TTNDFD decreases when GDD and DMatH increase. Also the negative relationship of ADCIP with TTNDFD suggests that is affected during the silage process.
Forages and Pastures: Posters Posters Forages and Pastures 7/11/2021 0:00 t84470   P230 Type of harvester impacts on corn silage quality in Brazilian dairy farms. 2 G. F. M. Leão dairy cattle forage conservation pH G. F. M. Leão1, E. R. Gaida1, C. D. Neufeldt1, L. L. Damasceno1, D. E. Moreira1, P. H. M. Santana1, A. A. Meierjurgen1, C. J. Risden1, H. P. Janssen1, E. M. Ribas1 1Negócios Leite, Castrolanda Cooperativa Agroindustrial, Castro, PR, Brazil, Quality of corn silage depends on a range of factors, including the type of harvester. The goal of this study was to investigate the influence of the harvester on nutritional parameters of corn silage under dairy farm conditions. Two hundred and 53 samples were collected from 193 dairy farms located in southern of Brazil. Samples were divided in 2 treatments depending of the type of harvester used in the farm during the ensiling process: Pull-type (PT) or Self-propelled (SP). Sequentially, samples were submitted for nutritional quality analysis and data were analyzed using the MIXED procedure of SAS. Silage dry matter after the conservation process was higher (34.20 vs. 32.30%; SEM = 0.45; P = 0.01) and pH was lower (3.94 vs. 3.89; SEM = 0.02; P = 0.01) for SP silages. In addition, SP silages showed higher values of in vitro digestibility of DM (73.15 vs. 72.45%; SEM = 0.17; P = 0.03) and lower levels of acid detergent fiber (23.26 vs. 22.57%; SEM = 0.24; P = 0.05), lignin (2.21 vs. 2.08; SEM = 0.02; P = 0.01) and ash (3.71 vs. 3.49%; SEM = 0.05; P = 0.01). Values of crude protein, fat, starch, neutral detergent fiber (NDF), starch digestibility, NDF digestibility and total digestible nutrients were not affected by the treatments (P > 0.05). It is important to highlight that due to the high number of samples and the great variability between farms, some results are of minor biological significance. Overall, the results suggest a better conservation and nutritional quality of SP silages in dairy farm conditions.
Forages and Pastures: Posters Posters Forages and Pastures 7/11/2021 0:00 t83918 Watch P231 Effect of kernel breakage on the fermentation profile, N fractions, and in vitro starch digestibility of whole-plant corn silage and ensiled corn grain. 3 B. A. Saylor corn silage fermentation profile ruminal starch digestibility B. A. Saylor1, E. C. Diepersloot1, C. Heinzen Jr.1, C. L. McCary2, L. F. Ferraretto1 1Department of Animal and Dairy Sciences, University of Wisconsin–Madison, Madison, WI, 2Department of Animal Sciences, University of Florida, Gainesville, FL The objective of this experiment was to analyze the effect of kernel breakage on the fermentation profile, N fractions, and in vitro starch digestibility (ivSD) of whole-plant corn silage (WPCS) and ensiled corn grain. Whole corn plants were harvested, and ears were separated from the forage portion and shelled. Corn kernels were either left intact or broken manually using a hammer. The remaining forage portion of the plants was chopped. Samples of the intact and broken kernels were ensiled for 0 or 30 d in quadruplicate vacuum pouches. Remaining intact and broken kernels were each reconstituted with the chopped forage portion to simulate “whole-plant” corn forage. Reconstituted whole-plant corn forage samples were also ensiled for 0 or 30 d in vacuum pouches. Data for the reconstituted WPCS, kernels separated from WPCS, and the ensiled corn grain were analyzed separately. Data were analyzed as a completely randomized design using PROC GLIMMIX of SAS. The model included kernel form, ensiling, and their interaction as fixed effects. Concentrations of N fractions and organic acids were unaffected (P > 0.05) by kernel form (intact or broken) in WPCS. Soluble CP and ammonia-N concentrations were affected by ensiling (P < 0.001), with elevated concentrations of both N fractions in WPCS stored for 30 d. In kernels separated from WPCS, kernel form had no effect (P = 0.88) on zein protein concentrations. However, an interaction between kernel form and ensiling was observed (P < 0.001) for ivSD. Starch digestibility increased with ensiling, from 23.7 to 35.7% of starch, only in kernels that were broken. In ensiled corn grain, an interaction between kernel form and ensiling was observed (P < 0.001) for concentrations of soluble CP and ammonia-N. These N fractions increased with ensiling to a greater extent when kernels were broken. This study gives insight into the importance of kernel breakage to improve starch digestibility in corn silage through means other than a reduction in particle size.
Forages and Pastures: Posters Posters Forages and Pastures 7/11/2021 0:00 t83964 Watch P232 Effects of tillage system and cutting height at harvest on dry matter yield, chemical composition, and digestibility of forage maize. 4 O. I. Santana crop system digestibility fiber O. I. Santana1, A. Peña-Ramos1, J. I. Sanchez-Duarte2, A. Reyes-Gonzalez2 1INIFAP Campo Experimental Pabellon, Pabellon de Arteaga, AGS, Mexico, 2INIFAP Campo Experimental Laguna, Matamoros, COAH, Mexico The aim was to assess the effects of 3 tillage systems [no-tillage (NT), minimal tillage (MT; only plowing), and conventional tillage (CT; subsoiling and plowing)] and 2 cutting heights at harvest (15 vs. 40 cm) on dry matter (DM) yield, chemical composition, and digestibility of forage maize. A randomized complete block design with 4 replicates and 3 × 2 factorial arrangement was conducted in a field with subplots where each tillage system was carried out for 10 yr. Experimental unit was 4 rows of 0.76 m width and 5.0 m long. A white-dent hybrid (Supremo, Aspros) was planted at 90,000 seeds/ha. Maize was harvested when kernel had one-half milkline by cutting all plants on the 2 central rows at either 15 or 40 cm stubble height. Swaths were weighed and 5 whole-plants were chopped and a sample was dried to determine DM content. Dried samples were ground for chemical analysis and for in situ digestibility of DM (DDM) and neutral detergent fiber (DNDF) at 36 h using 2 rumen-cannulated cows. Data were analyzed in R studio using the same statistical model for all variables. Forage DM yield was not affected by treatments (mean ± SD; 26.7 ± 2.8 t/ha), but DM content was greater (P = 0.05) in NT (33.4%) compared with MT (31.3%) and CT (31.0%). Content of NDF was greater (P < 0.01) in forage cut at 15 than 40 cm (50.9 vs. 47.6%, respectively). There were differences (P = 0.04) among tillage systems for content of nonfiber carbohydrates (36.0, 32.4 and 34.1% for NT, MT and CT, respectively), which also differed (P < 0.01) between cutting heights (32.5 vs. 35.8% for 15 and 40 cm, respectively). There were interactions between tillage system and cutting height for DDM and DNDF (both P < 0.01). Former was greater in NT and MT cut at 40 than 15 cm (74.7 vs. 66.0% and 70.1 vs. 68.6%, respectively) but similar in CT (67.1 ± 1.4%). In contrast, DNDF was similar in MT (38.9 ± 0.8%) but lower in NT and CT cut at 40 than 15 cm (37.6 vs. 33.4% and 36.1 vs. 34.3%, respectively). In conclusion, independently of tillage system used, harvesting at higher cut improved nutritional value of forage without reducing DM yield.
Forages and Pastures: Posters Posters Forages and Pastures 7/11/2021 0:00 t83575 Watch P233 Influence of the inclusion of passion fruit waste in forage maize silage. 5 I. Espinoza maize silage passion fruit chemical composition I. Espinoza1, M. Romero1, A. Barrera1, A. Sanchez1, M. Medina1, G. Muñoz1, E. Torres1, Y. Torres1, M. Barros2, L. Montenegro1 1Universidad Tecnica Estatal de Quevedo, Quevedo, Los Rios, Ecuador, 2Universidad Tecnica de Ambato, Ambato, Tungurahua, Ecuador The aim of this research was to evaluate the effect of the inclusion of passion fruit (Passiflora edulis sims) residue in forage maize silage harvested after 60 d growth. The silage treatments on a % fresh basis were: T1 = 100% maize silage; T2 = 75% maize silage + 25% P. edulis waste; T3 = 50% maize silage 50% + 50% P. edulis waste; T4 = 25% maize silage + 75% P. edulis waste; T5 = 100% P. edulis waste, with 5 replications per treatment. The silages were made in 3 kg capacity polyvinyl chloride mini silos, with silage treatments manually packed, and kept at room temperature (28°C to 30°C) for 30 d fermentation. Crude protein (CP), dry matter (DM), organic matter (OM), ash, neutral detergent fiber (NDF), acid detergent fiber (ADF) and fat were evaluated. Chemical composition data were analyzed with the GLM procedure of SAS, with treatment as a fixed effect, and the least squares means compared using the Tukey test. The treatments T1, T2 and T3 showed higher (P < 0.05) DM concentration (21.98, 22.62, and 22.70% respectively). The OM was higher (P < 0.05) in T1, T4, T5 (91.14, 90.37, and 90.83% respectively). The CP was higher (P < 0.05) in T3, T4 and T5 (8.63, 8.71, and 8.41% respectively). The NDF, ADF and fat were higher for T5 (68.49, 55.02, and 14.15% respectively) and lower in T3 (58.37; 41.81 and 8.13% respectively) than other treatments (P < 0.05). Under the conditions of this study, it can be concluded that the incorporation of waste from passion fruit in forage maize silage increases the protein and fat content, and decreases the fiber content.
Forages and Pastures: Posters Posters Forages and Pastures 7/11/2021 0:00 t84001 Watch P234 Effects of microbial inoculation and variety on fermentation profile of whole-plant sorghum silage under short-term fermentation. 6 M. R. Pupo heterofermentative inoculant sorghum silage 1,2-propanediol M. R. Pupo1, E. C. Diepersloot1, L. G. Ghizzi2,3, J. O. Gusmão2,4, C. Heinzen Jr.1, C. L. McCary2, M. O. Wallau5, L. F. Ferraretto1 1Department of Animal and Dairy Sciences, University of Wisconsin, Madison, WI, 2Department of Animal Sciences, University of Florida, Gainesville, FL, 3Department of Animal Nutrition and Animal Production, University of São Paulo, Pirassununga, São Paulo, Brazil, 4Department of Animal Sciences, University of Lavras, Lavras, MG, Brazil, 5Agronomy Department, University of Florida, Gainesville, FL Our objective was to assess the effects of sorghum variety, microbial inoculation, and storage length on fermentation profile, nutrient composition and NDF ruminal disappearance of whole-plant sorghum silage. Samples from 3 varieties [forage sorghum, sorghum-sudangrass, and sweet sorghum] were collected at harvest, immediately inoculated [CON (50 mL distilled water) or LBLD (Lactobacillus plantarum, L. buchneri, and L. diolivorans; 300,000 cfu/g of wet forage)] and ensiled in experimental silos for 14, 28, or 56 d. Data were analyzed as a completely randomized design with a 3 × 2 × 3 factorial arrangement of treatments using the PROC GLIMMIX of SAS with fixed effects of variety, inoculation, storage length, and their 2- and 3-way interactions. After 56 d, pH was greatest (P = 0.02) in LBLD sweet sorghum and CON forage sorghum, while no differences (P > 0.05) were observed in sudangrass, with all pH values below 4.00. The LBLD treatments had greater (P = 0.001) acetic acid concentration than CON in forage sorghum. Regardless of variety, CON silage had no detectable 1,2-propanediol (1,2-PD) concentration. On the other hand, LBLD sweet sorghum and forage sorghum had greater (P = 0.001) levels of 1,2-PD at 56 d, with no differences (P > 0.10) observed for LBLD sudangrass. Neither CON nor LBLD in sudangrass or LBLD forage sorghum had detectable propionic acid. Furthermore, the concentration of propionic acid in CON sweet sorghum was undetectable at 14 d, while LBLD sweet sorghum was greater (P = 0.001) at 14 d and CON forage sorghum (P = 0.001) at 56 d. For sudangrass and sweet sorghum, LBLD decreased (P = 0.01) yeast counts compared with CON. The ruminal disappearance of NDF for forage sorghum was greater (P = 0.01) than sudangrass, while sweet sorghum was similar to other treatments (P > 0.10). Results indicate L. buchneri and L. diolivorans are actively involved in a heterofermentative co-fermentation resulting in the production of acetic acid and 1,2-PD. Additionally, the effects of these strains were pronounced in sweet and forage sorghum varieties before 30 d of ensiling.
Forages and Pastures: Posters Posters Forages and Pastures 7/11/2021 0:00 t84054 Watch P235 Effects of hybrid, season and trait on nutrient composition, dry matter yield, and predicted milk production of whole-plant sorghum grown in Florida. 7 M. R. Pupo forage quality brown midrib fiber disappearance M. R. Pupo1, C. Heinzen Jr.1, M. O. Wallau2, L. F. Ferraretto1 1Department of Animal and Dairy Sciences, University of Wisconsin, Madison, WI, 2Agronomy Department, University of Florida, Gainesville, FL Sorghum is becoming an important forage source for dairy cows in regions susceptible to adverse growing conditions for corn production. This study aimed to retrospectively assess the effects of season [summer vs. Spring], hybrid (forage sorghum vs. Sorghum-sudangrass) and trait [brown midrib (BMR) vs. non-BMR] on nutrient composition, DM yield and predicted milk yield of whole-plant sorghum grown in Florida. Twenty-four field trials were established from 2008 to 2019 and harvested at a targeted DM of 32%. Data were analyzed as a completely randomized design with a 2 × 2 × 2 factorial arrangement of treatments with the fixed effects of hybrid, trait, season, and their interaction, and year as a random effect. Spring sorghum had (P = 0.01) greater predicted milk yield per Mg (1,360 vs. 1,307 kg/Mg) and ha (22,731 vs. 14,710 kg/ha) than summer. This was related to greater (P = 0.001) DM yield (20.7 vs.14.1 Mg/ha) and starch concentration (14.4 vs. 10.4% of DM) but reduced NDF concentration (P = 0.02; 56.0 vs. 57.3% of DM) in the spring than summer. Season did not affect NDF digestibility (P = 0.63; 47.3% of NDF, on average). Despite a tendency (P = 0.06) for lower DM yield (16.9 vs. 17.9 Mg/ha), forage sorghum had (P = 0.001) greater predicted milk yield per forage (1,424 vs. 1,244 kg/Mg) and area (19,688 vs. 17,953 kg/ha) than sudangrass. Forage sorghum had (P = 0.001) 5.6%-units lower NDF concentration, but 2.3, 4.2, and 6.2%-units greater NDF digestibility (% of NDF), TDN and starch concentrations, respectively. Greater (P = 0.01) DM yield (19.1 vs.15.7 Mg/ha) and predicted milk unit of forage (19,767 vs. 17,874 kg/ha) was observed for non-BMR than BMR. In contrast, BMR sorghum had greater (P = 0.001) NDF digestibility (49.8 vs. 44.8% of NDF) and corresponding greater predicted milk yield per Mg of forage (1,385 vs. 1,283 kg/Mg) than non-BMR. These results indicate summer season might negatively affect yield and nutritive value of sorghum crop for silage. Sorghum trait and hybrid could be important alternatives to minimize discrepancies between seasons.
Forages and Pastures: Posters Posters Forages and Pastures 7/11/2021 0:00 t84469 Watch P236 Effect of down corn plants on fermentation profile and nutrient composition in whole-plant corn forage and silage. 8 E. C. Diepersloot lodging predicted energy content silage quality E. C. Diepersloot1, J. P. Goeser2, G. R. Dahlke3, D. Meyer2, L. F. Ferraretto1 1University of Wisconsin–Madison, Madsion, WI, 2Rock River Laboratory Inc, Watertown, WI, 3Iowa Beef Center, Ames, IA This study aimed to evaluate the effect of down corn on fermentation profile and nutrient composition of whole-plant corn forage and silage. For case study 1 (June 2019; Lee, FL), corn was blown down by a severe thunderstorm and harvested at silage maturity similarly for both down (3 fields) and standing corn (STN; 4 fields) and ensiled in Ag-Bag silos for similar periods of time before samples were collected (down = 6 silos; STN = 8 silos) and analyzed for fermentation profile and nutrient composition. For case study 2 (summer 2020; Ames, IA), corn was blown down by a derecho. Corn plants down and STN were both cut from 6 fields each to a similar stubble height, processed and forage samples were analyzed for nutrient composition. Data from each case study were analyzed separately using Proc Glimmix of SAS with the fixed effect of treatment. In study 1, STN had a lower pH (P = 0.001; 3.86 vs 4.02, respectively) and greater lactic acid concentration (P = 0.001; 4.6 vs 3.5% DM, respectively) compared with silage from down corn. Additionally, down silage had greater NDF (P = 0.03; 41.4 vs 36.7% DM, respectively), ADF (P = 0.01; 25.0 vs 20.8% DM, respectively) but lower starch (P = 0.04; 32.1 vs 36.6% DM, respectively) concentration. Thus, STN silage had greater predicted TDN (P = 0.001; 72.0 vs 67.2% DM), NEL (P = 0.001; 0.71 vs 0.65 Mcal/kg, respectively) and milk yield (P = 0.001; 3,340 vs 2,975 kg/Mg, respectively) based on the Milk2006 predictions. Conversely, these metrics were not affected (P > 0.05) in study 2, highlighting the potential for quality silage to be made from down corn. In this experiment the STN corn was affected by high winds while vegetative, thus corn likely recovered to some extent. However, the results from these studies demonstrate the potential for down or lodged corn silage to have an equivalent to lesser silage quality and nutritive value. The contrasting observations between study 1 and 2 could be due to down corn silage being in the field 2 weeks longer than STN corn in study 1, and a potential interaction between maturity and plant damage.
Forages and Pastures: Posters Posters Forages and Pastures 7/11/2021 0:00 t84464   P237 Effects of the fungicide application on corn silage quality in dairy farms. 9 G. F. M. Leão dairy cattle NDF digestibility starch digestibility G. F. M. Leão1, R. G. Oliveira1, F. P. Basco1, L. Goltz1, S. T. Guerra1, J. S. Ribas1, H. P. Janssen1, E. M. Ribas1 1Negócios Leite, Castrolanda Cooperativa Agroindustrial, Castro, PR, Brazil, Quality of corn silage depends on a range of factors, including management practices related to the culture. The goal of this study was to investigate the influence of the fungicide application on nutritional parameters of corn silage in dairy farm conditions. Two hundred and forty-one corn silage samples were collected from 193 dairy farms located in southern of Brazil. Samples were divided in 2 treatments depending of the fungicide application during corn management in the field: with fungicide (FUNG) or without (CONT). Sequentially, samples were submitted for nutritional quality analysis and data were analyzed using the MIXED procedure of SAS. FUNG silages presented higher values of in vitro digestibility (73.27 vs. 72.48%; SEM = 0.18; P = 0.01), crude protein (8.23 vs. 7.95%; SEM = 0.08; P = 0.02), starch digestibility (76.14 vs. 74.28%; SEM = 0.50; P = 0.01) and neutral detergent fiber (NDF) digestibility (49.41 vs. 48.58%; SEM = 0.30; P = 0.04). The FUNG silages showed lower levels of NDF (40.82 vs. 41.91%; SEM = 0.30; P = 0.01), acid detergent fiber (22.53 vs. 23.15%; SEM = 0.20; P = 0.03) and lignin (2.08 vs. 2.16; SEM = 0.02; P = 0.04). Values of dry matter content, pH, fat, ash, starch and total digestible nutrients were not affected by the treatments (P > 0.05). It is important to highlight that due to the high number of samples and the great variability between farms, some results are of minor biological significance. Overall, the results suggest a better nutritional quality of FUNG silages in dairy farm, claiming the relevance of fungicide application during the management of corn culture.
Forages and Pastures: Posters Posters Forages and Pastures 7/11/2021 0:00 t83582 Watch P238 Projected impact of future climate conditions on the agronomic performance of 4 binary alfalfa-grass mixtures in Quebec dairy farms. 10 C. Payant alfalfa-grass mixture whole-farm model climate change C. Payant1, G. Jego2, V. Ouellet1, P. Grenier3, G. F. Tremblay2, G. Bélanger2, É. Charbonneau1 1Université Laval, Quebec, QC, Canada, 2Agriculture and Agri-Food Canada, Quebec, QC, Canada, 3Ouranos, Montreal, QC, Canada Timothy is widely grown on dairy farms in association with alfalfa in Northern regions but may be more impacted by future climate conditions (FCC) than other mixtures. Our objective was to assess the agronomic performance of alfalfa with timothy, tall fescue, meadow fescue, or meadow bromegrass and corn, soybean, barley, and spring wheat on 2 virtual farms representative of Eastern Quebec (EQ) and Southwest Quebec (SWQ), Canada, under reference and FCC. The Integrated Farm System Model (IFSM) was used to simulate yield and nutritive value of all crops grown under reference (REF: 1971–2000), near (NF: 2020–2049) and distant (DF: 2050–2079) future climates using 6 climate scenarios of different intensity with 2 representative concentration pathways (RCP 4.5 and RCP 8.5) and 4 climate models. In these scenarios growing degree-days (GDD base 5°C) are projected to increase by 161 to 412 GDD in near future and by 487 to 930 in distant future. The IFSM has been previously calibrated and validated to predict yield and nutritive value of most crops used in Quebec. For forages that were not previously calibrated, data from literature, and field results were used for additional calibration of the model. Compared with REF, yields of the 4 alfalfa-grass mixtures are expected to increase with FCC. Yield of the alfalfa-tall fescue mixture is predicted to increase the most (REF: 6.8 ± 0.8, NF: 9.0 ± 1.5, DF: 10.2 ± 1.2, and REF: 9.4 ± 1.0, NF: 12.0 ± 1.55, DF: 12.3 ± 1.4 t/ha, in EQ and SWQ) and that of the alfalfa-timothy mixture the least (REF: 7.0 ± 0.9, NF: 8.7 ± 1.2, DF: 9.6 ± 1.2, and REF: 9.2 ± 1.0, NF: 11.1 ± 1.5, DF: 11.1 ± 1.3 t/ha in EQ and SWQ). Proportion of alfalfa should increase in the mixture with FCC, increasing the crude protein and decreasing the neutral detergent fiber concentrations of the 4 mixtures. In both areas, corn and soybean yields are projected to increase, while those of wheat and barley are projected to remain stable or to slightly decrease. Our results suggest that tall fescue and meadow fescue in mixture with alfalfa could benefit more from climate change than timothy.
Forages and Pastures: Posters Posters Forages and Pastures 7/11/2021 0:00 t84615 Watch P239 Effects of planting density on nutritive value and in situ dry matter degradability of alfalfa cultivars adapted to the southeastern United States. 11 S. S. Lee alfalfa hybrid in situ degradability S. S. Lee1,3, E. F. Rios2, A. Anju2, D. Vyas3 1Institute of Agriculture and Life Science, Gyeongsang National University, Jinju, Gyeongsangnam-do, South Korea, 2Agronomy Department, IFAS, University of Florida, Gainesville, FL, 3Department of Animal Sciences, IFAS, University of Florida, Gainesville, FL We aimed to evaluate the effects of different planting densities on nutritive value and in situ dry matter (DM) degradability of alfalfa Medicago sativa L. adapted to southeastern United States. Three alfalfa cultivars (FL77, FL99 and B805) and 2 breeding lines from the University of Florida Forage Breeding program (AP15, AP17) were seeded in 4 replicated plots at a seeding rate of 20 and 27 kg·ha−1. Plots were planted at Plant Science Research and Education Center in Citra, Florida. Plots were harvested on June 24 and July 23 2020, and harvested forage was dried, ground (1 mm), and analyzed for nutritive value using near-infrared spectroscopy. Dry matter yield (DMY, kg·ha−1) was analyzed for both harvests as a factorial for seeding rate and cultivars considering harvest as repeated measures. In situ ruminal DM disappearance was measured for AP15 and B805 after ruminal incubation for 0, 3, 6, 9, 12, 24, 48, 72, and 96 h in triplicates using 2 nonlactating Holstein dairy cows. Data were analyzed as 5 × 2 factorial using GLIMMIX procedure of SAS using planting densities (2 levels) and cultivars (5 levels) as fixed factors while harvest was used as random factor in the model. Mean separation was performed by a Tukey test and differences were declared significant at P ≤ 0.05. No interaction effect was observed between planting density and cultivars on the nutritive value and DMY of alfalfa. AP15 (1908 kg·ha−1) and AP17 (2,131 kg·ha−1) produced the highest DMY among all cultivars. B805 produced the lowest DMY (1,362 kg·ha−1). Cultivar B805 had lowest lignin concentration, greater net energy of lactation, and greater milk per ton of forage. Neutral detergent fiber degradability (NDFD) was greater for B805, FL77, and FL99 when seeded at 20 kg·ha−1; however, when cultivars were seeded at 27 kg·ha−1, NDFD was greater for B805 compared with other cultivars. Both the rate and extent of DM degradation was greater for B805 compared with AP15. In conclusion, B805 had greater nutritive value, while AP15 and AP17 had greater DMY compared with other cultivars.
Forages and Pastures: Posters Posters Forages and Pastures 7/11/2021 0:00 t84751 Watch P240 Effects of seeding intensity and cutting on the nutritional quality of grass-legume mixtures. 12 K. V. Almeida forage legume sugar K. V. Almeida1, L. H. P. Silva1,2, J. P. Sacramento1, D. C. Reyes1, R. G. Smith1, N. Warren1, A. F. Brito1 1University of New Hampshire, Durham, NH, 2Western Kentucky University, Bowling Green, KY Objectives were to compare the nutritive value of 4 binary legume-grass (LG) mixtures, and 2 complex LG mixtures under different seeding strategies over 2 years following a 3-cutting schedule. We hypothesized that different LG mixtures would result in varying supplies of N and NSC, thus better balancing the RDP:energy ratio in forages. A randomized complete block design with a 6 × 3 factorial arrangement of treatments and 4 replicates for each treatment was used. Legumes selected were alfalfa (ALF), red clover (RC), birdsfoot trefoil (BFT), and white clover (WC) in binary mixtures with orchardgrass at 70:30 LG seeding rate, a high legume mixture (HI) with 70% of all 4 legumes and 30% orchardgrass, and 30:70 LG seeding rate, a low legume mixture (LO) with 30% of all 4 legumes and 70% orchardgrass. After plots were harvested, a representative sample of 200 g was collected for later analyses. Data were analyzed using GLIMMIX procedure of SAS. The statistical model included treatment and cutting as fixed effects with block and year as random factors. Main effects of treatments are shown in Table 1. Crude protein increased in HI compared with ALF and BFT, with HI and LO showing reduced NDF concentration relative to ALF and BFT. Starch was greater in LO vs. WC but it did not differ compared with the other treatments. The RC, HI, and LO treatments resulted in greatest ESC and NSC (ESC plus starch) and ALF the lowest. In vitro NDF digestibility was lower for HI and LO compared with the binary LG mixtures. In general, second and third cuttings improved nutritive value via greater CP, IVNDFD, NSC:N, and NEL. Table 1. Nutritional composition of binary and complex legume-grass mixtures
Item Treatment SEM P-value
ALF RC BFT WC HI LO Treat
CP, % of DM 13.3c 15.0a 13.5bc 14.3ab 14.8a 14.3ab 0.51 <0.01
aNDFom, % of DM 50.0a 46.3b 50.6a 48.6ab 45.4b 45.8b 1.28 <0.01
Starch, % of DM 2.77ab 2.85ab 2.65ab 2.14b 3.12ab 3.18a 0.46 0.05
ESC, % of DM 7.14b 8.72a 7.67ab 8.23ab 8.90a 8.84a 0.45 <0.01
NSC, % of DM 9.92b 11.6ab 10.3ab 10.4ab 12.0a 12.0a 0.63 <0.01
NSC:N 4.99 4.94 5.08 4.87 5.22 5.45 0.33 0.47
IVNDFD, % of DM 59.7b 55.8bc 59.9b 64.6a 53.4c 56.0bc 1.44 <0.01
NEL, Mcal/kg 1.40b 1.49a 1.40b 1.47ab 1.47ab 1.48a 0.02 <0.01
Forages and Pastures: Posters Posters Forages and Pastures 7/11/2021 0:00 t84533 Watch P241 Effect of grazing fall-stockpiled tall fescue, meadow fescue, or orchard grass on heifer growth and greenhouse gas production. 13 K. G. Wells dairy heifer grazing stockpile forage K. G. Wells1, M. A. Wattiaux1, D. M. Pizarro1, J. S. Cavadini2, M. S. Akins1 1Department of Animal and Dairy Sciences, University of Wisconsin–Madison, Madison, WI, 2Marshfield Agricultural Research Station, University of Wisconsin–Madison, Stratford, WI By extending the grazing season through the fall by stockpiling pastures, dairy heifers could be raised with lower costs and in a more environmentally conscious way. Our study examined average daily gain (ADG) and the production of CH4 and CO2 by dairy heifers grazing stockpiled pastures during fall in Wisconsin. The study was designed as a randomized complete block using 9 pastures established in triplicate with 1 of 3 grass species mixed with red clover (tall fescue (TF), meadow fescue (MF), or orchard grass (OG)). Heifers (n = 36) with body weight ranging from 267 to 333 kg, were blocked by weight (low, medium, high) and randomly assigned to 1 of the 3 grass specie replicates with 4 heifers per pasture. Heifers grazed for 48 d from October 7 to November 24, 2020 and were allocated new pasture areas daily based on pre-grazing forage availability to allow for a dry matter intake (DMI) of 2.5% of body weight. Water was provided free-choice and mineral offered at 0.11 kg/d per heifer. Pasture consumption by heifers (DMI) was determined based on the area grazed and weekly pre- and postgrazing forage availability. Individual heifer ADG was based on weights collected over 3 consecutive days pre- and post–study. A GreenFeed pasture system (C-Lock Inc., Rapid City, SD) was used to measure CH4 and CO2 production (g/d per heifer). Pasture was considered the experimental unit and data were analyzed with R studio using a mixed model ANOVA to determine the fixed effect of grass specie and the random effect of heifer within species. There was no difference in DMI among treatments (9.2, 10.0, and 10.6 kg/d per heifer for MF, OG, and TF, respectively, P = 0.49), but there was a tendency in ADG (0.98, 1.07, and 0.95 kg/d for MF, OG, and TF, respectively, P = 0.09). Average CH4 production was 206, 214, and 197 g/d per heifer for MF, OG, and TF, respectively (P = 0.41). Average CO2 production was 6,861, 6973, and 7,082 g/d per heifer for MF, OG, and TF, respectively (P = 0.37). Overall, grazing stockpiled pastures resulted in optimal heifer growth with no effect of grass species on greenhouse gas production by heifers.
Forages and Pastures: Posters Posters Forages and Pastures 7/11/2021 0:00 t84184 Watch P242 Effect of defoliation frequency around flowering time on the productivity and nutritive value of tall fescue. 14 F. Díaz tall fescue defoliation regime nutritive value J. C. Marrero1,2, F. A. Lattanzi1, C. Cajarville2, F. Díaz3, J. M. Arroyo1,4 1Instituto Nacional de Investigación Agropecuaria, Colonia, Uruguay, 2Instituto de Producción Animal de Veterinaria, Facultad de Veterinaria, Universidad de la Republica, Libertad, San José, Uruguay, 3Dellait Dairy Research Center, Brookings, SD, 44Institute of Animal Science, University of Bonn, Bonn, Germany Increasing the defoliation regimen of pastures allows to improve its nutritive value for ruminants but it can be detrimental for total biomass production. An experiment was carried out to study the effect of the defoliation regimen around flowering time on productivity, chemical composition and nutritional value of tall fescue. The experiments were carried out on 2-year old tall fescue (Festuca arundinacea cv ‘INIA Fortuna’) pastures, at the experimental station “La Estanzuela” (INIA, Uruguay). Three defoliation regimens –cut at 1.5 leaf-stage, at 2.5 leaf-stage, or 1.5 leaf-stage before flowering and at 2.5 leaf-stage afterward– were studied in 2 paddocks. Pasture A was not grazed during the previous winter whereas pasture B was. At each paddock, defoliation treatments were arranged in a completely randomized block design with 4 repetitions (blocks). DM, OM, NDF, CP and in vitro digestible NDF (NDFD; Ankom Technology Corp., Macedon, NY) production (kg/ha/d) were determined for each treatment and paddock for the spring season (09/01/2018 to 11/26/2018). The data were analyzed independently for each paddock using a General Linear Model ANOVA. In paddock A there was no effect of defoliation regimen (Table 1). On the contrary, in paddock B cut at 1.5 leaf-stage resulted in lower DM production. Increase in quality, higher CP and lower NDF content, were not enough to offset the lower productivity of higher defoliation frequency. These results suggest that winter management of pasture strongly affects its productive and nutritional value responses to defoliation regimen during spring. Table 1. Effect of the defoliation regime on nutrient production (kg/ha per day) of tall fescue
Item Treatment (leaf stage) SEM P-value
1.5 1.5–2.5 2.5
Location A          
 DM 57.3 61.1 58.7 2.15 0.486
 OM 51.6 54.7 52.4 1.92 0.521
 CP 13.0 14.2 12.0 0.87 0.108
 NDF 29.9 31.5 31.5 1.37 0.660
 NDFD 21.4 22.2 21.0 0.90 0.634
Location B          
 DM 37.7c 43.7b 57.6a 1.35 <0.001
 OM 33.7c 39.0b 51.4a 1.17 <0.001
 CP 8.82b 9.91b 11.3a 0.280 0.002
 NDF 18.9b 22.2b 30.5a 0.77 <0.001
 NDFD 13.4b 14.8b 20.7a 0.46 <0.001
a–cMeans within a row with different superscripts are significantly different (P < 0.05).
Forages and Pastures: Posters Posters Forages and Pastures 7/11/2021 0:00 t84163 Watch P243 Physiochemical alterations during germination of hydroponically sprouted cereal grains. 15 S. Jenkins hydroponic forage enzymes S. Jenkins1, F. Diaz2 1HydroGreen Incorporated, CubicFarm Systems Corporation, Sioux Falls, SD, 2Dellait Dairy Research Center, Brookings, SD The increasing negative influence of abiotic factors on crop production coupled with the fragility of the global animal feed supply chain accentuates the importance of investigating hydroponically sprouted cereal grains for implementation in the dairy industry. Physical and chemical properties of hydroponically sprouted barley (Hordeum vulgare) and hard red winter wheat (Triticum aestivum) were investigated over a period of 7 d in an automated HydroGreen vertical farming system. Within the system, crops were seeded at a 14.6 kg m2–1 density with environmental controls maintaining 22°C, 70% relative humidity, and an 18-h photoperiod schedule; irrigation was supplied via overhead spray nozzles throughout development. Replicated (n = 2) samples collected at 0, 24, 48, 72, 96, 120, 144, and 168 h after initial seeding revealed parallel physiochemical transformational trends for both barley and wheat. After 144 h, initial starch concentration decreased 40 percentage points (SE = 1.2 pp, P < 0.01) on average for both crops, while sugars (ethanol soluble carbohydrates) concentration increased 25.9 pp (SE = 1.1 pp, P < 0.01) from the original value. The increase in the concentration of sugars at 144 h was accompanied by significant gains in overall concentrations of ADF (+6.4 pp; SE = 0.3 pp, P < 0.01) and NDF (+10.0 pp; SE = 0.6 pp, P < 0.01). Relative moisture content of the hydroponically sprouted product increased 63% on average. Dry matter yields closely paralleled those of the reported enzymatic activity, with the highest enzymatic and dry matter yields occurring at 144 h after seeding. Compared with the original starting grain, the hydroponic sprouting process in the HydroGreen system resulted in similar energy yields, with other dramatic shifts in overall nutrient composition facilitated by enzyme hydrolysis. Observed results highlight the potential of hydroponically sprouted cereal grains in dairy diets and provide direction for future implementation within this feedstuff category. Further work is needed to quantify the sprouted grain’s enzymatic activity and elucidate its impacts on overall diet nutrient digestibility.
Growth and Development: Orals Orals Growth and Development 7/11/2021 0:00 s9635                  
Growth and Development: Posters Posters Growth and Development 7/11/2021 0:00 s9582                  
Growth and Development: Posters Posters Growth and Development 7/11/2021 0:00 t83422 Watch P244 Sodium butyrate and monensin supplementation to postweaned heifer diets: Effects on growth performance, nutrient digestibility, and health. 1 T. C. Stahl sodium butyrate monensin coccidia T. C. Stahl1, E. Hatungimana1, K. D. Klanderman2, S. C. Moreland2, P. S. Erickson1 1University of New Hampshire, Durham, NH, 2Adisseo USA, Inc, Alpharetta, GA Objectives of this study were to compare sodium butyrate (SB) to monensin (MON) on growth, digestibility, and health of postweaned heifers. Forty Holstein heifers (age = 84.2 ± 1.2 d; average BW = 99.78 ± 10.77 kg) were fed diets ad libitum. Heifers were blocked by birth date and assigned to 1 of 4 treatments in a randomized complete block. The control group (CON) was fed 100 g of SBM carrier, while treatments were supplemented with carrier + 0.75 g SB/kg of BW, 1 mg MON/kg of BW, or 1 mg MON/kg of BW + 0.75 g SB/kg of BW (MSB). Amounts of orts and feed offered to each heifer were measured daily. Initial BW, skeletal measurements and blood samples were taken d1 before the receiving treatment, and every wk thereafter for 12 wk. Fecal grab samples were taken weekly from each heifer for coccidia counts. Two total-tract digestibility phases: 21–27 d (wk 3) and 63–69 d (wk 9) were used. Digestibility was measured by acid detergent insoluble ash. Single degree freedom contrasts for CON vs. ADD (control vs. additive), SB vs MON, and SB+M vs MSB (single additives vs. MSB) were determined. Compared with CON, ADD tended to increase average BW (P = 0.10), final BW (P = 0.09), and heart girth (P = 0.10). Compared with CON, ADD increased DMI (CON = 4.0, SB = 4.5, MON = 4.2, MSB = 4.5 kg/d; P = 0.03). Compared with CON, ADD decreased coccidian oocysts (CON = 1,248.9, SB = 697.9, MON = 762.5, MSB = 781.8 coccidia/kg of feces; P = 0.03). Compared with MON and SB, MSB tended to increase heart girth (P = 0.07). Compared with MSB, MON and SB tended to have greater plasma glucose (P = 0.09). Compared with SB, ADG/DMI was improved in MON supplemented heifers (CON = 0.27, SB = 0.25, MON = 0.28, MSB = 0.27; P = 0.04). Besides heart girth, no other differences were observed for skeletal measures (P ≥ 0.24). Week 3 total-tract digestibility (DM, NDF, ADF, Hemicellulose, OM, and fat) were similar (P ≥ 0.16). Week 9 total-tract digestibility (DM, CP, ADF, Hemicellulose, Starch, OM, and fat) were similar (P ≥ 0.12). Overall, additive supplementation offers positive results in growth performance, and reduced coccidia counts
Growth and Development: Posters Posters Growth and Development 7/11/2021 0:00 t83423 Watch P245 Growth, feed efficiency, and health of female Holstein calves cooled during the preweaning period. 2 A. B. Montevecchio cooling Holstein performance A. B. Montevecchio1, W. Frota1, V. R. Merenda1, J. G. Martin III2, R. C. Chebel1 1Department of Large Animal Clinical Sciences & Department of Animal Sciences, University of Florida, Gainesville, FL, 2Dairy Design Engineers, Gainesville, FL Our objectives were to determine the effects of cooling female Holstein calves through forced air ventilation on growth, feed efficiency, and health. At birth (0d), calves were assigned randomly to: SH (n = 125) shade with no cooling, SHF (n = 101) shade with cooling through ceiling fans. Hutches were placed in a barn and SH and SHF treatments were applied in 3 alternating sections of the barn. Calves received milk replacer twice a day (0 to 13d = 3.8L, 14 to 18d = 5.6L, 19 to 49d = 7.6L, 50 to 57d = 3.8L, 58 to 64d = 0.9L) and starter ad libitum starting at 14d. All calves were weighed (BW) and had the wither (WH) height measured at birth, 71 d (weaning), and 146d. A subset of calves (SH = 54, SHF = 43) was weighed and had WH measured at 12, 19, 26, 34, 47, 54, and 61d. Intakes of milk solids and starter were evaluated daily. Health was scored in the AM, including rectal temperature (RT), every 3.5 ± 1.1d from 2 to 68d. Hutches (SH = 18, SHF = 17) were evaluated for air speed and temperature at 1000 and 1600 h and calves in these hutches had RT and respiratory frequency (RF) measured at the same time. Data were analyzed by ANOVA. The SHF treatment resulted in greater (P < 0.01) air velocity (AM: SH = 0.41 ± 0.05, SHF = 1.22 ± 0.05m/sec; PM: SH = 0.42 ± 0.05, SHF = 1.22 ± 0.06m/sec) and reduced (P ≤ 0.10) air temperature in the (AM: SH = 30.5 ± 0.1, SHF = 30.2 ± 0.1°C; PM: SH = 32.7 ± 0.1, SHF = 32.5 ± 0.1°C). Calves in the SHF treatment had lower RT in the AM (38.8 ± 0.0 vs 38.7 ± 0.0°C), but RT did not (P = 0.43) differ in the PM. The percentage of calves with at least one RT ≥ 39.3°C tended (P = 0.08) to be greater for SH treatment (66.4 ± 0.1 vs 49.5 ± 0.1%). No differences in RF were observed. From 12 to 146d, BW was not (P > 0.10) different between treatments. Although an interaction between treatment and age affected (P = 0.01) WH, the WH at 71d was not (P = 0.19) different between treatments. Average daily gain (633.4 ± 12.5 g/d) and feed efficiency (0.60 ± 0.04 ADG/DMI) from 12 to 71d were not (P ≥ 0.71) affected by treatment. Health scores and mortality up to 71d were not (P > 0.20) different between treatments. We did not detect an effect of cooling on calf growth but cooling reduced RT and the risk of hyperthermia.
Growth and Development: Posters Posters Growth and Development 7/11/2021 0:00 t83486 Watch P246 Growth performance and apparent total-tract nutrient digestibility of limit-fed diets containing wet brewer’s grains to Holstein heifers. 3 E. Hatungimana wet brewer’s grains growth digestibility E. Hatungimana1, T. C. Stahl1, P. S. Erickson1 1University of New Hampshire, Durham NH The objective of this study was to evaluate the growth performance and apparent total-tract nutrient digestibility of Holstein heifers limit-fed diets containing different amounts of wet brewer’s grains (WBG). A 12-wk randomized complete block study was conducted using 30 yearling Holstein heifers (378 ± 27 d of age, and BW of 357.8 ± 27.6 kg (mean ± SD)). Treatments were 0%, 10% and 20% of WBG on a DM basis and diets were formulated to be limit-fed for DMI at 2.35% of BW and provided 15% CP and 2.27 Mcal ME / kg of DM. Dry matter intake was recorded daily while BW and skeletal measurements were measured every 2 wk. During wk 12, fecal samples were collected directly from the rectum over 4 consecutive days and composited by heifer to determine apparent total-tract nutrient digestibility using acid detergent insoluble ash (ADIA) as a marker. Data were analyzed using the MIXED procedure of SAS. Dry matter intakes, BW, ADG were not different among treatments (P = 0.2, P = 0.4, P = 0.6 respectively). Dry matter intakes ranged from 8.6 to 9.0 kg/d. Average BW were 404.4, 411.5 and 409.3 kg for heifers fed the 0, 10 and 20%WBG diet respectively. Average daily gains were 1.03, 1.04 and 0.96 kg/d for heifers fed the 0, 10 and 20%WBG diet respectively. Skeletal measurements and body condition scores were not different among treatments. Apparent total-tract digestibilities of DM, organic matter (OM), CP, fat and hemicellulose were greater in heifers fed 0% WBG (53.6, 57.9, 45.3, 66.8 and 58.2% respectively) and 20% WBG (51.2, 55.2, 50.1, 72.3, and 55.9% respectively) than heifers fed 10% WBG (44.8, 49.7, 39.5, 65.6 and 50.8%; P = 0.04, P = 0.04, P = 0.06, P = 0.06 and P = 0.01 respectively). Neutral detergent fiber, ADF and fat digestibilities were not different among treatments (P = 0.2, P = 0.3, P = 0.3 respectively). During the digestibility phase, DMI tended to be greater ((10.0 kg/d; P = 0.08) for the 10% WBG treatment These results demonstrate that limit-feeding heifers with diets containing up to 20% WBG could replace soybean and corn-based concentrates in diets without adverse consequences to heifer growth performance.
Growth and Development: Posters Posters Growth and Development 7/11/2021 0:00 t83487 Watch P247 Effect of storage of wet brewer’s grains with incremental levels of salt on in vivo total-tract nutrient digestibility and purine derivative excretion in dairy heifers. 4 E. Hatungimana wet brewer’s grain salt digestibility E. Hatungimana1, T. C. Stahl1, P. S. Erickson1 1University of New Hampshire, Durham NH The objective of this study was to evaluate the in vivo total-tract nutrient digestibility and purine derivative excretion in heifers fed diets containing wet brewer’s grains (WBG) treated with salt. A-12 wk replicated 4 × 4 Latin square study was conducted using 8 Holstein heifers of 224.5 ± 19.4 d of age, and BW of 483.9 ± 66.3 kg (mean ± SD). Treatments were 0%, 0.8%, 1.6% and 2.4% salt added to fresh WBG and stored for 4 d before being included in diets at 20% DM basis. Similar amounts of salt were added in reverse order to diets during the feeding time to equalize the amount of salt consumed by heifers. Diets were formulated to be limit-fed at 2.15% of BW (DM) to provide 14% CP and 2.27 Mcal ME/kg of DM. Heifers were adapted to diets for 14 d followed by 7 d of collection. Dry matter intake was recorded daily during the collection week while BW was recorded weekly. Fecal and urine samples were collected during the last 4 d of the collection period and composited by heifer. Composites of feces were used to determine in vivo total-tract nutrient digestibility using acid detergent insoluble ash (ADIA) as a marker, while composites of urine samples were used to determine purine derivative excretion. Data were analyzed using the MIXED procedure of SAS. Dry matter intake resulted in a quadratic effect (P < 0.01), and were 5.09, 4.97, 5.13 and 5.10 kg/d for the 0, 0.8, 1.6 and 2.4% salt treatment respectively. Body weight, ADG and feed efficiency increased linearly (P = 0.04, P = 0.03 and P = 0.03 respectively). Body weight ranged from 261.1 to 265.2 kg. Average daily gains ranged from 0.73 to 1.05 g/d. Digestibility of DM, OM, CP decreased linearly (P = 0.03, P = 0.03 and P = 0.04 respectively). Urinary volume, allantoin, and uric acid excretion and total purine derivative excretion were not affected by treating WBG with salt (P = 0.4, P = 0.4, P = 0.3 and P = 0.4 respectively). Limit-feeding heifers with diets containing WBG treated with salt decreased nutrient digestibility but may enhance heifer growth performance
Growth and Development: Posters Posters Growth and Development 7/11/2021 0:00 t83512   P248 Body weight and average daily gain of one-year-old Holstein heifers supplemented with colostrum replacer. 5 M. O. Moura calf nutrition dairy heifer growth M. O. Moura1, V. Chiogna Junior2,1, M. C. Rodrigues1, M. Dias1, E. A. Collao-Saenz1 1Universidade Federal de Jatai, Jatai, Goias, Brazil, 2Milk Mais Consultoria, Rio Verde, Goias, Brazil Scientific studies evaluating long-term effects of colostrum replacers (CR) supplementation to dairy calves are limited. The average daily gain (ADG) needed to reach a target body weight depends upon body weight at weaning. The objective was to evaluate the effects of a 5-d period supplementation with colostrum replacer (CR) on BW and ADG in heifers at 12 mo. Sixty Holstein calves (39 ± 1.6 kg BW) from one herd received 6 L of colostrum (4 L after birth via esophageal feeder + 2 L after 6 h) and were assigned to 1 of 2 groups. All calves presented adequate immunity (serum IgG > 10.0 g/L). Calves assigned to the control group received 6 L of milk with 18% solids (milk + 55 g/L of a milk replacer with 22% protein:19% fat) without CR inclusion. The treatment group received 60 g of supplemental CR powder dissolved in 6 L of milk with 18% solids from d 2 to 6 of life. From d 6, all calves received the same quantity of milk (18% solids) and ad libitum calf starter. After 30 d calves received 4 L twice a day until weaning with 60 d of life. From the experimental calves, 52 heifers (n = 26 in each group) were reared under the same circumstances regarding nutrition, health, and environment, weighed the same day after 12 mo and their BW adjusted for 365 d. BW 365 and ADG were analyzed using a mixed model, treatment as fixed effect with calf birth weight as a covariable; heifer within treatment was considered random effect. There was no interaction treatment × period. Calves in CR group were 3.2 kg heavier and gained 0.05 kg/d more than control at weaning (Table 1). The BW and ADG differences observed at weaning of calves in CR treatment were not sustained until 365 d. No difference for both variables was found between treatments when the heifers reached one year of age. Table 1. Body weight in the first year and ADG of Holstein heifers
 Item Control CR Min Max P-value
ADG at weaning (kg/d) 0.86 ± 0.13 0.91 ± 0.15 0.68 1.04 0.14
Weaning weight (kg) 90.8 ± 8.0 94.0 ± 8.0 78.0 108.0 0.02
ADG at 365 d (kg/d) 0.92 ± 0.07 0.95 ± 0.09 0.79 1.10 0.24
BW at 365 d (kg) 364 ± 25 372 ± 32 326 441 0.53
Growth and Development: Posters Posters Growth and Development 7/11/2021 0:00 t83995 Watch P249 Evaluation of body dimensions as predictors of body weight in slick- and wild-type–haired Puerto Rican Holstein calves. 6 H. L. Sánchez-Rodríguez slick-haired body dimensions body weight H. L. Sánchez-Rodríguez1, I. Colón-Rodríguez1, N. M. Cruz-González1, N. K. Pérez-Rosario1, A. D. Ramos-Gerena1, D. Y. Vega-Martínez1, J. D. López-Colón1, K. Domenech-Pérez1 1University of Puerto Rico at Mayagüez, Mayagüez, Puerto Rico In Puerto Rico, commercial weighing tapes are frequently used to predict dairy cattle body weight (BW) when weighing scales are not available. However, such tapes were developed with Pennsylvania’s Holstein cows; while cattle’s growth may be limited in warmer countries. Thus, the present study evaluated BW relationship with thoracic perimeter (TP), withers height (WH), and barrel (BA) in 10 slick- (SLICK) and 9 wild-type–haired (WT) Holstein female calves at the University of Puerto Rico’s herd. Data were collected weekly from birth to 8 weeks of age (preweaning period; Pre-WP), and then monthly, during 10 consecutive samplings (postweaning period; Post-WP). During Pre-WP, calves were individually housed; where milk (6 L/d/calf), as well as water and starter were provided. After weaning, heifers (allocated as one group) received starter (2 kg/d/heifer) and ad libitum hay and water. Data were analyzed by Proc REG (SAS). During Pre-WP, there were linear relationships between BW and TP in both the SLICK (BW = 1.42 TP – 72.75; R2 = 0.84; P < 0.0001) and WT calves (BW = 1.52 TP – 81.31; R2 = 0.83; P < 0.0001). Similarly, the BW-TP relationships were linear during the Post-WP in the SLICK (BW = 3.22 TP – 236.63; R2 = 0.96; P < 0.0001) and WT heifers (BW = 2.97 TP – 212.87; R2 = 0.95; P < 0.0001). At Pre-WP, BW and WH were linearly associated in the SLICK (BW = 1.78 WH – 92.25; R2 = 0.75; P < 0.0001) and WT calves (BW = 2.19 WH – 124.04; R2 = 0.73; P < 0.0001). Linear BW-WH relationships were observed during the Post-WP, with equations of BW = 4.90 WH – 345.96 (R2 = 0.96; P < 0.0001) and BW = 4.93 WH – 351.61 (R2 = 0.95; P < 0.0001) in the SLICK and WT heifers, respectively. During Pre-WP, BW and BA were linearly related in the SLICK (BW = 0.75 BA – 19.64; R2 = 0.79; P < 0.0001) and WT calves (BW = 0.88 BA – 33.49; R2 = 0.88; P < 0.0001). Quadratic regression equations fitted the BW-BA data during Post-WP in the SLICK (BW = 0.03 BA2 – 4.68 BA + 259.79; R2 = 0.94; P < 0.0001) and WT heifers (BW = 0.02 BA2 – 4.32 BA + 244.75; R2 = 0.96; P < 0.0001). Therefore, TP, WH, or BA may represent feasible ways to predict BW in Puerto Rican Holstein calves and heifers.
Growth and Development: Posters Posters Growth and Development 7/11/2021 0:00 t84106 Watch P250 Growth patterns in slick and wild-type–haired Puerto Rican female Holstein calves. 7 I. Colon-Rodríguez body weight Holstein calves hair coat I. Colon-Rodríguez1, K. Domenech-Pérez1, N. M. Cruz-González1, N. K. Pérez-Rosario1, A. D. Ramos-Gerena1, D. Y. Vega-Martínez1, J. D. López-Colón1, H. L. Sánchez-Rodríguez1 1University of Puerto Rico at Mayagüez, Mayagüez, Puerto Rico Doubling the birth body weight (BW) by 56 d of age has been established as the gold standard when raising dairy calves. However, this benchmark may differ for dairy calves raised in tropical countries. Therefore, the current study aimed to evaluate the growth patterns (i.e., BW) of 10 slick and 9 wild type-haired Puerto Rican Holstein female calves. At birth, contemporaneous female calves from the Agricultural Experiment Station herd (Lajas, Puerto Rico) were visually classified and enrolled into the slick or wild type-haired experimental groups. The BW experimental samplings (ES) were performed weekly, during the first 8 weeks of life (preweaning period) and then monthly, for 10 consecutive months (postweaning period). During the preweaning stage, whole pasteurized milk (6 L/calf/d; 26% CP and 28% fat; DM basis), starter (22% CP and 3% fat; DM basis), and water were provided. Starter (2 kg/heifer/d) and ad libitum hay and water were provided during the postweaning period. Data were analyzed by the GLIMMIX and REG procedures of SAS. When the pre- and postweaning periods were analyzed together, no interaction was observed between hair coat type and ES affecting calves’ BW (P = 0.8928). Similarly, BW differences were undetected due to hair coat types (P = 0.7489). However, BW continually increased throughout ES (P < 0.0001). On average, both slick and wild type-haired calves doubled their birth BW between the 9 to 10 ES (57 to 81 d old, respectively). During the preweaning period BW increased linearly in the slick (BW = 3.19 ES + 31.72; R2 = 0.74; P < 0.0001) and the wild type-haired calves (BW = 3.23 ES + 30.56; R2 = 0.73; P < 0.0001). In the postweaning period, BW also increased linearly for both the slick (BW = 20.99 ES −138.29; R2 = 0.80; P < 0.0001) and the wild type-haired heifers (BW = 19.38 ES – 122.06; R2 = 0.73; P < 0.0001). No differences between hair coat groups were observed for BW during the evaluated periods. Generally, calves grew faster through the postweaning period. Under the established nutritional management both hair coat groups doubled their birth BW later than the established gold standard of 8 weeks of age.
Lactation Biology: Orals Orals Lactation Biology 7/11/2021 0:00 s9636                  
Lactation Biology: Orals Orals Lactation Biology 7/11/2021 0:00 t83473 Watch 123 The impact of incomplete milking on mammary gland transcriptome changes under 3× milking frequency. 1 W. Li incomplete milking mammary gland transcriptome W. Li1, J. Kuehnl2, T. Walker2, L. Hernandez2 1US Dairy Forage Research Center, Madison, WI, 2Department of Dairy Science, University of Wisconsin–Madison, Madison, WI Increased milking frequency (3× vs. 2× per day) and incomplete milking (IM) have differential effects on milk yield and mammary gland physiology. In our previous work, we have demonstrated that cows milked 3× tended to have increased milk production rate (MPR) and significantly increased milk fat percent compared with the cows milked 2× daily. Additionally, IM has significantly negative impacts on milk production (70% vs. 100% milking). However, the underlying molecular mechanisms remain uncharacterized. Our main objective is to study the impacts of IM on the mammary gland transcriptome profile in cows milked 3× daily. Four cows were included in this study. Within each cow, a contralateral half-udder was randomly assigned to be either IM (30% milk remaining in the gland) or milked completely (CM). Total RNA sequencing was used to identify differentially expressed genes (DEGs) ((fold-change > = 2, normalized read count ≥1 and P < 0.1) between the IM and CM mammary glands. Alignment of reads to the Bos taurus genome (UMD 3.1), DEG analysis between the 2 treatments, and pathway analysis were done using STAR (v.2.5.2b), Cufflinks (Cuffdiff, v.2.2.1), and DAVID (v.6.8), respectively. A total of 456 of the DEGs were upregulated (URG), while 104 DEGs were downregulated (DRG) in CM. URGs were predominantly involved with glycoprotein (181, P ≪ 0.0001) and disulfide bond synthesis (155 genes, P ≪ 0.0001). DRG were involved with regulation of cell differentiation (22, P ≪ 0.001), extracellular organelle (23, P ≪ 0.001) and response to cyclic AMP (5, P ≪ 0.001). Notably, glycoproteins were reported to play a key role in the biomodulatory properties of milk and ultimately determine the nutritional quality of milk. The disulfide isomerase family of endoplasmic reticulum proteins had a reported function in immunity and inflammation. Our results provided a transcriptome level understanding of the impact of incomplete milking on mammary gland. Such knowledge may facilitate future targeted-gene based strategies for improving mammary gland health and milk production rate in dairy cattle.
Lactation Biology: Orals Orals Lactation Biology 7/11/2021 0:00 t83580 Watch 124 Factors influencing milking performance of teatcup liners. 2 J. F. Penry liner performance liner compression milk flow rate J. F. Penry1, J. Upton3, P. D. Thompson2, G. A. Mein4, D. J. Reinemann2 1Dairy Australia, Melbourne, Victoria, Australia, 2The University of Wisconsin–Madison, Madison, WI, 3Animal and Innovation Research Centre, Teagasc, Fermoy, Co Cork, Ireland, 4Scientific adviser, Werribee, Victoria, Australia Experiments assessing the relationship of factors influencing liner performance conducted at the University of Wisconsin–Madison Dairy Cattle Centre, using a single, highly instrumented quarter milking device and 2 methods of estimating liner overpressure, are summarized. Liner performance can be described as milking gentleness, speed and completeness of milk-out. In addition to milking vacuum and pulsation settings, liner performance is influenced by liner geometry, material and teatcup shell mounting tension. The liner applies a compressive force (liner compression or LC) to the teat-end during the closed (d) phase and part of the closing (c) phase and opening (a) phase of pulsation. Effective pulsation circulates blood within the teat and limits congestive effects which reduce the teat-canal cross-sectional area (CA) during the open (b) phase of pulsation. Liner compression cannot be directly measured easily but can be estimated through a biologically relevant measurement described as overpressure. Eight liners assessed at UW-Madison showed a range in overpressure measurements from 0 to 18 kPa. Based on results from a central composite experimental design using 9 unique combinations of vacuum and pulsation applied to 8 cows (32 teats), the predictors of milk flow rate (MFR, kg/min) and teat-end congestion during the peak milk flow rate period were: liner compression (kPa overpressure), teat-end vacuum (kPa), mouthpiece chamber vacuum (kPa) and the open (b) phase of pulsation (ms). Increasing teat-end vacuum and open (b) phase time increased MFR but reduced CA. Increasing mouthpiece chamber vacuum reduced both MFR and CA. Liners with a higher LC had an increased range of potential MFR across combinations of teat-end vacuum and open (b) phase time. A 2 × 2 factorial experiment assessing teat-end and mouthpiece chamber vacuum demonstrated that milking conditions designed to induce teat-barrel congestion also increased teat-end congestion. Combined, these experiments illustrate the importance of balancing milking speed and milking gentleness and highlight the importance of characterizing LC in liner performance assessment.
Lactation Biology: Orals Orals Lactation Biology 7/11/2021 0:00 t83626 Watch 125 Correlation of plasma purine derivatives with production, rumen fermentation and blood biochemical parameters of lactating dairy cows. 3 S. G. Zhao plasma purine derivatives rumen fermentation blood biochemical M. Li1,3, S. G. Zhao1,2, N. Zheng1,2, J. Q. Wang1,2 1State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, P. R. China, 2Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, P. R. China, 3College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, P. R. China Purine derivatives are often used to calculate rumen microbial protein yield. Although studies on the relationship between purine derivatives and microbial protein yield have made great progress, the factors affecting the purine derivatives are still not clear, especially the individual physiological factors of dairy cows influencing on purine derivatives has not been reported. Because blood was easier to collect, we hypothesized plasma purine derivatives were influenced by individual physiological factors in dairy cows. Studying on plasma purine derivatives can provide a basis for optimizing the prediction model of microbial protein yield based on purine derivatives. The purpose of this experiment was to reveal the influencing factors of plasma purine derivatives. This study analyzed the Spearman correlation of plasma purine derivatives with production, rumen fermentation and blood biochemical of lactating dairy cows by SPSS 26.0. There were 2-hundred and 84 healthy dairy cows in second lactation between 24 and 77 d in lactation, milk yield was recorded and milk samples were collected 3 times a day in the morning, noon and night, rumen fluid and blood were collected within 2 h after feeding. Thereby we tested milk components, rumen fermentation parameters, blood biochemical parameters, plasma Δ15N and purine derivatives. The results showed that days in lactation, milk protein yield and milk yield were correlated with purine derivatives (P < 0.05). Ruminal isovalerate and valerate were negatively correlated with purine derivatives (P < 0.05), butyrate was positively correlated with purine derivatives (P < 0.05). Meanwhile, the plasma Δ15N and creatinine were negatively correlated with purine derivatives (P < 0.05), free fatty acids and glucose were positively correlated with purine derivatives (P < 0.05). In conclusion, the days in lactation, milk protein yield, milk yield, isovalerate, valerate, butyrate, plasma Δ15N, creatinine, free fatty acids and glucose effect plasma purine derivatives.
Lactation Biology: Orals Orals Lactation Biology 7/11/2021 0:00 t84048   126 Rapamycin alleviated lipopolysaccharides-induced inflammatory response in bovine mammary epithelial cells via autophagy and NF-κB/MAPK pathway. 4 L. B. Xu rapamycin inflammation NF-κB/MAPK L. B. Xu1, Y. F. Ren1, W. Lan1, P. F. Hou1, J. X. Liu1, H. Y. Liu1 1College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China Mastitis is a prevalent disease of dairy cows, which results in significant economic losses for dairy producers. Previous work showed that rapamycin had anti-inflammatory effect. However, the association between rapamycin and inflammatory response in bovine mammary epithelial (MAC-T) cells and the underlying mechanism need to be further investigated. Establishment of inflammatory model of MAC-T cells was performed first by using different concentration of lipopolysaccharides (LPS). After that, the MAC-T cells were randomly cultured in standard medium (CON), standard medium with 100 μg/mL LPS (LPS), standard medium with 10 mmol/L rapamycin (RAP), or standard medium with 100 μg/mL LPS plus 10 mmol/L rapamycin (LPS+RAP) for 24 h. Cells and culture supernatant were collected at the end of treatment. Incubation with 100 μg/mL LPS for 24 h significantly increased the IL-8, IL-1β and TNF-α concentrations in MAC-T cells (P < 0.01), while 10 mmol/L rapamycin administration abolished the elevated inflammatory cytokines production induced by LPS treatment (P < 0.05). Compared with the LPS group, the MAC-T cells in LPS+RAP group exhibited lower phosphorylation and translocation of p65 protein in nuclear factor-kB (NF-κB) signaling pathway (P < 0.01). The LPS+RAP stimulation significantly reduced the c-Jun NH2-terminal kinase (JNK) and p38 protein phosphorylation in mitogen-activated protein kinase (MAPK) signaling pathway than those with LPS treatment (P < 0.01). In addition, rapamycin supplementation significantly elevated the autophagy of MAC-T cells with or without the presence of LPS (P < 0.01). These results indicated that rapamycin may alleviate LPS-induced inflammatory response via autophagy and NF-κB/MAPK pathway in MAC-T cells, which give a reference for the therapeutic potential of rapamycin in mastitis.
Lactation Biology: Orals Orals Lactation Biology 7/11/2021 0:00 t84375 Watch 127 Mitochondrial adaptations in liver and skeletal muscle of lactating dairy cattle. 5 V. R. Favorit oxidative phosphorylation metabolism V. R. Favorit1, A. N. Kavazis2, W. R. Hood2, P. Villamediana1, A. L. Skibiel1 1University of Idaho, Moscow, ID, 2Auburn University, Auburn, AL Lactation alters nutrient and energy demands, requiring metabolic adaptations in mammary and extramammary (e.g., liver and skeletal muscle) tissues. Mitochondria are essential to the bioenergetic capacity of tissues, yet mitochondrial adaptations for lactation are understudied. Mitochondria produce ATP through oxidative phosphorylation, which results in formation of reactive oxygen species (ROS) that must be neutralized by antioxidants. We assessed temporal variation in mitochondrial function and oxidative stress across lactation. Liver and skeletal muscle (biceps femoris) biopsies were collected from multiparous Holsteins (n = 11) at early (8 ± 2 d in milk [DIM]), peak (75 ± 4 DIM), and late lactation (199 ± 6 DIM). Milk yield (MY) was recorded the day before biopsy. Mitochondria were isolated from liver and skeletal muscle and coupling for complex I (NADH-linked) and II (FADH2-linked) of the electron transport chain was measured as the respiratory control ratio (RCR, maximal/basal respiration). Isolated mitochondrial ROS emission and tissue superoxide dismutase (SOD) activity, glutathione peroxidase (GPx) activity, and oxidative damage (i.e., protein carbonyls) were also quantified. Changes in mitochondrial function and oxidative stress across lactation and in relation to MY were assessed using general linear mixed models with lactation stage and MY as fixed effects and cow ID as a random effect. Liver complex II RCR increased with MY (P = 0.02), indicating greater coupling of fatty acid oxidation to ATP production. Liver mitochondrial ROS emission was highest at peak lactation (P < 0.001) but no change in skeletal muscle ROS was detected (P = 0.19). Muscle SOD activity increased (P = 0.03) and GPx activity decreased (P < 0.01) across lactation. Liver antioxidant activity was similar across lactation (P > 0.1). Protein carbonyl content of muscle was highest at early and late lactation (P < 0.001) but was not associated with lactation stage for liver (P = 0.65). These results suggest that greater MY is associated with enhanced liver complex II mitochondrial efficiency but also greater ROS emission when energy demand is highest at peak lactation.
Lactation Biology: Orals Orals Lactation Biology 7/11/2021 0:00 t84417   128 Effects of di-2-ethylhexyl phthalate (DEHP) exposure on lactation performance in mice. 6 P. Hou Di-2-ethylhexyl phthalate (DEHP) lactation omics P. Hou1, Y. Zhan1, C. Wang1, H. Liu1 1Zhejiang University, Hangzhou, China Di-2-ethylhexyl phthalate (DEHP), as a type of environmental endocrine disruptors (EEDs), can interfere with the synthesis, release, transport and metabolic process of normal endocrine substances after entering the body. However, the effects of DEHP on lactation is still unclear. In the present study, 32 pregnant female Institute of Cancer Research mice were intragastrically administered with 500 mg/kg body weight of DEHP or corn oil (CON) from pregnancy d 8 until lactational d 12. Integrated transcriptomic and metabolomics analysis of mouse mammary gland was performed in combination with serum hormone and histopathological evaluation to investigate the potential mechanism. The results showed that DEHP exposure significantly decreased milk yield (P < 0.05) and food intake (P < 0.05). In serum, the concentration of PRL (P < 0.05), GH (P < 0.05), IGF-1 (P < 0.05) and Insulin (P < 0.05) were significantly decreased and the concentration of leptin (P < 0.05) were significantly increased after DEHP exposure. Moreover, DEHP exposure induced changes in mammary morphology with smaller shaped and isolated alveoli and widened interstitial spaces. Metabolomic analysis showed that carbohydrate metabolism, lipid metabolism and amino acid metabolism were the major metabolic pathways involved in DEHP-induced poor lactation performance. Meanwhile, transcriptomic analysis showed that 91 differential expressed genes were found in significantly enriched metabolic pathways, which were mainly involved in catalytic activity. Notably, a fully connected network of metabolites and genes in these pathways was built, which can increase the credibility of the selected metabolites. In summary, DEHP exposure induced poor lactation performance by altering hormone levels, damaging mammary gland structure and disordering metabolism of precursors of milk synthesis.
Lactation Biology: Orals Orals Lactation Biology 7/11/2021 0:00 t84648 Watch 129 Identification and network analyses of long noncoding RNA (lncRNA) regulating cattle lactation. 7 M. Rijnkels long noncoding RNA lactation dairy cattle Y. Xing1, H. Lyman2, B. Davis1, I. Korf2, D. Lemay2,3, A. Cullum4, J. Dobson4, K. Oden4, A. Molenaar5, K. Singh4, C. Couldrey8, R. Weikard6, C. Kühn6,7, M. Rijnkels1 1Department of Integrative Veterinary Biosciences, Texas A&M university, College Station, TX, 2Genome Center, University of California-Davis, Davis, CA, 3USDA ARS Western Human Nutrition Center, Davis, CA, 4AgResearch Ltd, Ruakura Research Station, Hamilton, New Zealand, 5AgResearch Ltd., Grassland Research Center, Palmerston North, New Zealand, 6Institute of Genome Biology, Leibniz Institute for Farm Animal Biology, Dummerstorf, Germany, 7Faculty of Agricultural and Environmental Sciences, University Rostock, Rostock, Germany, 8LIC, Hamilton, New Zealand LncRNAs are non-protein-coding RNA molecules larger than 200 nt that regulate gene expression at transcriptional or post-transcriptional levels. In this study LncRNA were predicted based on mammary gland RNA-seq data from 16 Holstein-Frisian animals at peak lactation and virgin using FEELnc. Differential gene expression between lactation and virgin was determined. LncRNA overlap with lactation QTL and conservation in mammals was determined. Weighted gene coexpression network analyses (WGCNA) were used to identify correlations between co-expressed gene modules and lactation or virgin state, or differentially expressed lncRNAs. Furthermore, gene sets based on these analyses were used as candidate genes to conduct Regulatory Impact Factor Analysis (RIF) and PCIT analysis. Pathway and GO enrichment analyses were conducted for gene modules, and lncRNA correlation partners from lactation and virgin networks. 2,210 lncRNA transcripts (1,500 loci) were predicted. 88 loci (102 transcripts) were new lncRNA genes. A total of 373 differentially expressed lncRNA genes (636 transcripts) were identified. 55 lncRNA and 117 positional partner RNA genes overlapped with lactation QTLs. 39.4% and 53.2% of lncRNA transcripts were conserved in mouse and human respectively. Of these, 45.3%, 53.9% had lncRNA as biotype respectively. 58.9%, and 68.7% of the partner RNA transcripts were conserved in mouse and human respectively, more than 67% of these are protein coding. Based on the RIF-PCIT constructed networks, 69 lncRNA transcripts are key regulators in lactation and 116 in the virgin. Of these, 10 and 16 were transcripts from predicted new lncRNA genes respectively. A proportion of the key regulators’ network partners were in the same WGCNA gene module. Overall, 100 out of 185 key regulators were conserved in at least one other mammal, several have known mammary gland function. Genes regulated by key-regulatory lncRNA are involved in Milk protein, PI3K-Akt, Calcium, and prolactin signaling pathways among others. The lncRNAs identified are potentially important regulators of lactation in livestock, human and mouse.
Lactation Biology: Orals Orals Lactation Biology 7/11/2021 0:00 t84716 Watch 130 Segmenting mammary gland tissue of preweaned dairy calves using spatial pyramid pooling networks. 8 D. A. B. Oliveira neural network parenchymal tissue polar transformation D. A. B. Oliveira1, T. Bresolin1, S. G. Coelho2, M. Magalhaes3, C. Lage2, L. G. R. Pereira1,3, L. Hernandez1, J. R. R. Dorea1 1University of Wisconsin–Madison, Madison, WI, 2Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil, 3Brazilian Agricultural Research Corporation – Embrapa, Juiz de Fora, MG, Brazil Mammary gland development of dairy cows can be detrimentally affected by environmental effects, including suboptimal nutritional strategies and heat stress early in life. These negative impacts can drastically reduce lactation performance and feed efficiency of adult animals. A novel, non-invasive, and simple technology to evaluate mammary gland characteristics is ultrasonography. Recently, machine learning algorithms have been used in medical image analyses for soft tissue segmentation, creating a powerful support tool for clinical diagnostic, feature extraction, and pattern recognition. In this context, the objective of this study was to investigate the use of spatial pyramid pooling deep networks for segmenting parenchymal tissue in mammary gland ultrasound images from pre-weaned dairy calves. A total of 405 ultrasound mammary gland images (front and rear quarters) were obtained from 29 crossbred F1 Holstein × Gyr, at wk 1, 2 and 3 of age, using a B-mode ultrasound equipped with microconvex transducer at a frequency of 6 MHz (DP 2200, Mindray, Shenzhen, China). Parenchyma tissue was manually labeled using VGG Image Annotator. We trained the deep neural networks in a leave-one-animal-out schema, where for each iteration (n = 29) all images of a given animal was removed for final validation. Due to the small training set (405 images), we proposed a novel data augmentation procedure that uses a polar transformation to enable shifting of the ultrasound image in a similar way a moving probe would. The average F1-score in wk 1 was 54% on the testing set; in wk 2, 70%; wk 3, 75%. Our results indicated that for images where parenchyma was very small (wk 1) the algorithm did not perform well, but as the mammary gland developed, the identification and segmentation of the parenchymal tissue drastically improved. A larger data set and high-resolution images could potentially improve deep learning performance to segment small tissues. Our results show that using deep learning networks to segment parenchymal tissue in mammary gland ultrasound images can be a promising tool for tissue identification and feature extraction.
Lactation Biology: Posters Posters Lactation Biology 7/11/2021 0:00 s9584                  
Lactation Biology: Posters Posters Lactation Biology 7/11/2021 0:00 t83550 Watch P251 Postpartum milk yield and immunoglobulin concentration, and factors related to colostrum quality at quarter level in dairy cows after parturition. 1 J. J. Gross quarter colostrum immunoglobulin G E. C. Kessler1, G. C. Pistol1,2, R. M. Bruckmaier1, J. J. Gross1 1Veterinary Physiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland, 2Laboratory of Animal Biology, National Institute for Research and Development in Animal Biology and Nutrition, Ilfov, Romania We analyzed milk production and IgG concentration at the individual quarter level in 29 multiparous Holstein cows during the first 5 milkings after calving. The objective was to investigate to which extent cow- and calf-related factors contribute to quarter milk production and IgG concentration after parturition. Cow- and calf-related factors (interval between calving and first milking, parity number, previous lactation yield, gestation length, dry period length, sex, birth weight of the calf) were assessed. Milking of first colostrum was carried out between 30 and 180 min postpartum. Further milkings were performed twice daily. Quarter milk yield at the first milking varied between 0.1 and 5.5 kg and between 1.4 and 5.1 kg at the fifth milking relative to parturition. Quarter IgG concentration ranged between 18.8 and 106.0 mg/mL at the first milking and between 0.8 and 46.1 mg/mL at the fifth milking. Mixed models (SAS) were used to assess repeatability with quarter and milking number as fixed effects, whereas effects of cow- and calf-related factors on milk yield and IgG concentration were included as class variables in GLM models. Milk yield and IgG concentration among quarters was not entirely repeatable during the first 5 successive milkings after parturition, i.e., the ranking of quarters changed (intraclass correlation coefficients for quarter milk yield and IgG concentration: 0.64 and 0.79, respectively). Milk production increased in all quarters ranging from 0.02 to 0.26 kg/h between the first 2 milkings up to values ranging from 0.11 to 0.45 kg/h between the fourth and fifth milking. First colostrum yield was not affected by any of the evaluated cow- and calf-related factors. Quarter colostrum IgG concentration was higher in cows with a higher previous lactation yield, whereas a lower colostrum IgG content was observed in cows with a longer gestation period and consequently heavier calves. In conclusion, milk yield and IgG concentration of individual quarters varied considerably, and their distribution among quarters within cows was moderately repeatable in consecutive milkings and changed partially over time. The decline of IgG concentration was not totally dependent of the concomitant increase in milk secretion with changes occurring at different rates in individual quarters. Results confirm the independency of the single mammary quarters at the onset of lactation.
Lactation Biology: Posters Posters Lactation Biology 7/11/2021 0:00 t83408 Watch P252 Different microRNA contents between mammary epithelial cells and milk fat globules is not a random process? 2 C. Leroux miRNA mammary epithelial cell milk fat C. Leroux1, K. Pawlowski1,3, D. Lago-Novais1,4, C. Bevilacqua2, L. Mobuchon1,2, N. Crapart2,5, Y. Faulconnier1, S. Bes1, C. Boby1, G. Carvalho4, P. Martin2 1INRAe-UMRH, Saint Genès-Champanelle, France, 2INRAe-Gabi, Jouy-en-Josas, France, 3University of Life Sciences, Warsaw, Poland, 4Universidade Federal da Bahia, Bahia, Brazil, 5Excilone, Elancourt, France MicroRNAs (miRNAs) are small noncoding RNAs that act as posttranscriptional regulators of gene expression. They are present in milk-derived extracellular vesicles as milk fat (MF) globules that are secreted in large amounts in milk. Discrepancies exist between the miRNA content of lactating mammary tissue (MT) and that found in milk fat. Our objective was to study the abundance of example miRNAs from different sources (MT, Mammary epithelial cell (MEC), MF), addressing the question of the origin of these miRNAs fate. Moreover, we wanted to evaluate the existence of a possible mechanism sorting miRNAs that will or will not be exported from the MEC to bovine MF. With these objectives, we used RT-qPCR to compare the abundance of 4 miRNA (miR-125b-5p, miR-126–3p, miR-141–3p, and miR-204–5p) in lactating cow MT, MF, and laser capture-microdissected MECs. After normalization (using U6-snoRNA and let-7–5p), statistical analyses, were performed on ΔCt values with a Mann-Whitney test and FDR correction. The significance level was predefined as Padj ≤ 0.05. Two miRNAs (miR-125b-5p and miR-141–3p) were detected in the MT as well as in MF and MECs. MiR-204–5p was detected, with reliability only in the MT (mean Ct of 25.7 whereas it was more than 30 in MF and MEC), suggesting that it is very likely expressed in a cell type other than MECs. MiR-126–3p was detected both in the MT (mean Ct: 17.7) and in MECs (mean Ct: 19.1) but not in MF (mean Ct: more than 30), suggesting a targeting mechanism for miRNAs in MECs. In conclusion, this study highlights differences in miRNA content between MECs and milk fat, possibly due to a mechanism for loading milk fat with miRNA cargos that may not be a random process but could involve a variable distribution in MECs or a sorting mechanism.
Lactation Biology: Posters Posters Lactation Biology 7/11/2021 0:00 t83458 Watch P253 Comparison of miRNome from cow milk fat fraction and mammary gland tissue during inflammation. 3 C. Leroux milk miRNome inflammation C. Leroux1, P.-A. Billa1, K. Pawlowski1,2, S. Bes1, J. Pires1, Y. Faulconnier1 1INRAe-UMRH, Saint Genès-Champanelle, France, 2University of Life Sciences, Warsaw, Poland MicroRNAs (miRNA, small noncoding RNAs) regulate the expression of genes involved in many biological processes, including inflammation and mammary gland (MG) development and lactation. MicroRNAs are present in milk-derived extracellular vesicles including fat globules (FG) that are secreted in large amounts in milk. Our objectives were to study the bovine FG miRNome and to ensure that FG miRNAs are representative to MG miRNome during inflammation for the use of FG as a noninvasive source of miRNAs, which could be potential inflammation biomarkers. To achieve these objectives, we compared the miRNome of MG and FG, in an experimental model of inflammation in early-lactation cows. MG biopsies and milk FG were collected during the same milking, from 6 early-lactation multiparous Holstein cows, 24 h after intramammary injection of 50 µg of lipopolysaccharide to induce an inflammation. Total RNAs were extracted from FG and MG using TRIzol. Customized 8 × 60K miRNA microarrays were hybridized using a single-color method. Normalized with 75th percentile shift, data were analyzed using GeneSpring software. Statistical analyses were performed using paired t-tests, Benjamini-Hochberg correction, and significance considered at Padj ≤ 0.10. Analyses of MG and FG miRNome showed that 97% of the more than 2,500 detected sequences did not differ statistically between MG and FG. However, among the 47 differentially abundant miRNAs in MG compared with FG, 29 had a fold change ≥1.5. Bioinformatics analyses of coding genes potentially targeted by these miRNA revealed that they are involved cellular pathways such as calcium signaling, adherents, tight and gap junction and endocytosis pathways. Among miRNAs presenting highest FC, were let-7c, miR-126–3p and the miR-200 family, which were more abundant in MG than FG. These latter could target genes involved in cell adhesion, migration or vascular integrity, as in the epithelial-mesenchymal transition, therefore determining the epithelial cell phenotype. In conclusion, these results show that 24 h after an intramammary LPS challenge, FG miRNome is mostly representative of the MG miRNome. However, the observed differences may be related to the secretion of miRNA in FG and/or due to the LPS inflammation challenge inducing changes in mammary tissue. These hypotheses must be confirmed by further investigations.
Lactation Biology: Posters Posters Lactation Biology 7/11/2021 0:00 t83542 Watch P254 Influence of nutrients in milk on the in vitro growth of major bovine mastitis pathogens. 4 R. M. Bruckmaier bovine mastitis bacterial growth pathogen R. Stürmlin1, J. J. Gross1, O. Wellnitz1, L. A. Wagner1, C. Monney2, A. Oevermann2, R. M. Bruckmaier1 1Veterinary Physiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland, 2Division of Neurological Sciences, Vetsuisse Faculty, University of Bern, Bern, Switzerland The growth of 3 major bovine mastitis pathogens Escherichia coli, Staphylococcus aureus, and Streptococcus uberis was investigated in ultra-high-temperature (UHT) treated milk with different contents of fat, protein and carbohydrates. Additionally, the bacterial growth was studied in diluted milk with subsequent addition of individual nutrients (carbohydrates, nitrogen sources, minerals and B vitamins). Statistical analysis used mixed models (SAS) with type of medium and pathogen as fixed, and replicates as random factors. Data of growth rates are presented as log10cfu/h, calculated from the difference of log10-transformed cfu/mL between smears of time points 0h and 8h, and based on 3 independent setups. Varying contents of fat [0.1–25.1% wt/vol], protein [2.5–7.0%] and carbohydrates [4.0–5.0%] did not affect bacterial growth rates, except for increased growth (P < 0.01) of S. uberis in protein-enriched milk (0.754 ± 0.016 [growth rate ± SD]) compared with growth in whole milk (0.641 ± 0.014). The addition of lactose [4%] or minerals [0.2‰] to diluted milk [1:20 for E. coli, 1:10 for S. aureus and S. uberis] did not affect bacterial growth. The growth rate of E. coli was decreased when diluted milk was enriched by urea [3%] (0.507 ± 0.007; P < 0.001) or by a mixture of B vitamins [1%] (0.552 ± 0.012; P < 0.001) compared with growth in diluted milk without additives (0.654 ± 0.002). Growth rate of S. aureus was decreased by the addition of a mixture of amino acids [0.2‰] (0.384 ± 0.008; P < 0.001), urea [3%] (0.351 ± 0.011; P < 0.001) and B vitamins [1%] (0.349 ± 0.012; P < 0.001) to diluted milk in comparison to growth in diluted milk without additives (0.482 ± 0.004). The growth rate of S. uberis was increased by the addition of B vitamins [1%] (0.487 ± 0.014; P < 0.05) to diluted milk compared with growth in diluted milk without additives (0.234 ± 0.021). Changes of bacterial growth were only achieved by changes of the milk composition beyond the respective physiologically possible range. Our study confirmed that milk is abundantly saturated with nutrients for pathogen growth. We conclude that physiologically relevant changes of milk composition are unlikely to affect pathogen growth during mastitis.
Lactation Biology: Posters Posters Lactation Biology 7/11/2021 0:00 t84323 Watch P255 Yes-associated protein expression of mammary epithelial cells from mammary glands subjected to increased milking frequency. 5 G. Perez-Hernandez milking frequency cell proliferation Yes-associated protein G. Perez-Hernandez1, K. Tate1, K. D. Hardin1, C. Parsons1, R. M. Akers1, B. A. Corl1 1Virginia Tech, Blacksburg, VA Increased milking frequency (IMF) during early lactation increases milk yield and has been associated with mammary epithelial cell (MEC) proliferation. Nevertheless, clear delineation if milk yield enhancement is driven by cell proliferation or cell differentiation with IMF is unclear. Yes-associated protein (YAP) promotes cell proliferation when dephosphorylated and translocated to the nucleus. The objective of this study was to evaluate the spatial expression of YAP, as a novel marker of cell proliferation, in mammary glands subjected to IMF at the beginning of lactation. Eight multiparous cows were milked at IMF for the first 21 d of lactation using the unilateral frequent milking method. Mammary biopsies from each rear quarter were obtained on d 21 and d 60. Immunofluorescence in formalin fixed paraffin embedded tissue was used to evaluate YAP expression. Data were analyzed using the UNIVARIATE procedure of SAS for descriptive statistics. The averages for intensity were analyzed using the GLIMMIX procedure. Cellular YAP staining intensity was reduced 47% from d 21 (940 ± 143) to d 60 (495 ± 143) when cows were milked twice per day. YAP epithelial staining intensity increased by 90% when 4X (938 ± 143) IMF was used compared with 2X (495 ± 143) at 60 DIM, but there was no effect of IMF at 21 DIM. YAP-positive nuclei proportion increased on d 60 (0.29 ± 0.02) compared with d 21 (0.22 ± 0.02) regardless of treatment. Mammary gland tissue samples from cows milked 4X had a higher proportion of positively stained nuclei (0.28 ± 0.02) than cows milked 2X (0.22 ± 0.02) regardless of day. More YAP in the nuclei of mammary cells of glands milked at 4X compared with glands milked 2X could indicate an increase in cell proliferation associated with IMF. This study provides new information on the relative amount and location of YAP in the mammary gland. Further research should investigate whether there is an increase in cell proliferation associated with increased YAP expression in mammary glands following IMF.
Lactation Biology: Posters Posters Lactation Biology 7/11/2021 0:00 t84281 Watch P256 Intramammary infection prevalence and mammary secretion characteristics of primigravid dairy heifers. 6 L. R. Larsen mastitis heifer mastitis heifer SCC L. R. Larsen1, P. H. Baker1, K. M. Enger1, L. E. Moraes2, B. D. Enger1 1The Ohio State University, Wooster, OH, 2The Ohio State University, Columbus, OH Intramammary infections (IMI) in primigravid dairy heifers can impair growth and development of the mammary gland which reduces milk yield after calving. Detection of IMI in heifers often involves time-consuming culture-based approaches. The objective of this study was to determine if prepartum mammary secretion SCC and viscosity was associated with infection status. A total of 270 heifers were enrolled. Mammary secretion samples were aseptically collected from a randomly selected quarter of each heifer at 75 d prepartum (75PP), and another randomly selected quarter of each heifer was sampled 35 d prepartum (35PP). The remaining 2 quarters of each heifer were not utilized in this study. Mammary secretion samples underwent bacteriological examination to determine IMI status, quantitative SCC measurement, and were also visually scored for viscosity. Viscosity data were analyzed using PROC GLIMMIX, with the fixed effects of sampling day and IMI status, while heifer was a random effect. Prevalence of IMI was 26% and 28% at 75 and 35 d prepartum. Samples from 35PP were 1.7 times (95% CI: 1.1–2.8) more likely to be of thin viscosity than samples from 75PP. Uninfected samples were 68.2 (95% CI: 14.8–313.6) times more likely to be thick compared with samples infected with a major pathogen and 14.6 (95% CI: 8.6–24.7) times more likely to be thick compared with samples infected with a minor pathogen. SCC data were analyzed with PROC MIXED; sampling day and IMI status were fixed effects and heifer was a random effect. Log SCC were greater in samples infected with a major pathogen (6.6 ± 0.1) than those infected with a minor pathogen or uninfected (6.3 and 6.0 ± 0.04, respectively; P ≤ 0.01). These results indicate that mammary secretion viscosity and SCC measurement may be accurate and useful tools in identifying primigravid heifer quarters with IMI. The simplicity of a viscosity measure that may be taken cow-side might allow for rapid identification of IMI and subsequent treatment of infected quarters to diminish the negative physiological effects an IMI causes, ensuring increased milk production when lactation begins.
Lactation Biology: Posters Posters Lactation Biology 7/11/2021 0:00 t84201 Watch P257 Effect of increased milking frequency during early lactation on bovine mammary epithelial cell differentiation. 7 G. Perez-Hernandez cytological classification MEC differentiation increased milking frequency G. Perez-Hernandez1, K. Tate1, K. D. Hardin1, C. Parsons1, R. M. Akers1, B. A. Corl1 1Virginia Tech, Blacksburg, VA The cytological classification of mammary epithelial cells (MEC) and its use as an indicator of cell activity and cell differentiation allow investigation of the undetermined mechanism of how the mammary gland adapts to increased milk production. The objective of this study was to determine the effect of increased milking frequency (IMF) during early lactation on mammary epithelial cell differentiation through histological analysis. A scoring evaluation of the cytological differentiation of mammary tissue samples was completed on mammary biopsy samples from multiparous cows (n = 8) subjected to unilateral milking frequency for the first 21 d of lactation. The right udder half was milked 4× and the left udder half milked 2×. Tissue was formalin fixed, embedded in plastic-resin, and stained with Azure II for histochemical analysis. Mammary epithelial cell differentiation scoring was completed by reviewing collected images and categorizing them in 1 of 3 cell differentiation score levels, based on cell organelles characteristics as previously reported in the literature, in 0.1 increments, poor (1), intermediate (2), and complete (3). Scores were recorded and averaged for each animal by right or left udder half. Data were analyzed using the UNIVARIATE procedure for descriptive statistics, and differentiation score was analyzed using the GLIMMIX procedure of SAS. Milk yield was increased in the 4× udder halves (11.5 ± 1.1 kg/d) compared with the 2× udder halves (8.5 ± 1.1 kg/d) on 21 DIM. Mammary epithelial cell differentiation at 21 DIM was higher (2.32 ± 0.17) than d 60 (1.73 ± 0.17). Mammary gland samples from udders milked 4× exhibited the greatest mammary cell differentiation (2.41 ± 0.17) compared with 2× (1.64 ± 0.019), demonstrating an effect on mammary epithelial cell differentiation when IMF is used in early lactation. Results indicate that mammary cell differentiation is reduced at d 60 compared with d 21, coinciding with peak lactation, and increases after an IMF treatment at the beginning of the lactation in multiparous cows.
Lactation Biology: Posters Posters Lactation Biology 7/11/2021 0:00 t83989   P258 Proteomic analysis of the xanthosine-treated lactating goat mammary gland. 8 R. K. Choudhary goat mammary gland xanthosine protein profile S. Choudhary1, S. Kumar2, A. K. Mohanty2, R. K. Gandham3, R. K. Choudhary1 1College of Animal Biotechnology, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India, 2Animal Biotechnology Center, National Dairy Research Institute, Karnal, Haryana, India, 3National Institute of Animal Biotechnology, Hyderabad, Telangana, India Xanthosine (Xs) increases mammary epithelial cell proliferation in vitro and increases stem cells, and favorably affects milk secretion in goats. We determined the protein profile of mammary tissue during early lactation in the Xs-treated gland. Six primiparous Beetle goats were used in this study. Five days after kidding, one gland was infused (2 times for 3 d) with Xs, and the other gland served as control. Using 2-dimensional difference gel electrophoresis combined with MALDI-TOF/TOF mass spectrophotometry, we identified 144 differentially expressed proteins (DEP), of which 46 proteins were upregulated, and 98 were downregulated in the Xs-treated gland. These DEP analyses by ingenuity pathway analysis (IPA) showed 5 highly significant protein networks namely, 1) Energy production, Nucleic acid metabolism, 2) Cellular assembly and organization, 3) Connective tissue disorder, 4) Drug metabolism, and 5) Cell death and survival with a respective score of 46, 44, 44, 38 and 20. Pathway of cell death was downregulated in Xs-treated glands, indicating a favorable condition for survival and growth of mammary tissue. Functional annotation clustering of DEP using Database for Annotation, Visualization, and Integrated Discovery (DAVID) revealed 8 significant clusters (Enrichment score > 2.0). Interestingly, the first annotation cluster with an enrichment score of 3.58 was the cluster of antibiotic biosynthesis. Identified clusters of antibiotic synthesis were consistent with our RNa-seq data reported earlier. The novel role of Xs in nucleic acid metabolism, favoring cell survival and association of DEP in the antibiotic role is novel and requires further experimental validation. This work provides insights into protein interactions to further investigate the mechanisms underlying the role of Xs in lactating goats.
Lactation Biology: Posters Posters Lactation Biology 7/11/2021 0:00 t83892 Watch P259 An improved method for isolating epithelial cells from lactating dairy cow secretory tissue. 9 A. C. Hruby cell culture fibroblast A. C. Hruby1, I. A. M. A. Teixeira2, M. D. Hanigan1 1Department of Dairy Science, Virginia Tech, Blacksburg, VA, 2Department of Animal Science, UNESP, Jaboticabal, Brazil Bovine mammary epithelial (BME) cell cultures are commonly used to better understand mammary metabolism and growth. BME cells have been established using a variety of methods including enzymatic digestion (Zavizion et al., 1992) and direct plating of explants (Hu et al., 2009). Enzymatic digestion is more expensive and cell yields are not high. Direct plating of explants results in migration of cells out from the explants that have attached to collagen-coated plates; however, fibroblasts also migrate out. Partial trypsinization (PT) is used to separate fibroblasts from BME cells in the culture system, however, details such as timing and enzyme concentrations are not well documented. Further, given that the explants are the source of the BME cells, we hypothesized that PT to remove fibroblasts followed by normal trypsinization to harvest epithelial cells could be performed, and if the explants remained attached, additional BME cells would migrate from the explant. Therefore, the objectives of this study were to 1) assess conditions for PT; and 2) assess explant retention as a method of improving BME cell yield. Secretory tissue was collected from the udder of a primiparous Jersey cow (16 DIM) at slaughter. Tissue was rinsed in Hanks' buffer until free of milk and manually reduced to 1 mm3 using scalpels and scissors, plated at a density of 1 explant/cm2 in collagen-coated, 75 cm2 flasks without medium, and incubated at 38°C under 5% CO2. Explants were kept wet. After ~4 h, 4 mL of basal growth medium was gently added to each flask. Medium was changed the following morning and every 24 h thereafter. After approximately 4 d, fibroblasts were observed emerging from the tissue pieces; at d 8.4 ± 0.2 mixed cultures were observed, and the PT was done by application of 0.05% trypsin-EDTA for 4 min. PT removed fibroblasts and did not remove well-attached explants or BME cell colonies. It was observed that clearing space around the explant allowed additional migration of cells from the explant. When pure BME cells were observed to surround the explant, BME cells were passaged (0.25% trypsin-EDTA) with care taken to avoid explant detachment. After BME cell removal, additional BME cells migrated from the explants yielding another crop of BME cells for harvest within 1 wk. In summary, the use of PT starting at 8 d on attached cells from explants and continued harvest of remaining epithelial cells improves upon the original method.
Lactation Biology: Posters Posters Lactation Biology 7/11/2021 0:00 t83878 Watch P260 Prepartum feeding of X-Zelit increases blood ionized calcium and colostrum IgG concentrations. 10 J. P. Campolina dairy dry period hypocalcemia J. P. Campolina1, W. S. Frizzarini2, P. L. J. Monteiro2, A. Vang2, L. L. Hernandez2 1Universidade Federal de Minas Gerais, Belo Horizontes, MG, Brazil, 2University of Wisconsin–Madison, Madison, WI Colostrum is the first secretion of the mammary gland after parturition and the primary source of immune transfer for the newborn calf. Calcium is the primary mineral in colostrum, resulting in extensive demand on the cow. The aim of this study was to evaluate colostrum quality and blood ionized calcium concentrations before and after the first milking from dairy cows receiving 3 dietary treatments pre-partum. One hundred eight multiparous Holstein cows were randomly assigned to one of 3 dietary treatments 21 d before estimated calving date: control (CON; +190.24 mEq/kg; n = 32), negative dietary cation-anion difference (DCAD; −64.71 mEq/kg; n = 35), and a diet with sodium aluminum silicate (XZ; +277.40 mEq/kg with 500 g/day X-Zelit, Protekta Inc.; n = 38). After parturition, blood samples were collected to measure ionized calcium at parturition (iCaP) using a portable device (VetScan iSTAT System). After, cows were milked, colostrum weighed, and samples collected for further laboratory analysis. A second blood sample was collected to measure ionized calcium after colostrum removal (iCaM). Colostrum quality was analyzed using a Brix refractometer. Colostrum IgG concentrations were measured using a commercial bovine IgG ELISA kit (Bethyl Laboratories), and colostrum calcium concentrations were analyzed by atomic absorption. Data were analyzed in R Studio using the GLS function on NLME package. No differences between dietary treatments were observed for colostrum weight, Brix analysis or calcium content (P > 0.05). Increased IgG concentrations were observed in the XZ group (91.4 ± 3.9 mg/mL) compared with DCAD (80.7 ± 4.1 mg/mL) and CO (78.9 ± 4.2 mg/mL, P = 0.04). The XZ cows had 7% and 14% higher iCaP (1.084 ± 0.02) and 9% and 19% higher iCaM (1.089 ± 0.02) when compared with DCAD and CO cows (P < 0.001), respectively. Feeding XZ prepartum improved colostrum immunological composition and helped maintain normalcalcemia when compared with DCAD and CO dietary treatments.
Physiology and Endocrinology: Orals Orals Physiology and Endocrinology 7/11/2021 0:00 s9637                  
Physiology and Endocrinology: Orals Orals Physiology and Endocrinology 7/11/2021 0:00 t83544 Watch 131 Fuel oxidation and heat production differences between high and low feed efficient dairy cows. 1 K. M. Kennedy oxidation efficiency dairy cow K. M. Kennedy1, H. M. Hammon1, B. Kuhla1 1Institute of Nutritional Physiology, Dummerstorf, Germany Our objective was to determine if lactating dairy cows grouped by high or low feed efficiency differed in fuel oxidation and heat production across 2 nutritional levels. From a herd of 15 dairy cows (parity = 2), 10 cows were retrospectively grouped into either a high (H) or low (L) feed efficiency group (n = 5/group) based on weekly energy-corrected milk (kg) divided by dry matter intake (kg; ECM/DMI) from wk 4 through 30 of lactation. Cows were fed a common ration throughout lactation. In wk 5.70 ± 0.82, cows spent 2 d in respiration chambers (RC) in which CO2, O2, and CH4 gases were measured every 6 min for 23 h. Measured CO2 was corrected for CH4 to calculate metabolic CO2 and the latter used in subsequent energy calculations except heat production (HP). Fatty acid oxidation (FOX), carbohydrate oxidation (COX), metabolic respiratory quotient (RQ), and HP were calculated from gas measurements. Cows were fed ad-libitum (AD-LIB) on d 1 and had feed withdrawn (RESTRICT) on d 2. Data were analyzed with mixed models using SAS software. As planned, H (body weight (BW): 628 ± 58.1 kg; BCS: 2.45 ± 0.42) was more efficient than L (BW: 703 ± 73.5 kg; BCS: 2.95 ± 0.52) in feed efficiency (1.80 vs. 1.64; P = 0.02). Neither DMI, BW, milk yield nor COX differed between groups during the RC period (P > 0.10). However, HP (133 vs. 115 MJ/23 h; P = 0.05) and HP per metabolic BW (mBW) was greater for L than H (967 vs. 1,032 kJ/(kg of BW0.75 × 23 h); P = 0.04). Additionally, FOX tended to differ between groups across days (interaction, P ≤ 0.06), and L was greater than H during AD-LIB when unadjusted (1,607 vs. 1,011 g/23 h; P = 0.01) and adjusted for mBW [13.2 vs. 9.66 g/kg of BW0.75 × 23 h); P = 0.02] but not during RESTRICT (P > 0.10). The RQ average tended to differ between groups across days (interaction, P = 0.06) with L tending to be lower than H during AD-LIB (0.85 vs. 0.89; P = 0.07) but not during RESTRICT (P = 0.47). Greater FOX likely contributed to the greater HP loss in L compared with H. Considering no differences in DMI, BW, or milk yield during the RC period, these results suggest that lower feed efficiency may result from greater HP loss.
Physiology and Endocrinology: Orals Orals Physiology and Endocrinology 7/11/2021 0:00 t84119 Watch 132 Physiological state influences circulating and mammary calcium and serotonin concentrations. 2 M. Connelly calcium parathyroid hormone-related protein (PTHrP) serotonin M. Connelly1, T. Walker1, J. Kuehnl1, S. Henschel1, L. Hernandez1 1University of Wisconsin–Madison, Madison, WI At the onset of lactation, the dairy cow experiences a dynamic change in calcium physiology as large amounts of calcium are lost through milk. Thus, normal calcium homeostatic mechanisms are challenged and mammary-derived responses, such as parathyroid hormone-related protein (PTHrP) and serotonin, aid in responding to this change in calcium metabolism. The objective of this study was to evaluate physiological adaptations in response to induced subclinical hypocalcemia in lactating and dry, non-pregnant dairy cows. Using a randomized complete block design, 12 dry, non-pregnant multiparous Holstein cows and 12 early-lactation (5–20 DIM) multiparous Holstein cows received either (1) a continuous 24-h intravenous solution of 0.9% saline or (2) 5% ethylene glycol tetraacetic acid (EGTA) in 0.9% saline (n = 6 lactating, n = 6 dry, non-pregnant/treatment) with the aim of maintaining blood ionized calcium (iCa) less than 1.0 mM. Mammary gland biopsies were taken immediately after termination of infusion and 48 h later. Mammary tissues were analyzed using qPCR to evaluate gene expression and normalized to the geometric mean of ribosmal protein S9, cyclophilin A, and keratin 8. Groups were compared using a mixed model ANOVA. Circulating serotonin concentrations and mammary serotonin content were elevated in early-lactation cows relative to dry, non-pregnant cows (P = 0.002 and P = 0.03, respectively), but were not different between chelated and non-chelated groups (P > 0.05). Interestingly, mRNA of tryptophan hydroxylase 1 was decreased in the mammary gland of lactating cows when compared with dry, non-pregnant cows (P = 0.03). Lactating EGTA-infused cows had increased PTHrP expression compared with dry, non-pregnant cows (P < 0.01), with mRNA expression of PTHrP robustly upregulated in lactating EGTA-infused cows compared with lactating saline-infused cows (P < 0.01). These data support calcium and serotonin metabolism differing among early-lactation and dry, non-pregnant cows. Further, these data suggest mammary-derived endocrine signals, such as PTHrP and serotonin, may be coordinators in the peripartal cow’s adaptation to lactation.
Physiology and Endocrinology: Orals Orals Physiology and Endocrinology 7/11/2021 0:00 t84454 Watch 133 Effects of recombinant bST on mammary gland growth of Holstein × Gyr heifers. 3 A. L. L. Sguizzato crossbred prepuberty somatotropin A. L. L. Sguizzato1, S. E. F. Guimarães1, G. M. Santos2, F. A. Castaño1, M. I. Marcondes3,1 1Universidade Federal de Viçosa, Viçosa, MG, Brazil, 2Cenva Post Graduation, Viçosa, MG, Brazil, 3Washington State University, Pullman, WA New technologies to improve mammary gland (MG) growth in high-performance dairy heifers are warranted, especially if they could improve their future milk production. We aimed to evaluate the effects of rbST on MG growth of prepubertal Holstein × Gyr (HG) heifers. Thirty-four HG heifers with average initial body weight (iBW) of 218 ± 49 kg and 14 ± 4 mo of age received rbST (500 mg) or sodium chloride (0.9%) shots every 14 d for 84 d. They were fed a diet to gain 1 kg/d (NRC, 2001) with a metabolizable protein/metabolizable energy ratio of 42 g/Mcal. We performed ultrasound measurements in each MG quarter on d 1, 28, 56, and 84. Then, we evaluated the pixel value using ImageJ software, collecting 3 random squares of 4 mm2 for parenchyma (PAR) and 16 mm2 for fat pad (FP) areas. PAR would present pixel values close to 0 (black = hypoechoic), and FP would present pixel values close to 255,000 (white = hyperechoic; Albino et al., 2017). We also performed MG biopsy in 18 randomly selected heifers on d 86. A RT-PCR analysis was carried out to assess the effects of rbST on expression of IGF1, IGF1R, IGFBP3, FASN, and ESR1. All variables were analyzed using the GLIMMIX procedure (SAS 9.4) in a randomized block design, [using iBW (±56 kg) as blocking criteria, and repeated measures, if needed] adopting 5% as critical level of type I error. All interactions were non-significant (P > 0.05). There was a reduced pixel value for PAR and FP of rbST heifers, and no changes in gene expression, except for IGFBP3 (Table 1). Although a rise in PAR pixel was noticed along the days, the PAR/FP ratio increased around 7% from d 1 to 84, suggesting PAR growth toward FP tissue. In conclusion, the reduced pixel value for PAR and FP observed in rbST heifers, would indicate a greater amount of proliferative tissue (i.e., epithelial cells) with lower FP accumulation in the gland. Table 1. Ultrasound and gene expression results in the mammary gland of Holstein × Gyr heifers
Item no rbST rbST Day SEM P-value1,2
1 28 56 84 Treatment Day
Ultrasound                  
 Parenchyma 73.84 64.95 59.79b 72.08a 72.30a 73.40a 3.32 0.003 <0.001
 Fat pad 119.96 113.86 103.04c 124.31a 122.71a 117.59b 2.02 0.031 <0.001
Genes                  
 IGF1 0.016 0.010         0.004 0.201  
 IGF1R 0.019 0.028         0.006 0.337  
 IGFBP3 0.278 0.151         0.035 0.023  
 FASN 0.005 0.006         0.002 0.705  
 ESR1 0.059 0.048         0.015 0.605  
1Means within a row with different superscripts differ (P = 0.05). 2All interactions were nonsignificant (P > 0.05).
Physiology and Endocrinology: Orals Orals Physiology and Endocrinology 7/11/2021 0:00 t84402 Watch 134 Quantifying whole-body calcium flux following immune activation. 4 J. Opgenorth immune activation hypocalcemia J. Opgenorth1, E. J. Mayorga1, M. A. Abeyta1, S. Rodriguez-Jimenez1, B. M. Goetz1, A. D. Freestone1, C. H. Stahl2, L. H. Baumgard1 1Iowa State University, Ames, IA, 2University of Maryland, College Park, MD To further understand immune activation-induced hypocalcemia, we evaluated whole-body Ca flux following an intramuscular lipopolysaccharide (LPS) challenge. Pigs (n = 12; 44 ± 2.6 kg) were randomly assigned 1 of 2 treatments: 1) saline control (CON; 2 mL sterile saline; n = 6) or 2) LPS (40 µg LPS/kg BW in 2 mL sterile saline; Escherichia coli O55:B5; n = 6). Pigs were housed in individual metabolism stalls and restricted access to feed and water for 2 h before and during the challenge. Immediately following treatment administration, urine and feces were continuously collected. Pigs were euthanized 6 h post-injection and the Ca content of the entire heart, kidneys, liver, and spleen and luminal contents of the stomach, small intestine and large bowel were determined; likewise, samples of skeletal muscle, pancreas, adipose tissue, bone marrow, urine, ascites, serum, and bile were obtained to determine Ca concentration. Data were analyzed with PROC MIXED. LPS increased rectal temperature (39.2 and 40.7°C, in CON and LPS, respectively; P < 0.01) and decreased circulating glucose (39%; P < 0.01). Serum ionized Ca decreased in LPS relative to CON 6 h after LPS administration (1.09 vs 1.28 mmol/L; P < 0.01). The estimated total circulating Ca was decreased (P = 0.04) in LPS vs CON (95 vs 135 mg; respectively). LPS increased fecal Ca (130%; P = 0.05), at least partially explained by increased fecal output (246 vs 104 g for LPS vs CON, respectively). Ca increased and tended to increase in skeletal muscle and kidneys (55 and 35%; P ≤ 0.09), and numerically increased in the liver (28%; P = 0.12) and bone marrow (96%; P = 0.12) in LPS injected pigs. Considering its contribution to total empty carcass weight, Ca primarily was sequestered in skeletal muscle (806 mg increase) following LPS administration. LPS decreased Ca in adipose (55%; P = 0.02) and urine (75%; P = 0.05). Ca content did not differ in the heart, pancreas, spleen, ascites, or digesta within different segments of the gastrointestinal tract. In summary, immune activation causes severe hypocalcemia, which is primarily explained by Ca sequestration in skeletal muscle.
Physiology and Endocrinology: Orals Orals Physiology and Endocrinology 7/11/2021 0:00 t84718 Watch 135 Effects of recombinant bST on carcass characteristics and blood metabolites of Holstein × Gyr heifers. 5 A. L. L. Sguizzato performance ultrasound hormones A. L. L. Sguizzato1, M. S. Duarte1, P. V. F. Correa1, E. A. C. Lopes1, M. I. Marcondes2,1 1Universidade Federal de Viçosa, Viçosa, MG, Brazil, 2Washington State University, Pullman, WA Recombinant bovine somatotropin (rbST) is frequently used to improve lean gain in animals fed high-performance diets. We aimed to evaluate the effects of rbST on performance, rib eye area (REA), back fat thickness (BFT), and blood metabolites of prepubertal Holstein × Gyr (HG) heifers fed a high-performance diet. Thirty-four HG heifers with average initial body weight (iBW) of 218 ± 49 kg and 14 ± 4 mo of age received rbST (500 mg) or sodium chloride (0.9%) subcutaneous shots every 14 d for 84 d. They were fed a diet to gain 1 kg/d (NRC, 2001) with a metabolizable protein/metabolizable energy ratio of 42 g/Mcal. Heifers were fasted weighted for 3 consecutive days, each 28 d to assess average daily gain (ADG). We performed carcass ultrasound (US) analyses on d 1, 28, 56 and 84, to measure the gluteus medius and the biceps femoris muscle intercessions, and the longissimus dorsi. Images were recorded and later analyzed for REA and BFT. Moreover, blood samples were collected on the same days to evaluate IGF-1 and insulin, and on d 84 to evaluate T3 and T4. All variables were analyzed using the GLIMMIX procedure of SAS 9.4 in a randomized block design, [using iBW (±56 kg) as blocking criteria, and repeated measures, when necessary] adopting 5% as critical level of type I error. There was no difference for ADG of heifers (P = 0.730), where they gained around 1.14 kg/d. The REA was 20% greater for animals receiving rbST (P < 0.001), but there was no effect of rbST on BFT (P = 0.108). Both characteristics increased along the days assessed (P < 0.001). We observed a treatment × day interaction on IGF-1, where heifers receiving rbST had greater IGF-1 concentrations, mainly on d 28 (P = 0.005). Insulin was greater on d 84 (P = 0.025), but no rbST effect was observed (P > 0.05). A tendency of increased T3 (P = 0.064) and an increase in T4 concentration were found in rbST heifers (P = 0.002). In summary, the use of rbST improves lean gain of high-performance HG heifers during the prepubertal phase by increasing IGF-1, T3, and T4 concentrations. These differences among treatments can be responsible for promoting protein synthesis and deposition instead of adipose tissue.
Physiology and Endocrinology: Orals Orals Physiology and Endocrinology 7/11/2021 0:00 t84736 Watch 136 Changes in biomarkers of metabolic stress during late gestation of dairy cows associated with colostrum volume and IgG content across seasons. 6 R. M. Rossi oxidant status colostrogenesis immunoglobulins R. M. Rossi1, F. Cullens1, P. Bacigalupo1, L. M. Sordillo1, A. Abuelo1 1Michigan State University, East Lansing, MI The objective of this study was to compare the metabolic status of dairy cows during the last 6 wk of gestation based on colostrum volume and IgG content across seasons during a year. For this, healthy Holstein cows were randomly selected from 3 commercial herds in Michigan. In each farm, 4 cohorts of 21 cows (one per season), stratified by parity, were enrolled. Cows were blood sampled weekly during the last 6 wk of gestation, and biomarkers related to nutrient utilization, oxidant status, and inflammation were quantified in serum. Cows were milked within 6h of calving and the volume of colostrum produced was recorded and an aliquot collected. Concentration of IgG was measured by radial immunodiffusion. Cows were grouped into high colostrum producer (HCP) or low (LCP) and high IgG (HG) or low (LG). For volume category, we arbitrarily defined 6 L of colostrum (4 L for first and 2 L for second feeding of calves) as the cut-off point, whereas for IgG we used the industry standard of ≥ 50g/L. Data were analyzed statistically through mixed models with repeated measures including the fixed effects of groups (HCP vs LCP or HG vs LG), time, and their interaction; and the random effects of cow, season, lactation number, and farm (P < 0.05). Compared with LCP, HCP cows had higher concentrations of albumin, antioxidant potential, BHB, magnesium, and lower cholesterol and oxidant status index. For IgG group, HG cows had higher concentrations of albumin, glucose, and total protein. Collectively, these data show that producing high volumes of colostrum or IgG is associated with changes in nutrient utilization pre-calving. Nevertheless, the differences observed did not result in changes in inflammatory status in either HCP or HG, suggesting that physiological homeostasis was not disrupted during late gestation in association with the colostrum variables studied. Moreover, our results suggest that greater availability of antioxidants might support the production of higher volumes of colostrum.
Physiology and Endocrinology: Posters Posters Physiology and Endocrinology 7/11/2021 0:00 s9708                  
Physiology and Endocrinology: Posters Posters Physiology and Endocrinology 7/11/2021 0:00 t83470 Watch P261 Branched-chain amino acids and branched-chain ketoacids alter lipid metabolism and triacylglycerol content in primary liver cells enriched with hepatocytes. 1 K. Gallagher branched-chain amino acids branched-chain ketoacids lipid metabolism K. Gallagher1, J. Laguna1, Z. Zhou1 1Michigan State University, East Lansing, MI Plasma branched-chain amino acids (BCAAs) are negatively associated with liver triacylglycerol (TAG) level in dairy cows in early lactation. While seminal study demonstrated that BCAAs have the lowest rate of removal by liver in dairy cows under various nutritional and physiological conditions, their transamination products, branched-chain α-keto acids (BCKAs), are mostly catabolized in the liver. Our objectives were to quantify intracellular TAG content and expression of genes related to lipid metabolism primary liver cells enriched with hepatocytes (PLEH) exposed to BCAAs or BCKAs. PLEH were isolated from 3 nonpregnant mid-lactation multiparous Holstein cows previously. A customized medium (CM) was created to mimic the profile of circulating AAs, glucose, insulin, choline, and albumin levels observed for dairy cows on d 4 postpartum. Treatments were CM, FA (CM + 1mM FA cocktail mimicking circulating FAs), 1.3BCAA (FA + 33% circulating BCAA concentrations), 2BCAA (FA + 100% of circulating BCAA concentrations), 1/3BCKA (FA + 33% of BCKA of corresponding circulating BCAA concentration), and BCKA (FA + 100% of BCKA of corresponding circulating BCAA concentration). After 72 h, neutral lipids were stained with a fluorescent dye to quantify intracellular TAG content using flow cytometer. Expression of genes controlling lipid metabolism was also quantified in PLEH after 48 h. Treatment effects were determined using PROC MIXED in SAS. As expected, intracellular TAG content in FA was higher (P < 0.01) compared with CM. BCAA (1.3BCAA and 2BCAA) and BCKA (1.3BCKA and 2BCKA) treatments reduced (P < 0.01) intracellular TAG level in PLEH. Compared with FA, increasing BCKA (1/3BCKA (P = 0.08) and BCKA (P = 0.02)) led to lower SLC27A5 (hepatic long chain FA transporter) expression in PLEH. Expression of β-oxidation genes were also greater (P < 0.05) in 1.3BCAA (HADH and ECHS1) and 2BCAA (HADH and ACOX1) compared with FA. In response to BCKA, expression of β-oxidation genes (ACOX1 and ECHS1) was greater (P < 0.05) compared with FA. Additionally, 1.3BCAA, 2BCAA and 1/3BCKA also led to higher (P < 0.05) expression of UCP2 and lower (P < 0.05) expression of KEAP1, suggesting enhanced antioxidant defense compared with FA. Overall, results indicate that BCAAs and BCKAs altered lipid metabolism and reduced intracellular TAG level in PLEH.
Physiology and Endocrinology: Posters Posters Physiology and Endocrinology 7/11/2021 0:00 t83572 Watch P262 Different feeding conditions and their relationship with milk and blood urea nitrogen contents in Brown Swiss and Holstein dairy cows. 2 J. J. Gross milk urea nitrogen Holstein Brown Swiss E. C. Kessler1, R. M. Bruckmaier1, J. J. Gross1 1Veterinary Physiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland Milk urea nitrogen (MUN) content is closely related to plasma urea nitrogen (PUN) concentration, and reflects the balance of dietary crude protein and energy supply for rumen fermentation. The present study is based on 2 experiments and investigated if the higher MUN content in Brown Swiss (BSW) compared with Holstein (HOL) cows is related to milk production and feeding conditions. In addition, the relationships between PUN and MUN assessed either by an enzymatic method or by infrared spectroscopy were analyzed. For the first experiment, milk and blood samples (1,112 samples each) were collected in parallel bi-weekly from d 5 until d 150 of lactation from 72 BSW and 69 HOL cows housed at 4 different farms with diverse feeding regimens. The second experiment consisted of test-day records of 3 consecutive official milk recordings from 86 BSW and 200 HOL cows kept on the same farm under identical feeding and management conditions. Statistical analysis (SAS, v9.4) used mixed models with parity, breed, and parity × breed as fixed and cow as random effects. Concentrations of MUN in the first experiment determined either enzymatically (MUNENZ) or by FTIR (MUNIR) were regressed on the PUN concentrations of the concomitantly obtained blood samples (Bland-Altmann analysis and Pearson correlations). Both MUNIR and MUNENZ were highly correlated with PUN (Pearson correlation coefficients r = 0.93 and 0.89, respectively; P < 0.0001). Concentrations of MUN and PUN were higher in BSW compared with HOL independently of lactational stage, parity and feeding regimen (P < 0.0001). Protein and fat content were higher in BSW than in HOL. Primiparous cows had lower energy-corrected milk yield than multiparous cows in both breeds (27.9 vs. 31.7 kg/d, P < 0.001 for BSW; 29.8 vs. 35.4 kg/d, P < 0.0001 for HOL). Multiparous BSW had a similar milk production than primiparous HOL (31.7 vs. 29.8 kg/d, P = 0.13), whereas multiparous HOL had a greater ECM yield than multiparous BSW (35.4 vs. 31.7 kg/d, P < 0.0001). In conclusion, BSW cows have higher MUN than HOL under different as well as identical feeding conditions. The higher MUN in BSW compared with HOL cows is not related to milk production, and therefore rather genetically determined. However, the impact of potential differences in protein ingestion warrants further research.
Physiology and Endocrinology: Posters Posters Physiology and Endocrinology 7/11/2021 0:00 t83925 Watch P263 Responsiveness of bovine patatin-like phospholipase domain-containing protein 3 and transcription factors to fatty acids. 3 S. Erb lipase fatty liver lipid metabolism S. Erb1, H. White1 1University of Wisconsin–Madison, Madison, WI Bovine hepatic patatin-like phospholipase domain-containing protein 3 (PNPLA3) abundance is associated with increased liver triglyceride (TG) content and knockdown in vitro increased hepatocyte TG content. In vitro, PNPLA3 protein, but not sterol regulatory element-binding protein 1c (SREBP1c) mRNA or protein, was responsive to fatty acids (FA). In other species, PNPLA3 is regulated by FA-mediated transcription factors (TF). The objective of this study was to quantify bovine PNPLA3, FA-mediated gene, and TF mRNA responsiveness to FA that mimic in vivo physiological states during liver TG accumulation (ACCUM) and recovery (RECOV). Hepatocytes isolated from bull calves (n = 4) were cultured in monolayer for 24h then treated with mixtures of FA (C14:0, C16:0, C18:0, C18:1, C18:2, C22:6) combined to reflect ACCUM or RECOV (0.25, 0.5, 0.75, or 1 mM) or individual FA at 0.5 mM of RECOV (iRECOV0.5), or 0.25 mM (iFA0.25) for 24 h. Cells were harvested for RNA quantification of FAS, CPT1A, CPT2, PPARGC1A, PPARA, PNPLA3, SIRT1, SIRT3, and UCP2. Data, relative to reference genes, were transformed for normality. Response to mixture or individual FA were analyzed separately in mixed models with fixed effect of concentration and FA and random effect of calf (SAS 9.4). Linear contrasts were considered significant when P ≤ 0.10. Expression of PNPLA3 was not altered by FA. Expression tended to increase with RECOV vs. ACCUM for PPARGC1A (P = 0.07; 0.89 vs. 0.71 ± 0.19 arbitrary units (AU)) and SIRT1 (P = 0.10; 0.88 vs. 0.77 ± 0.15 AU) but tended to decrease for UCP2 (P = 0.09; 0.37 vs. 0.45 ± 0.08 AU). Increasing concentrations of RECOV tended to increase (P = 0.08) FAS and decrease (P = 0.004) ChREBP. Expression of CPT1A, CPT2, and SIRT3 were not affected by treatments. Expression of genes were not affected by iFA0.25 nor iRECOV0.5 (P ≥ 0.20). Responsiveness of genes to FA was concentration and profile dependent and was not discernable with individual FA. Previous reported increases in PNPLA3 abundance with increased concentration of RECOV are apparently due to translational regulation since mRNA expression was not altered.
Physiology and Endocrinology: Posters Posters Physiology and Endocrinology 7/11/2021 0:00 t84032 Watch P264 Effect of 3 prepartum dietary strategies to manage calcium on ionized calcium concentrations of Holstein cows. 4 W. Frizzarini dairy cow transition period calcium W. Frizzarini1, J. Campolina2, A. Vang1, P. M. Junior1, L. Hernandez1 1University of Wisconsin, Madison, WI, 2Federal University of Minas Gerais, Belo Horizonte, MG, Brazil Hypocalcemia is the most common metabolic disease during the periparturient period due to the high demand for calcium of the mammary gland for colostrum and milk synthesis. Our objective was to assess ionized calcium concentrations from whole blood in cows fed 3 different prepartum diets. Multiparous Holstein cows (n = 122) were randomly assigned, according to parity, to one of 3 different diets with low potassium corn silage (1.11 ± 0.03%), beginning 21 d before expected parturition date: control (CN; +190.24 mEq/kg; n = 40), control with anions (DCAD; −64.71 mEq/kg; n = 41; mean urine pH = 6.2), and control with sodium aluminum silicate (XZ; +277.40 mEq/kg with 500 g/day X-Zelit, Protekta Inc., Lucknow, Ontario, CA/Vilofoss, Fredericia, DK, n = 41). Ionized calcium (iCa, mmol/L), sodium (mmol/L) and potassium (mmol/L) were measured daily beginning 9 d before parturition (-D9) until parturition (D0), and subsequently evaluated on d 1, 2, 3, 6, 9, 12, 15, 18, and 21 postpartum. Data were analyzed using the GLIMMIX procedure of SAS. Between -D9 and -D2 (except for -D6) iCa was decreased in cows fed CN compared with DCAD and XZ diets (P < 0.01). On D0, cows fed DCAD and CN diets (1.01 ± 0.02 and 0.91 ± 0.02, respectively) had decreased iCa concentrations compared with XZ (1.08 ± 0.02, P < 0.01), and this difference was maintained on D1 (1.03 ± 0.02, 0.93 ± 0.02, and 1.12 ± 0.02, for DCAD, CN, and XZ, respectively; P < 0.01). On D2, cows fed XZ had higher iCa concentrations (1.16 ± 0.02, P < 0.05), with no differences among cows receiving DCAD and CN (1.08 ± 0.02 and 1.07 ± 0.02, respectively, P = 0.84). There was no difference in iCa concentration among diets on D3 (P = 0.10) and D6 (P = 0.51). The sodium concentrations were not different among dietary treatments (P = 0.16) but differed over time (P < 0.01), with the highest concentrations on D1 (144.11 ± 0.14) and lowest concentrations on D21 (136.55 ± 0.18). During the prepartum period, potassium concentrations were higher for the DCAD diet (4.44 ± 0.03) compared with CN and XZ diets (4.24 ± 0.03 and 4.12 ± 0.02, respectively). In conclusion, feeding cows with XZ diet improved calcium metabolism after parturition.
Physiology and Endocrinology: Posters Posters Physiology and Endocrinology 7/11/2021 0:00 t84069 Watch P265 Effects of peripartum omega-3 fatty acid supplementation on endocannabinoid tone and inflammation in liver of dairy cows. 5 M. Zachut liver endocannabinoid inflammation G. Kra1,2, U. Moallem1, R. Kocvarová3, A. Nemirovski3, J. Tam3, G. A. Contreras4, M. Zachut1 1Agriculture Research Organization, Volcani Center, Rishon Lezion, Israel, 2Faculty of Agriculture, the Hebrew University in Jerusalem, Rehovot, Israel, 3Obesity and Metabolism Laboratory, The Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel, 4Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, Lansing, MI Dietary supplementation of omega-3 (n-3) fatty acids may affect the endocannabinoid system (ECS) by reducing the availability of arachidonic acid (AA; C20:4n-6), and elicit anti-inflammatory effects. We aimed to examine the effects of 2 sources of n-3 FA, encapsulated flaxseed oil (FLX) or fish oil (FO) on hepatic ECS “tone,” and inflammatory and metabolic markers in blood of peripartum dairy cows. Late pregnant cows were fed from 21 d prepartum a diet supplemented with encapsulated fat: i) CTL–saturated fat (n = 14); ii) FLX (n = 14); or iii) FO (n = 14). Plasma prostaglandin E metabolite (PGEM) and G-2-α metabolite (PGFM) and FA profile were examined. Liver biopsies were obtained at 10 d postpartum (n = 5 per treatment) for expression of ECS components and inflammatory genes and proteins. Endocannabinoids (eCBs) in liver and plasma at biopsy were examined by LC-MS/MS. Continuous measures were analyzed by PROC MIXED; genes, proteins, and eCBs were analyzed by GLM procedure of SAS. The n-6/n-3 ratio in plasma was lowest in FLX and highest in CTL. Milk production was similar, and feed intake during the first 21 DIM was lower in FLX than in CTL. The FLX cows had lower PGEM concentration and tended to have lower PGFM in plasma during the first week in lactation compared with CTL. In liver, the relative gene expressions of the cannabinoid receptors CNR1 and CNR2 as well as the proinflammatory gene IL-6 were lower in FLX than in other groups. Protein abundances of TNF-α, IL-10 and cannabinoid receptor 1 (CB1) in liver were lower in FO than in CTL, while the abundance of NFKB was higher in FLX than in other groups. In liver, levels of eCB 2-arachidonoylglycerol (2-AG) were 1.7-fold higher in FLX than in other groups, while in plasma anandamide levels were lower in FLX and FO compared with CTL, and AA was lower in FLX than in CTL. Peripartum supplementation of n-3 FA seems to lower the ECS 'tone' in bovine liver, with some differential effects of FLX and FO on liver ECS components. We provide evidence for the involvement of ECS in bovine liver metabolism and inflammation, and dietary n-3 can attenuate ECS “tone” in liver of peripartum dairy cows.
Physiology and Endocrinology: Posters Posters Physiology and Endocrinology 7/11/2021 0:00 t84110 Watch P266 Elevated circulating serotonin alters immune cell expression of serotonin receptor and metabolism genes in the lactating dairy cow. 6 M. Connelly serotonin immune 5-HTP M. Connelly1, L. Hernandez1 1University of Wisconsin–Madison, Madison, WI Serotonin’s role in the periphery has been demonstrated through its action in modulating calcium metabolism, energy homeostasis, and immune function. Manipulation of the serotonergic axis has been demonstrated by administering 5-hydroxy-L-trytophan (5-HTP) and fluoxetine to alter serotonin bioavailability. Much of serotonin’s action is believed to be receptor mediated, with signaling cascades and feedback also regulating serotonin transport and metabolism-related genes. Therefore, our objective was to explore alterations in expression of serotonin receptor-, metabolism-, and immune-related genes in peripheral leukocytes in response to 5-HTP infusion in the lactating dairy cow. Twelve mid-late lactation multiparous Holstein cows were randomly assigned to intravenous infusion of (1) 1 L of 1.5 mg/kg 5-HTP dissolved in saline (n = 6/treatment) or (2) 1 L of saline solution (n = 6/treatment) for 3 d in a randomized complete block design. Blood samples and Tempus Tubes were collected at 48h, 56h, and 72h relative to termination of first infusion. Peripheral leukocyte expression was analyzed via qPCR. Data were analyzed using a mixed model ANOVA with time as a repeated measure. Infusion of 5-HTP increased circulating serotonin concentrations (P = 0.001) and peripheral leukocyte mRNA expression of monoamine oxidase-A and serotonin receptor 7 across the experimental period (P = 0.01 and P = 0.005, respectively). Forty-eight hours from termination of first infusion mRNA of monoamine oxidase-A, serotonin reuptake transporter, and serotonin receptor 7 were increased relative to control (P = 0.0009, P = 0.03, and P = 0.0001, respectively). No differences were observed in interleukin-8 in circulation or at the mRNA level (P > 0.05), but a decrease in tumor necrosis factor α expression occurred in 5-HTP infused cows 48h after termination of the first infusion relative to control cows (P = 0.09). Collectively, these data suggest infusion of 5-HTP has the ability to alter serotonin metabolism, transport and receptor dynamics and cytokine mRNA expression in peripheral leukocytes in the lactating dairy cow.
Physiology and Endocrinology: Posters Posters Physiology and Endocrinology 7/11/2021 0:00 t84361 Watch P267 Temporal profiles of plasma T3, T4, and insulin in dairy cows fed diets containing soybean meal or canola meal at 2 protein concentrations during early lactation. 7 J. Kuehnl canola meal transition period early lactation J. Kuehnl1, S. Moore1, K. Kalscheur2 1Department of Animal and Dairy Sciences, University of Wisconsin–Madison, Madison, WI, 2U.S. Dairy Forage Research Center, USDA-ARS, Madison, WI Substitution of soybean meal (SBM) with canola meal (CM) increases milk production in early-lactation dairy cows. However, limited data exists regarding the effect of CM substitution on the temporal profile of plasma metabolites during early lactation. Our objective was to determine the effect of feeding a low (15.4%) or high (17.6%) crude protein (CP) diet formulated with SBM or CM as the main protein source to early-lactation dairy cows on plasma concentrations of triiodothyronine (T3), thyroxine (T4), and insulin. At calving, multiparous Holstein cows (n = 79) enrolled in a 2 × 2 factorial arrangement of treatments in a randomized complete block design. Cows were blocked by calving date. Diets were formulated to contain 55% forage and 45% concentrate mix on DM basis. Canola meal was included at 19.4% and 11.9% DM and SBM was included at 14.5% and 8.9% DM. Plasma was collected twice weekly 3 h postfeeding from the coccygeal vein of each cow during wk 1, 2, 3, 4, 6, and 8 of lactation and composited by wk for each cow. Plasma concentrations of T3, T4, and insulin were determined using ELISA. Data were analyzed using the MIXED procedure of SAS. Dietary CP concentration and protein source were not significant for any metabolite. Week of lactation was significant (P < 0.05) for all metabolites. The interaction of protein source and wk was significant (P = 0.03) for T4. Concentrations of T4 increased in CM cows during wk 3 and 4 compared with SBM cows, whereas concentrations decreased in CM cows during wk 8 compared with SBM cows. The lowest and highest concentrations of insulin occurred in wk 2 (0.20 ± 0.01 µg/L) and 8 (0.55 ± 0.03 µg/L), respectively. The lowest and highest concentrations of T3 occurred in wk 6 (1.37 ± 0.06 ng/mL) and 2 (1.57 ± 0.06 ng/mL), respectively. Overall, CP concentration did not affect any metabolite and protein source did not affect T3 nor insulin. The interaction of CP and protein source was not significant for any metabolite. The protein source and wk interaction for T4 resulted from differences measured in wk 3, 4, and 8.
Physiology and Endocrinology: Posters Posters Physiology and Endocrinology 7/11/2021 0:00 t84142 Watch P268 Effect of medium-chain fatty acids added to milk replacer on growth performance in calves. 8 A. Inukai medium-chain fatty acids milk replacer calf A. Inukai1, R. Osawa2, K. Konda3, T. Okimura4, T. Takeuchi5, M. Jindo6, N. Nakamura7, K. Nishimura8, Y. Ueno9, K. Murayama10, K. Sakamoto11, N. Isobe13, S. Kushibiki12, K. Kawashima1, T. Sugino13 1Chiba Prefectural Livestock Research Center, Chiba, Japan, 2Saitama Prefectural Agricultural Technology Research Center, Saitama, Japan, 3Kanagawa Prefectural Livestock Industry Technology Center, Kanagawa, Japan, 4Toyama Prefectural Agricultural, Forestry and Fisheries Research Center, Toyama, Japan, 5Ishikawa Prefectural Agriculture and Forestry Research Center, Ishikawa, Japan, 6Yamanashi Prefectural Livestock and Dairy Technology Center, Yamanashi, Japan, 7Shimane Prefectural Livestock Technology Center, Shimane, Japan, 8Miyazaki Livestock Research Institute, Miyazaki, Japan, 9Shinshu University, Nagano, Japan, 10ZENRAKUREN, Fukushima, Japan, 11YP Tech Co, Tokyo, Japan, 12Institute of Livestock and Grassland Science, NARO, Tsukuba, Japan, 13The Research Center for Animal Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan Medium-chain fatty acids (MCFA) are rapidly metabolized in the body and can be used as an energy source for calves. MCFA can stimulate ghrelin and GH secretion in dairy cows. This study investigated the effect of adding MCFA to milk replacer (MR) on growth performance in calves. Forty-one Holstein heifer calves [Body weight (BW) at brith, 41.0 kg] were randomly assigned to one of 2 experimental MR [28% CP, 18% fat either containing 3.2% caprylic acid and 2.8% capric acid (CONT; n = 20) or containing 6.7% caprylic acid and 6.4% capric acid (MCFA; n = 21)] from 2 to 42d of age. After initial colostrum feeding, all calves were fed MR twice daily by nipple bottle. MRs were increased from 600 to 1,200 g/d over a 10 d period to adapt calves to intensive liquid feeding. Calves were fed MR at 1,200 g/d from 1.5 to 4 wk of age, were reduced to 800 g/d at 5 wk of age, and weaned at 6 wk of age. All calves fed calf starter, chopped timothy hay and water ad libitum. From 1 to 13 weeks after birth, BW was measured weekly. Feed intake was recorded daily, and the total-tract digestion test was performed at 13wk of age. Plasmaconcentrations of GH, IGF-1, progesterone and IL-6 were investigated every 2 wk to 41 wk, rumen lipopolysaccharide (LPS) activity was investigated at 8 and 13 wk of age. Data were analyzed by one-way ANOVA using Fit Model procedure of JMP 15 Pro. Calf starter and hay intakes for all calves rapidly increased at weaning (day effect: P < 0.001). But BW, ADG, dry matter digestibility, nitrogen retention at 13 wk and VFA concentration in rumen were not affected by MCFA. Plasma concentrations of GH and IGF-1 were higher for MCFA than for CONT group (treatment effect: P < 0.05). Rumen LPS activity tended to have a lower MCFA than CONT. And, plasma IL-6 level was low value for MCFA than that of CONT group. The percentage of cows showing first ovulation before 41 wk of age, calculated by plasma progesterone level, were higher for MCFA than for CONT group (treatment effect: P < 0.05). These results indicate that MCFA inclusion in MR stimulated GH and IGF-1 secretions before weaning, and may have positive effects on early first ovulation in calves.
Physiology and Endocrinology: Posters Posters Physiology and Endocrinology 7/11/2021 0:00 t84480 Watch P269 Inflammatory and immunological responses of Holstein dairy cows around dry-off and calving. 9 T. N. Marins milking cessation parturition inflammation T. N. Marins1, J. Gao1,2, J. O. S. Calix1, Z. Qi2, J. K. Bernard1, S. Tao1 1Department of Animal and Dairy Science, University of Georgia, Tifton, GA, 2Department of Animal Nutrition and Feed Science, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, China To evaluate stress, immune and inflammatory responses of multiparous dairy cows, 2 groups of cows were enrolled: around dry-off (n = 6, SCC <200,000 cells/mL before dry-off) and around calving (n = 7, SCC averaged 128,791 cells/mL after calving). Blood was collected on −8, 3, 7, and 15 d relative to dry-off (RTD), or on −7, 3, 7, and 21 d relative to calving (RTC) to analyze circulating immune cells, prolactin (PRL), cortisol and inflammatory products, and isolate peripheral blood mononuclear cells (PBMC). In vitro, PBMC were cultured with PRL, hydrocortisone, LPS, and concanavalin A (ConA), or in different combinations for 68 h to assess proliferation using MTT assay. Data were analyzed using PROC MIXED of SAS. Plasma cortisol concentration was not affected (P > 0.10) by time around dry-off or calving. Plasma PRL concentration was unchanged (P > 0.10) around calving, but declined (P = 0.01) after dry-off. After dry-off, serum tumor necrosis factor-α and interleukin 10 concentrations increased (P ≤ 0.07) until d 15, but haptoglobin and fibrinogen concentrations peaked at 7 d RTD (P = 0.02). No differences were observed for circulating cytokines and fibrinogen from gestation to lactation, but plasma haptoglobin concentration was greater (P = 0.07) at 7 d RTC. Concentrations of monocytes and neutrophils reached nadir (P ≤ 0.06) at 3 d RTD. Around calving, circulating monocytes peaked (P = 0.01) at 3 d RTC, but neutrophils remained unchanged (P > 0.10). Regardless of time, addition of hydrocortisone on the cell culture reduced (P < 0.01) PBMC proliferation to LPS, but PRL had no effect (P > 0.10). No time effect (P > 0.10) was observed for proliferation of PBMC collected from cows around dry-off, but PBMC collected at 21 d RTC had higher (P ≤ 0.05) proliferative responses to LPS or ConA than other time points around calving. In conclusion, results confirmed lower PBMC proliferation around calving, and suggested that cows transitioning from late lactation to dry period maintained unchanged cell-mediated immune function. The period immediately after dry-off is characterized with upregulated systemic inflammation.
Physiology and Endocrinology: Posters Posters Physiology and Endocrinology 7/11/2021 0:00 t84628 Watch P270 Feeding rumen-protected lysine affects hepatic transcription of genes related to inflammation and oxidative stress in Holstein cows during the transition period. 10 L. K. Fehlberg immunity lysine transition period L. K. Fehlberg1, A. R. Guadagnin1, B. L. Thomas1, Y. Sugimoto2, I. Shinzato2, F. C. Cardoso1 1University of Illinois, Urbana, IL, 2Ajinomoto Co. Inc, Tokyo, Japan During the periparturient period, a negative protein balance due to decreased intake and increased demand may result in compromised immune and liver function. This experiment was conducted to determine the effects of feeding rumen-protected lysine (RPL; AjiPro-L Generation 3, Ajinomoto Heartland Inc., Chicago, IL) from 27 ± 5 d prepartum (0.54%DM of TMR) to 28 d postpartum (0.39%DM of TMR) on the hepatic transcription of inflammatory and oxidative stress-related genes. Seventy-five multiparous Holstein cows, blocked by parity, previous 305-d mature-equivalent milk production, expected calving date, and body condition score during the far-off dry period were assigned to 1 of 4 dietary treatments in a randomized, complete block design with a 2 × 2 factorial arrangement. Treatments consisted of TMR top-dressed prepartum with RPL (PRE-L) or without (PRE-C) and with RPL prepartum and postpartum (PRE-L POST-L), with RPL prepartum and without RPL postpartum (PRE-L POST-C), without RPL prepartum and with RPL postpartum (PRE-C POST-L), and without RPL prepartum and postpartum (PRE-C POST-C). Liver samples were collected via biopsy on −14 ± 0.8 and 14 ± 0.1 d relative to calving and analyzed for mRNA gene expression. Statistical analysis was performed using MIXED procedure of SAS. There was decreased (P = 0.04) expression of nuclear factor kappa B1 (NFKB1) postpartum for cows in PRE-L compared with PRE-C. There was also a tendency for greater (P = 0.10) expression of interleukin 1 β (IL1B) for cows in POST-L compared with POST-C. Additionally, expression of serum amyloid A3 (SAA3) was less (P = 0.02) for cows in PRE-L POST-L, PRE-L POST-C, and PRE-C POST-L compared with PRE-C POST-C. Postpartum expression of superoxide dismutase 1 (SOD1) was less (P = 0.04) for cows in PRE-L compared with cows in PRE-C. In conclusion, when cows consumed RPL prepartum and/or postpartum there was decreased oxidative stress (SOD1) and acute-phase response (SAA3 and NKFB1) related genes in the liver and the tendency for greater proinflammatory IL1B gene expression postpartum likely indicates immune activation.
Physiology and Endocrinology: Posters Posters Physiology and Endocrinology 7/11/2021 0:00 t84407 Watch P271 Whole-body mineral trafficking following immune activation. 11 J. Opgenorth immune activation minerals J. Opgenorth1, E. J. Mayorga1, M. A. Abeyta1, S. Rodriguez-Jimenez1, B. M. Goetz1, A. D. Freestone1, C. H. Stahl2, L. H. Baumgard1 1Iowa State University, Ames, IA, 2University of Maryland, College Park, MD Objectives were to evaluate mineral dynamics in tissues, fluids, and digesta following immune activation. Pigs (n = 12; 44 ± 2.6 kg) were randomly assigned to 1 of 2 treatments: 1) saline control (CON; 2 mL sterile saline; n = 6) or 2) LPS (LPS; 40 µg LPS/kg BW; E. coli O55:B5; n = 6) and euthanized 6 h later. Pigs were housed in metabolism stalls with restricted access to feed and water for 2 h before and during the challenge. Immediately following administration, urine and feces were continuously collected. Whole tissues of heart, kidneys, liver, spleen, and lumen contents of the stomach, small intestine, and large intestine were weighed and homogenized. Likewise, samples of skeletal muscle, pancreas, adipose tissue, bone marrow, urine, ascites, serum, and bile were obtained to determine Na, K, P, Mg, Cr, Zn, Fe, Cu, Se, Mn, Mo, and Co concentrations. Data were analyzed with PROC MIXED. LPS increased rectal temperature (39.2 and 40.7°C in CON and LPS, respectively; P < 0.01), and decreased circulating glucose (39%; P < 0.01). Serum Zn concentrations were reduced by LPS (39%; P = 0.04) but no changes in the other minerals were detected in circulation. Zn, P, Se, and Cu increased in ascites fluid (124, 31, 235, and 163%, respectively; P ≤ 0.09). LPS increased Zn and Cu in the kidneys (28 and 75%, respectively; P = 0.07). LPS increased Fe and Mo in the spleen (86 and 70%, respectively; P < 0.01) and Fe concentrations in bone marrow (47%; P = 0.02). Muscle Mg increased 18% with LPS (P = 0.04). LPS increased liver Na, Mg, K, P, Mg, Cr, and Zn concentration (P ≤ 0.05). Bile Cu tended to decrease (38%; P = 0.07) with LPS. LPS increased fecal Fe, Mn, Cr, and Co (P ≤ 0.05) and tended to increase fecal Zn and Cu (P ≤ 0.07), at least partially explained by increased fecal output (104 vs 246 g for CON vs LPS, respectively). Digesta within the stomach of LPS pigs contained more Na (123%; P = 0.04). Small intestine contents from LPS pigs contained more Se (162%; P < 0.01) and tended to have increased P (70%; P = 0.10). Urine from LPS pigs tended to contain more P (29%; P = 0.10). In summary, systemic immune activation caused acute alterations in mineral trafficking throughout the body.
Physiology and Endocrinology: Posters Posters Physiology and Endocrinology 7/11/2021 0:00 t84738 Watch P272 Alterations in one-carbon metabolism due to methionine supplementation and lipopolysaccharide challenge in Holstein fetal liver explants. 12 A. Aboragah methyl donors nutritional programming pregnancy A. Aboragah1, Y. Liang1, D. N. Coleman1, J. J. Loor1 1University of Illinois, Urbana, IL The objective was to investigate effects of methionine (Met) supplementation on one-carbon metabolism in fetal liver tissue without and with a lipopolysaccharide (LPS) challenge to induce an inflammatory stress. Fetal liver samples were harvested at slaughter from 6 multiparous pregnant Holstein dairy cows averaging 136 ± 3 d in milk and 37 ± 6 kg milk/d before slaughter. Cows were free of clinical disease and were fed a typical corn silage/alfalfa hay-based diet. Whole liver suspended in warm DMEM:F12 medium containing 1% penicillin/streptomycin was transported to the laboratory upon harvest. Tissue slices (0.2 ± 0.02 g) from each fetus were incubated for 4 h at 37°C with each of the following treatments: ideal profile of amino acids (control; Con, Lys:Met 2.9:1), increased Met supplementation (incMet, Lys:Met 2.5:1), Con plus LPS (1 µg/mL; LPS), and incMet plus LPS (incMetLPS). A custom high-glucose DMEM devoid of essential amino acids was used to prepare each individual treatment. Tissue was used for 14C radio-labeling assays to measure betaine-homocysteine S-methyltransferase (BHMT) and cystathionine-β-synthase (CBS) activity. Upon completion of the incubations, tissue was immediately frozen at −80°C until analysis of enzyme activity, Western blot, and metabolomics. Data were analyzed as a 2 × 2 factorial (without Met or with Met; without LPS or with LPS) using the MIXED procedure of SAS. The activity of CBS, rate-limiting enzyme in the transsulfuration pathway, was not affected (P > 0.05) and averaged 119 ± 24 nmol/h/mg protein across treatments. In contrast, there was an interaction (P < 0.05) for BHMT, which is involved in remethylation of homocysteine to Met. This effect was due to a 44% increase in activity in response to incMet (24.1 ± 3.2 nmol/h/mg protein) compared with Con (17.4 ± 3.2 nmol/h/mg protein). Preliminary observations suggested that the Met cycle and transsulfuration pathway are functional in bovine fetal liver. Remethylation via BHMT appears responsive to enhanced Met supply.
Physiology and Endocrinology: Posters Posters Physiology and Endocrinology 7/11/2021 0:00 t84757 Watch P273 Effects of amino acids and hyperinsulinemic clamp on plasma concentrations and mammary extraction of energy substrates. 13 V. Pszczolkowski insulin clamp amino acids energy metabolism V. Pszczolkowski1, H. Hu1, J. Zhang1,2, M. Connelly1, A. Munsterman1,3, S. A. Apelo1 1University of Wisconsin–Madison, Madison, WI, 2Northwest A & F University, Yangling, China, 3Michigan State University, East Lansing, MI Insulin and certain AA, including Leu and Met, interact to regulate mTORC1 activity in mammary epithelium. The objective of this study was to test whether Leu and Met stimulate mammary extraction efficiency of energy substrates, and if insulin potentiates the effect of AA. Six lactating Holstein cows (155 ± 9 DIM) were ruminally cannulated and had the right carotid artery subcutaneously transposed. Cows were fed a 20% protein-restricted diet and abomasally infused with water (8 L/d) or AA (Met 26 g/d, Leu 70 g/d) 8 h/d, for 7 d. The last day of each period, cows were intravenously infused with saline (0.9% NaCl, 110 mL/h) or subject to 8h hyperinsulinemic clamp alongside abomasal infusions. The experiment had an incompletely replicated Latin square design with a 2 × 2 factorial arrangement of treatments (abomasal and intravenous infusion). For the clamp, insulin was infused at 1 µg/kg/h. Normoglycemia was maintained by varying glucose (50% wt/vol saline) infusion rate based on coccygeal vein glucose concentration. Carotid arterial and subcutaneous abdominal (mammary) vein blood samples were collected at 0, 2, 4, and 6 h from start of infusions. Plasma was assayed for insulin, glucose, acetate, β-hydroxybutyrate (BHB), nonesterified fatty acids (NEFA), and triglycerides (TG) using commercial kits. Data were analyzed by ANOVA with repeated measures and Bonferroni adjustment. Interactions between abomasal and intravenous infusions were not significant. Arterial insulin was increased by insulin infusion (P < 0.01) with no effect of AA (P = 0.94). Arterial glucose was increased by AA (P = 0.04) and decreased by insulin (P = 0.01). Amino acids tended to increase arterial acetate at 6 h (P = 0.06). Insulin clamp decreased arterial BHB at 4 h and 6 h (P < 0.05), TG at 4 h (P < 0.01), and arterial NEFA overall (P < 0.01). Insulin tended to decrease mammary extraction efficiency of glucose (P = 0.07) and decreased it for acetate and BHB (P < 0.01). The arteriovenous difference for NEFA was always negative and was decreased by AA at 2 h (P = 0.02). Overall, AA and insulin did not improve mammary extraction efficiency of energy substrates.
Physiology and Endocrinology: Posters Posters Physiology and Endocrinology 7/11/2021 0:00 t84404 Watch P274 Metabolic alterations of heat-stressed and pair-fed lactating dairy cows during a hyperketonemic clamp. 14 S. Rodriguez-Jimenez heat stress hyperketonemia S. Rodriguez-Jimenez1, E. J. Mayorga1, M. A. Abeyta1, B. M. Goetz1, J. Opgenorth1, A. D. Freestone1, N. Reisinger2, J. Faas2, L. H. Baumgard1 1Department of Animal Science, Iowa State University, Ames, IA, 2BIOMIN Research Center, Tulln, Austria Study objectives were to investigate ketone clearance and metabolic consequences of hyperketonemia in heat-stressed and nutrient-restricted Holstein cows. Primiparous cows (604 ± 3 kg BW; 156 ± 5 DIM; n = 12) were allowed 10d to acclimate in thermoneutral conditions with ad libitum feed intake (baseline) and then assigned to 1 of 2 environmental treatments for 8d: 1) heat stress using an electric heat blanket with ad libitum feed intake (HS; Thermotex Therapy Systems Ltd., Calgary, AB, Canada; n = 6) or 2) thermoneutral conditions and pair-fed (PF; n = 6) to their HS counterparts. Overall, HS increased rectal temperature 2.2°C (P < 0.01) and decreased DMI (45%). Milk yield was reduced in the PF and HS cows by 20 and 36%, respectively compared with baseline. On d8, basal insulin was increased (82%; P < 0.01) in HS cows but NEFA (444 µEq/L), β-hydroxybutyrate (BHB; 0.78 mmol/L) and glucose (62 mg/dL) concentrations did not differ between environments (P > 0.50). Cows were then fasted and a 12 h hyperketonemic clamp was conducted. A BHB priming dose (700 µmol BHB/kg BW; KetoTech, Inc., Seymour, IL) was administered i.v. followed by continuous infusion (2.2 M) for 12 h. Blood samples were obtained every 10 min and immediately analyzed for BHB concentrations utilizing a hand-held meter (PortaCheck, Moorestown, NJ). Rate of BHB infusion (ROBI) was adjusted to achieve a “clamped” BHB concentration of 1.7 ± 0.17 mmol/L. Overall, HS increased ROBI (109 vs 43 g/h; P < 0.01) compared with the PF cows. During the clamp, glucose concentrations did not differ, but insulin concentrations were markedly decreased (67%; P < 0.05) in both groups. At h 1 of the clamp, NEFA concentrations were severely reduced (71%; P < 0.01) similarly among groups, but gradually increased with time and returned to basal levels at h 12. In summary, reduced feed intake only accounted for ~50% of the decrease in milk yield. Further, HS markedly increased BHB clearance (153%) compared with thermoneutral cows on the same plane of nutrition. HS-induced increased ketone utilization is similar to what we have reported during experimental immune activation (Rodriguez-Jimenez et al., 2020).
Physiology and Endocrinology: Posters Posters Physiology and Endocrinology 7/11/2021 0:00 t84779 Watch P275 Identification of prepartum plasma lipid biomarkers for postpartum metabolic risk in Holstein dairy cows. 15 J. E. Rico dairy cow lipidomics peripartum J. E. Rico2,1, J. W. McFadden1 1Department of Animal Science, Cornell University, Ithaca, NY, 2Department of Animal and Avian Sciences, University of Maryland, College Park, MD Our objective was to characterize the bovine plasma lipidome during the periparturient period and to determine its association to circulating fatty acids (FA) and β-hydroxybutyrate (BHB), common proxies for disease risk. Fifty-nine multiparous Holstein cows in a commercial dairy herd (Dixie Creek Dairy, Hanford, CA) were enrolled 14 d prepartum (ap) and fed close-up and fresh cow diets to meet their dietary requirements. Blood samples were obtained at d −14, 3, and 10, relative to parturition. Risk thresholds for metabolic disease were defined as 570 µEq/L for FA and 10 mg/dL for BHB. Untargeted lipidomics was performed using LC/MS, and univariate and multivariate methods were used for data analysis. Plasma FA were 3.8-fold higher postpartum (pp), relative to ap (P < 0.01), and BHB tended to be higher pp, relative to ap (1.1-fold; P = 0.10). A total of 241 plasma lipids were detected. The lipidome of the transition period was distinguishable by day, and specific lipid signatures were found that predict time points relative to parturition (e.g., sphingomyelin [SM]-40:3 and sphingosine-18:0 were differentially expressed across time; variable importance project scores >1.77). While many lipid concentrations increased pp (e.g., SM-41:2, triglyceride (TAG)-16:0/18:1/18:1, and phosphatidylcholine (PC)-34:4; false-discovery rate [FDR] < 0.05), some lipid concentrations decreased pp (PC-36:1, TG-18:0/16:1/16:1; FDR <0.05), relative to ap. Similarly, while many TAG, SM, and PC were positively related to FA (r = 0.50–0.65; P < 0.05), some PC and TAG were inversely associated with FA (r = 0.50 to 0.60; P < 0.05). Associations between complex lipids and BHB were weak (r = 0.15 to 0.20; P < 0.05). Several ap lipids were predictive of increased pp FA (e.g., diacylglycerol-18:0/22:0 and PC-36:5 for d 3 FA; SM-34:1 and PC-34:0 for d 10 FA; AUC = 0.70 to 0.72), with similar or higher predictive value than ap FA (AUC = 0.68). Our results indicate that prepartum plasma lipidome metabolites are related to elevated postpartum plasma FA; however, their ability to predict postpartum disease requires evaluation.
Physiology and Endocrinology: Posters Posters Physiology and Endocrinology 7/11/2021 0:00 t84372 Watch P276 Role of dietary Ca and 1,25-dihydroxyvitamin D3 on gastrointestinal absorption of Ca in ruminants. 16 A. Vieira-Neto vitamin D calcium digestibility A. Vieira-Neto1, P. R. Menta2, C. DeWit2, L. Fernandes2, A. C. M. Silva3, F. X. Amaro3, M. A. Ballou2, V. S. Machado2, J. E. P. Santos3 1Kansas State University, Manhattan, KS, 2Texas Tech University, Lubbock, TX, 3University of Florida, Gainesville, FL Objectives were to determine the effects of dietary Ca content and 1,25-dihydroxyvitamin D3 on Ca transport in the gastrointestinal tract (GIT). Holstein bull calves (n = 24) at 90 d of age were blocked by body weight and intake during a 5-d adaptation period and randomly assigned to 1 of 4 treatments. Treatments were arranged as a 2 × 2 factorial with 2 levels of dietary Ca (CaDef = 0.33%; vs. CaAde = 1.19% of diet DM) and 2 doses of 1,25-dihydroxyvitamin D3 (0, placebo; PCBO vs. 50 µg; 125D) administered subcutaneously as a single injection on experimental d 5. Blood was sampled on d 4, 5, 6, 7 and 8. Feed, urine, and fecal samples were collected from d 2 to 7 to determine Ca digestibility. On d 8, calves were euthanized and tissues, including ruminal epithelia and duodenum, were subjected to RNA-seq analysis. Data for Ca digestibility and transcriptome is expected to be available for presentation at the conference. Calves fed CaDef had lower (P < 0.01) blood iCa before 125D treatment compared with CaAde (CaDef = 1.35 vs. CaAde = 1.43 mM). An interaction (P < 0.01) between dietary Ca and injectable 1,25-dihydroxyvitamin D3 was observed for blood iCa because 125D increased blood iCa to a greater extent in CaAde than in CaDef calves (CaDef-PCBO = 1.38 vs. CaDef–125D = 1.46 vs. CaAde-PCBO = 1.41 vs. CaAde-125D = 1.64 mM). Calves fed CaDef had lower (P = 0.01) concentration of plasma total Ca before 1,25-dihydroxyvitamin D3 treatment compared with CaAde (CaDef = 2.46 vs. CaAde = 2.59 mM). After 1,25-dihydroxyvitamin D3 treatment, plasma total Ca concentration was lower (P < 0.01) in CaDef compared with CaAde, whereas it was greater (P < 0.01) for 125D compared with PCBO (CaDef-PCBO = 2.49 vs. CaDef–125D = 2.72 vs. CaAde-PCBO = 2.66 vs. CaAde-125D = 3.05 mM). Plasma Mg did not differ between dietary Ca treatments before 1,25-dihydroxyvitamin D3 treatment. After 1,25-dihydroxyvitamin D3treatment, plasma Mg concentration was lower (P < 0.01) for 125D compared with PCBO (125D = 0.77 vs. PCBO = 0.85 mM). Our preliminary data suggest that vitamin D-mediated changes in blood Ca are dependent on GIT Ca availability.
Physiology and Endocrinology: Posters Posters Physiology and Endocrinology 7/11/2021 0:00 t84196 Watch P277 Effects of peripartum supplementation with omega-3 from flaxseed or fish oil on expression of inflammatory genes in several tissues of dairy cows. 17 U. Moallem omega-3 transition cow immune U. Moallem1, G. Kra1,2, L. Lifshitz1, N. Nemes-Navon1,2, S. Druker2, M. Zachut1 1Department of ruminants Science, Volcani Center, Rishon LeZion, Israel, 2Department of Animal Science, the Hebrew University of Jerusalem, Rehovot, Israel The objectives were to determine the effects of various omega-3 fatty acids supplemented to peripartum dairy cows on inflammatory gene expression in several tissues. Forty-two 256-d pregnant multiparous cows were supplemented until 60 d postpartum (PP) with encapsulated fats, in treatments designated as i) SFA – saturated fat at 255 g/d/cow prepartum and 640 g/d/cow PP; ii) FLX – flaxseed oil at 300 g/d/cow prepartum and 750 g/d/cow PP; and iii) FO – fish oil at 300 g/d/cow prepartum and 700 g/d/cow PP. Blood samples were taken twice weekly from 21 d prepartum to 21 d PP from 8 cows from each group. Samples of cotyledons of placenta were taken from 4 to 5 cows from each group. Biopsies of adipose tissue (6 cows from each group) were obtained at ~7 DIM, and liver biopsies at 10 DIM (5 cows from each group). Biopsies of the uterus were taken at 40 DIM from 10 cows from each group, and all tissue samples were analyzed for expression of proinflammatory genes. Data were analyzed with GLM procedure of SAS. The average TNF-α concentrations from wk 1 prepartum to 2 wks PP tended to be lower in FO than in SFA (P = 0.1). The concentrations of IL-6 tended to be lower in FO compared with the SFA L (P = 0.1). In cotyledons, the relative mRNA expression of IL1B, IL6 and IL10 were higher in FO than in other groups. In adipose, the relative mRNA expression of TNFA was lower in FO than in SFA. In liver, the relative mRNA expression of IL6 in liver tended to be lower in FLX than in SFA (P = 0.06), the expression of SAA2 tended to be lower in FLX than in FO (P = 0.06), and IL10 tended to be higher in FLX than in FO (P = 0.1). In uterus, the relative mRNA expression of TNFA was lower in FO (P = 0.006) and tended to be lower in FLX than in SFA (P = 0.1). The expression of IL10 was higher in FLX than in SFA (P = 0.02) and tended to be higher in FO than in SFA (P = 0.08). This study demonstrates several anti-inflammatory effects of dietary n-3 FAs in peripartum dairy cows.s.
Physiology and Endocrinology: Posters Posters Physiology and Endocrinology 7/11/2021 0:00 t84191 Watch P278 Proteomic analysis of peripheral blood mononuclear cells from postpartum dairy cows supplemented peripartum with omega-3 fatty acids from flaxseed or fish oil. 18 G. Kra proteomics PBMC inflammation G. Kra1,2, N. Nemes-Navon1,2, J. R. Daddam1, Y. Levin3, U. Moallem1, M. Zachut1 1Agriculture Research Organization, Volcani Center, Rishon Lezion, Israel, 2Faculty of Agriculture, the Hebrew University in Jerusalem, Rehovot, Israel, 3The Nancy and Stephen Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, Rehovot, Israel Peripheral blood mononuclear cells (PBMC) consist of lymphocytes and monocytes, and proteomic analysis of PBMC is used in other species to monitor health disorders. Postpartum (PP) dairy cows experience subacute inflammation; therefore, our objective was to examine the effect of different sources of dietary n-3 fatty acids (FA), which are known as anti-inflammatory, on the proteome of PBMC in transition dairy cows. Forty-two 256-d pregnant multiparous cows were individually supplemented with encapsulated fats, as following: i) SFA – saturated fat at 255 g/d/cow prepartum and 640 g/d/cow PP, rich in C16:0 and C18:0; ii) FLX – flaxseed oil at 300 g/d/cow prepartum and 750 g/d/cow PP, rich in C18:3n-3; and iii) FO – fish oil at 300 g/d/cow prepartum and 700 g/d/cow PP, rich in C20:5n-3 and C22:6n-3. PBMC were isolated from blood from 5 cows from each group at wk 1 postpartum by centrifugation with Ficoll for proteomic analysis, and differential abundance of proteins were examined in FLX and FO relative to SFA (at P < 0.05 and fold change ± 1.5). Bioinformatics was performed using Ingenuity (Qiagen). The total n-3 FA content in plasma and PBMC was higher in FLX and FO than in SFA. In PBMC, a total of 3,807 proteins were quantified, from which 44 were differentially abundant between FLX and SFA. The abundance of NF-kappa B transcription factor p65 subunit (RELA), apolipoprotein H (APOH), kininogen 1 (KNG1) and serpin family D member 1 (SERPIND1) were higher, while albumin (ALB), C4b-binding protein, serum amyloid P component (APCS) and complement factor H (CFH) were lower in FLX vs. SFA. The main pathways enriched by the FLX treatment were: the acute-phase response signaling (based on ALB, APCS, APOH, C4BPA, RELA and SERPIND1), LXR/RXR and FXR/RXR activation (ALB, APOH, GC vitamin D binding protein, KNG1 and RELA), the coagulation system (KNG1 and SERPIND1) and the complement system (C4BPA and CFH). Other 42 proteins were different between FO and SFA PBMC; lipopolysaccharide-binding protein was higher and CD59 molecule complement regulatory protein was lower in FO vs. SFA. In conclusion, dietary n-3 FA from FLX or FO supplemented to peripartum cows were incorporated into PBMC and affected their proteome in a different manner.
Production, Management and the Environment: Orals Orals Production Management and the Environment 7/11/2021 0:00 s9638                  
Production, Management and the Environment: Orals Orals Production Management and the Environment 7/11/2021 0:00 t83558 Watch 137 Milk production of grazing dairy cows fed a supplementary grain ration formulated to complement nutrients from pasture during autumn. 1 M. Douglas nutrient intake pasture M. Douglas1,2, M. Auldist1,3, M. Wright1, L. Marett1,3, V. Russo1,3, M. Hannah1, S. Garcia2, W. Wales1,3 1Agriculture Victoria Research, Ellinbank, Victoria, Australia, 2The University of Sydney, Camden, New South Wales, Australia, 3Centre for Agricultural Innovation, School of Agriculture and Food, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Melbourne, Victoria, Australia Formulating grain rations for grazing dairy cows can be improved by taking into account the expected nutrient supply from pasture, which is known to vary throughout the year. The objective of this experiment was to use the nutritive characteristics of perennial ryegrass to formulate grain rations for lactating dairy cows during autumn in Gippsland, Victoria, Australia to optimize milk production. Ninety-six spring-calving, Holstein-Friesian cows grazed pasture at an allowance of 36 kgDM/cow per day (measured to ground level) and supplemented with 6.0 kgDM/cow per day of oaten hay fed in the paddock and one of 4 grain rations fed in the parlor during milking: control (CON), consisting of wheat and barley grain (8.0 kgDM/cow per day); standard grain mix (SGM), consisting of wheat, barley and corn grain, and canola meal (8.0 kgDM/cow per day); designer grain mix 1 (DGM1) consisting of the same ingredients as SGM but formulated to complement the expected nutrients from pasture (8.0 kgDM/cow per day); and designer grain mix 2 (DGM2) consisting of wheat, barley and corn grain, urea and a fat supplement (7.5 kgDM/cow per day). Dry matter intake, milk production and BW were measured over a 14-d experimental period following a 14-d adaptation period. Data were averaged over time for each cow fed each ration and analyzed by ANOVA. There were no differences in pasture or hay DMI between cows fed any of the 4 rations, however cows fed DGM2 consumed less grain and had the lowest total DMI (P < 0.05). The CP intake from the grain ration was highest for cows consuming SGM (P < 0.001), however overall intake of CP was lowest for cows consuming CON but was not different for cows consuming the other grain rations (P = 0.001). Milk yield was greatest for cows fed SGM and DGM1, as were milk fat and protein concentrations (P < 0.001). We conclude that formulating a grain ration based on the nutritive characteristics of the pasture can result in a ration that complements the nutrient intake from pasture without a decrease in milk production.
Production, Management and the Environment: Orals Orals Production Management and the Environment 7/11/2021 0:00 t83621 Watch 138 Metabolomics analysis underlay mechanisms in the renal impairment of mice caused by combination of aflatoxin M1 and ochratoxin A. 2 Z. Wang aflatoxin M1 ochratoxin A nephrotoxicity Z. Wang1,2, Y. Gao1,2, X. Huang1,2, J. Wang1,2, N. Zhen1,2 1State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, P. R. China, 2Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, P. R. China Aflatoxin M1 (AFM1) and ochratoxin A (OTA) are pernicious mycotoxins widely existing in the environment. Co-occurrence of AFM1 and OTA may cause additive or synergistic effects, posing greater risks to public health. However, nephrotoxicity and underlying mechanism induced by AFM1 plus OTA still remain to be explored. In this study, CD-1 mice were treated with 3.5 mg/kg b.w. AFM1, OTA, and AFM1+OTA for 35 d, and LC-MS-based metabolomics method was applied to investigate metabolomic profiles of mice kidney. Subsequent experiments on human renal proximal tubular (HK-2) cells were performed to dig out the causal connections between distinguished differential metabolites and nephrotoxicity. The results showed that, compared with control, AFM1 and OTA alone and in combination significantly reduced final body weight and kidney index, remarkably elevated blood urea nitrogen (BUN), serum creatinine (SCr), and uric acid (UA) values, and induced abnormal histological phenotypes (represented by H&E staining and Masson trichrome staining), indicating the occurrence of renal injury. Besides, by means of multivariate analysis of metabolomics, AFM1+OTA caused more extensive disturbances in metabolic pathways in comparison with single toxin treatment. Among those differentially expressed metabolites affected by AFM1+OTA, lysophosphatidylcholines (LysoPCs) were identified as the main type with significant upregulation. Western blotting of HK-2 cells further demonstrated that AFM1+OTA significantly increased the expression of apoptotic factors (caspase 3, PARP, and SAPK/JNK), which can be relieved by baicalein (BE), a verified inhibitor of LysoPCs. It could be speculated that LysoPCs were the pivotal metabolites in response to the combined toxins engendering renal injury, which might be served as a sensitive and specific biomarker of nephrotoxicity. The results of this study underlay latent mechanisms in the renal impairment induced by AFM1 and OTA, and importantly, pointed out the necessity of more attentions and relevant limitation standards of co-existed mycotoxins in the milk and food safety controlling.
Production, Management and the Environment: Orals Orals Production Management and the Environment 7/11/2021 0:00 t83978 Watch 139 Net partial cashflow of dairy cows with different voluntary waiting periods until first insemination. 3 E. E. A. Burgers economic result extended calving interval extended lactation length E. E. A. Burgers1,2, A. Kok1, R. M. A. Goselink2, H. Hogeveen3, B. Kemp1, A. T. M. van Knegsel1 1Adaptation Physiology group, Wageningen University & Research, Wageningen, the Netherlands, 2Wageningen Livestock Research, Wageningen University & Research, Wageningen, the Netherlands, 3Business Economics group, Wageningen University & Research, Wageningen, the Netherlands Based on modeling studies, a 1-yr calving interval is generally considered optimal from an economic point of view. Recently some dairy farmers are deliberately extending the voluntary waiting period for insemination (VWP) to extend the calving interval. Reasons to extend the VWP are to reduce the frequency of transitions such as dry-off and calving to improve health, to reduce labor related to these transitions, and to reduce the number of surplus calves. This study aimed to evaluate yearly net partial cashflow in a randomized controlled trial for individual cows with a VWP of 50, 125, or 200 d. The net partial cashflow included revenues and costs for milk yield, calves born, number of inseminations, concentrate supply, roughage supply, disease treatments, discarded milk due to disease treatments, culling, and labor (for calving cows, inseminations, and disease treatments). Holstein-Friesian dairy cows (n = 153) within one herd were blocked for parity, calving season, and 305-d milk yield, randomly assigned within the blocks to one of 3 VWP (50 d, 125 d, or 200 d; VWP50, VWP125, or VWP200), and monitored from wk 6 postpartum until 6 wk after the next calving. Revenues and costs were calculated per individual cow, and expressed per cow per year. Primiparous and multiparous cows were evaluated separately. Revenues from milk and costs for roughage and concentrate contributed most to the yearly net partial cashflow. For primiparous cows, the VWP did not affect yearly revenues from milk. For multiparous cows, yearly milk revenues were greater in VWP50 compared with VWP200 (€3,487 vs €3,089). For primiparous cows, the VWP did not affect yearly concentrate costs, while for multiparous cows, yearly concentrate costs were greater in VWP50 compared with VWP200 (€517 vs €413). Primiparous cows in VWP200 had lower yearly insemination costs compared with VWP50 (€26 vs €62), and multiparous cows in VWP200 tended to have lower yearly insemination costs compared with VWP50 (€37 vs €57). The VWP did not affect the net partial cashflow per cow per year for both primiparous and multiparous cows.
Production, Management and the Environment: Orals Orals Production Management and the Environment 7/11/2021 0:00 t84167 Watch 140 Genome, ruminal metabolome, and milk associations in lactating Holsteins. 4 H. M. Golder acidosis genome-wide association H. M. Golder1,2, I. J. Lean1,2, S. J. LeBlanc3, T. Duffield3, H. A. Rossow4, R. Bogdanich5, L. Hernandez6, E. Block7, J. Thomson8 1Scibus, Camden, NSW, Australia, 2Dairy Science Group, Faculty of Veterinary Science, The University of Sydney, Camden, NSW, Australia, 3Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada, 4Veterinary Medicine Teaching and Research Center, School of Veterinary Medicine, University of California-Davis, Tulare, CA, 5Cross Street Veterinary Clinic, Tulare, CA, 6Department of Animal and Dairy Sciences, University of Wisconsin–Madison, Madison, WI, 7Arm & Hammer Animal and Food Production, Princeton, NJ, 8Montana State University, Department of Animal and Range Sciences, Bozeman, MT Holstein cows (n = 293; DIM = 11 to 110) from first to seventh parity from 36 farms in Canada, USA, and Australia were enrolled to examine associations among genome, ruminal metabolome, and milk composition and yield. Diets ranged from pasture supplemented with concentrates to TMR (NFC = 17 to 47 and NDF = 27 and 58% of DM). Rumen samples were collected < 3 h after feeding and analyzed for pH, and ammonia, d- and l-lactate, and VFA concentrations. Eigenvectors were produced using cluster and discriminant analysis from a combination of all rumen measures and were used to calculate the probability of the risk of ruminal acidosis based on proximity to the centroid of 3 clusters. DNA of sufficient quality was successfully extracted from whole blood (218 cows) or hair (65 cows) collected simultaneously with the rumen samples and sequenced using the Geneseek Genomic Profiler Bovine 150K Illumina SNPchip. Genome-wide association used an additive model and linear regression with principal components analysis (PCA) population stratification and a Bonferroni correction for multiple comparisons. Population structure was visualized using PCA plots. One farm from Australia had differentiated population structure when the first 2 PCA eigenvectors were plotted and data were coded by farm ID, hence these eigenvectors were included as covariates in the analysis to correct for underlying population structure or any underlying genetic variation such as regional or country variation. There were single genomic markers associated with milk fat yield, milk protein percent, ruminal acetate, butyrate, and isovalerate concentrations, and probability of acidosis. More than one genomic marker was associated with ruminal isobutyrate and caproate concentrations. No genomic markers were associated with milk yield, fat percent, protein yield, total solids, energy-corrected milk, SCC, ruminal pH, ammonia, propionate, valerate, total VFA, and d-, l- or total lactate concentrations. Genome-wide associations with the ruminal metabolome and milk yield and composition were present across a wide geographical and management range of farms, suggesting markers for ruminal acidosis susceptibility exist.
Production, Management and the Environment: Orals Orals Production Management and the Environment 7/11/2021 0:00 t84317 Watch 141 Seasonal effects on multiparous lactating dairy cow behavior. 5 I. M. Toledo freestall housing lying time eating time I. M. Toledo1, L. T. Casarotto1, G. E. Dahl1 1University of Florida, Gainesville, FL Controlled studies have shown that heat stress abatement positively influences health, productivity, behavior and reproductive performance of dairy cows during all stages of the lactation cycle. Based on previous findings, the present study focused on a better understanding of how seasonal changes affect the behavior of multiparous lactating dairy cows kept in typical freestall housing with the objective to aid in the management of lactating cows exposed to variable environmental conditions. Automated monitoring devices (Nedap, Netherlands) were used to document behavioral activity of mature Holstein dairy cows during the “hot season” (HS; n = 19; July, August and September) and the “cool season” (CS; n = 15; December, January and February). Cows received a leg tag to measure daily lying time, number of steps and standing bouts and a neck tag to measure eating and rumination time. All cows were housed in sand-bedded freestall barns equipped with cooling systems (soakers and fans). Behavior was recorded for the first 9 weeks of lactation after calving. Statistical analysis was conducted using the mixed model of SAS. Average THI was 78 in the HS and 54 in the CS. Compared with CS, during HS cows spent less time eating (134 ± 13.1 vs 199 ± 14.2 min/d; P < 0.01), lying (717 ± 21.1 vs 814 ± 23.9 min/d; P < 0.01), and tended to spend less time ruminating (558 ± 25.8 vs 629 ± 28.2 min/d; P = 0.07). In addition, exposure to ambient heat resulted in increases in standing bouts (15 ± 0.7 vs 12 ± 0.7 stands/d; P < 0.01), and overall standing time (720 ± 21.3 vs 626 ± 24.0 min/d; P < 0.01) in HS compared with CS. No differences in number of steps (3,172 ± 138.7 vs 3,288 ± 156.7 steps/d; P < 0.01), was observed between HS and CS. In summary, exposure to high THI during lactation seems to negatively affect the behavior and consequent daily time budget of lactating Holstein cows, even under normal housing conditions with active cooling. A better understanding on how different seasons affect the daily time budget of lactating dairy cows may contribute to the development of more effective management strategies to decrease the negative effects of heat exposure.
Production, Management and the Environment: Orals Orals Production Management and the Environment 7/11/2021 0:00 t84500 Watch 142 Feeding behavior of heifers monitored through computer vision systems. 6 T. Bresolin deep learning feeding behavior machine learning T. Bresolin1, F. Baier1, J. Van Os1, J. R. R. Dorea1 1University of Wisconsin–Madison, Madison, WI Feeding behavior can be used as an important indicator of health issues, estrus events, feed intake, and welfare. However, in large dairy operations, the daily monitoring of feeding behavior is laborious, and the large number of animals becomes a limiting factor. Furthermore, validated methods of determining individual feeding behavior in group-housed settings are lacking. The objective of this study was to develop a computer vision system to individually monitor feeding behavior of group-housed dairy heifers. Eight Holstein heifers (96 ± 6 d old) were housed in a group and a total of 25,214 images were acquired using one RGB camera. Images were collected every second for a total period of 7 h of video streaming (13:30 to 20:30 h). A total of 2,209 images were randomly selected and each animal in the image was labeled with its respective identification. The label was annotated only on animals that were eating in the feed bunk (head through the feed rail). From the labeled images, 1,392 random images were used to train a deep learning algorithm for object detection YOLOv3 (“You Only Look Once”) and the 154 images were used for tuning. A total of 663 images were used as a testing set to validate the trained algorithm. Analyses were implemented in Python using the computational resources provided by UW-Madison Center for High Throughput Computing (CHTC). The average precision for identifying individual animals in the testing set was 96.0%, and for each individual heifer was: 99.2%, 99.6%, 99.2%, 99.6%, 99.6%, 99.2%, 99.4%, and 99.6% for heifers 1–8, respectively. After identifying the animals at the feed bunk, we computed total time spent at the feed bunk, average time per visit, number of visits, and average interval between visits for each heifer using 8,883 sequential images from 4-time points, and the correlation between observed and predicted values were 0.99, 0.85, 0.33, and 0.49, respectively. Our results indicate that computer vision systems can be used to individually monitor feeding behavior of group-housed Holstein heifers, generating precise predictions of total time spent at the feed bunk and the average time per visit.
Production, Management and the Environment: Orals Orals Production Management and the Environment 7/11/2021 0:00 t84624 Watch 143 Predicting body weight of lactating and pregnant dry dairy cows using an RGB-D sensor camera. 7 L. M. Campos image descriptors multiple linear regression prediction L. M. Campos1, G. Morota2, M. D. Hanigan1 1Dairy Science Department, Virginia Tech, Blacksburg, VA, 2Animal Science Department, Virginia Tech, Blacksburg, VA Daily body weight (BW) measurements of lactating dairy cows can be used for deriving health diagnosis, reproductive efficiency, feeding strategies, and animal performance. Currently, animals are weighed using walk-over or stationary electronic scales. The former is not commonly used on production dairies due to cost and maintenance, and the latter is very labor inefficient. Thus, utilization of BW data for on-farm decision-making is not common. The objective of this study was to develop prediction equations relating body measurements derived from a red-green-blue (RGB) sensor camera equipped with depth-sensing devices (Intel RealSense D435) to measure BW. Ten lactating, Holstein cows (286 DIM) with an average initial BW (SD) of 780 (137) kg and 2 pregnant, nonlactating, Jersey cows with an initial BW of 520 (12) kg at 12- and 21 d ante-parturition were chosen to capture the variability in BW associated with physiological state, parity, and changes over time during the lactation cycle. Animals were video recorded (top view) every day for 30d while the animal was restrained on the walk-over scale for 10 s. The camera was set to capture depth images at 640X480 resolution and 30 frames per second. Body weights were recorded automatically 2x/d as the lactating animals transited the scale when exiting the parlor (2 a.m. and 2 p.m.), after milking. Nonlactating animals were manually weighed 1x/week until they calved. One lactating animal was removed from the study after the first week of measurements due to behavior inconsistency. Each video frame was processed by the MATLAB Image Processing Toolbox. Four morphological image descriptors, length, width, height, and volume, were extracted from depth images. The Pearson correlation coefficients between scale-based BW records (average of the AM and PM weights) and morphological image descriptors were 0.83 (length), 0.88 (width), 0.85 (height), and 0.91 (volume). A goodness of fit obtained by multiple linear regression when regressing observed BW on the morphological image descriptors was 0.92 in adjusted R2. Volume was most correlated with BW records. We conclude that the depth images derived from the RGB-D sensor camera could potentially provide an effective way to predict the BW of cows. Additional work is required to develop descriptors capable of predicting BW change over time when the frame size is not changing.
Production, Management and the Environment: Orals Orals Production Management and the Environment 7/11/2021 0:00 t84625 Watch 144 The effect of calcareous marine algae on feed intake, milk production, mineral status, energy metabolites, and inflammatory markers in transition dairy cows. 8 E. W. Neville dairy cow feed intake E. W. Neville1, A. G. Fahey2, F. J. Mulligan1 1School of Veterinary Medicine, University College Dublin, Dublin, Ireland, 2School of Agriculture and Food Sciences, University College Dublin, Dublin, Ireland Feeding highly fermentable diets in early lactation is necessary to minimize the extent of negative energy balance but can lead to periods of low rumen pH and subsequently induce an inflammatory response. The objective of this experiment was to investigate the effects of supplementing calcareous marine algae (CMA) to cows during the transition period on feed intake, milk production, energy balance, serum mineral concentrations and inflammatory markers compared with a control in both the pre- and postpartum period. Twenty-two multiparous and 10 primiparous cows were assigned to 2 dietary treatments 25 d before expected parturition until 42 d postpartum. Cows were blocked by parity and randomly assigned to their treatments based on pre-experimental BCS (multiparous: 2.88 ± 0.33, primiparous: 3.3 ± 0.26), previous 305-d milk yield (7,009 ± 1,404) kg and fat and protein yield (556 ± 97) kg for multiparous cows and PTA for milk yield (255 ± 127) kg and fat and protein yield (22 ± 7) kg for primiparous cows. Cows were fed a negative DCAD (−50 mEq/kg) TMR based on maize silage, grass silage, and straw during the pre-partum and a 50:50 forage: concentrate TMR based on grass silage, maize silage and concentrate during the postpartum period. The 2 dietary treatments consisted of a control (CON) and calcareous marine algae (CMA) included at 0.42% and 0.47% DM for the pre- and postpartum periods, respectively. Data were analyzed using the MIXED procedure (SAS, version 9.4). The model included fixed effects of treatment, week, parity, and treatment by week interaction. The CMA treatment had higher dry matter intake in both the prepartum (1.08 kg, P < 0.05) and postpartum (0.94 kg, P < 0.05) compared with the control diet. The CMA treatment had reduced NEFA concentrations in plasma during the prepartum (−0.11 mmol/L, P < 0.10) and the postpartum (−0.03 mmol/L, P < 0.05) compared with the control treatment. Fat concentration (0.43%, P < 0.05), 4% fat-corrected milk (1.56 kg, P < 0.05) and energy-corrected milk (1.32 kg, P < 0.10) were higher on the CMA treatment compared with the control. Results from this experiment demonstrate the benefits, on feed intake and some production parameters, of supplementing CMA to dairy cows during the transition period.
Production, Management and the Environment: Orals Orals Production Management and the Environment 7/11/2021 0:00 t84690 Watch 145 Effect of evaporative cooling on systemic and mammary inflammatory responses of lactating dairy cows during summer. 9 Y.-C. Chen lactation inflammation heat stress Y.-C. Chen1, R. M. Orellana Rivas1, T. N. Marins1, V. Lacerda1, Z. Wang2, M. Garrick1, H. Liu2, J. K. Bernard1, S. Tao1 1Department of Animal and Dairy Science, University of Georgia, Tifton, GA, 2College of Animal Sciences, Zhejiang University, Hangzhou, China To examine the impact of evaporative cooling on systemic and mammary inflammation of lactating dairy cows during summer, multiparous Holstein cows (n = 30, parity = 2.4, DIM = 156 d) were randomly assigned to either cooled (CL) with fans and misters or not (NC). Temperature-humidity index averaged 78.4 during the 36-d experiment. Milk yield (MY) and DMI were recorded daily. Blood and milk samples were collected from a subset of cows (n = 18) on d −3, 1, 3, 7, 14, and 28 of the experiment to measure cortisol, interleukin (IL)10, tumor necrosis factor (TNF)α, haptoglobin (HP), and lipopolysaccharide (LPS) binding protein (LPSBP). Mammary biopsies were collected from another subset of cows (n = 12) on d −7, 2, 10, and 36 to analyze gene expression of TNFα, IL10 and HP. Fourteen cows received a bolus of LPS in left rear quarter on d 30. Blood and milk samples from the LPS infused quarter were collected at −4, 0, 3, 6, 12, 24, 48, 96 and 144 h relative to infusion to analyze inflammatory products. Data were analyzed using PROC MIXED of SAS. Significance and tendency were declared at P ≤ 0.05 and 0.05 < P ≤ 0.15. Deprivation of cooling decreased (P ≤ 0.03) MY and DMI. Plasma cortisol concentration of NC cows was higher on d 1 but lower on d 28 than CL (environment [E] × time [T]: P < 0.01). Deprivation of cooling tended to reduce serum IL10 concentrations on d 14 (E × T: P = 0.02) but did not affect circulating TNFα, HP, or LPSBP. Compared with CL, NC cows tended (P = 0.08) to have higher milk IL10 concentrations but did not affect TNFα or HP. No differences were observed in mammary gene expression of TNFα, IL10 and HP. MY reduced after LPS infusion but not affected by treatments. NC cows had similar circulating IL10 and TNFα but tended (P = 0.06) to have higher HP concentrations than CL. Milk IL10 and TNFα concentrations were higher (P ≤ 0.01) 3 h after LPS infusion (E × T: P ≤ 0.15) for NC cows compared with CL. In conclusion, deprivation of cooling had minimal effects on lactating cows’ basal inflammatory status, but upregulated systemic and mammary inflammatory responses after mammary inflammation induced by LPS.
Production, Management and the Environment: Orals Orals Production Management and the Environment 7/11/2021 0:00 t83491 Watch 146 The effect of time away from pasture on milk production and grazing behavior. 10 M. Douglas time budget milk yield M. Douglas1, M. Wright1, P. Alvarez-Hess1, V. Russo1,2, M. Hannah1, W. Wales1,2, M. Auldist1,2 1Agriculture Victoria Research, Ellinbank, Victoria, Australia, 2Centre for Agricultural Innovation, School of Agriculture and Food, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Melbourne, Victoria, Australia The average herd size of Australian dairy farms has increased by 30% in the last 10 years. A challenge of larger herds in pasture-based systems is to provide optimal nutrition for cows that may have compromised time budgets due to long wait times at the parlor for milking and the need to walk long distances to and from the paddock each day. As there is a consistency in milking order, it is repeatedly the same cows that spend the longest time away from pasture. The objective of this experiment was to measure the effect of time away from pasture on DMI, milk production and grazing behavior of dairy cows in late lactation. For 15 d, 40 spring-calving, Holstein-Friesian cows were split into 5 groups of 8 cows and returned to a common paddock in 45-min intervals following milking. Pasture allowance was 25 kgDM/cow per day (measured to ground level) and cows were fed cereal grain (4.0 kgDM/cow per day) in the parlor during milking. Data were averaged over time for each group and analyzed by ANOVA, with the corresponding covariate data included in the model. Milk yield was greatest for cows that returned to the paddock immediately after milking and 45-min later, intermediate for cows that returned to the paddock 90- and 135-min later, and lowest for cows that returned to the paddock 180-min after the first cows (P < 0.001). Cows that returned to the paddock first produced 6.1 kg milk more than cows that returned to the paddock last (P < 0.001). This was due partly to the amount of pasture available as 38% of the pasture DM mass had been removed by the time the last cows returned to the paddock, with a trend for available ME in pasture to be lowest when the last cows entered (P = 0.093). RumiWatch devices (Itin+Hoch, Switzerland) showed that cows that returned to the paddock last spent more time eating than those that returned first (P < 0.028). We conclude that time away from pasture affects milk yield primarily by reducing the amount and quantity of pasture on offer to later cows, rather than by compromising their time budgets. Future research will look at strategies to re-allocate pasture allowance and the amount of grain offered to ensure a greater consistency of feed to all cows.
Production, Management and the Environment: Orals Orals Production Management and the Environment 7/11/2021 0:00 t84704 Watch 501 Effects of wildfire smoke on innate immunity and metabolism of dairy cows 11 A. Anderson Hematology Blood Chemistry PM2.5 A. Anderson1, P. Rezamand1, A. Skibiel1 1University of Idaho, Moscow, ID, U.S. Wildfires are prevalent in the Pacific Northwest, home to more than two million dairy cows that produce more than 25% of U.S. milk. Wildfires emit particulate matter (PM2.5), which is toxic to humans and is thought to contribute to disease by affecting metabolism and inducing inflammation. However, the physiological responses of dairy cows to wildfire PM are unknown. Lactating Holstein cows (primiparous, n=7; multiparous n=17) were monitored across the wildfire season (July-September 2020). In August, ten of the multiparous cows were dried off. Cows were housed in open air free-stall pens (lactating) or on pasture when dry. Air temperature, PM2.5, and relative humidity were obtained from a monitoring station 5.9 km from the farm. Cows were considered to be exposed to wildfire PM if daily average PM2.5 >35 µg/m3 and Airpact-5 PM maps indicated the PM derived from active wildfires. Based on these conditions, cows were exposed to wildfire PM for 7 consecutive days in mid-September. Blood was taken from the jugular vein once per week for 8 wk prior to exposure, twice during the wk of exposure, and 1-2 wk after exposure and assayed for hematology, blood chemistry (K+, Cl-, CO2), NEFA, BHB, glucose, and inflammatory markers (haptoglobin, serum amyloid A). Associations between PM and blood analytes were analyzed using mixed models including PM2.5, temperature-humidity index (THI), and their interaction, parity (primiparous or multiparous), and production stage (lactating or dry) as fixed effects and cow ID as a random effect. Nonsignificant variables were removed in the final models. Daily PM was negatively associated with circulating neutrophils, NEFA, Cl- (all P <0.0001), and white blood cell count (P = 0.06). Daily PM was positively associated with blood CO2, K+, glucose (all P < 0.01) and haptoglobin concentrations (P = 0.06). PM and THI had interactive positive effects on lymphocyte (P < 0.01) and eosinophil (P < 0.001) counts and interactive negative effects on red blood cell count, hemoglobin, and hematocrit (all P < 0.0001). Our results suggest that exposure to high wildfire-derived PM alters systemic metabolism and the innate immune response.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 s9596                  
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t83919 Watch P279 Economic viability and benchmarking associated with dairy farms in Brazil. 1 J. De Souza Pinheiro cows financial milk production J. De Souza Pinheiro1, M. I. Marcondes1,2 1Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brasil, 2Washington State University, Pullman, WA Dairy operations have adopted benchmarking as a methodology to rank farms and stablish target indexes, however a connection between benchmarking and farmers in the tropics is still warranted. We aimed to stablish benchmarking based on economic outcomes in dairy farms in different regions. We collected data from 128 dairy farms from Minas Gerais, Brazil. Farms were grouped into Center, South and Triangle regions. The farms were subdivided into 3 groups within each region according to the return on assets (ROA, %), where 25% of the farms that presented the lowest ROA were classified as first quartile (1Q), 50% of farms were classified as intermediate quartile (IQ) and the 25% remaining farms were classified as fourth quartile (4Q). Data were analyzed in a randomized block design in a split-plot scheme, where the production systems were blocks, the regions are the main plots and the groups the split plots. Differences were declared when P ≤ 0.10. All economic indexes were affected by regions and quartiles (P > 0.10). South region and 1Q had the greatest accrual operating cost (AOC) whereas Triangle and 4Q had the greatest net margin and profit. In conclusion, triangle region and fourth quartile presented the greater economic indexes, indicating the need for specific benchmarks by regions and for farms with different return on assets. Table 1. Economic indexes for dairy farms in different regions and groups
Item1 Region Quartile SEM P-value2
Center South Triangle First Intermediate Fourth Region Group
AOC, $/L 0.265b 0.274a 0.263b 0.302a 0.261b 0.238c 0.009 0.0603 <0.0001
Net margin, $/L 0.047c 0.057b 0.073a 0.021c 0.064b 0.092a 0.007 <0.0001 <0.0001
Profit, $/L 0.020c 0.029b 0.043a −0.016c 0.037b 0.071a 0.004 <0.0001 <0.0001
ROA (%) 0.009b 0.013a 0.015a −0.003c 0.012b 0.029a 0.002 0.0240 <0.0001
ATR (%) 0.169c 0.189b 0.207a 0.133c 0.184b 0.248a 0.008 0.0010 <0.0001
Means within a row with different superscripts differ (P < 0.10). 1AOC = accrual operating cost; 1ROA = assets turnover rate with land; ATR = assets turnover rate. 2All interactions were nonsignificant (P > 0.12).
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t83480 Watch P281 Profitability and environmental performance of Quebec dairy farms when 4 binary alfalfa-grass mixtures are compared under future climate conditions. 2 C. Payant climate change dairy farm forage C. Payant1, G. Jégo2, V. Ouellet1, P. Grenier3, G. F. Tremblay2, G. Bélanger2, D. Pellerin1, A. Vanasse1, É Charbonneau1 1Université Laval, Quebec, QC, Canada, 2Agriculture and Agri-Food Canada, Quebec, QC, Canada, 3Ouranos, Montreal, QC, Canada Objective of this study was to project the impact of choice in alfalfa-grass mixture on profitability and environmental performance of 2 Quebec dairy farms located in contrasting climates in near (NF: 2020–2049) and distant (DF: 2050–2079) future when modifications in crop production arising from climate change are considered. Yield and nutritive value of 4 alfalfa-grass binary mixtures were projected through a climatic reference period (REF: 1971–2000), and through NF and DF using a mechanistic model (Integrated Farm System Model): 1) alfalfa-timothy; 2) alfalfa-tall fescue; 3) alfalfa-meadow fescue; 4) alfalfa meadow bromegrass. Projected yield and nutritive attributes of REF, NF and DF were then transferred in an optimization model (Nutrient Cycling: Crops, Livestock, Environmental and Soil) which was adjusted beforehand to account for constraints associated with climate change, to simulate profitability and environmental performance. Results of simulations showed that relative to REF, net income could increase in both farms, with a highest difference of CAD 13.4 and 3.2 /100 kg of fat and protein corrected milk (FPCM) for the farms in the coolest and the warmest regions, respectively. The on-farm N and P balance should decrease in the future because of the increase in crop sold. Greenhouse gas emissions projections showed no major modification to the whole-farm total (mean of 1.9 and 1.8 CO2eq/kg FPCM for the coolest and the warmest regions, respectively), but more greenhouse gas emissions is expected to be allocated to cash-crop (+0.4 and +0.1 CO2eq/kg FPCM for the coolest and the warmest regions, respectively), and less to milk production (−0.3 and −0.1 CO2eq/kg FPCM for the coolest and the warmest regions, respectively) in the future relative to REF. Forage mixtures with the highest net income were alfalfa with tall fescue or meadow bromegrass depending on the region and the climatic simulations. Projections of the net income and environmental parameters using a whole-farm model approach should be used to improve crop allocation on dairy farms.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t83488 Watch P282 Low milk fat test in confinement and pasture-based systems: Forage source and content? 3 M. N. Méndez confined and grazing cows fiber fat milk M. N. Méndez1,3, L. Grille2, M. Oborsky3, V. Rodríguez2, L. Olazábal4, J. P. Damián5, P. Chilibroste3 1Red Tecnológica Sectorial, Montevideo, Uruguay, 2Facultad de Veterinaria, Paysandú, Uruguay, 3Facultad de Agronomía, Paysandú, Uruguay, 4Laboratorio Tecnológico del Uruguay, Montevideo, Uruguay, 5Facultad de Veterinaria, Montevideo, Uruguay We aimed to study the nutritional causes that led to low milk fat (MF) test on 16 cows fed a total mixed ration (TMR) ad libitum (TMRG) and 16 cows fed with TMR (PM, 50% of TMRG) + AM access to fresh pasture (PMRG) randomly assigned to the treatments after calving. TMR composition changed twice (experimental wk 12 and 19), generating 3 feeding periods. The hypothesis was that the low MF test in P1 and P2 was due to changes in neutral detergent fiber (NDF) content of the diet. All cows were milked at 4:00 a.m. and PM. Feed components and chemical composition of the TMR by period (P0, P1 and P2) are presented in Table 1. Milk samples were taken to determine MF at P1 and P2. A MIXED procedure was performed to analyze MF in P1 and P2, with treatment, period and its interaction as fixed effects and cows as random effect. Results were considered significant at α ≤ 0.05. In average TMRG cows consumed 29.1 ± 1.1 kg DM/day and produced 40.5 ± 2.1 L/day/cow, while PMRG consumed 14.3 ± 1.2 kg DM/day of TMR + 7.2 ± 2.9 kg DM/day of pasture, and produced 32.3 ± 1.6 L/day/cow. There were no effects of treatment nor interaction on MF percentage. MF decreased from P1 to P2 (P ≤ 0.01): 3.6% vs 2.5% in TMRG and 3.7% vs 2.8% in PMRG, respectively. Although PMRG had a greater diet NDF content than TMRG (Table 1), due to pasture inclusion, MF was not different between treatments. These led to reject the hypothesis that feed fiber content was the main responsible for the low MF test. So, other TMR components such as carbohydrates from maize silage or fatty acids from concentrate could have altered ruminal environment and therefore MF production. Table 1. Feed components and NDF (%) in 3 different periods
Diet Components Period
P0 P1 P2
TMR Forage (%) Maize silage 25 35 35
    Ryegrass silage 22
    Fescue hay 2 6
  Concentrate (%)   53 63 59
TMR NDF (%)   42 37 35
P+TMR1 NDF (%)   50 41 38
1P+TMR = average from pasture (P) and TMR % NDF weighted by intake.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t83540 Watch P283 A 16S-metagenomic analysis of compost-bedded pack barns in dairy farms from Argentina. 4 J. L. Monge compost-bedded packs barns 16S-metagenomic nitrifying bacteria J. L. Monge1, L. Palma2,1, C. Peralta1 1Universidad Nacional Villa María, Villa María, Córdoba, Argentina, 2Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina In compost-bedded pack dairy barns (CBP) microbial communities play an essential role in the process. The aim of this work was to study the bacterial community structure at different CBP using 16S-metagenomics to identify nitrifying bacteria. Two CBP (MB: Martin Bono Dairy Farm; AT: Angela Teresa Dairy Farm) were sampled during the winter (Julie 2019) in Córdoba province, Argentina. MB was 30 mo and AT was 20 mo age. MB had concrete feed alleys, CBP was started over the natural ground without bedding addition, was deep-tilled 2x/d and the cow stockig density (CSD) averaged 14.5 m2/cow (plus 2.4 m2/cow concrete feed alley area). AT had not concrete feed alleys, CBP was started with 40 cm of peanut shells, with bedding addition (5.5 kg/cow/day). CBP was deep-tilled and rototilled 2×/d, CSD averaged 13.75 m2/cow (including feed alley area without concrete). Two samples were collected per CBP at 30 cm deep. Each sample was dried by lyophilization. Dried-compost samples were homogenized with high-speed universal disintegrator (FW100 model). Total DNA was purified using PureLink Microbiome DNA Purification Kit and sequenced at INDEAR (Rosario, Santa Fe province). Raw Illumina reads were filtered as follows: 1) removeal of duplicate reads, 2) removeal of chimeric reads and 3) 16S biodiversity analysis using Geneious R11 (geneious.com). For both CBP taxonomic hits distribution results at domain level was 99% bacteria and 1% archaea. In MB taxonomic classification hits distribution at genus level for nitrifying bacteria was 5% Nitrosococcus, 0.06% Nitrococcus, 20% Nitrosomonas and 0.05% Nitrobacter; in AT was 0.02% Nitrosococcus, 0.004% Nitrococcus, 0.07% Nitrosomonas and 0.0005% Nitrobacter. Nitrifying bacteria showed greater values for MB than AT. We concluded that nitrifying bacteria hits distribution are affected by CBP design, CSD and the bedding use.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t83526 Watch P284 Low milk fat test in confinement and pasture-based systems: Unsaturated fatty acids? 5 L. Grille dairy cow fatty acid TMR L. Grille1, M. N. Méndez2,4, V. Rodríguez1, L. Olazábal3, M. Oborsky2, J. P. Damián5, P. Chilibroste2 1Facultad de Veterinaria, Paysandú, Uruguay, 2Facultad de Agronomía, Paysandú, Uruguay, 3Laboratorio Tecnológico del Uruguay, Montevideo, Uruguay, 4Red Tecnológica Sectorial, Montevideo, Uruguay, 5Facultad de Veterinaria, Montevideo, Uruguay We aimed to study the nutritional causes that led to low milk fat (MF) test on 16 cows fed a total mixed ration (TMR) ad libitum (TMRG) and 16 cows with access to fresh pasture supplemented with a partial mixed ration (PMRG) randomly assigned to the treatments after calving. TMR changed in experimental wk 12 and 19, generating 3 periods (P0, P1 and P2). The hypothesis was that low MF test was caused by an increase in TMR unsaturated fatty acids proportion which resulted in a surge in intermediate rumen fatty acids. Milk samples were taken to determine MF at wk 15 (P1) and 23 (P2) of lactation. Six cows of each treatment were selected to analyze milk fatty acid profile (FAP). At wk 10 (P0), P1 and P2, TMR samples were taken to determine FAP (Table 1). A MIXED procedure was performed to analyze MF and milk FAP as repeated measures, with treatment, period and its interaction as fixed effects and cows as random effect. In both groups, MF decreased from P1 to P2 (P ≤ 0.01); 3.6% vs 2.5% in TMRG and 3.7% vs 2.8% in PMRG (P1 and P2, respectively). De novo fatty acid was affected by period (P ≤ 0.01); 0.74% vs 0.43% in TMRG and 0.85% vs 0.54% in PMRG (P1 and P2, respectively). A stepwise regression analysis shows that C18:1 trans in milk explained 41% of the variability in MF content and the C18:2 cis explained an additional 19% variation. C18:2 cis in milk increased from P1 to P2 in both treatments (P ≤ 0.01), while C18:1 trans-had no change between periods. The C18:2 cis TMR increase and de novo milk fatty acid decrease, supported by stepwise regression results, suggest an incomplete ruminal biohydrogenation with an increase in intermediate fatty acids, which might have inhibited MF synthesis. Even though there was no significant increase in C18:1 trans in milk, the isomer C18:1 trans-10 (main inhibitor of MF synthesis) could have increased without a rise in total C18:1 trans. Hence, TMR unsaturated fatty acids proportion increase could have decreased MF. Table 1. Total mixed ration fatty acid profile in 3 different periods
Fatty acid (g/100 g fat) Period
P0 P1 P2
C18:1 cis 28.5 27.8 29.2
C18:1 trans 0.07 0.03 0.05
C18:2n-6 cis 30.8 36.3 35.6
C18:2 trans 0.01 0.04 0.05
C18:3n-3 7.6 6.3 3.3
Total milk fat (g/100 g of TMR) 3.8 3.8 4.2
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t83867 Watch P285 Properties of alternative bedding materials for compost-bedded pack barns. 6 R. A. Black compost-bedded pack barn dairy bedding R. A. Black1, B. M. Karle2 1University of California Cooperative Extension, Santa Rosa, CA, 2University of California Cooperative Extension, Orland, CA Compost-bedded pack barns (CBPB) require frequent addition of bedding material to absorb moisture and sustain composting activity. The “gold standard” for CBPB bedding is kiln-dried wood shavings; however, this material may be expensive or difficult to obtain in adequate quantities. The objective of this study was to determine chemical and physical properties of by-products to understand their suitability as an alternative bedding source. Materials tested included a variety of local by-products. Water-holding capacity (WHC) was determined using the ASTM D7367–19 Standard on one sample per material. Samples were tested for Carbon to Nitrogen ratio (C:N) on one sample per material by The Pennsylvania State University Agricultural Analytical Services Laboratory. To test for dry matter, 3 samples of each material were weighed in aluminum trays, dried for 24 h at 60°C, and reweighed to determine moisture content. Dry matter data were analyzed using a mixed linear model. Results are reported in Table 1. Variability was high, indicating the need for selectivity and testing of material before use. Grapevine C:N was numerically similar to kiln-dried shavings, but had lesser WHC. Further processing of grapevines into shavings may improve suitability for bedding. Almond hulls had lower C:N but may act as an absorptive material in CBPB. Additional research monitoring composting efficiency and bacterial populations and determining optimal material combinations will further inform dairy producers of the suitability of by-products as alternative CBPB bedding. Table 1. Physical and chemical properties of alternative bedding materials
Material C:N DM (% ± SE) Water-holding capacity (%)
Kiln-dried shavings 135.4 89.9±1.2ab 327.8
Almond hulls A 85.8 86.9±1.2b 166.8
Almond hulls B 84.0 90.4±1.2a 356.1
Chipped almond trees 91.5 90.2±1.2ab 51.1
Chipped grapevines 130.9 92.7±1.2a 99.8
Chipped grapevine canes 79.0 92.9±1.2a 112.5
Chipped hemp stalks A 24.8 90.6±1.2a 187.9
Chipped hemp stalks B 35.8 93.2±1.2a 210.7
Rice hulls A 71.0 91.7±1.2a 139.9
Rice hulls B 74.9 91.1±1.2a 116.4
Rice straw 31.3 93.0±1.2a 411.7
abDifferent superscripts within a column indicate significance (P < 0.05).
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t83898 Watch P287 Predicting dairy cattle heat stress using machine learning techniques. 7 C. A. Becker heat stress machine learning shade sprinklers C. A. Becker1, A. Aghalari1, M. Marufuzzaman1, A. E. Stone1 1Mississippi State University, Mississippi State, MS The objectives of the study were to use a heat stress scoring system to evaluate the severity of heat stress on dairy cows using different heat abatement techniques. The scoring system ranged from 1 to 4, where 1 = no heat stress; 2 = mild heat stress; 3 = severe heat stress; and 4 = moribund. The analyses were performed in Python version 2.7, using scikit-learn libraries to predict the accuracy of the scoring system using 3 machine learning techniques: logistic regression, Gaussian naïve Bayes, and random forest. To predict the accuracy of the scoring system, these techniques used factors including temperature-humidity index, respiration rate, lying time, lying bouts, total steps, drooling, open-mouth breathing, panting, location in shade or sprinklers, somatic cell score, reticulorumen temperature, hygiene body condition score, milk yield, and milk fat and protein percent. Three different treatments, namely, portable shade structure, portable polyvinyl chloride pipe sprinkler system, or control with no heat abatement, were considered, where each treatment was replicated 3 times with 3 s-trimester lactating cows in each treatment pen. Results indicate that random forest outperformed the other 2 methods, with respect to both accuracy and precision, in predicting the sprinkler group's heat stress score. Both logistic regression and random forest were consistent in predicting scores for control, shade, and combined groups. The mean probability of predicting non-heat-stressed cows was highest for cows in the sprinkler group. Finally, the logistic regression method worked best for predicting heat-stressed cows in control, shade, and combined. The insights gained from these results could aid dairy producers to detect heat stress before it becomes severe, which could decrease the negative effects of heat stress, such as milk loss.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t83909   P288 Performance and welfare of Nili Ravi buffaloes subjected to different cooling strategies during subtropical summer. 8 M. Q. Shahid dairy buffaloes heat stress sprinkler cooling M. Bah1,3, M. A. Rashid2, K. Javed1, T. N. Pasha2, M. Q. Shahid1 1Department of Livestock Management, University of Veterinary and Animal Sciences, Lahore, Pakistan, 2Department of Animal Nutrition, University of Veterinary and Animal Sciences, Lahore, Pakistan, 3School of Agriculture and Environmental Sciences, University of The Gambia, Serekunda, Republic of The Gambia Water buffaloes wallow in water to combat heat stress during summer. With the decreasing reservoirs for wallowing, the farmers cool buffaloes by applying water using hand-held hose. This method uses a large quantity of groundwater which is becoming scarce. The objective of this study was to evaluate the effects of different cooling strategies on milk yield, physiological, and behavioral responses of Nili Ravi buffaloes during subtropical summer in Pakistan. Thirty Nili Ravi buffaloes were randomly assigned to 3 treatments: 1) CNT buffaloes cooled with application of water using hand-held hosepipe twice daily, 3 min each with a water flow rate of 50 L/min; 2) 2SS, buffaloes cooled with sprinklers twice daily; 3) 3SS, buffaloes cooled with sprinklers thrice daily. Each of the sprinkler sessions lasted for 1 h with a 12 min cycle (3 min water on, 9 min off). The trial was carried out from mid-July till the end of September, 2019. The average ambient afternoon temperature-humidity index was 86.9. The results indicated that the buffaloes in the 3SS group had lower respiration rate and rectal temperature than those in the CNT and the 2SS groups (P < 0.0001). The 3SS group had more daily milk yield (P = 0.0188) and milk fat % (P = 0.001) than the CNT and 2SS groups. The lying time and the lying bouts length were significantly longer in the 3SS than in the CNT and 2SS groups. Blood cortisol levels tended to be lower in the 3SS group than in the CNT and 2SS groups (P = 0.051). The volume of water uses for cooling in the CNT group was higher than the 2SS and 3SS groups. In conclusion, the 3SS cooling strategy had more milk yield, more milk fat, and better welfare than the CNT strategy using less groundwater and both performed better than the 2SS strategy.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t83935 Watch P289 The evaluation of different spraying frequencies on cooling effects for cows in summer. 9 D. Bu heat stress spraying frequency cooling strategy Z. Guo1, S. Gao1, L. Ma1, L. Baumgard2, D. Bu1 1Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Haidian, Beijing, China, 2Iowa State University, Ames, IA The aim of the present study was to evaluate the effect of spraying frequencies on alleviating heat stress symptoms based on performances including physiological as well as antioxidant status, milk production and intestinal barrier of dairy cows. Twenty multiparous, lactating Holstein cows (DIM 175 ± 25d, daily milk production 27.5 ± 2.5 kg of milk/d) were housed in a freestall barn with HS condition (THI >72). The study included 2 consecutive periods (14d for each period) with 2 spraying treatments. In period 1, sprinklers were activated for 3min at 6-min intervals (3|6). In period 2, sprinklers were activated for 1.5min with 3-min intervals (­1.5|3), while the fans operated 24h/d. Samples of urine, feces, milk, blood, rumen fluid, and TMR were collected on d 7 and 14 of each period, while rectal temperature, skin temperature, and respiratory rate of each cow were recorded 3 times (0700, 1400 and 2200 h) daily. Data analysis was analyzed using Proc Mixed model in SAS 9.4 with THI and DIM used as covariate. Compared with 3|6, spraying with 1.5|3 reduced the respiratory rate (64.2 vs 55.2 times per minute, P < 0.01) as well as skin (32.8 vs 33.8°C P < 0.01) and rectal temperature (38.4 vs 38.8°C, P < 0.01), meanwhile increased evening milk production (8.21vs 7.25 kg, P < 0.05) and DMI (22.02 vs 19.92 kg, P < 0.01). Blood concentration of LPS (2.19 vs 0.70 10−4 EU/mL, P < 0.01), NO (3.22 vs 1.72 μmol/L, P < 0.1) and D-lactate (17.05 vs 8.35 μmol/L, P < 0.1) of 1.5|3 cows were lower than 3|6 cows. The activity of SOD (7.03 vs 11.30 U/mL, P < 0.01) and CAT (5.35 vs 6.79 U/mL, P < 0.01) in blood were increased by 1.5|3 compared with 3|6. These data suggested that a spraying frequency of 1.5|3 alleviates the detrimental effects of HS compared with 3|6, suggesting that increased spraying frequency is a more efficient evaporative cooling strategy for HS dairy cows.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t83932 Watch P290 Cooling ameliorates the decrease of milk protein of lactating Holstein cows under heat stress. 10 D. P. Bu heat stress sprinklers and fans milk protein S. T. Gao1, Z. T. Guo1, L. H. Baumgard2, L. Ma1, D. P. Bu1 1Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China, 2Department of Animal Science, Iowa State University, Ames, IA The objective of the present study was to evaluate the relief effect of cooling on the decrease in milk protein concentration during heat stress, and elucidate the potential metabolic mechanism. Thirty lactating multiparous Holstein cows (DIM 175 ± 25 d, milk yield 27.5 ± 2.5 kg/d) were assigned to 1 of 3 treatments: heat stress (HS, n = 10), cooling (CL, n = 10), and cooling with pair-feeding (PFCL, n = 10). The daily feed intake of PFCL cows was equal to HS cows. The barns for PFCL and CL cows were equipped with sprinklers and fans, whereas the barn for HS cows were not. The local average THI during the experiment period ranged from 74 to 83. The spraying was activated automatically 2 times per day (1130 to 1330 h and 1500 to 1600 h) with 3 min on and 6 min off in the first 2 weeks, and 1.5 min on and 3 min off in the last 2 weeks, while the fans operated 24 h/d. The experiment lasted for 4 weeks in total and with 7d adaptation before the experiment. Milk, urine, feces, TMR, blood, and rumen fluid samples were collected weekly. Compared with HS, feed efficiency (1.24 and 1.49, P < 0.05), milk protein yield (0.82 and 0.94 kg/d, P < 0.05), and milk fat yield (0.98 and 1.26 kg/d, P < 0.05) were increased in PFCL compared with HS, while the differences between CL and HS were not significant. Compared with HS cows, PFCL and CL cows had lower respiratory rate (70.6, 59.1, and 60.3 bpm, respectively, P < 0.05), rectal temperature (38.95, 38.61, and 38.51 centigrade, P < 0.01), and sholder skin temperature (33.95, 33.25, 33.40 centigrade, P < 0.01), while higher milk protein (3.41, 3.72, and 3.69%, P < 0.05) and milk fat (4.08, 4.97, 4.65%, P < 0.01) percentages. Both the blood activity of CAT (increased by 12.8 and 41.0%, P < 0.01) and GSH-Px (12.6 and 40.4%, P < 0.01) of PFCL and CL cows were higher than the HS cows. Compared with HS, cooling increased the blood content of glucose, methionine, threonine, and cysta by 10.7% and 10.3% (P < 0.05), 19.0% and 9.5% (P < 0.05), 15.8% and 12.0% (P < 0.05), and 9.5% and 23.8% (P < 0.05) in PFCL and CL respectively. The results indicate that cooling rescues milk protein synthesis from depression induced by heat stress, and the potential mechanism may due to decreased oxidative stress.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84385 Watch P291 Performance of Holstein × Gyr crossbred heifers supplemented with increasing crude protein levels in the supplement. 11 M. M. D. Castro Brachiaria decumbens performance supplementation M. M. D. Castro1, P. V. F. Correia1, M. M. Ferreira1, A. F. Machado1, M. I. Marcondes2 1Universidade Federal de Vicosa, Vicosa, MG, Brazil, 22Washington State University, Pullman, WA Studies evaluating the effects of increasing levels of crude protein (CP) in supplements and their interactions with season are scarce. Thus, our aim was to evaluate the effect of providing increasing levels of CP in the supplement on performance of Holstein (1/2) × Gyr (1/2) crossbred heifers grazing intensively managed Brachiaria decumbens throughout year. The heifers were randomly assigned to 4 treatments: 3 supplements (SUP) fed at 5g/kg of body weight, plus a control group (CON). The supplement CP levels were 12, 24 and 36%. The experimental period was divided into 4 seasons: rainy, dry and transition rainy-dry and dry-rainy. Feces and pasture were collected during 4 d, at the end of each period, chromium oxide, titanium dioxide, and indigestible neutral detergent fiber were used to estimate fecal excretion, supplement and pasture intake, respectively. The data were analyzed using the PROC MIXED of the SAS (Version 9.2) in a repeated-measures scheme. There was no interaction between SUP and period. SUP animals had greater dry matter intake, metabolizable protein and energy intake, and average daily gain (ADG, P < 0.01; Table 1) than CON. Among SUP treatments, there was a positive linear effect on metabolizable protein intake (P < 0.01), a quadratic effect (concave response) on ADG and a trend of quadratic effect (concave response) on pasture intake and DMI. In summary, SUP animals had greater intake and performance than CON and the supplementation with 24% of CP showed the best results. Table 1. Intake and performance of Holstein × Gyr heifers supplemented with increasing crude protein levels
Item Treatment1 SEM P-value2
CON S12 S24 S36 T SUP L Q
Pasture (kg/d) 5.9 5.8 6.1 5.3 0.24 0.15 0.53 0.16 0.08
DM (kg/d) 5.9 6.9 7.3 6.4 0.26 <0.01 <0.01 0.13 0.06
ME (Mcal/d) 9.9 12.8 13.0 12.5 0.56 <0.01 <0.01 0.72 0.35
MP (g/d) 432.8 509.4 626.7 660.7 24.98 <0.01 <0.01 <0.01 0.02
ADG (kg/d) 0.39 0.46 0.49 0.42 0.02 <0.01 <0.01 0.19 0.04
1CON = control, S12 = 12% CP; S24 = 24% CP, S36 = 36% CP. 2T = treatments, SUP = supplemented vs non-supplemented; L = linear; Q = quadratic.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t83951 Watch P292 Effect of a feed additive blend of chestnut and quebracho extracts, and saponins on the milk malondialdehyde concentration in dairy cows. 12 L. M. Luque dairy cow malondialdehyde tannins L. M. Luque1, F. M. Masía1,2, M. B. Pedraza1, M. Larrauri1,2, J. M. Baeck3, C. Cabral3, A. R. Castillo4 1Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba, Córdoba, Argentina, 2CONICET, Córdoba, Argentina, 3Silvafeed S.A, Buenos Aires, Argentina, 4University of California, Merced, CA Malondialdehyde (MDA) is a marker used to assess the peroxidation status in dairy cows and as an indicator for mammary gland inflammation. The aim of this study was to evaluate the effect of feeding a blend of chestnut and quebracho extracts, and saponins on milk MDA concentration. Sixteen Holstein cows, balanced by milk yield and parity, were randomly assigned to 2 treatments in a 28-d crossover design (21 d of adaptation and 7-d sampling collection), control (CON), fed a basal diet composed of alfalfa hay (8.4%), corn silage (55.9%), soybean meal (20.7%), ground corn grain (13.4%), and a mineral vitamins premix (1.5%), and the blend of chestnut and quebracho extracts, and saponins (BLE) fed in the CON diet at 0.08% of DMI. The DMI and milk yield was measured daily throughout all the experimental periods. Data were analyzed using a linear mixed model with treatments, periods, and parity groups as fixed effect, and cows as random effect. The DMI was lower in BLE vs CON (25.28 vs 27.52 kg/d; P < 0.0001), no differences in milk yield were observed (BLE 37.68 and CON 37.41 milk L/d; P = 0.1716). The BLE treatment improved feed conversion efficiency (1.50 vs 1.38 milk L/Kg DMI; P < 0.0001). Milk MDA was lower in BLE compared with CON (489.45 vs 980.62 ng/mL; P < 0.001). The BLE improved the feed conversion efficiency and the peroxidative status of lactating dairy cows by reducing MDA milk contents.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t83966 Watch P293 Production costs, economic viability, and risks associated with compost-bedded pack, freestall, and drylot systems in tropical dairy farms. 13 J. De Souza Pinheiro dairy operations milk yield profitability J. De Souza Pinheiro1, M. I. Marcondes1,2 1Universidade Federal de Viçosa, Viçosa, MG, Brazil, 2Washington State University, Pullman, WA The adoption of intensive production systems, such as compost-bedded pack (CB) and freestall (FS), has increased recently in tropical regions, mainly replacing drylot system (DL). Thus, our objectives were to compare production costs, economic outcomes, and risk of dairy operations in CB, FS, and DL systems. We collected data from 960 Brazilian farms over 120 consecutive months. All costs were modeled for 2 animal production categories: milking cows and nonmilking animals. We used a regression model that included linear and quadratic parameters, and we added the production system as a fixed variable for all parameters tested with this model. Further, we simulated annual technical and economic indexes per farm. In addition, we developed a risk analysis to measure the probability of negative profit of the farms based on a 14-year historical series of milk prices. All production costs were affected by the system. Feed, medicine, sundry, and labor costs per farm per year were greater in DL farms when milk yield (MY) was greater than 3,500 L/d. The variables milk yield, assets per liter, asset turnover rate, return on assets, operational profit, profit per cow and per liter of milk variables were greater in CB and FS with high MY (>3,000 L/d). Nonetheless, DL had greatest economic indexes with a lower MY (<3,000 L/d), with lower operating costs and greater economic outcomes. The risk analysis indicated that the probability of negative profit (risk) was reduced for CB and FS as MY increased, but DL had the lowest risk with low MY levels. In conclusion, we suggest DL as the most attractive system for tropical farms with a MY between 150 and 3,000 L/d once the DL had lowest risk and greatest profit in this production scale. Despite similar outcomes for CB and FS in most of the farms, the profit per cow ($/year), assets turnover rate (%), risk (%) and expected profit ($/L) analysis indicated that CB can be recommended for farms with MY greater than 3,200 L/d, whereas based on risk (%) and expected profit ($/L) FS would be the most profitable system in dairies producing more than 8,000 L/d of milk.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84098 Watch P294 Weight at calving relative to mature body weight rather than age at first calving affects milk production in primiparous Holstein cows. 14 M. R. Lauber weight milk production age at first calving M. R. Lauber1, M. S. Akins1, P. D. Carvalho1, P. M. Fricke1 1Department of Animal and Dairy Sciences, University of Wisconsin–Madison, Madison, WI Our objective was to determine the effect of weight and age at first calving of primiparous Holstein cows on milk production (kg/d) during first lactation. Mature body weight (MBW; 686 kg) was estimated by weighing third- and fourth-lactation cows (n = 76) at 30 to 40 DIM, and weight at 30 DIM relative to MBW (%MBW) was calculated for each primiparous cow. Primiparous Holstein cows (n = 2,280) from a commercial dairy farm were grouped into quartiles (Q) by mean (±SEM) body weight (%MBW) at 30 DIM: Q1 (n = 570) 511.9 ± 0.9 kg (74.6%); Q2 (n = 570) 554.6 ± 0.4 kg (80.8%); Q3 (n = 570) 587.5 ± 0.4 kg (85.6%), and Q4 (n = 570) 641.8 ± 1.4 kg (93.5%). Age (mo) at first calving (AFC) for cows was 21 (n = 782), 22 (n = 846), or ≥23 (n = 652). Data analyzed included: milk production at 4, 8, and 12 wk and pregnancies per artificial insemination (P/AI) at first service as a nulliparous heifer. Milk production was analyzed using the GLM procedure of SAS with the fixed effects of weight quartile, AFC, and weight quartile x AFC. First service P/AI as nulliparous heifers were analyzed using the GLIMMIX procedure of SAS with the fixed effect of weight quartile. First service P/AI of nulliparous heifers decreased (P < 0.01) as weight quartile increased (71%, 60%, 53%, and 46%, respectively). The weight quartile × AFC interaction did not affect milk production at 4, 8, or 12 wk of lactation. Further, milk production did not differ (P = 0.66, P = 0.82, and P = 0.84) based on AFC at 4, 8, and 12 wk of lactation, respectively. Milk production at 4, 8, and 12 wk of lactation increased (P < 0.01) as weight quartile at 30 DIM relative to %MBW increased (wk 4: 30.6, 33.0, 33.8, and 35.9 kg/d; wk 8: 33.4, 35.9, 36.5, and 38.7 kg/d; wk 12: 34.2, 36.7, 37.3, and 39.5 kg/d). In conclusion, decreased P/AI at first service as nulliparous heifers was associated with increased weight relative to MBW at 30 DIM. Further, increased weight relative to MBW at 30 DIM rather than AFC was associated with increased milk production at 4, 8, and 12 wk in primiparous Holstein cows. Supported by NIFA USDA Hatch project 1019532.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84138 Watch P295 Effects of body condition score at calving, parity and calving season on performance of dairy cows and their offspring. 15 R. Almeida dairy calves fetal programming transition period M. Poczynek1, I. F. Carrari1, J. H. Carneiro1, G. F. M. Leão2, R. Almeida1 1Universidade Federal do Paraná, Curitiba, Paraná, Brazil, 2Negócios Leite, Castrolanda Cooperativa Agroindustrial, Castro, Paraná, Brazil The aim of this study was to evaluate the impact of body condition score (BCS) at calving, parity and calving season on the performance of dairy cows and their offspring. Data from 521 Holstein cows that calved a female calf and had their BCS evaluated at calving from a single commercial farm located at Southern Brazil were used. Cows were categorized into 5 BCS classes: class 1: < 3.0 (n = 19); class 2: 3.0 - 3.25 (n = 134); class 3: 3.5 - 3.75 (n = 160); class 4: 4.0 - 4.25 (n = 142); and class 5: > 4.25 (n = 66). Data were also categorized by calving order (primiparous and multiparous dams) and by 4 calving seasons. Variables with normal distribution were analyzed by GLM procedure of SAS, while reproductive and culling outputs were analyzed by GLIMMIX procedure of SAS. Daughters from primiparous dams were born lighter (39.1 ± 0.42 vs. 41.4 ± 0.29 kg; P < 0.01), but they had the same weight (121.5 ± 1.67 vs. 120.4 ± 1.58 kg; P = 0.20) than the daughters from multiparous cows at weaning. As expected, primiparous cows showed lower (P < 0.01) 305-d milk yields; 8,633 ± 363 vs. 10,761 ± 249 kg, respectively. Regarding calving season, cows that calved in the winter were the most productive ones and those that calved in the fall had lower milk yields (P = 0.01). Calves born in the winter were heavier at birth (P < 0.01), calved younger (P = 0.04) and produced more milk at first lactation (P = 0.03). The BCS class had an impact (P < 0.01) on calves’ birth weight; daughters from class 1 cows (BCS <3.0) were lighter (38.01 ± 1.0 kg) than the calves from class 5 cows with BCS >4.25 (41.9 ± 0.57 kg). Calves from dams with BCS <3 (Class 1) had 31.8% culling rate until weaning, while calves from cows with BCS 3.0 - 3.25 (Class 2) had 9.6% culling rate (P = 0.12). Maternal BCS had no influence in both age at first calving and reproductive performance. The results suggest that maternal and environmental factors, such as calving season and parity, besides dams’ body condition score at calving, are associated with different offspring performances.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84218 Watch P296 Screening of macroalgae species for enteric methane mitigation effect in vitro. 16 D. E. Wasson enteric methane macroalgae rumen fermentation D. E. Wasson1, H. Stefenoni1, S. Welchez1, C. Lage1, S. Räisänen1, A. Melgar1, M. Fetter1, C. Yarish2, A. N. Hristov1 1The Pennsylvania State University, University Park, PA, 2The University of Connecticut, Stamford, CT Methanogenesis and mitigation of enteric methane emissions from ruminants have been the focus of ongoing research to address livestock contribution to climate change. This experiment investigated the effects of 70 species of macroalgae on methanogenesis and rumen fermentation in vitro. Species were analyzed for their effect on cumulative gas production and composition, and volatile fatty acid (VFA) concentration. Incubations were carried out for 24 h and replicated. Rumen inoculum was collected from 2 rumen-cannulated lactating Holstein cows fed a standard 52% forage (corn silage and alfalfa haylage) and 48% concentrate feeds diet. Dried and ground total mixed ration fed to the donor cows was used as substrate in the incubations at 0.01% (wt/vol) and macroalgae were included in the feed mix at 2.0% (dry matter basis). Negative control (total mixed ration alone) was also included in each incubation in triplicate. Gas production was continuously monitored with an automated gas production system and headspace samples were collected at 12 h and 24 h and analyzed for methane concentration. VFA concentrations were analyzed at 24 h. Data were analyzed by incubation set with the MIXED procedure of SAS with treatment in the model. Methane production (per unit of feed substrate) was decreased (P ≤ 0.001) 99% by Asparagopsis taxiformis (AT). Mastocarpus papillatus and Sargassum fluitans increased (P ≤ 0.05) methane production 11 and 10%, respectively. Total VFA concentration was decreased (P ≤ 0.05) 5 to 8% by 3 species in addition to AT which reduced (P = 0.03) total VFA by 10%. Acetate proportion in total VFA was decreased (P < 0.001) 9% by AT, along with an increase (P < 0.001) in propionate by 14%. Propionate proportion was also decreased (P ≤ 0.05) by Laminaria farlowii and Ulva spp. by 9%. AT increased (P < 0.001) butyrate and valerate molar proportions by 7 and 24%, respectively, whereas 3 macroalgae species decreased (P ≤ 0.05) butyrate 3 to 5%. In this screening experiment, AT was the only macroalgae that produced a large reduction in enteric methane emission in vitro.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84222 Watch P297 Effects of dietary betaine on body temperature indices, performance, and metabolism of dairy heifer calves during summer hot conditions. 17 M. Al-Qaisi heat stress betaine dairy calves M. Al-Qaisi1, M. Abuajamieh1, M. A. Abdel-Majeed1, M. A. Alnimer1, R. Irshaid1, A. Abdelqader1, H. H. Titi1, A. A. Al-Fataftah1, L. H. Baumgard2 1Department of Animal Production, The University of Jordan, Amman, Jordan, 2Department of Animal Science, Iowa State University, Ames, IA Study objectives were to evaluate the effects of supplementing dietary betaine on body temperature indices, productive performance, and metabolism in hyperthermic dairy heifer calves. Fourteen Holstein heifer calves (4 mo old) were individually housed and randomly assigned to 1 of 2 dietary treatments: 1) a control diet (CON; n = 7) or 2) a control diet supplemented with 21 g/d of natural betaine (BET; n = 7; Betafin S4; Danisco Animal Nutrition, UK) top-dressed once daily. The trial lasted for 28 d during which all animals were subjected to natural cyclic heat stress (HS) conditions (26.1 to 39.2°C; 73.2 to 84.0 THI). Rectal temperature (Tr) and respiration rate (RR) were measured twice daily (0700 and 1500 h), while dry matter intake (DMI) was measured once daily (0800 h). Hip height (HH), hip width (HW), and body length (BL) were measured on d 7, 14, 21, and 28 of the study. In addition, blood samples (collected from jugular vein) were analyzed for metabolites and complete blood count on d 7, 14, 21, and 28. Effects of treatment, day, and treatment × day were analyzed using PROC MIXED. Relative to CON, BET supplementation decreased Tr on d 23 of the experiment (39.6 vs. 39.3°C; P = 0.04). On the other hand, RR was similar between dietary treatments (P = 0.73). Feeding BET did not affect DMI, HH, HW, and BL compared with CON during HS conditions (P ≥ 0.35). Furthermore, circulating glucose, albumin, and triglycerides were similar between dietary treatments (P ≥ 0.55). Compared with CON, BET supplementation did not change circulating white blood cells, neutrophils, lymphocytes, and hematocrit during HS conditions (P ≥ 0.17). In summary, BET supplementation had little to no effects on the metrics measured in this experiment.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84262 Watch P298 Dairy cattle body weight estimation using surveillance cameras. 18 J. P. Boerman video analytics body weight automation H. Liu1, M. Ramesh1, J. P. Boerman2, A. R. Reibman1 1School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, 2Department of Animal Sciences, Purdue University, West Lafayette, IN Accurate body weight (BW) estimation of dairy cattle provides important information about animal health and welfare status. Observations of BW changes in dairy cattle may be used to assess both nutrient and health status of individual animals as well as populations of animals. To obtain BW information regularly, automated low-cost methods that do not intrude on normal farm operations are essential. Our objective was to utilize video images and video analytics to localize and estimate BW of animals walking from the milking parlor to freestall pens. We measured the BW (655 ± 77.1 kg; range 458 - 876 kg) and recorded the age and days in milk of lactating dairy cattle (n = 168) over 5 time points to use as our reference population directly after exiting the milking parlor. Video from 2 synchronized Ubiquiti surveillance cameras was automatically recorded to a removable hard drive as the cows walked. Each video was then analyzed using our video analytics system that combines a deep-learning module with domain knowledge to localize the cow and the location of key body points on the dairy cow, despite challenges such as occluding fences and a distracting background. From this, features were automatically extracted about the shape of the cow, including side-view body length, diagonal length, height, and area as well as front-view body width and area. The prediction model is trained with videos from 4 d and evaluated on clips from d 5. We repeat this process to train 5 different models and test each with unseen data. Three regression models were applied to estimate bodyweight of dairy cattle from these features and compared: linear regression, support vector regression with radial basis function kernel, and a random forest (RF) regressor. The RF performed best when applied to videos captured within the constraints of an operating dairy farm on 5 distinct days, demonstrating a root mean squared prediction error of 34 kg, representing less than 6% error. A model with only the front view performs better than the one with only the side view; combining both views and adding age as a feature achieves the best performance.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84423   P300 How Brown Swiss milk production and quality can be affected by heat waves. 19 A. Maggiolino heat stress heat waves Brown Swiss A. Maggiolino1, V. Landi1, N. Bartolomeo2, U. Bernabucci3, A. Rossoni4, P. De Palo1 1Department of Veterinary Medicine, Bari, Italy, 2Medical Statistics, Department of Biomedical Science and Human Oncology, Bari, Italy, 3Department of Agriculture and Forest Sciences, Viterbo, Italy, 4Italian Brown Breeders Association, Bussolengo, Italy The temperature-humidity index (THI) is effective in estimating effects of the environment on dairy cows’ efficiency and welfare. Heat waves (HW) have been entered as concept of long duration of warm environmental climatic conditions, able to affect dairy cows. The present study aims to estimate the effect of HW on the Italian Brown Swiss (IBS) population production efficiency. The definition of HW was adapted to the study’s aims considering it as a period lasting from 2 to 5 consecutive days with a THI (minimum, mean and maximum) over the known threshold for the IBS population. The aim of this study was to estimate the effects of HW of different duration (from 2 to 5 d) in IBS, considering some production traits: fat-corrected milk (FCM) yield, protein and fat yield, protein and fat concentration. Ten years data from test-day record system at national level were considered and merged with data from 76 weather stations. The data set was subdivided according to parity in 4 categories: first, second, third, and ≥fourth parity. A mixed-effects model for repeated measures was applied to evaluate the effects of HW on each production trait. Month, parity class and DIM class were considered as fixed effects, while herd and year were considered as random effects. When recorded THI exceeded the maximum THI threshold, cows yielded from 32g (2 d) to 40 g (5 d) of daily protein less (P < 0.0001). When THI exceeded the minimum THI threshold, cows produced from 30g (2 d) to 32 g (5 d) less (P < 0.0001) of daily protein yield. The FCM yield was lower in cows subjected to HW over the maximum THI, worsening in relation to the HW duration (from 554g for a duration of 2 d to 850g at 5 d lasting HW; P < 0.0001). It is clear how HW affect efficiency in this breed, although it is considered more tolerant than others. Moreover, although from a physiological perspective minimum and maximum THI values have a different meaning, both showed to be equally effective in estimating how HW affect milk production traits in IBS.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84401 Watch P301 A bi-seasonal evaluation of somatic cell count, production measures, hygiene scores, and bedding cultures of Holstein cows housed in a compost-bedded pack barn. 20 J. Carter SCC hygiene compost-bedded pack barn G. Mould1, M. Hollis1, J. Carter1 1Middle Tennessee State University, Murfreesboro, TN Cows housed on compost-bedded pack barns are known to exhibit reduced somatic cell counts (SCC) compared with other types of housing. This study aimed to evaluate the relationship between SCC (transformed to somatic cell score (SCS)), milk yield (MY), conductivity (COND), activity behaviors (avg. activity (AA), avg. rest bout (RB), and avg. rest time (RT)), milk and bedding bacterial cultures (BC), and hygiene scores (HS) of cows. Holstein cows (n = 18) were monitored for 28 d during fall and spring seasons. Cows were sorted into high (H) and low (L) groups based on SCC from the most recent DHIA herd report of each season. Weekly milk samples were collected as a sterile composite from all 4 quarters and measured for SCC using the DeLeval Cell Counter. Milk samples testing > 250,000 cells/mL were cultured using a Tri-plate agar of Factor, MacConkey, and Focus media (University of Minnesota Easy Culture) for identification of Staphylococcus species, Streptococcus species, or gram-negative bacteria. MY, COND, AA, RB, and RT were measured daily using the Afimilk parlor system and averaged by week. Cows were scored weekly for udder cleanliness (1 = very clean to 4 = very dirty; Cook, 2002) to assess exposure to pathogens. Bedding samples were taken at the beginning and end of the project and analyzed for bacterial counts. Statistical analysis of SCS, MY, COND, AA, RB, and RT with main effects of season and treatment group were conducted using the MIXED procedure in SAS (v9.4). Analysis of BC and HS incidence were evaluated using the FREQ procedure in SAS (v9.4). High cows had lower MY (P = 0.0001), higher SCS (P = 0.0003) and lower AA (P < 0.0001) than L cows. Seasonally, cows exhibited lower MY in the fall (P < 0.0001) and higher SCS (P = 0.0003), AA (P < 0.0001) and RB (P < 0.0001). There were no significant differences in HS. Cows in the H group were more frequently cultured (52.0% vs. 10.7%). These results insinuate SCS and season contribute to cow productivity and udder health.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84430 Watch P302 Assessing the response of ruminal bacterial and fungal microbiota to whole-rumen contents exchange in dairy cows. 21 M. S. Cox microbiota rumen contents exchange milk production efficiency M. S. Cox1,2, C. L. DeBlois1, G. Suen1,2 1Department of Bacteriology, University of Wisconsin–Madison, Madison, WI, 2Microbiology Doctoral Training Program, University of Wisconsin–Madison, Madison, WI With the advent of advanced methods for characterizing microbial communities, efforts are underway to improve milk production efficiency (MPE) by manipulating the rumen microbiome. Our previous work demonstrated that a total exchange of whole-rumen contents between pairs of lactating Holstein dairy cows of disparate MPE resulted in a reversal of MPE status for ~10 d. This was accompanied by a ~10-d persistence of the introduced bacterial community in the recipient rumen. However, this work did not include in-depth analysis of the microbial community response or interrogation of specific taxa correlating to production metrics. In this work, we sought to better understand the response of rumen communities to this exchange protocol, including consideration of the rumen fungi. Rumen samples were collected from 8 d before 56 d following the exchange and were subjected to 16S rRNA and ITS amplicon sequencing to assess bacterial and fungal community composition, respectively. Our results show that the rumen fungal community did not differ between hosts of disparate efficiency before the exchange (permutational multivariate ANOVA, P > 0.05), and no change in fungal community structure was observed over the time course (permutational multivariate ANOVA, P > 0.05). Rumen bacterial communities lost correlation network connectivity early in the exchange (Kruskall-Wallis, P < 0.05) and were able to recover in high-efficiency cows, but not in low-efficiency cows, suggesting lower resilience and elasticity in bacterial communities associated with lower efficiency. Spearman correlations of microbial taxa to production metrics identified one fungal operational taxonomic unit (OTU) in the genus Neocallimastix that correlated positively to energy-corrected milk production (P = 0.025) and MPE (P < 0.001). Within the highly abundant rumen fluid associated genus Prevotella, Prevotella_1 was found to be more abundant in high-efficiency cows and Prevotella_7 more abundant in low-efficiency cows (Kruskall-Wallis, P < 0.05), though phenotypic differences between these taxa are not known. Overall, our results suggest that the rumen bacterial community is a primary microbial driver of MPE, that ruminal fungal community variation may not significantly contribute to variation in MPE, and that more work is needed to better understand the functional roles of specific ruminal community members in modulating MPE.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84756 Watch P303 Fatty acid composition changes with stage of lactation and subclinical mastitis. 22 S. C. Allen de novo fatty acids somatic cell count mastitis S. C. Allen1, D. M. Barbano2, B. E. Faulkner1, D. H. Poole1, M. A. Drake1, J. Odle1, S. H. Ward1 1North Carolina State University, Raleigh, NC, 2Cornell University, Ithaca, NY The objectives of this study were to evaluate the change in milk fatty acid (FA) composition throughout lactation and during periods of elevated somatic cell count (SCC) in Holstein (HO) and Jersey (JE) cows. Data were collected from April 2019 to March 2020. Cows were classified by stage of lactation: transition (0 to 14 d in milk (DIM), early (15 to 120 DIM), mid (121 to 140 DIM), and late lactation (>140 DIM). Milk samples were collected weekly and analyzed for FA composition (de novo, DNFA; mixed origin, MOFA; and preformed, PRFA). Cows were classified as having subclinical mastitis (SCM, SCC >200,000 cells/mL) or normal milk (NORM, SCC <200,000 cells/mL) at each milk sampling. Data were analyzed using PROC MIXED. Cow classification and DIM were considered independent variables, and all other variables were dependent. Significance was declared when P < 0.05. Both JE and HO cows increased milk production between the transition period and early lactation, and milk yield decreased as lactation progressed. Fat decreased after the transition period and subsequently increased throughout lactation in HO cows. Jersey cows had similar fat percent between early and mid lactation that declined throughout lactation. Fat yield followed the trend of milk yield in both breeds. Proportion of DNFA increased between the transition period and early lactation while proportion of PRFA decreased among both breeds (4.13 and 4.70% increase in g/100 g FA for HO and JE cows, respectively). Milk yield was reduced during SCM for both breeds (2.38 and 3.19 kg/d reduction for HO and JE cows, respectively), however milk fat percent was unaffected in HO cows and increased in JE cows during SCM. Milk from HO NORM cows tended to be greater in MOFA (g/100 g fat) compared with SCM cows. No other FA variables were affected by classification of HO cows. Both DNFA and MOFA (g/100 g milk) were greater in JE SCM cows compared with NORM cows and PRFA (g/100 g FA) was greater in JE NORM cows compared with SCM. Fatty Acid content may be indicative of energy status of cows, particularly in the transition period, and could be used to make targeted management decisions.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84524 Watch P304 The impact of season on daily rhythms of body temperature and milk synthesis. 23 K. Kamau seasonality daily rhythms body temperature K. Kamau1, R. Bomberger2, K. Harvatine2, I. Salfer1 1University of Minnesota, St. Paul, MN, 2The Pennsylvania State University, University Park, PA Dairy cows, like other animals, possess both seasonal and circadian rhythms that coordinate behavior and physiology with the external environment. Evidence from dairy farms suggests that the circadian rhythm of body temperature and cow behavior differs among seasons. The objective of the experiment was to examine the impact of season on daily rhythms of body temperature and milk synthesis in dairy cows. We hypothesize that the rhythm of body temperature and the morning to evening ratio of milk yield will differ by season with the greatest amplitude occurring in the summer and lowest amplitude occurring in the winter. The experiment utilized 147 lactating Holstein cows in a randomized block design with data collected in 3 1-wk blocks at the beginning of each of the 4 seasons (n = 30 to 44 cows/season). Body temperature was collected every 10 min using indwelling vaginal temperature probes and activity. Milk yield was collected at 0500 and 1700 h, and the ratio of AM to PM milk yield and components was used as a proxy for the daily rhythm of milk synthesis. Daily rhythms of body temperature and activity were determined by fitting data to the linear form of cosine functions with a 24 h period in R ver. 4.0.2. A zero-amplitude test was used to determine the fit of daily rhythms and cosine rhythmometry was used to compare daily rhythms among seasons, and to characterize annual rhythms of milk yield and components. Responses were compared by using a mixed-effects model with the fixed effect of season and the random effect of block nested within season using the nlme package of R. Body temperature fit a rhythm in fall, spring, and summer but not winter. Spring had a lower amplitude rhythm than fall and summer (P < 0.05). The peak of the daily rhythm in summer (0025) occurred 2 and 4 h later than spring and fall, respectively (P < 0.05). Season tended to affect the AM:PM ratio of milk yield (P = 0.09). Season did not affect the AM:PM ratio of fat and protein yield or concentration (P > 0.10). Results suggest that season impacts daily rhythms of body temperature but has minimal effects on daily rhythms of milk yield.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84721 Watch P305 Effects of dietary butyrate supplementation and oral nonsteroidal anti-inflammatory drug administration on performance, inflammation, and metabolites in transition dairy cows. 24 L. E. Engelking inflammation metabolites transition cow L. E. Engelking1, D. J. Ambrose1, M. Oba1 1University of Alberta, Edmonton, AB, Canada The objective was to evaluate the effects of dietary butyrate supplementation and oral nonsteroidal anti-inflammatory drug (NSAID) administration on milk production, feed intake, serum inflammatory markers, and plasma metabolites in transition cows. Eighty-three Holstein cows were blocked by parity and calving date and randomly assigned to isoenergetic diets containing calcium butyrate at 1.42% of diet dry matter (DM) or control supplement (1.04% palm fat and 0.38% calcium carbonate of diet DM). The close-up diet contained 13.5% starch and 43.0% neutral detergent fiber, and the postpartum diet contained 22.4% starch and 34.6% neutral detergent fiber on a DM basis. Diets were fed from 28 d before expected calving to 24 d after calving. Cows received an oral NSAID (1 mL/15 kg bodyweight Meloxicam in carrier solution) or a placebo (1 mL/15 kg bodyweight food dye in carrier solution) at 12 to 24 h after calving. Butyrate supplementation did not affect milk yield (P = 0.86) or serum amyloid A (P = 0.45) and haptoglobin concentrations (P = 0.67). Similarly, NSAID administration did not affect milk yield (P = 0.39) or serum amyloid A (P = 0.49) and haptoglobin concentrations (P = 0.85). Cows fed butyrate tended to have lower milk crude protein yield compared with cows fed control diet (1.21 vs. 1.27 kg/d; P = 0.06). Cows fed butyrate also had higher β-hydroxybutyrate (8.30 vs. 6.81 mg/dL; P = 0.03) and tended to have higher plasma free fatty acids (524 vs. 365 μEq/L; P = 0.06) at 4 d before calving, but tended to have lower plasma free fatty acids (825 vs. 993 μEq/L; P = 0.07) on d 7 after calving compared with cows fed the control diet. A parity by treatment interaction was observed for DM intake (P = 0.03), where DM intake was lower for the NSAID treatment compared with the placebo (16.7 vs. 19.2 kg/d; P = 0.02) in multiparous cows fed the control diet. These results suggest dietary butyrate supplementation and oral NSAID administration may not have overall positive effects on production performance of transition dairy cows.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84720 Watch P306 Dairy producer attitudes towards calf rearing. 25 E. R. Russell calf rearing weaning producer views E. R. Russell1, M. A. G. von Keyserlingk1, D. M. Weary1 1The University of British Columbia, Vancouver, BC, Canada Rearing replacement stock is integral to dairy farming. The calf rearing phase, from birth to weaning, has received considerable attention with much of the biological research focusing on housing and feeding, including the best practices to wean calves. Despite this body of research, there is tremendous variation in calf management practices. Little research has examined how dairy producers view calf rearing. Therefore, the aim of this study was to investigate the attitudes and perceptions of Western Canadian dairy producers toward calf rearing, with a focus on calf weaning and the characterization of weaning success. Eighteen participants were interviewed from British Columbia, Manitoba, and Alberta; participants were identified as the farm manager or owner (n = 15) and primary calf caretaker (n = 3). Interviews were semi-structured and conducted between July and September 2020. Participants were asked to describe their calf rearing and weaning practices, and what they viewed as successes and challenges in rearing and weaning calves. Interviews were recorded, transcribed and underwent a thematic analysis that resulted in a codebook and the identification of major themes. Four major themes were identified: (1) reliance on calf-based factors (e.g., health, growth and behavior); (2) personal beliefs and vested interest (e.g., ease, consistency and habit); (3) perceived environmental influences (e.g., facilities, environment and equipment); (4) characterization of weaning success. These results provide insight into how dairy producers view calf rearing and weaning; and can be used to design future applied research and extension projects to better address producer perceptions, beliefs, and concerns.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84700 Watch P307 Adoption of precision technologies by Brazilian dairy farms: The farmer’s perception. 26 L. G. R. Pereira sensors smart farm survey R. R. Silvi1, L. G. R. Pereira2,5, C. A. V. Paiva2, T. R. Tomich2, V. T. Amorim3, S. G. Coelho3, J. P. Sacramento4, M. M. Campos2, F. S. Machado2, R. E. P. Ferreira5, J. R. R. Dorea5 1Universidade Estadual de Santa Cruz, Ilhéus, BA, Brazil, 2Brazilian Agricultural Research Corporation–Embrapa Dairy Cattle, Juiz de Fora, MG, Brazil, 3Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil, 4Universidade Federal de São João Del Rei, São João Del Rei, MG, Brazil, 5Department of Animal and Dairy Sciences, University of Wisconsin, Madison, WI The use of precision farming technologies, such as milking robots, automated calf feeders, wearable sensors, and others, has significantly increased in dairy operations over the last few years. The growing interest in farming technologies to reduce labor, maximize productivity, and increase profitability is becoming noticeable in several countries, including Brazil. Information regarding technology adoption, perception, and effectiveness in dairy farms could shed light on challenges that need to be addressed by scientific research and extension programs. The objective of this study was to characterize Brazilian dairy farms based on technology usage. Factors as willingness to invest in precision technologies, adoption of sensor systems, farmer profile, farm characteristics, and production indexes were investigated in 378 dairy farms, located in Brazil. A survey with 22 questions was developed and distributed via Google Forms, from July 2018 to July 2020. The most productive dairy farms were located in the south and southeast of the country. The most frequent technologies adopted by producers were automatic weight and milk flow systems (31.7%), smart gate (14.5%); sensor systems to detect mastitis (8.4%), cow activity (7.1%), and body temperature (7.9%). Producers indicated “available technical support” (mean; σ2) (4.55; 0.80) as the most important criterion, followed by “return on investment” (4.48; 0.80), “user-friendly” (4.39; 0.88), “upfront investment cost” (4.36; 0.81) and “compatibility with the farm, management software” (4.2; 1,02). The most important factors precluding investment in precision dairy technologies were: the need for investment in other sectors of the farm (36%), uncertainty of return on investment (24%), and lack of integration with other farm systems and software (11%). Farmers indicated that the most useful technologies were: automatic weight and milk flow systems (mean; σ2) (4.05; 1.66); sensor systems for mastitis detection (4.00; 1.57); automatic feeding systems (3.50; 2.05); cow activity (3.45; 1.95), and in-line milk analyzers (3.45; 1.95). Overall, the concerns related to data integration, return on investment and user-friendly technologies are similar to other dairy farms located in other countries. Increasing available technical support for sensing technology can potentially have a positive impact on technology adoption.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84686 Watch P308 Effect of propylene glycol and vitamin B12 treatment on concurrent subclinical hyperketonemia and hypoglycemia in early postpartum dairy cows. 27 A. Hubner hyperketonemia hypoglycemia propylene glycol A. Hubner1, I. F. Canisso1, P. M. Peixoto1, W. M. Coelho Jr.1, L. Ribeiro1, B. M. Aldridge1, F. S. Lima2 1Department of Veterinary Clinical Medicine, University of Illinois, Urbana, IL, 2Department of Population Health and Reproduction, University of California, Davis, Davis, CA Cow-side β-hydroxybutyrate (BHB) testing is a convenient way to screen early postpartum cows for subclinical hyperketonemia (HK). However, the large proportion of cows needing treatment is a roadblock for widespread implementation of this diagnosis strategy. Potential integration of concurrent metabolic cow-side testing could target treatment to cows with the largest benefits from treatment and improve cow-side diagnosis and treatment implementation in dairy farms. Glucose is a relevant metabolite altered during the early postpartum period that can be tested using a HK cow-side device. We hypothesized that cows with concurrent HK (BHB ≥1.2 mmol/L) and hypoglycemia (HG, glucose ≤2.2 mmol/L) would have less postpartum disease and greater milk production than cows with HK or HG after treatment. Cows (n = 2,651) from 5 commercial dairies were tested between 3 and 9 d in milk using a previously validated hand-held device (Precision Xtra, Abbott). Cows were categorized into 3 groups: HK only (HK = 230), HG only (HG = 171), and concurrent HK and HG (HKHG = 201). Cows in each group were randomly assigned to receive 10,000 µg Vitamin B12 on d 1 + 5 d of 300 mL oral propylene glycol or to remain untreated. Statistical analysis was performed with JMP Pro 15 (SAS Institute Inc.). There were no differences (P > 0.05) between treatment and control for the 3 metabolic groups for cows diagnosed with LDA, mastitis, and metritis. Treatment reduced [FSdL1] (P = 0.04) the proportion of cows subsequently diagnosed with clinical ketosis in the HG group (HG-Treat, 2.6 ± 2.4%; HG-control 11.8 ± 2.3%). [FSdL2] Energy-corrected milk (ECM) for the first 3 DHIA tests was increased [FSdL3] (P = 0.02) by treatment in the HK group (HK-treat, 45.4 ± 0.9 kg; HK-control, 42.4 ± 1.0 kg) but not within the other 2 groups. In conclusion, treatment reduced clinical ketosis in HG cows and increased ECM in HK, but no benefits of treatment were found for cows with concurrent HK and HG.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84683 Watch P309 Association of metabolic status with postpartum health disorders diagnosed by farm personnel. 28 A. Hubner hyperketonemia hypoglycemia postpartum health A. Hubner1, I. F. Canisso1, P. M. Peixoto1, W. M. Coelho Jr.1, L. Ribeiro1, B. M. Aldridge1, F. S. Lima2 1Department of Veterinary Clinical Medicine, University of Illinois, Urbana, IL, 2Department of Population Health and Reproduction, University of California, Davis, Davis, CA We hypothesized that cows with concurrent hyperketonemia (HK) and hypoglycemia (HG) would have greater incidence diseases diagnosed by farm personnel than cows without concurrent HK and HG. Cows (n = 2,651) had blood samples collected between 3 and 9 d postpartum (DPP) and whole-blood β-hydroxybutyrate (BHB) and glucose were measured using a cow-side device validated in dairy cows (Precision Xtra, Abbott). Hyperketonemia was defined as BHB ≥1.2 mmol/L and hypoglycemia was defined as glucose ≤2.2 mmol/L. Cows were categorized into 4 groups: no HK and HG (Norm, n = 1996), HK only (HK, n = 260), HG only (HG, n = 181), and concurrent HK and HG (HKHG, n = 214). Statistical analysis was carried out using JMP Pro 15 (SAS Institute Inc.), and the on-farm recorded health events clinical ketosis (CK), clinical metritis (CM), left displaced abomasum (DA), mastitis (MAST), culled (sold + dead), and any disease event (AD), which was a combination of all individual disease events, were evaluated. Cows in the HK group were more likely (P = 0.02) to be diagnosed with any disease when compared with cows in the Norm group (HK, 57.8 ± 3.6%, HKHG, 56.4 ± 3.9%, HG, 50.9 ± 4.3%, Norm 43.7 ± 1.6%), Cows in the HK and HKHG were more likely (P < 0.03) to be diagnosed with CK than cows in the Norm group (HK, 9.9 ± 1.5%, HKHG, 15.2 ± 1.6%, HG, 7.5 ± 1.8%, Norm 2.3 ± 0.6%), cows in the HKHG group were more likely (P < 0.03) to be diagnosed with LDA than cows in the HK or Norm group (HK, 4.3 ± 1.0%, HKHG, 7.8 ± 1.1%, HG, 5.0 ± 1.2%, Norm 0.7 ± 0.4%), cows in the HK group were more likely (P < 0.05)to be culled than cows in any of the other 3 groups (HK, 15.8 ± 2.0%, HKHG, 11.2 ± 2.2%, HG, 9.9 ± 2.3%, Norm 6.1 ± 1.0%). The incidence of CM was greater (P < 0.02) in HK than the other groups (HK, 27.6 ± 2.4%, HKHG, 17.7 ± 2.6%, HG, 5.6 ± 2.9%, Norm 10.8 ± 1.1%). Cows in the HKHG had a lower incidence (P = 0.01) of MAST than Norm cows (HK, 21.6 ± 3.0%, HKHG, 17.2 ± 3.2%, HG, 26.7 ± 3.6%, Norm 21.3 ± 1.3%). In conclusion cows with HKHG were more likely to be diagnosed with LDA compared with HK, however the HKHG cows were less likely than HK cows to be diagnosed with metritis.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84679 Watch P310 Economics of fixed-timed artificial insemination with or without sexed semen in a high-producing, pasture-based dairy production system in Ireland. 29 D. P. Walsh fixed-timed artificial insemination sexed semen stochastic model D. P. Walsh1, P. Lonergan1, A. G. Fahey1, M. Wallace1 1School of Agriculture and Food Science, University College Dublin, Dublin, Ireland Fixed-timed AI (FTAI) can increase the pregnancy rate per AI (P/AI) and improve the calving profile in seasonal pasture-based systems. Sexed semen has the potential to increase genetic gain of dairy herds through increased selection intensity on the dam side. However, the reduced P/AI of sexed to unsorted semen increases the costs associated with breeding and culling. FTAI can be employed as a complementary technology to sexed semen use by inducing ovulation in a large proportion of cows, and thus optimizing the P/AI. A stochastic simulation model was used to evaluate the impacts of FTAI on the distribution of economic profit including genetic gain. A 2 × 2 scenario design evaluated FTAI with either conventional unsorted (TCONV) or sexed (TSEX) semen and treatment applied to heifers only (H) or both heifers and cows (HC). The scenarios were compared with a baseline (BASE) in which heifers and cows were inseminated with unsorted semen after estrus detection. The mean (±SD) profit advantage (ΔPROFIT) over the baseline for TCONV-H, TCONV-HC, TSEX-H and TSEX-HC scenarios were €5.81/cow ± 5.76, €35.84/cow ± 19.28, €15.07/cow ± 8.29 and €63.25/cow ± 40.91, respectively. Combined application of both technologies has been shown to return a greater ΔPROFIT on average compared with that achievable from FTAI alone. However, the risk of not returning a ΔPROFIT varied across the scenarios with higher risk in TCONV-H and TSEX-HC. Specifically, TCONV-H and TSEX-HC had respectively a 16% and 8% chance of not returning a positive ΔPROFIT. The range in ΔPROFIT was most sensitive to the 21-d P/AI followed by genetic gain, calf and cull cow prices. FTAI with unsorted or sexed semen can increase profitability of pasture-based, dairy production systems but risk factors such as lower P/AI mean that its adoption is most suitable in herds with good baseline fertility.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84673 Watch P311 Edge processing approaches for behavior classification of grazing cows. 30 B. R. dos Reis grazing cow behavior detection sensor B. R. dos Reis1, D. Fuka2, Z. Easton2, R. White1 1Department of Animal Science, Virginia Tech, Blacksburg, VA, 2Department of Biological Systems Engineering, Virginia Tech, Blacksburg, VA Reliable, remote, real-time behavioral monitoring for pasture-based production has potential to improve efficiency and precision of management without increasing labor costs or requiring changes to housing systems. In confinement operations, behavioral monitoring using inertial measurement unit (IMU) sensors has expanded; however, real-time behavioral classification using IMU sensors in pasture-based settings has been limited due the lack of networking access, low-power supplies and the price associated with acquiring these devices. In order for IMU sensors to be effective in pasture settings, the computational load for behavioral classification must be moved to the network edge to minimize the energetic cost of transmitting data from the cow to the farm hub. Our objective was to explore behavioral-classification techniques suitable for edge processing to identify grazing, walking, laying, and standing behaviors from an open source, low-cost wearable IMU sensor placed on extensively grazed cows. Ten Angus crossbred cows were fitted with sensors for 24 h. Visual behavior observations were used as ground truth and were recorded each minute. Sensor data were logged to local storage at 100 Hz. Simplistic edge processing techniques based on ranges, means, and linear associations were insufficient to reliably classify behaviors (<10% precision). A random forest algorithm was capable of distinguishing among behaviors with improved accuracy and precision for grazing (83% sensitivity, 92% specificity, 87% precision, 89% accuracy), laying (87% sensitivity, 91% specificity, 87% precision, 89% accuracy), standing (65% sensitivity, 92% specificity, 68% precision, 87% accuracy), and walking (58% sensitivity, 95% specificity, 9% precision, 96% accuracy). As microprocessors continue to advance and become more capable of running machine learning algorithms, edge processing using random forests or similar approaches may help improve the usability of IMU sensors for behavioral monitoring in extensive production systems.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84663 Watch P312 Evaluation of a protocol for the treatment of metritis in a northwest Texas dairy herd. 31 J. A. Garcia Buitrago metritis open days services per conception J. A. Garcia Buitrago1, G. R. Hagevoort1, E. R. Ellen2, E. A. Taylor3 1Department of Animal and Ranch Sciences, Dairy Extension Program, New Mexico State University, Clovis, NM, 2Department of Animal Science, Texas A&M University, College Station, TX, 3Department of Veterinary Pathobiology, Texas A&M University, College Station, TX To evaluate a protocol to treat of metritis in a dairy herd in the Texas Panhandle, reproductive records of Holstein-Friesian cows calving in the spring and fall of 2017 were analyzed. Thirty-three cows (16 cows in spring and 17 in fall) were diagnosed with metritis in the first postpartum week and the they were treated with a protocol of 2 doses of ceftiofur crystalline-free acid (3.3 mL/ 100 kg BW): one on the day of the diagnosis, and another 72 h later. Each treated cow was assigned a control cow calved and examined on the same day. After a 56-d voluntary waiting period the cows were enrolled in an Ovsynch protocol and subsequently inseminated. All the service dates, pregnancy confirmation date, and results were registered. The conception rate for each group (CR), open days (OD) and the number of services per conception (SC) were calculated. Records were classified by group (GR): treated (T), control (C); calving season (CS): spring (S), fall (F); and lactation (LT): primiparous (P), multiparous (M). Two-sample t-tests were performed for OD and SC by each of the effects GR, CS and LT using the Minitab statistical software. Results showed CR of 78.8% for GR-T and 87.9% for GR-C. OD general mean was 101 ± 47 d, the OD means were 89 ± 32 and 114.2 ± 57 d for C and T; 105 ± 61 and 99 ± 40 d for M and P; 81 ± 20 and 118 ± 57 d for F and S groups respectively. SC general mean was 2.1 ± 1.3; SPC means were 1.9 and 2.4 for C and T; 2.2 and 2.1 for M and P; 1.6 and 2.5 for F and S groups respectively. Despite that Group’s CR was greater for the C group the statistics results pointed that there is not enough evidence to conclude that the OD and SC mean differ by a significance level of 0.05 due to the effect of any of the variables considered in this study. These results suggest that the cows treated with this metritis protocol had a reproductive performance similar to that of the control group.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84656 Watch P313 Assessing best herd management practices in commercial dairy farms using on-farm records. 32 D. Warner farm management dairy herd improvement decision support D. Warner1, R. Lacroix1, J. Gunn1, D. E. Santschi1 1Lactanet, Sainte-Anne-de-Bellevue, QC, Canada A major challenge for extension services involves the large variability among dairy herds and, thus, identifying the main factors explaining herd performance. The objective of this observational study was to examine the association of herd-level management factors and energy-corrected milk (ECM) production across 71 commercial Holstein herds in New Brunswick, Canada. Enrolled farms were equipped with a parlor (n = 31), pipeline (24) or automatic (16) milking system. Herd performance records from September to December 2020 were assembled from a DHI database and farm practices were collected through a survey completed by advisors. Herds were segmented based on annual ECM production using k-means clustering. Herd performance and farm practices were assessed for clusters using, respectively, a linear mixed model and a generalized linear mixed model approach with milking system as random effect. Multivariate analysis of clusters was conducted using decision tree induction with the aim to help with the decision-making. Three herd clusters differing in ECM (P < 0.05) were identified as low (8,374 ± 593 kg ECM per year; mean ± SD), medium (10,303 ± 573 kg) and high (12,263 ± 773 kg) producing cluster. The herd genetic potential for ECM did not differ (P > 0.05) among clusters. Decision tree induction allowed to highlight the importance for reproduction indicators, with the high performing cluster explained by a good transition (Transition Cow Index), lower age at first calving, lower BHB, lower turnover and lower calving interval. A preliminary analysis of the survey results suggested that certain management practices were associated with clusters. Particularly, the low performing cluster had a greater probability of an annual trimming frequency of ≤ 1 (P < 0.05) and of smooth alley surface (P < 0.07). These results suggest that management practices influencing performance can be identified to highlight specific opportunities for improvements.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84652 Watch P314 Characterization of metabolic profile of Holstein dairy cows diagnosed with concurrent hyperketonemia and hypoglycemia. 33 A. Hubner hyperketonemia hypoglycemia metabolites A. Hubner1, I. F. Canisso1, P. M. Peixoto1, W. M. Coelho Jr.1, L. Ribeiro1, B. M. Aldridge1, P. Menta2, V. S. Machado2, F. S. Lima3 1Department of Veterinary Clinical Medicine, University of Illinois, Urbana, IL, 2Department of Veterinary Sciences, Texas Tech University, Lubbock, TX, 3Department of Population Health and Reproduction, University of California, Davis, Davis, CA The objective of this study was to characterize the metabolic profile of cows diagnosed with hyperketonemia (HK, BHB ≥1.2 mmol/L) and hypoglycemia (HG, glucose ≤2.2 mmol/L). Glucose and BHB concentrations in whole blood were assessed using a Precision Xtra device (Abbott) in lactating dairy cows (n = 1,102) between 3- and 9 d postpartum. Cows were categorized into 4 groups: no HK or HG (Norm = 500); HK only (HK = 230), HG only (HG = 171), concurrent HK and HG (HKHG = 201). Serum collected the day of cow-side diagnosis was evaluated for nonesterified fatty acids (NEFA), total calcium (tCa), magnesium (Mg), triglycerides (Tr) and urea (Ur)[FSdL1] using an automated chemistry analyzer (Randox Daytona). Statistical analysis was carried out using JMP 15 Pro. Previously established thresholds were used to define elevated NEFA (NEFA ≥0.7mmol/L) and hypocalcemia (tCa ≤2.14 mmol/L). For Mg, Ur, and Tr, receiver operator characteristic (ROC) curve analysis were used to determining the optimal threshold to detect on-farm recorded disease for the first 100 d in milk (Mg ≤0.76; Ur ≤4.77; Tr ≥0.145). Using these thresholds prevalence of each metabolic aberration was evaluated according to cow-side status. Prevalence of hypocalcemia was greater (P < 0.01) in HK and HKHG than HG and Norm (HK, 35.2 ± 3.7%; HKHG, 35.3 ± 4.3%; HG, 13.5 ± 4.3%; Norm 14.4 ± 3.4%), [FSdL2] prevalence of elevated NEFA was greater (P < 0.02) in HKHG than HG and Norm (HK, 50.0 ± 4.7%; HKHG, 56.2 ± 5.4%; HG, 42.1 ± 5.5%; Norm 46.8 ± 4.3%), prevalence of hypomagnesemia was greater (P < 0.01) among HK than the other 3 groups (HK, 46.5 ± 4.3%; HKHG, 33.3 ± 4.9%; HG, 25.2 ± 5.0%; Norm 25.8 ± 3.9%), prevalence of decreased urea was greater (P < 0.01) among Norm cows than HG cows (HK, 68.7 ± 4.4%; HKHG, 66.7 ± 5.0%; HG, 56.7 ± 5.1%; Norm 69.8 ± 4.0%), and prevalence of increased triglycerides was not different (P > 0.05) among groups. Elevated HK was associated with metabolic abnormalities, but concurrent HK and HG had no additional effects to metabolic disturbances and cows with hypoglycemia had similar metabolic profiles as healthy cows.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84633 Watch P315 Effects of an acidified diet prepartum on performance of Holstein cows and validation of 2 pH strips to measure urine pH. 34 L. K. Fehlberg DCAD pH urine L. K. Fehlberg1, A. Pineda2, F. C. Cardoso1 1University of Illinois, Urbana, IL, 2University of Guelph, Guelph, ON, Canada There is a need for an inexpensive and accurate method to measure urine pH during the prepartum period to assess the extent of metabolic acidosis achieved and determine the subsequent effect on performance. The study aimed to determine the accuracy of Fisher pH sticks (pHF; Thermo Fischer Scientific) and pHion balance test strip (pHI; pHion Balance) compared with a portable pH meter (pHP; Accumet AP115, Thermo Fisher Scientific) in measuring urine pH (UpH) and the association of UpH on pre- and postpartum dry matter intake (DMI) and yields of milk and milk components. Cows consumed a total mixed ration with a DCAD of −118 mEq/kg for 4 wk prepartum and 397 mEq/kg for 4 wk postpartum. Prepartum UpH measurements for each cow were averaged and utilized to classify cows as Low (mean ± standard deviation; UpH ≤ 5.54; 5.44 ± 0.07), Med (5.54 > UpH ≤ 5.90; 5.67 ± 0.09), or High (UpH > 5.90; 6.42 ± 0.36). Milk yield and DMI were recorded daily and averaged weekly. Cows were milked 2 × per d and milk samples were taken on d 7, 14, and 28. Bland-Altman plots and Lin’s concordance correlation coefficient (CCC) were used to assess the agreement between pHP and pHF and pHI. Receiver operating characteristic curves were used to determine the threshold with pHF and pHI that best discriminated between UpH >6.0 and ≤6.0 compared with pHP and area under the curve (AUC) assessed the accuracy. At UpH threshold of 5.75 for pHF and pHI, the sensitivity, specificity, and AUC were 89.5 and 87.4, 99.1 and 97.0, and 0.94 and 0.92, respectively. The CCC was 0.93 for pHF and pHI, indicating near-perfect agreement with pHP. The UpH did not affect pre- nor postpartum DMI (P = 0.14). Tendencies for UpH × wk interaction for milk yield and total solids content showed decreased milk yield for Low and Med UpH cows and greater total solids content for Low UpH cows during wk 1 postpartum (P < 0.10). In conclusion, the pHI and pHF are accurate methods for measuring UpH. Additionally, when fed an acidified diet cows’ UpH was not associated with pre- nor pospartum DMI, but when UpH was Low or Med, milk yield decreased at wk 1 postpartum.
Production, Management and the Environment: Posters Posters Production Management and the Environment 7/11/2021 0:00 t84553 Watch P316 Increased calving rate reduced pre- and postpartum dry matter intake and milk yield in Holstein dairy cows. 35 G. M. Schuenemann calving rate dry matter intake dairy cattle G. M. Schuenemann1, B. T. Menichetti1, J. Fontana2 1Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, OH, 2Departamento de Zootecnia y Granja, Universidad Nacional de Cuyo, Mendoza, Argentina The objective was to assess the association of calving rate (CR) with stocking density (SD) of pre- and postpartum pens, dry matter intake (DMI) 7 d before calving (dpp), postpartum DMI for the first 12 d in milk (DIM), and milk yield at 30 DIM (MILK) in Holstein dairy cows. A total of 3,561 animals (1,262 heifers and 2,299 multiparous) were assessed during 2 yr from a large dairy herd in Argentina. Transition heifers and cows were housed in deep bedded compost barns. Prepartum heifers and cows were comingled and exposed to an acidogenic diet for 25 ± 3 dpp. Postpartum cows were comingled for the first 25 ± 3 DIM. Linear feed bunk space was maintained at 80 ± 9 cm per cow. The mean SD was computed as the number of cows within 7 dpp or first 12 DIM. The mean DMI was computed by subtracting the total offered minus residual feed per day and then divided by the number of cows within pens once calving date was known. PROC CORR or MIXED procedures of SAS were used to assess the association of CR with SD, DMI, and MILK. Pen was the experimental unit for DMI. Correlations were adjusted by parity, season, and year. The mean CR was 23 births per week (rage: 6 to 45). The mean pre- and postpartum SD was 65 (range: 6 to 116) and 86 cows (range: 45 to 133), respectively. The mean DMI was 14 (range: 8 to 21) and 19.9 (range: 15 to 26) kg/d for pre- and postpartum cows, respectively. Mean MILK was 35.9 kg/d for primiparous and 51.8 kg/d for multiparous cows. Parity, season, and year were associated (P < 0.05) with CR, pre- and postpartum DMI, and MILK. Calving rate was associated with pre- (r = 0.30) and postpartum SD (r = 0.38; P < 0.001). Prepartum SD had a negative association with DMI within 7 dpp (r = −0.45; P < 0.001). Prepartum DMI had a positive association with postpartum DMI within the first 12 DIM (r = 0.30; P < 0.001), which was associated with milk yield (r = 0.25; P < 0.001). The combination of CR, DMI prepartum, and postpartum SD explained at least 3.2 k/d and 2.4 kg/d of the observed variation in postpartum DMI and MILK. These findings provide evidence that flow of cows determined by CR affected pre- and postpartum SD, which in turn reduced postpartum DMI and MILK.
Reproduction: Orals Orals Reproduction 7/11/2021 0:00 s9639                  
Reproduction: Orals Orals Reproduction 7/11/2021 0:00 t84074 Watch 147 Changes in uterine metabolome associated with metritis in dairy cows. 1 C. C. Figueiredo uterine health disease C. C. Figueiredo1, L. O. Balzano-Nogueira1, D. Z. Bisinotto1, A. C. Conesa1, K. N. Galvão1, R. S. Bisinotto1 1University of Florida, Gainesville, FL The objective was to characterize changes in uterine metabolome associated with metritis in lactating Holstein cows. This prospective cohort study was conducted from February to November 2018 in 3 dairy herds located in Florida. Vaginal discharge was evaluated between 2 and 15 DIM using the Metricheck device and metritis was characterized by the presence of watery, fetid, reddish-brownish vaginal discharge (study d 0). Cows with metritis (MET; n = 24) were paired with counterparts without metritis of similar DIM and parity (NoMET; n = 24). Uterine lumen was flushed with 15 mL of saline solution using a plastic infusion pipette attached to a plastic syringe and cows with metritis received parenteral antimicrobial therapy. A second uterine flush was performed on d 6. A total of 8 cows with metritis underwent clinical cure at d 6. Uterine metabolome was evaluated using untargeted gas chromatography time-of-flight mass spectrometry (GC-TOF-MS). Normalized data were analyzed in R using Canonical Analysis of Populations (CAP), considering 4 groups as follows: MET_d0, NoMET_d0, MET_d6, and NoMET_d6. A MANOVA analysis was performed and a total of 657 out of 884 metabolites identified by GC-TOF-MS were considered statistically significant (P < 0.05). The first 2 canonical variables explained 67.2 and 25.2% of the total variation among groups respectively and exhibit mainly a separation given by cows with or without metritis on d 0. From these 657 metabolites, a total of 128 showed a quality of representation larger than 0.99 and are tightly associated with the metabolism of spermidine and putrescine, long-chain fatty acids (i.e., docosahexaenoic acid and arachidonic acid), histidine, β-alanine, pentose phosphate, propanoate, glutathione, arginine and proline, tryptophan, and aminoacyl-tRNA biosynthesis. This demonstrates that metritis is associated with changes in uterine metabolome before antimicrobial therapy is applied. Finally, CAP showed no significant differences between MET and NoMET on d 6; thus, supporting that uterine metabolome in cows treated for metritis converged to a pattern similar to that observed in non-affected counterparts.
Reproduction: Orals Orals Reproduction 7/11/2021 0:00 t84723 Watch 148 Use of recombinant bST to improve reproductive characteristics and oocyte quality. 2 A. L. L. Sguizzato follicular development ovary size phenotypical classification oocytes A. L. L. Sguizzato1, J. D. Guimarães1, E. F. Santos1, V. A. P. Alfradique1, M. I. Marcondes2,1 1Universidade Federal de Viçosa, Viçosa, MG, Brazil, 2Washington State University, Pullman, WA Reducing the age at puberty is a wise alternative to reduce the non-productive phase of a cows’ life in the dairy herd. Thus, we aimed to evaluate the effects of recombinant bovine somatotropin (rbST) on the average number and size of follicles (ANF; ASF), the average size of ovaries (ASO), and oocyte quality of Holstein × Gyr (HG) heifers. Thirty-four HG heifers with average initial body weight (iBW) of 218 ± 49 kg and 14 ± 4 mo of age received either rbST (500 mg) or sodium chloride (0.9%) shots every 14 d for 84 d. They were fed a diet to gain 1 kg/d (NRC, 2001) with a metabolizable protein/metabolizable energy ratio of 42 g/Mcal. We performed rectal ultrasound measurements in each heifer every 7 d for 84 d. We collected data for ovaries and dominant follicle sizes, and number of follicles in each ovary. On d 84, heifers went through a 6 d-synchronization protocol for ovum pick-up (OPU). Then, oocytes were classified based on cytoplasm characteristics and the number of cumulus cell layers (Leibfried and First, 1979). All variables were analyzed using the GLIMMIX procedure of SAS 9.4 in a randomized block design, [using iBW (±56 kg) as blocking criteria, and repeated measures, when necessary] adopting 10% as critical level of type I error. The use of rbST did not affect ANF or ASF (P > 0.353); however, ANF and ASF changed over time (P < 0.015), following the follicular wave phase. There was a treatment × day interaction for ASO (P = 0.050), with the highest ASO on d 50 for rbST heifers. Phenotypical data presented a greater percentage of class 2 oocytes (P = 0.062; Table 1), but no differences for the other oocyte classes or number of follicles harvested (P > 0.10). In summary, the use of rbST on HG heifers does not improve reproductive traits and oocyte quality, although there was an increase in ASO. Table 1. Phenotypical data from ovum pick-up procedure in Holstein × Gyr heifers
Phenotypical data Treatment SEM P-value
no rbST rbST Treatment
Follicles harvested 19.91 20.55 0.144 0.908
% Follicles recovered 40.89 38.33 0.090 0.772
% Class 1 11.24 21.58 0.085 0.322
% Class 2 32.54 13.57 0.085 0.062
% Class 3 31.19 39.91 0.086 0.484
% Class 4 25.03 25.03 0.075 0.999
Reproduction: Posters Posters Reproduction 7/11/2021 0:00 s9601                  
Reproduction: Posters Posters Reproduction 7/11/2021 0:00 t83607 Watch P318 Trace-mineral supplementation reduces early pregnancy losses on an in vitro embryo production program. 1 R. V. Sala minerals early pregnancy loss IVP embryos R. V. Sala1, E. Peralta2, L. Carrenho-Sala1, M. Fosado2, D. C. Pereira3, V. A. Absalón-Medina1,4 1STgenetics, South Charleston, OH, 2STgenetics, Kewaskum, WI, 3STgenetics, De Forest, WI, 4The Ohio State University, Columbus, OH The main objective of this study was to investigate the effects of injectable trace minerals on the probability of pregnancy and pregnancy losses on an in vitro embryo production (IVP) program. Additional objectives were to measure collateral effects from luteal tissue area, among others. A total of 885 heifers were randomly allocated in 2 groups: control vs. treatment with 10 mL of injectable trace minerals (Multimin) at the beginning of the synchronization protocol consisting of a modified 5-d CIDR Synch i.e., D-8 CIDR insertion, D-3 CIDR removal plus PGF and D0 GnRH where heifers were assumed in estrus viz., d 0 of estrous cycle. Moreover, heifers were evaluated by ultrasonography on D5 to determine presence and size of the CL. On D7 ± 1-d, heifers received a fresh IVP embryo and pregnancy diagnosis was performed on D32 and D60, respectively. Data on P32, P60 and pregnancy losses was fitted into a nominal logistic model using JMP version 15 of SAS. CL-tissue area in mm2, BCS (1–5 scale), recipient age in months, times bred, IETS-based embryo evaluation and days post-estrus at embryo transfer (ET) were also included in the model as covariates. Results showed that means between control vs. treatment were not different in terms of luteal tissue area (25.3 ± 0.55 mm2 vs. 25.7 ± 0.54 mm2), BCS (3.04 ± 0.02 vs. 3.06 ± 0.02), age (16.2 ± 0.15 mo vs. 16.3 ± 0.20 mo) nor times bred (0.6 ± 0.05 vs. 0.6 ± 0.05). Likewise, no significant differences were found in terms of probability of pregnancy at P32 and at P60 (48.7% vs. 47.7% and 40.8% vs. 41.9%; respectively). However, there was a significant interaction between embryo stage, days post-estrus at ET and treatment that resulted in less pregnancy losses on heifers receiving trace minerals (main effect: P = 0.03). Post hoc analysis indicated losses were different for stage 7 embryos transferred into recipients at d 7 post-estrus compared with other subgroups. To further examine the relationship of nominal data corresponding to stage 7 embryos transferred into d 7 post-estrus uteri, a contingency analysis was performed. Results showed pregnancy losses by the presumptive d 60 of gestation were indeed lower for the trace-mineral treated group (9.5% vs. 22.2%; Fisher’s Exact Test P = 0.04). We, therefore, conclude that an injection of trace minerals at the beginning of an estrus synchronization protocol reduced pregnancy losses when compared with controls.
Reproduction: Posters Posters Reproduction 7/11/2021 0:00 t83917 Watch P319 The relative relationship between type 1/type 2 immunity and fertility in Holstein cows. 2 A. Ahmadzadeh type1-type 2 immunity fertility lactating cow W. Sandberg1, A. Ahmadzadeh1, P. Rezamand1, Q. Huo2 1University of Idaho, Moscow, ID, 2University of Central Florida, Orlando, FL Maternal immunity shifts from a type 1/type 2 balance to a type 2-biased immunity, and lack of such a shift may contribute to unsuccessful pregnancy in animals. There may be a shift in type 1/type 2 balance as animals enter the estrus phase of the estrous cycle and before AI, which could be a predictor of their fertility. The objective of the study was to examine the relationship between relative balance between type 1 and type 2 and fertility in lactating Holstein cows subjected to timed AI for the second time or greater. After the first AI, and upon non-pregnancy diagnosis (d 0 of the experiment), lactating cows eligible for a second or greater AI (n = 221) were enrolled in a 5-d CIDR-Cosynch protocol (mean DIM = 177). On d 8, cows received GnRH and AI, and blood samples were collected form all cows to be examined for type1/type 2 balance and progesterone (P4). D2Dx nanoparticle immunity assay, a rapid blood test, was used to detect type 1/type 2 immune balance by measuring the relative quantity ratio of immunoglobulin G1 and G2 subclasses (IgG1/IgG2). Pregnancy status was confirmed by ultrasonography between 40 to 45 d after AI. Data were analyzed by general linear model and logistic regression. Mean relative quantity of IgG1/IgG2 was not different between non-pregnant and pregnant cows. In addition, no relationship between probability of pregnancy to AI and IgG1/IgG2 relative quantity were detected under these experimental conditions. There was no correlation between serum P4 concentrations and IgG1/IgG2 ratio. Although IgG1/IgG2 could not predict the probability of pregnancy to second and greater AI, the relation between type 1/type 2 balance and fertility in dairy cows requires further investigation.
Reproduction: Posters Posters Reproduction 7/11/2021 0:00 t84055 Watch P320 Luteal regression, follicle growth, and time to ovulation in dairy heifers treated with different formulations of prostaglandin F 3 S. G. Umana Sedo luteolysis ovulation prostaglandin S. G. Umana Sedo1, C. C. Figueiredo1, T. D. G. Rojas1, G. A. Duarte1, M. B. U. Ugarte Marin1, C. A. Crawford1, K. G. Pohler3, R. C. Chebel1, T. R. Bilby2, R. S. Bisinotto1 1University of Florida, Gainesville, FL, 2Merck Animal Health, Madison, WI, 3Texas A&M University, College Station, TX Objectives were to evaluate the effect of prostaglandin F (PGF) treatments on CL regression, follicle growth, and time to ovulation. Holstein heifers were randomly allocated to receive 1 dose of cloprostenol (CLOx1; n = 48), 1 dose of dinoprost (DINx1; n = 47), 2 doses of cloprostenol 24 h apart (CLOx2; n = 45), or 2 doses of dinoprost 24 h apart (DINx2; n = 46) starting 7 d after a synchronized estrus. Ovaries were scanned every 12 h until estrus and every 6 h thereafter until ovulation. Blood samples were collected before treatment and every 6 h until ovulation for measurement of progesterone concentrations. Luteolysis was defined as progesterone concentration <0.5 ng/mL. Binary data were analyzed using logistic regression and continuous data using ANOVA. Proportion of heifers that underwent luteolysis (CLOx1 = 82.2 ± 5.7, CLOx2 = 100.0 ± 0.0, DINx1 = 58.1 ± 7.5, DINx2 = 95.5 ± 3.1%) and that ovulated (CLOx1 = 86.7 ± 5.1, CLOx2 = 100.0 ± 0.0, DINx1 = 55.8 ± 7.6, DINx2 = 93.2 ± 3.8%) were smaller for DINx1. Time to luteolysis was affected by type of PGF (CLO = 23.4 ± 1.5 vs. DIN = 30.0 ± 1.7 h) and dose (x1 = 29.1 ± 1.8 vs. x2 = 24.2 ± 1.5 h), yet, an interaction between PGF type and dose was not observed (CLOx1 = 24.3 ± 2.2, CLOx2 = 22.5 ± 2.1, DINx1 = 34.0 ± 2.7, DINx2 = 25.9 ± 2.0 h). Time to ovulation was not affected by treatment (CLOx1 = 69.4 ± 1.3, CLOx2 = 71.4 ± 1.3, DINx1 = 71.9 ± 1.7, DINx2 = 71.3 ± 1.3 h). Follicle diameter in the last 60 h before ovulation did not differ between CLOx1 and CLOx2 (16.2 ± 0.2 vs. 16.3 ± 0.1 mm) but it was greater for DINx1 compared with DINx2 (16.7 ± 0.2 vs. 16.3 ± 0.1 mm). Luteal area did not differ between CLOx1 and CLOx2 (193.3 ± 5.2 vs. 190.7 ± 5.3 mm2) whereas DINx1 had larger area than DINx2 (221.5 ± 5.1 vs. 196.4 ± 5.3 mm2). Progesterone concentrations in the first 72 h after treatment did not differ between CLOx1 and CLOx2 (0.88 ± 0.06 vs. 0.73 ± 0.07 ng/mL) but it was greater for DINx1 compared with DINx2 (1.16 ± 0.06 vs. 0.85 ± 0.06 ng/mL), which was largely explained by heifers that did not undergo luteolysis. A similar pattern was observed for CL blood flow. Treatment did not affect time to ovulation, but CL regression and ovulatory response were impaired in heifers receiving a single dose of dinoprost.
Reproduction: Posters Posters Reproduction 7/11/2021 0:00 t84081 Watch P321 Association of estrous expression detected by an automated activity monitoring system within 40 days in milk and reproductive performance of lactating Holstein cows. 4 S. Borchardt estrous expression automated activity monitor reproductive performance S. Borchardt1, C. Tippenhauer1, J.-L. Plenio2, A. Bartel2, A. Madureira3, R. Cerri3, W. Heuwieser1 1Clinic of Animal Reproduction, Free University Berlin, Berlin, Germany, 2Institute for Veterinary Epidemiology and Biostatistics, Free University Berlin, Berlin, Germany, 3Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada The objective of this observational study was to evaluate the association of estrous expression within 40 d in milk using a neck-mounted automated activity monitor (AAM; Heatime Pro; SCR Engineers Ltd., Netanya, Israel) with estrous characteristics of the first postpartum AI and reproductive performance in lactating Holstein cows. A total of 2,077 cows from 5 commercial dairy farms were included in the statistical analyses. Cows were classified according to the number of estrus events from d 7 until d 40 postpartum into 3 categories: 1) no estrus event (ANESTRUS); 2) one estrus event (ESTRUS1) and 3) 2 or more estrus events (ESTRUS2+). Generalized linear mixed models were used to analyze continuous or categorical data. Shared frailty models were used for time to event data. Overall, 52.7% (1,095/2,077) of cows had no estrus event detected by an AAM system from d 7 until d 40 postpartum. Herd-level prevalence of ANESTRUS ranged from 37.5% to 58.4%. Estrous expression from d 7 until d 40 postpartum affected estrous duration (P = 0.001) at first postpartum AI. Cows in ANESTRUS had the shortest duration (13.2 ± 0.33 h) compared with cows in ESTRUS1 (13.8 h ± 0.36) and ESTRUS2+ (14.8 h ± 0.41). Cows in ESTRUS2+ had a longer estrous duration at first postpartum AI compared with cows in ESTRUS1. For ANESTRUS, ESTRUS1, and ESTRUS2+ cows pregnancy per AI was 29.4%, 30.9%, and 37.8%, respectively. Estrous expression from d 7 until d 40 postpartum affected time to first AI and time to pregnancy. Compared with ANESTRUS cows, cows in ESTRUS1 (Hazard risk (HR) = 1.74; 95% CI 1.55 - 1.94; P = 0.001) and ESTRUS2+ (HR = 1.77; 95% CI 1.52 - 2.05; P = 0.001) had an increased hazard of being inseminated within 100 DIM. Median DIM to first AI were 70, 59 and 58 for cows in ANESTRUS, ESTRUS1, and ESTRUS2+, respectively. Compared with ANESTRUS cows, cows in ESTRUS1 (HR = 1.28; 95% CI 1.13 - 1.46; P = 0.001) and ESTRUS2+ (HR = 1.33; 95% CI 1.12 - 1.57; P = 0.001) had an increased hazard of becoming pregnant within 200 DIM. Median DIM to pregnancy were 127, 112, and 103 for ANESTRUS cows, ESTRUS1 and ESTRUS2+, respectively. In conclusion, cows with no estrous expression from 7 to 40 DIM had reduced estrous expression at first AI and inferior reproductive performance compared with cows that displayed estrous activity.
Reproduction: Posters Posters Reproduction 7/11/2021 0:00 t84319 Watch P322 Effects of feeding rumen-protected lysine prepartum on placental immunometabolic gene expression of Holstein cows. 5 A. R. Guadagnin gene expression lysine placenta A. R. Guadagnin1, L. K. Fehlberg1, B. Thomas1, Y. Sugimoto2, I. Shinzato2, F. C. Cardoso1 1University of Illinois, Department of Animal Sciences, Urbana, IL, 2Ajinomoto Co. Inc, Tokyo, Japan The maternal supply of lysine during late gestation results in a greater intake and improved health of their calves during the first 6 weeks of life. We hypothesize that these effects are possible due to changes in placental metabolism, which allow for improved passage of nutrients to the fetus and immunity. Therefore, we aimed to determine the effects of feeding rumen-protected lysine (RPL, AjiPro-L Generation 3, Ajinomoto Heartland Inc., Chicago, IL) prepartum (0.54% DM of TMR) on mRNA gene expression profiles of placental samples of Holstein cows. Sixty-six (n = 66) multiparous Holstein cows were randomly assigned to 1 of 2 dietary treatments, consisting of TMR top-dressed with RPL (PRE-L) or without (control, CON), fed from 27 ± 5 d prepartum until calving. After natural delivery (6.87 ± 3.32 h), 3 placentomes from each placenta were collected. A subset of each of the placentomes was combined and flash-frozen in liquid nitrogen, to evaluate the expression of genes related to protein metabolism and inflammation. After normalization with the geometric mean of the internal control genes, the triplicate averages of the qPCR data were log2 transformed to obtain a normal distribution of residuals. Data were analyzed using the MIXED procedure in SAS. The estimates were then log2 back-transformed to express the mRNA abundance. For ease of interpretation, the response in mRNA abundance in placental tissue of cows in PRE-L versus cows in CON is represented using fold-change values [(mRNA abundance at PRE-L – mRNA abundance at CON)/mRNA abundance at CON]. The mRNA expression of methionine adenosyltransferase 2A (MAT2A) was 7.9 times greater (P < 0.01) in the placenta of cows in PRE-L than in CON. There was no difference on the mRNA expression (P = 0.80) of Y+L amino acid transporter 1 (SLC7A7), interleukin 10 (IL10), interleukin-1β (IL1B), lysine-specific histone demethylase 1A (KDM1A), nor euchromatic histone-lysine N-methyl transferase 2 (EHMT2). In conclusion, it is likely that prepartum supply of RPL allows for a greater utilization of methionine, exemplified by the greater expression of MAT2A in the placenta of cows that were fed RPL prepartum.
Reproduction: Posters Posters Reproduction 7/11/2021 0:00 t84418 Watch P323 Associations between anogenital distance and measures of fertility in lactating North American Holstein cows: A validation study. 6 J. E. Carrelli dairy cattle fertility reproductive phenotype genetic selection J. E. Carrelli1, M. Gobikrushanth1,2, M. Corpron3, W. Sandberg3, A. Ahmadzadeh3, M. Oba1, D. J. Ambrose4,1 1Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada, 2Department of Large Animal Clinical Sciences, University of Saskatchewan, Saskatoon, SK, Canada, 3Department of Animal, Veterinary and Food Sciences, University of Idaho, Moscow, ID, 4Livestock and Crops Research Branch, Alberta Agriculture and Forestry, Edmonton, AB, Canada First reports on nulliparous Holstein heifers and first- and second-parity Holstein cows have demonstrated inverse relationships between anogenital distance (AGD) and measures of fertility in these respective populations. The objective of this study was to further validate the inverse relationship between AGD and measures of fertility in lactating cows, using a large population of North American Holstein cows. Cows (n = 5,173) from 19 herds (18 Canadian + 1 American) were subjected to AGD measurement (the distance from the center of the anus to the base of the clitoris) and reproductive performance data were obtained from herd records. Data were analyzed using UNIVARIATE, MIXED, CORR, REG, GLIMMIX, LOGISTIC, and LIFETEST procedures of SAS, where AGD and parity were considered independent variables in all statistical models. AGD was normally distributed with an overall mean (±SD) of 132.5 ± 11.8 mm (min, max: 94, 177). As the optimum AGD cut-point predictive of pregnancy was not obtainable, cows were categorized into short- (≤mean) and long-AGD (>mean) groups based on mean AGD for each parity group [first- (129 mm), second- (133 mm), and third+-parity (136 mm)]. AGD had a weak positive association with both parity (r = 0.21) and 305-d mature-equivalent milk yield (r = 0.04). Cows with short AGD had greater pregnancy to first artificial insemination (P/1stAI) than cows with long AGD (35.7 ± 2.1 vs. 31.4 ± 2.0%; P < 0.01); however, there was no difference in P/ second AI (37.4 ± 2.3 vs. 34.9 ± 2.2%) and third (41.8 ± 2.4 vs. 43.4 ± 2.4%) between AGD categories. Cows with short AGD tended to require fewer services per conception (2.3 ± 0.1 vs 2.4 ± 0.1; P = 0.06) and had fewer days open (136.9 ± 4.5 vs 140.9 ± 4.3 d; P = 0.05) compared with their long AGD counterparts. However, cumulative pregnancy risks up to 150 and 250 d in milk did not differ between AGD categories. Results indicate an inverse relationship between AGD and some measures of fertility in lactating cows, and is positively, but weakly associated with both parity and milk yield, strengthening the potential for AGD to be implemented as a reproductive phenotype in future breeding programs.
Reproduction: Posters Posters Reproduction 7/11/2021 0:00 t84547 Watch P324 Effects of dietary butyrate supplementation and oral nonsteroidal anti-inflammatory drug administration to transition cows on indicators of uterine inflammation and days to first ovulation. 7 L. E. Engelking reproduction uterine inflammation days to first ovulation L. E. Engelking1, M. Oba1, D. J. Ambrose1 1University of Alberta, Edmonton, AB, Canada Sixty-five Holstein cows were blocked by calving date and parity and randomly assigned to an isoenergetic diet containing calcium butyrate (BUT; 1.42% of diet dry matter (DM)) or a control (CON; 1.04% palm fat and 0.38% calcium carbonate of diet DM) from −28 to +24 d in milk (DIM). The close-up diet contained 14% starch and 43% neutral detergent fiber, and the fresh diet contained 22% starch and 35% neutral detergent fiber on a DM basis. Cows received an oral nonsteroidal anti-inflammatory drug (NSAID; 1 mL/15 kg BW; Meloxicam in carrier solution) or a placebo (1 mL/15 kg BW food dye in carrier solution) at 12 to 24 h after calving resulting in treatment groups: BUT-NSAID (n = 15), BUT-Placebo (n = 14), CON- NSAID (n = 18), and CON-Placebo (n = 18). Weekly ovarian ultrasonography was from 14 DIM until first ovulation or up to 56 DIM. Vaginal mucus was collected using a Metricheck at 28 DIM and scored from 0 to 3 (0 = clear, 3 ≥ 50% purulent or sanguineous). Endometrial cytology was performed at 28 DIM to assess uterine inflammation based on polymorphonuclear (PMN) leukocytes. Proportionate data were analyzed by Proc FREQ and the mean interval to first ovulation was determined by GLIMMIX in SAS. A smaller proportion of cows fed the butyrate diet ovulated by 14 DIM compared with cows fed the control diet (29 vs. 71%; n = 14; P = 0.05). The mean days to first ovulation tended to be longer in NSAID- than in placebo-treated cows (29 vs. 24 d; P = 0.09). Six cows did not ovulate by 56 DIM. Butyrate and NSAID treatment did not affect the mean PMN count or the proportion of low (≤18%) PMN cows; however, the proportion of cows with high (>18%) PMN tended to be greater in NSAID- than in placebo-treated cows (64 vs. 36%; n = 22; P = 0.10). Results may be attributed to too early NSAID administration, possibly interfering with natural postcalving inflammatory mechanisms that assist in uterine involution and return to estrus. Dietary butyrate and oral NSAID did not reduce uterine inflammation or days to first ovulation.
Reproduction: Posters Posters Reproduction 7/11/2021 0:00 t84555 Watch P325 Effect of a high dose of gonadotropin-releasing hormone (GnRH) at the first GnRH of the Resynch-25 on ovulatory response and fertility in lactating Holstein cows. 8 I. M. R. Leão Resynch ovulation GnRH I. M. R. Leão1, M. S. El Azzi1,2, E. Anta-Galván1, T. Valdés-Arciniega1, J. P. N. Martins1 1Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin–Madison, Madison, WI, 2Departamento de Zootecnia, Universidade Federal de Lavras, Lavras, MG, Brazil Our objective was to determine the effect of high vs. low dose of GnRH on ovulatory response, serum progesterone (P4) concentrations and pregnancy per AI (P/AI) in lactating Holstein cows receiving a Resynch-25 program for second+ AI. Cows (n = 2,375; primiparous: 789; multiparous:1,583) 25d after previous timed AI (TAI) were randomly assigned to receive either 100 (L) or 200 (H) µg of GnRH (gonadorelin hydrochloride; Factrel, Zoetis) for the d25 GnRH of the Resynch-25 program. On d32 after TAI, cows were diagnosed for pregnancy and checked for CL presence with ultrasound. Pregnant cows (n = 1,198) did not receive any further treatment. Non-pregnant cows without a CL on d32 (n = 126; L: 68; H: 58) were enrolled in a Ovsynch+CIDR protocol. Non-pregnant cows with a CL (n = 1,049) continued the resynch program to be rebred (d32: PGF – d33: PGF – d34(p.m.): GnRH – d35: TAI). Ovaries were scanned with ultrasound in a subset of cows (n = 549) on d 25 and 27 to determine ovulatory response (pregnant, n = 268; non-pregnant, n = 281). Blood samples (n = 285) were collected on d 25 and 32 to measure serum P4 in non-pregnant cows. A total of n = 953 cows were analyzed for treatment differences in P/AI. Binary variables were analyzed by logistic regression with PROC GLIMMIX of SAS. Most cows had a follicle ≥ 10 mm in diameter on d25 (95.8%). The proportion of cows with P4 ≥ 1.00 ng/mL on d25 was low and did not differ (P = 0.30) between L (48.4%) and H (42.2%). Treatment did not affect ovulatory response for all cows (P = 0.35; L: 27.8% vs. H: 31.5%) and for non-pregnant cows (P = 0.42; L: 34.7% vs. H: 39.4%). The proportion of cows with P4 ≥ 1.00 ng/mL on d32 was high and did not differ between treatments (P = 0.45; L: 87.9% vs. H: 90.7%). P/AI did not differ (P = 0.72) between L (46.4%) and H (47.6%). Ovulation after d25 GnRH tended to increase (P = 0.06) P/AI for cows diagnosed non-pregnant for previous TAI (ovulation: 59.8% vs. no ovulation: 46.6%). In summary, a higher dose of GnRH on d25 of the Resynch-25 was not effective in increasing ovulatory response, proportion of cows with CL on d32 and P/AI of second+ AI, based on preliminary data.
Reproduction: Posters Posters Reproduction 7/11/2021 0:00 t84620 Watch P326 Effect of gonadotropin-releasing hormone (GnRH) administered at the time of AI for dairy cows detected in estrus by an activity monitoring system or by conventional estrus detection. 9 A. Hubner estrus detection activity monitors GnRH A. Hubner1, I. F. Canisso1, P. M. Peixoto1, A. J. Conley2, F. S. Lima2 1Department of Veterinary Clinical Medicine, University of Illinois, Urbana, IL, 2Department of Population Health and Reproduction, University of California, Davis, Davis, CA We hypothesized that a GnRH treatment at the time of concurrent estrus detection and AI (AIDE) would increase ovulation rate, progesterone post-AI, and pregnancies per AI (P/AI). Holstein cows were randomly assigned to receive an injection of GnRH (GnRH) or remain untreated (Control) at the time of AIDE on farms using activity monitors (AM, n = 409) or conventional estrus detection methods (ED, n = 398). Ovarian structures, plasma progesterone (P4) and estradiol (E2) were assessed in a subset 107 cows from a conventional ED farm at the time of AI (For E2 and P4) and 7 d later (For P4). Cows in AM had activity level assessed and categorized as high (≥100 increase) vs. low (<100 increase). Statistical analysis was performed using logistic regression and general linear models with models including effects of treatment, ED methods, parity, season, farms, receiving or not PGF2α, service number and their interactions. There were no effects (P = 0.98) of GnRH on P/AI (GnRH = 35.1 ± 4.1%; Control = 35.7 ± 4.2%) or pregnancy loss (GnRH = 6.9 ± 3.0%; Control = 9.0 ± 3.1%). There was no interaction (P = 0.88) between treatment and method of ED nor between treatment and other variables included in the models. There was no difference (P = 0.56) in ovulation rate, P4 at AI, and E2 on d 0 between GnRH and Control. For quartile of E2, the highest quartile (Q4) had lower P/AI (P < 0.02) than cows in quartiles 1 to 3 (Q1 = 65.4 ± 9.1%, Q2 = 50.0 ± 9.1%, Q3 = 42.3 ± 9.1%, Q4 = 18.5 ± 8.8). For AM cows there was a tendency (P = 0.06) for higher P/AI in cows that did not received PGF before ED compared with those that did receive PGF (No PGF = 43.0 ± 3.1%, PGF = 30.6 ± 9.9%). For AM there was an interaction between (P = 0.04) treatment and activity level with the GnRH having a greater impact on cows with high activity level (Low-GnRH = 25.9 ± 3.4% Low-Control = 22.9 ± 3.4%, High-GnRH = 48.4 ± 3.3%, High-Control = 41.8 ± 3.3%). The current study does not support the use of GnRH to improve P/AI in heat-detected cows, but potential GnRH benefits in AIDE with low and high activity and E2 levels need further investigation.
Reproduction: Posters Posters Reproduction 7/11/2021 0:00 t84643 Watch P327 Pregnancy loss is preceded by elevated pregnancy-specific protein B (PSPB) in recipients of somatic cell nuclear-transfer embryos but preceded by reduced PSPB in recipients of IVF embryos. 10 G. Madureira clone embryo human chorionic gonadotropin G. Madureira1,5, G. Grillo1,2, V. Gomez-Leon1,3, J. P. Andrade1, M. Fosado4, R. Sala4, R. Sartori5, M. Mello2, M. Wiltbank1 1Department of Animal and Dairy Sciences, University of Wisconsin, Madison, WI, 2Departamento de Reproducao e Avaliacao Animal, Universidade Federal Rural do Rio de Janeiro, Seropedica, RJ, Brazil, 3Department of Animal Sciences and Industry, Kansas State University, Manhattan, KS, 4Sexing Technology, Kewaskum, WI, 5Department of Animal Science, University of Sao Paulo, Piracicaba, SP, Brazil This study compared circulating hormones in recipients of an embryo from somatic cell nuclear-transfer (SCNT) or in vitro fertilization (IVF). Further, the effect of increasing circulating progesterone (P4) was tested by production of accessory corpora lutea (CL). A total of 123 nulliparous Holstein were randomized to receive an IVF or SCNT embryo and further randomized to receive or not human chorionic gonadotropin (hCG; 3,300 IU on days 5 and 12 [day 0 = GnRH treatment at end of synchronization]). Thus, 4 groups were created: IVF+no hCG (n = 30), IVF+hCG (n = 29), SCNT+no hCG (n = 28), and SCNT+hCG (n = 36). Ultrasound evaluations and blood samplings for P4 and pregnancy-specific protein B (PSPB) were performed on days 5, 12, 19, 21, 28, 33, 42, 47, 54 and 63. Statistical analysis were performed using PROC GLIMMIX and MIXED of SAS. Treatment with hCG caused ovulation (day 5: 96.9%; day 12: 83.1%) and increased circulating P4 (day 19: 20.8 ± 1.3 vs. 10.1 ± 1.1 ng/mL). Treatment with hCG tended to increase pregnancies per ET (P/ET) in recipients of SCNT embryos at days 28 (41.7 vs. 21.4%; P = 0.07) and 42 (22.2 vs. 7.1%; P = 0.09). At days 28 and 33, P/ET was similar for IVF and SCNT embryos, but on day 42 the P/ET was greater for IVF than SCNT embryos due to greater (P = 0.05) pregnancy losses in SCNT than IVF from days 33–42 (44.4 vs. 15.0%). Despite recipients of SCNT and IVF embryos having similar circulating PSPB on Day 28, recipients of SCNT embryos had greater PSPB at all later times. Interestingly, recipients of IVF embryos that maintained the pregnancy had greater PSPB on days 28 (P = 0.006) and 33 (P = 0.003) than IVF recipients that later had pregnancy loss. In contrast, recipients of SCNT embryos that later lost the pregnancy had greater (P = 0.01) PSPB on Day 33 than SCNT recipients that maintained the pregnancy. Thus, although reduced PSPB may predict pregnancy loss in recipients of IVF embryos, greater circulating PSPB on Day 33 was associated with later pregnancy loss in recipients of SCNT embryos, perhaps indicating excessive numbers or activity of trophoblast binucleate cells preceding pregnancy loss of SCNT embryos.
Reproduction: Posters Posters Reproduction 7/11/2021 0:00 t84776 Watch P328 Impacts of transition health on reproductive performance based on detection of estrus in dairy cows. 11 T. C. Bruinjé fertility reproduction transition health T. C. Bruinjé1, E. I. Morrison1, D. Renaud1, E. S. Ribeiro2, S. J. LeBlanc1 1Department of Population Medicine, University of Guelph, Guelph, ON, Canada, 2Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada Our objective was to investigate associations between transition health and pregnancy outcomes in a reproductive program primarily based on detection of estrus for first AI. In 1,093 Holstein cows enrolled from 2 dairies, serum calcium (Ca), haptoglobin (Hp), and nonesterified fatty acids (NEFA) were assessed at 2 and 6 (±1) d in milk, and blood β-hydroxybutyrate (BHB) measured at 4, 8, 11, and 15 (±1) d. Cows were examined for metritis at the same times, and for purulent vaginal discharge (PVD) and endometritis (ENDO; ≥ 6% PMN) at wk 5. BCS and lameness were assessed from wk −3 to 9. Additional disease data were obtained from farm records. First AI occurred based on estrus detection by activity monitors starting at 50 d. Cows not detected in estrus received timed AI (Ovsynch) around 74 d (herd A) or received PGF2a at 75 d and Ovsynch 14 d later (herd B). Pregnancy was diagnosed at 33 d after AI, and subsequent AI occurred at detected estrus or resynchronization. Metabolites were categorized based on ROC curve cutpoints associated with ENDO and PVD. Pregnancy risk at first AI (P/AI) and hazard of pregnancy by 200 d were analyzed in multivariable logistic and hazard regression models including first AI method, parity, BCS, metabolites, and disease variables, with herd as random. 78% of cows received first AI at detected estrus, P/AI was 39%, and 81% were pregnant by 200 d. Prevalence of Ca ≤ 2.1 mmol/L was 53%, Hp ≥ 1.1 g/L 42%, NEFA ≥ 0.8mmol/L 30%, ENDO 31%, and PVD 20%. Risk factors for P/AI were parity (multiparous 32% vs. primiparous 42%; P < 0.01), prepartum BCS ≤ 3.00 (31 vs. 39%; P = 0.03), high Hp at both d 2 and 6 (25 vs. > 38% if low Hp at either d 2 or 6; P < 0.01), and both ENDO and PVD (25 vs. > 37% if neither ENDO nor PVD; P = 0.01). Hazard of pregnancy was lower in cows with high Hp at d 6 (HR = 0.8; 95% CI 0.7–0.9; P = 0.01), PVD (HR = 0.8; 95% CI 0.6–0.9; P = 0.01), or BCS at wk 9 ≤ 2.75 (HR = 0.6; 95% CI 0.6–0.9; P < 0.01). Results suggest that early postpartum systemic inflammation, chronic reproductive tract disease, and low body condition are risk factors for reduced reproductive performance primarily based on detection of estrus.
Reproduction: Posters Posters Reproduction 7/11/2021 0:00 t84784 Watch P329 Impact of systemic and uterine inflammation on luteal function in postpartum dairy cows. 12 T. C. Bruinjé fertility ovarian function transition health T. C. Bruinjé1, E. I. Morrison1, D. Renaud1, E. S. Ribeiro2, S. J. LeBlanc1 1Department of Population Medicine, University of Guelph, Guelph, ON, Canada, 2Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada The objective of this prospective cohort study was to evaluate the association of systemic and uterine inflammation on luteal function in postpartum Holstein cows. A total of 394 cows from 2 commercial herds were initially enrolled 3 wk before parturition. Serum haptoglobin (Hp), total calcium (Ca), and nonesterified fatty acids (NEFA) were measured at 2 and 6 (±1) d in milk, and blood β-hydroxybutyrate (BHB) and metritis assessed at 4, 8, 11, and 15 (±1) d. Serum progesterone (P4) were measured at 21 and again at 35 ± 3 d, when cows were examined for endometritis (≥6% PMN in cytology samples) and purulent vaginal discharge (PVD). Cows diagnosed with both Hp ≥ 0.8g/L at 2 or 6 d and endometritis, regardless of other diseases, were enrolled in the cohort study and classified as high risk for luteal dysfunction (n = 76). Cows were classified as low risk (n = 69) if they had Hp < 0.8 g/L, no record of retained placenta, metritis, endometritis, PVD, or lameness, and BCS ≥ 3 at 35 d. Cows in the cohorts had P4 measured every 3–4 d from 35 to 70 ± 3 d, and luteal phases were characterized as periods of P4 ≥ 1ng/mL. Data were analyzed using linear or hazard regression models including risk group, parity, interaction, and herd as random. BCS at wk −3 and 9 and Ca were similar between groups, and high-risk cows had greater NEFA (0.8 vs. 0.6 ± 0.1 mmol/L; P < 0.01) and BHB (1.2 vs. 0.9 ± 0.1 mmol/L; P < 0.01) than low risk cows. Hazard of cyclicity (first P4 sample ≥ 1ng/mL) by 50 d was lower in high-risk cows (HR = 0.7; 95% CI 0.5–0.9; P = 0.01), so day of onset of cyclicity was included as a covariate in subsequent models. High-risk cows had a longer first detected luteal phase (25 vs. 16 ± 3 d in length; P < 0.01), tended to have lower peak P4 (10 vs. 9 ± 0.3 ng/mL; P = 0.10), had fewer luteal phases by 70 d (1.6 vs. 2.2 ± 0.1; P = 0.05), and lower hazard of detection of estrus by 75 d (HR = 0.5; 95% CI 0.3–0.8; P < 0.01). Findings suggest that cows with early postpartum systemic inflammation and subsequent uterine inflammation have altered luteal function before and during the breeding period, which could underlie reduced fertility.
Reproduction: Posters Posters Reproduction 7/11/2021 0:00 t84797 Watch P330 Repeatability of anogenital distance measurements at different ages and physiological states in dairy cattle. 13 I. Rajesh reproductive phenotype genetic selection fertility I. Rajesh1, M. Gobikrushanth1,2, J. E. Carrelli1, M. Oba1, D. J. Ambrose1,3 1University of Alberta, Edmonton, AB, Canada, 2University of Saskatchewan, Saskatoon, SK, Canada, 3Alberta Agriculture & Forestry, Edmonton, AB, Canada Anogenital distance (AGD), measured from the anus to the clitoris, is inversely associated with fertility and moderately heritable in dairy cattle. For AGD to be considered useful in genetic selection, its repeatability (consistency in measurements at different time points) must be determined. Therefore, the objective was to determine the associations and repeatability of AGD a) from birth to breeding age (15 mo) in heifers (n = 48); and among phases of b) the estrous cycle (n = 20); c) gestation (n = 78); and d) lactation (n = 30) in cows. AGD was measured using digital calipers. The phases (proestrus, estrus, metestrus, and diestrus) of estrous cycle were established based on plasma progesterone concentrations and ovarian ultrasonography performed every 48 h. The differences in means and the association of AGD at different phases were determined by ANOVA and Pearson correlation coefficient, respectively. The AGD was modeled against time (phases) and parity, with cows being repeated subjects. Mean (±SEM) AGD differed by age, with a linear increase from birth to 15 mo (68.1 ± 0.8, 73.6 ± 0.8, 87.7 ± 0.8, 95.5 ± 0.9, 105.0 ± 1.1, 111.7 ± 1.1 mm at 0, 2, 6, 9, 12 and 15 mo, respectively; P < 0.01). AGD at birth and at 15 mo were not associated (r = 0.27; P = 0.21) but the AGD at 6 mo and at 15 mo were moderately associated (r = 0.41; P = 0.05). In contrast, AGD did not differ by the phases of the estrous cycle (pooled mean, 131.1 ± 2.1 mm) and lactation (pooled mean, 127.6 ± 1.4 mm), and were highly correlated among phases of estrous cycle (r ≥0.98; P < 0.01) and lactation (r ≥0.95; P < 0.01). The AGD measurements at 30, 90 and 180 d of gestation were strongly associated (r ≥0.97; P < 0.01), but AGD at 270 d (mean, 142.8 ± 1.2 mm; P < 0.01) differed from AGD of all earlier phases of gestation (mean, 127.0 ± 1.1 mm), yet remained correlated (r ≥0.62). We conclude that AGD measured in heifers at 6 mo of age is a reliable reflection of AGD at breeding age and that AGD is highly repeatable in dairy cows and could be reliably measured at any physiological state except during late gestation.
Reproduction: Posters Posters Reproduction 7/11/2021 0:00 t84448 Watch P484 Association between conceptus length and endometrial transcriptome on day 17 of gestation in dairy cows. 14 P. M. Peixoto uterus embryo growth gene expression P. M. Peixoto1, J. J. Broomfield1, E. S. Ribeiro2, J. E. P. Santos1, W. W. Thatcher1, R. S. Bisinotto3 1Department of Animal Sciences, University of Florida, Gainesville, FL, 2Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada, 3Department of Large Animal Clinical Sciences, University of Florida, Gainesville, FL The objective was to characterize endometrial transcriptome on d 17 of gestation in dairy cows according to conceptus length. Nonlactating Holstein cows (n = 48) enrolled in an experiment aimed at evaluating effects of follicular wave and progesterone concentration during ovulatory follicle growth were used. Cows were euthanized 17 d after AI and the uterine horn ipsilateral to the CL was flushed with saline. Recovered conceptuses were classified as small (1.2 to 6.9 cm; n = 10), medium (10.5 to 16.0 cm; n = 12), or large (18.0 to 26.4 cm; n = 10). Samples of inter-caruncular endometrium were dissected from the caudal, intermediate, and cranial portions of the uterine horn ipsilateral to the pregnancy. Total mRNA was extracted from endometrial tissue and subjected to transcriptome analyses using the Affymetrix Gene Chip Bovine array. Data were normalized using the GCRMA method and analyzed by robust regression using the Linear Models for Microarray library within Bioconductor in R. Transcripts with P ≤ 0.05 after adjustment for false discovery rate and fold change ≥1.5 were considered differentially expressed. Functional analyses were conducted using the Ingenuity Pathway Analysis platform. Comparisons between cows with small vs. medium (SvsM), medium vs. large (MvsL), and small vs. large (SvsL) conceptuses yielded a total of 38, 4, and 107 differentially expressed transcripts, respectively. Top canonical pathways for SvsM and SvsL included complement system, B cell development, antigen presentation, allograft rejection signaling (SvsM only), Th1 and Th2 activation pathway. IFNγ and IFNα were identified as activated upstream regulators primarily based on increased expression of IDO1, ISG20, and CXCL11 (SvsM and SvsL). Overall network summary revealed an upregulation of lymphocyte stimulation (C3, CASP4, CD40, CXCL11) and immune response of cells (ATXN3, C3, CD40), whereas IL10RA was downregulated (SvsL and SvsM). Differences in endometrial transcriptome according to conceptus length on d 17 of gestation were observed and highlighted pathways linked to immune-regulation and a potential role for interferon-regulated genes.
Reproduction: Posters Posters Reproduction 7/11/2021 0:00 t84435 Watch P485 Transcriptome changes associated with elongation of bovine conceptuses. 15 P. M. Peixoto embryo gene expression microarray P. M. Peixoto1, J. J. Broomfield1, E. S. Ribeiro2, J. E. P. Santos1, W. W. Thatcher1, R. S. Bisinotto3 1Department of Animal Sciences, University of Florida, Gainesville, FL, 2Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada, 3Department of Large Animal Clinical Sciences, University of Florida, Gainesville, FL Objective was to characterize transcriptome changes associated with elongation in bovine conceptuses during preimplantation stages. Nonlactating Holstein cows (n = 48) enrolled in an experiment aimed at evaluating effects of follicular wave and progesterone concentration during ovulatory follicle growth were used. Cows were euthanized 17 d after AI and the uterine horn ipsilateral to the CL was flushed with saline solution. Recovered conceptuses were classified as small (1.2 to 6.9 cm; n = 10), medium (10.5 to 16.0 cm; n = 12), or large (18.0 to 26.4 cm; n = 10). Total mRNA was extracted and subjected to transcriptome analyses using the Affymetrix Gene Chip Bovine array. Data were normalized using the GCRMA method and analyzed by robust regression using the Linear Models for Microarray library within Bioconductor in R. Transcripts with P ≤ 0.05 after adjustment for false discovery rate and fold change ≥1.5 were considered differentially expressed. Functional analyses were conducted using the Ingenuity Pathway Analysis platform. Comparisons between small vs. medium (SvsM), medium vs. large (MvsL), and small vs. large (SvsL) conceptuses yielded a total of 83, 184, and 731 differentially expressed transcripts, respectively. Top canonical pathways of known involvement with embryo growth that were upregulated in large conceptuses included actin cytoskeleton (SvsL), integrin signaling (SvsL and MvsL), ephrin receptor (SvsL), mesenchymal transition by growth factor (MvsL), and regulation of calpain protease (SvsL). Estradiol-17β was predicted as an upstream regulator for SvsL and MvsL. Based on expression of transcripts, estradiol-17β is indirectly associated with upregulation of TGFB, ILB1, TNF (SvsL) and IFNG, IL6, TNF (MvsL). Overall network summary revealed upregulation of invasion of cancer cells (ADREG5, BMP2, F2R), proliferation of embryonic cells (AGO4, BMP2, BRAF), cell movement (ACTA2, ACTN4, ADAM9); indirect downregulation of organismal death (HAND1, CALCRL, CEBPA), and aplasia/hypoplasia (HAND1, CALCRL, WIPF1). Conceptus length on d 17 was associated with biological pathways involved with cell structure, proliferation, migration, and survival.
Reproduction: Posters Posters Reproduction 7/11/2021 0:00 t84302   P486 Effects of 1 or 2 prostaglandin F injections on luteal function and pregnancy outcome in dairy cows resynchronized with a 5-d + CIDR protocol. 16 W. J. Sandberg prostaglandin F resynchronization progesterone W. J. Sandberg1, K. Carnahan1, P. Villamediana1, W. Price2, D. Konetchy1, A. Ahmadzadeh1 1University of Idaho, Animal Science, Moscow, ID, 2Statistical Programs, College of Agricultural & Life Sciences, University of Idaho, Moscow, ID There is evidence that 2 injections of prostaglandin F (PG) in a 5-d CO-Synch + CIDR timed-AI protocol (5-d CIDR) is necessary to induce complete luteolysis by the time of AI and improve pregnancy rate. The objectives of this study were to compare the effects of a single dose of high-concentration PG (HC) or 2 doses of conventional PG (2PG) on serum progesterone (P4) concentration, and pregnancy per AI (P/AI) in Holstein cows (n = 489) re-synchronized with a 5-d CIDR program at non-pregnancy diagnosis (d 0). On d 5, cows were stratified by parity (primi- and multiparous) and number of inseminations and assigned randomly to receive (at CIDR removal) either one dose of PG (HC; 25 mg; s.q.; n = 247) or 2 doses of PG (2PG; 25 mg each, i.m.; n = 242), 24 h apart. Estrual behavior was monitored from d 5 to d 8, and if cows were detected in estrus, they were bred on that day. On d 8, cows not detected in estrus were administered a second dose of GnRH and inseminated at a fixed time AI (TAI). Blood samples were collected (n = 242), on d 5 and 8 to measure serum P4 concentrations and determine luteolytic response. Pregnancy was confirmed via ultrasonography 40 to 45 d after TAI. Data were analyzed by logistic regression (GLIMMIX). No difference in P/AI was detected between treatments (P = 0.11), as mean P/AI was 20.0% vs. 25.7% for HC and 2PG, respectively. There was a treatment by parity effect on P4 (P < 0.05). Mean serum P4 concentrations at TAI were greater (P < 0.05) in HC compared with 2PG (n = 115), only in multiparous cows (n = 69). Regardless of parity, mean P4 at TAI was <0.5 ng/mL for both treatment groups (0.44 ± 0.06 and 0.17 ± 0.06 ng/mL for HC and 2PG, respectively). Incidence of luteolysis (defined as P4 ≥ 1.0 on d 5 and <0.7 ng/mL at TAI) was greater (P < 0.05) in 2PG (97%) than HC (87%) cows. Overall, 2PG was more effective in inducing luteolysis before TAI than HC, however, no difference in P/AI was detected between treatments. Thus, based the current data, one dose of HC may potentially be used as option in the 5-d CIDR program with fewer animal handlings, injections, and labor compared with 2 doses of 2PG.
Reproduction: Posters Posters Reproduction 7/11/2021 0:00 t84752 Watch P488 Use of a cow-side immune test to improve prediction of metritis. 17 J. Prim metritis immunity prediction J. Prim1, Q. Huo2, A. Mirzaei1, K. Galvao1, R. Chebel1 1University of Florida, Gainesville, FL, 2University of Central Florida, Orlando, FL Two branches of immune function work together to protect the animals from invading pathogens: cell-mediated immunity (type 1), and antibody-mediated immunity (type 2). Maintaining a proper balance of type1/type2 immunity is necessary to provide optimal protection to the animals against infectious diseases. The objectives were to investigate the benefits of adding information from a cow-side immune test to metritis-prediction models. Cows (n = 197) were examined by study personnel at 4, 7, and 10 DIM for the diagnosis of metritis (watery, fetid, pink/brown uterine discharge) and acute metritis (rectal temperature >39.5°C). Blood samples collected within 24 h of calving were used to determine the balance between type 1 and type 2 immune response by measuring the relative quantity of IgG1 and IgG2 in the blood serum (D2Dx immunity test). A high-test score indicates a stronger type 1 response, whereas a low-test score indicates a stronger type 2 response. Logistic regression was used to create multivariable models to predict the risk of metritis through a step-wise backward elimination (P < 0.20). The area under the curve and the max-scaled adjusted r-square were used to evaluate the precision of the models. Dairy, parity, gestation length, calf sex, dystocia, stillbirth, twining, vaginal laceration (VL), and retained fetal membranes (RFM) were initially included in the model. The final model to predict metritis included parity, twining, VL, and RFM and had AUC = 0.86 and max-rescaled r-square = 0.43. When D2Dx results were added to the model to predict metritis, the final model included parity, twining, VL, RFM, and D2Dx results and had AUC = 0.87 and max-rescaled r-square = 0.46. The only variable retained in the initial model to predict acute metritis was calf sex and the model had AUC = 0.63 and max-rescaled r-square = 0.04. Conversely, when D2Dx immunity test results were added to the model to predict acute metritis, the model included D2Dx results and had AUC = 0.67 and max-rescaled r-square = 0.10. Our preliminary results suggest that the cow-side test used herein could improve the accuracy of models to predict metritis.
Ruminant Nutrition - Calves & Heifers: Orals Orals Ruminant Nutrition 7/11/2021 0:00 s9641                  
Ruminant Nutrition - Calves & Heifers: Orals Orals Ruminant Nutrition: Calves and Heifers 7/11/2021 0:00 t84644 Watch 157 Effect of weaning pace and age on the blood cells and haptoglobin concentration of Holstein dairy calves. 1 B. C. Agustinho stress weaning white blood cells A. Wolfe1, B. C. Agustinho2, C. Y. Tsai2, D. E. Konetchy2, A. H. Laarman1, P. Rezamand2 1Agricultural, Life and Environmental Sciences, University of Alberta, Edmonton, AB, Canada, 2Department of Animal, Veterinary & Food Sciences, University of Idaho, Moscow, ID Weaning is a critical process to dairy calves, which can cause stress and stimulate body response. An objective of this study was to determine the effect of the weaning calves at 2 ages (49 vs. 63 d) and 2 weaning paces (abrupt over 3 d vs. gradual over 14 d) on the blood parameters. Forty Holstein dairy calves (20 male and 20 female), blocked by sex and body weight at birth, were randomly assigned in a 2 × 2 factorial arrangement of treatments (weaning age; weaning pace). The treatments included early-abrupt (EA), early-gradual (EG), late-abrupt (LA), and late-gradual (LG). The animals were housed in hutches (1 × 1.5 m) with free access to feed (alfalfa hay, starter grain) and water. Blood samples were obtained one-day post-weaning, and the blood counts and haptoglobin concentration were determined in a hematology analyzer. Data were analyzed using mixed model of SAS with significance declared at P ≤ 0.05 and the tendency at P ≤ 0.10. Results showed that animals weaned at the late-stage presented a greater haptoglobin concentration (12.3 vs. 11.5; P < 0.01) and hematocrit percentage (38.8 vs. 36.6; P < 0.01) in the blood when compared with early-weaned calves. In addition, hematocrit percentage (P < 0.01) was greater in animals weaned abruptly as compared with that for gradually weaned calves. There was a weaning stage × weaning pace interaction for neutrophil percentage (P = 0.01), lymphocyte percentage (P = 0.05), and absolute platelet numbers (P = 0.02) in the blood. Calves in LA had a higher neutrophil percentage and absolute platelet numbers compared with that for animals in the EA. On the contrary, lymphocyte was lower in LA compared with that for EA. Calves in LA showed a greater absolute platelet numbers compared with that for calves in LG (322 vs. 244). Overall, the weaning method, age at weaning, as well as the interaction of the 2 factors affected the blood cells and haptoglobin concentration of calves.
Ruminant Nutrition - Calves & Heifers: Orals Orals Ruminant Nutrition: Calves and Heifers 7/11/2021 0:00 t84419 Watch 158 Effect of weaning pace and age on the gene expression of inflammatory markers in hepatic, rumen, and intestinal tissues of Holstein dairy calves. 2 B. C. Agustinho stress weaning B. C. Agustinho1, A. Wolfe2, C. Y. Tsai1, D. E. Konetchy1, A. H. Laarman2, P. Rezamand1 1Department of Animal, Veterinary & Food Sciences, University of Idaho, Moscow, ID, 2Agricultural, Life and Environmental Sciences, University of Alberta, Edmonton, AB, Canada Weaning of the dairy calves can induce stress, which may elicit inflammatory response; however, the literature is limited. Therefore, an objective of this study was to determine the effect of the weaning at 2 ages (49 vs. 63 d) and 2 weaning paces (abrupt vs. gradual) on local inflammation status. Forty Holstein calves were blocked by sex and body weight at birth and randomly assigned in a 2 × 2 factorial arrangement (weaning age; weaning pace). The treatments included early-abrupt (EA), early-gradual (EG), late-abrupt (LA), and late-gradual (LG). Liver, rumen, and large intestine tissues were obtained at termination (one-day post-weaning) from 20 male calves for gene expression analysis using RT-qPCR. The target genes included interleukin 6 (IL-6), interleukin 8 (IL-8), tumor necrosis factor-α (TNF-α), interferon-γ (INF-γ), and nuclear factor κ-B (NF-κB). Cycle threshold (Ct) of target genes corrected by Ct of house-keeping genes (GAPDH and RPS-9) were used (ΔCt) for statistical analysis using the mixed model of SAS with significance declared at P ≤ 0.05 and the tendency at P ≤ 0.10. Results showed that calves weaned late-stage presented a reduced expression of IL-8 in the liver (P = 0.04) and in the large intestine (P = 0.10) when compared with that of the early-stage. In addition, the hepatic expression of IL-8 tended to reduce (P