ADSA 2023 Recordings

SessionSession_TypeScience_SectionSession_DTTracking_NumListenPresentationAbs #TitleSession_OrderPresenterKeywordsAuthorsInstitutionsAbstract
Dairy Foods Symposium: Todd R. Klaenhammer Memorial Symposium--Contributions to Our Understanding of Lactic Acid BacteriaSymposiumDairy Foods6/25/2023 14:00t87863ListenPresentation2000Extending the Klaenhammer legacy by engineering probiotics using CRISPR.1R. BarrangouCRISPR probiotic genome editingR. Barrangou11North Carolina State University, Raleigh, NCThe advent of CRISPR-based technologies has revolutionized our ability to manipulate the genetic content of organisms across the tree of life, and democratized genome editing across the globe. Repurposed from obscure adaptive immune systems in bacteria, CRISPR molecular machines have been broadly deployed in academia and industry in the past 10 years, to manipulate the genomes of organisms relevant to medicine, biotechnology and agriculture. We now have access to a portable CRISPR toolbox enabling flexible editing from a single nucleotide to large scale genome manipulation in diverse microbes, including lactic acid bacteria widely used as starter cultures and probiotics in the food supply chain. Extending the legacy of Todd R. Klaenhammer, I will discuss recent advances in engineering of starter cultures and probiotic bacteria spanning 1nt base editors from single Cas effectors, to >100,000 bp manipulations and island engineering using Cascade-Cas3 and CRISPR-associated Tn7-like transposons, spanning CRISPR-Cas systems classes and types, in endogenous and exogenous contexts. I will also highlight the practical limitations and implications of scaling up genome editing and deploying an expanded CRISPR toolbox, showcasing the path to engineering next-generation lactobacilli and bifidobacteria used as probiotics, to enhance human health and a more sustainable food supply chain.
Dairy Foods Symposium: Todd R. Klaenhammer Memorial Symposium--Contributions to Our Understanding of Lactic Acid BacteriaSymposiumDairy Foods6/25/2023 14:00t87570ListenPresentation2001Bacteriophage-bacterial interaction, then and now.2C. Hillbacteriophage genomes lactic acid bacteriaC. Hill11University College Cork, Cork, IrelandTodd Klaenhammer was a principal investigator at NCSU for almost 40 years. In that time he conducted pioneering work on probiotics, lactic acid bacterial (LAB) genetics and bacteriophages. In this presentation I will reflect on the advances in bacteriophage biology over the course of a single professional life, particularly focusing on areas where Todd made an outstanding contribution. Todd’s career spans from a time where no single LAB bacteriophage had ever been sequenced (and sequencing even a single gene was the work of many months) to a time where thousands of bacteriophage genomes can be determined in one metagenomic sequencing run. Science has of course benefitted enormously from these advances, but something has also been lost in an era where overwhelming amounts of data can be generated in real time with little effort.
Dairy Foods Symposium: Todd R. Klaenhammer Memorial Symposium--Contributions to Our Understanding of Lactic Acid BacteriaSymposiumDairy Foods6/25/2023 14:00t89941ListenPresentation2002Probiotics and prebiotics: A healthy gut and healthy aging.4M. A. Azcárate-Perilprebiotics probiotics aging gut microbiomeM. A. Azcárate-Peril1,2, M. Aljumaah2, J. Gunstad3, A. J. Ritter4, D. A. Savaiano5, J. W. Arnold1, J. M. Bruno-Barcena21University of North Carolina at Chapel Hill, Chapel Hill, NC, 2North Carolina State University, Raleigh, NC, 3Kent State University, Kent, OH, 4Myosin Therapeutics Inc, Jupiter, FL, 5Purdue University, West Lafayette, INAdvancing age coincides with declines in gut homeostasis and cognitive ability. Our studies aimed to assess probiotics for mild cognitive impairment (MCI) and prebiotic galacto-oligosaccharides (GOS) in the aging gut. The first study investigated the gut microbiome of middle-aged and older adults with MCI compared with neurologically healthy individuals and the impact of probiotic Lactobacillus rhamnosus GG (LGG) in a double-blind, placebo-controlled, randomized clinical trial. Microbiome analysis identified Prevotella ruminicola, Bacteroides thetaiotaomicron, and Bacteroides xylanisolvens as taxa correlated with MCI. Differential abundance analysis at baseline identified Prevotella as significantly more prevalent in MCI subjects than cognitively intact subjects. A decrease in the relative abundance of Prevotella in response to LGG in the MCI group was correlated with an improved cognitive score. Our second study aimed to confirm and extend our previous reports that a 30-d administration of pure GOS significantly reduced symptoms and altered the fecal microbiome in patients with lactose intolerance (LI). We assessed the fecal microbiome of 377 LI patients randomized to one of 2 GOS doses or placebo. Taxa impacted by treatment and subsequent dairy consumption included lactose-fermenting species of Bifidobacterium, Lactobacillus, Lactococcus, and Streptococcus. Secondary fermentation microorganisms included Coprococcus, Ruminococcus, Blautia, and Methanobrevibacterium. Finally, tertiary fermenters (use acetate to generate butyrate) included Faecalibacterium prausnitzii and Roseburia faecis. Microbiome analysis at 16 and 22 weeks after treatment further suggested relatively long-term benefits when individuals continued consumption of dairy products. Finally, we evaluated GOS in a pre-clinical study comparing gut aging in young versus old mice. Old animals had a distinct microbiome characterized by increased ratios of non-saccharolytic versus saccharolytic bacteria and a low abundance of β-galactosidases. We found that GOS reduced diversity and increased the abundance of specific saccharolytic and non-saccharolytic bacteria and β-galactosidases in young and old animals; however, a strong, homogeneous bifidogenic effect was not observed. Galacto-oligosaccharides reduced intestinal permeability and increased MUC2 expression and mucus thickness in aged mice. Our studies show that probiotic and prebiotic interventions targeting the gut microbiome can preserve and restore cognitive health protecting the aging brain via the gut-brain axis, improving gut dysbiosis, reducing intestinal permeability and inflammation, and ameliorating digestive issues.
Dairy Foods Symposium: Todd R. Klaenhammer Memorial Symposium--Contributions to Our Understanding of Lactic Acid BacteriaSymposiumDairy Foods6/25/2023 14:00t87609ListenPresentation2003Innovation toward a dairy-based platform for effective next-generation, probiotics.5D. MillsBifidobacterium whey protein phospholipid concentration probioticsD. Mills11University of California, Davis, CAMilk is well known to direct the enrichment of the neonatal gut microbiome, an assembled “organ” with important consequences on host health. A key driver of that guided enrichment are the glycans present in milk including free oligosaccharides, glycoproteins, and glycolipids. In the last decade, much research has focused on the molecular mechanisms by which free oligosaccharides enrich a beneficial gut microbiome in infants. Milk also contains an abundance of glycoconjugates presumed to participate in a similar enrichment of microbes in the gut, yet the molecular nature of this interaction is poorly defined. The dairy industry produces abundant glycoconjugate-rich streams that can be examined for their interaction with glycan-consuming commensal microbes. Recently, we employed a culturomics approach to identify specific bifidobacteria that grow on media containing whey protein phospholipid concentrate (WPPC), a glycoconjugate-rich byproduct of cheesemaking. Fecal enrichments with WPPC identified several bifidobacterial strains that acidified WPPC-containing media, suggesting it could grow on the glycans in WPPC. Comparative genomics of Bifidobacterium longum strains that grew well on WPPC with strains that grew poorly identified unique genes putatively associated with WPPC growth. Transcriptomic analysis of one such strain, B. longum YK1048, revealed differential upregulation of carbohydrate-active enzymes on WPPC including a β-glucuronidase present in only WPPC fermentable strains. Determination of the molecular mechanisms responsible for robust growth of bifidobacterial strains on WPPC advances novel WPPC-based synbiotics for use in animals and humans. More importantly, precise chemical characterization of dairy glycoconjugates and their molecular interactions with beneficial gut commensals set the stage for tailored use of these byproduct streams to increase the efficacy of “next-generation” live bacterial therapeutics and probiotics.
Dairy Foods Symposium: Todd R. Klaenhammer Memorial Symposium--Contributions to Our Understanding of Lactic Acid BacteriaSymposiumDairy Foods6/25/2023 14:00n8875ListenDiscussion, followed by reception6
ADSA-EAAP (European Federation of Animal Science) Speaker Exchange Symposium: Building a Resilient Dairy Sector--Circular Economies of Dairy Production and Dairy FoodsSymposiumRuminant Nutrition - Protein/Amino Acids6/26/2023 9:30t88775ListenPresentation2120Nutritional strategies to minimize carbon footprint and maximize nitrogen efficiency in dairy systems.1N. I. Nielsenphase feeding protein deficiency amino acidsN. I. Nielsen1, M. Ø. Kristensen1, M. Larsen21SEGES Innovation, Aarhus N, Denmark, 2Aarhus University, Foulum, DenmarkPrevious studies have shown that abomasal infusion with amino acids or casein in the first 28 DIM increase daily milk yield by 5–7 kg. The aim was to investigate the effect of alleviating the amino acid deficiency in the first 4 weeks (wk) after calving on performance in 15 wk using phase feeding strategies with feeds high in metabolizable protein (MP). Thirty-six multiparous Holstein cows were used in a randomized block design with 3 treatments and repeated measurements for the first 15 wk of lactation. At the day of calving, cows were randomly assigned to 1 of 3 treatments: 1) a control diet with 17 g of MP/MJ NEL fed for 15 wk (TMR1), 2) phase feeding with 20 and 16 g MP/MJ NEL (TMR2) fed wk 1 to 4 and wk 5 to 15 postpartum, respectively, and 3) phase feeding with 20, 17 and 15 g MP/MJ NEL (TMR3) fed wk 1 to 4, wk 5 to 10, and wk 11 to 15 postpartum, respectively. To achieve diets with high MP, soypass and corn gluten meal substituted partly barley, soybean meal, and canola meal. Treatments started on d 4 postpartum and all cows were fed the same diet until d 4 after calving. Data was analyzed with treatment (TMR1; TMR2; TMR3), period (period 1: wk 1–4; period 2: wk 5–10; period 3: wk 11–15) and their interaction as fixed effects, cow as random effect, and wk in milk within cow as repeated measurement. In period 3, dry matter intake was higher for TMR2 (26.2 kg/d) compared with TMR1 (24.9 kg/d) and TMR3 (24.1 kg/d) but did not differ in period 1 and 2 (P < 0.05; interaction). ECM yield was higher in period 1 for TMR2 (48.6 kg/d) and TMR3 (48.1 kg/d) compared with TMR1 (44.2 kg/d) whereas ECM yield did not differ among treatments in period 2 and 3 (P < 0.05; interaction). In period 1, N efficiency was higher for TMR1 compared with TMR2 and 3 and did not differ among treatments in period 2 and 3 (P < 0.05; interaction). In conclusion, increasing the postpartum MP supply using commercially available protein feeds starting at d 4 postpartum appeared to have limited effect on milk production and N efficiency after the transition period. However, it can be speculated that the extra MP supply should have been initiated before d 4 postpartum.
ADSA-EAAP (European Federation of Animal Science) Speaker Exchange Symposium: Building a Resilient Dairy Sector--Circular Economies of Dairy Production and Dairy FoodsSymposiumADSA-EAAP Joint Symposium6/26/2023 9:30t89962ListenPresentation2121Understanding the production of beef from dairy systems in the UK: An analysis of trends.2J. Gordonbreeding breed selection beef on dairyJ. Gordon1, K. Glenk1, V. Eory1, E. Wall1, D. Moran21SRUC, Edinburgh, United Kingdom, 2University of Edinburgh, Edinburgh, United KingdomThe breeding technologies and programs available to the dairy sector are allowing more dairy beef cross cattle (DBX) to be produced annually in the United Kingdom. This increase in DBX production is being driven by many factors including stakeholders, policy and public demand for high welfare and sustainable UK cattle production systems. This paper draws on comprehensive data from the UK cattle sector to analyze how DBX production has changed over time and what role the different actors play in the breeding decisions. It uses an interdisciplinary approach based on 47 semi structured interviews with farmers and stakeholders in the UK, and an analysis of the UK Cattle Tracing System database. The aim of the study is to provide further insights into risks and opportunities for future development of the cattle industry and to provide an insight to identify trends in the sector and underlying influencing factors. The results show that DBX are becoming an increasingly important production system in the UK cattle sector. The number of DBX animals slaughtered increased by 31% from 2010 to 2020. DBX animals are embedded in systems ranging from terminal intensive production to extensive breeding farms. The growth in DBX was accompanied by a growing reliance on two key breeds: the Aberdeen Angus and British Blue. Using interview data, we identify factors that influence breed selection for DBX. In the UK, DBX offers an opportunity to increase value of dairy calves to be marketed as beef animals. Farmers emphasize calving ease and ensuring marketability of the DBX calf as important considerations for breeding selection. Our analysis highlights both the challenges and opportunities for optimizing the DBX production to meet demand for high welfare and sustainable cattle. This includes achieving a better consensus in the breeding strategies, considering marketability and profitability both for the dairy (breeding) and beef (rearing) farmers involved in DBX production, and an increased involvement of genomic selection for better beef production traits in DBX animals.
ADSA-EAAP (European Federation of Animal Science) Speaker Exchange Symposium: Building a Resilient Dairy Sector--Circular Economies of Dairy Production and Dairy FoodsSymposiumADSA-EAAP Joint Symposium6/26/2023 9:30t89901ListenPresentation2122Dairy coproducts can be useful feedstocks for the circular bioeconomy.3J. Luceycircular bioeconomy feedstocks permeateJ. Lucey11University of Wisconsin-Madison, Madison, WIThe dairy processing sector generates large volumes of byproducts from cheesemaking and Greek yogurt products. Dairy processors routinely extract the proteins from cheese whey due to its high value, but that leaves large volumes of a byproduct called permeate. The solids in this permeate consist of primarily lactose and some salts. Currently permeate is mostly used as an animal feed, some is used to make various grades of lactose. Greek yogurt production results in the generation of acid whey, which lack significant protein. It’s high ash and lactic acid contents makes drying a challenge so much of it is land spread, risking potential negative environmental impacts due to possible leaching of nitrogen, phosphorus and other materials into soil and the groundwater. The large volumes, simple sugars (most lactose), and relatively consistent composition of these dairy byproducts makes them attractive as potential feedstock for biofermentation processes. Researchers are exploring the microbial engineering of microorganisms to efficiently ferment lactose into a range of chemicals. Some potential target chemicals include pure lactic acid, medium chain fatty acids, polyhydroxyalkanoates, various organic acids and various platform chemicals. Potential applications include bioplastics (currently only around 1% of plastics are biobased) and biochemicals to replacing fossil derived bulk/specialty chemicals (which are about 90% of currently used chemicals). Reactor conditions would need to be identified and optimized, and separation/purification methods would need to be developed to isolate the chemicals of interest to the required level of purity. Successfully achieving these steps could facilitate the dairy industry become a significant partner in the emerging circular bioeconomy, where dairy byproducts are no longer viewed as a type of “waste product” but instead become an important source of renewable feedstocks for biofermentation.
ADSA-EAAP (European Federation of Animal Science) Speaker Exchange Symposium: Building a Resilient Dairy Sector--Circular Economies of Dairy Production and Dairy FoodsSymposiumADSA-EAAP Joint Symposium6/26/2023 9:30t89873ListenPresentation2123Upcycling strategies of dairy byproducts and waste for value-added applications.4S. I. Martínez-Monteagudodairy streams value-added transdisciplinaryS. I. Martínez-Monteagudo1,21Family and Consumer Sciences, New Mexico State University, Las Cruces, NM, 2Department of Chemical and Materials Engineering, New Mexico State University, Las Cruces, NM, 3Center of Excellence in Sustainable Food and Agricultural Systems, New Mexico State University, Las Cruces, NMThe generation of waste and byproducts is ubiquitous in the dairy industry. Instead of landfilling or recycling, these streams can be turned into value-added products, such as sweeteners, micronutrients, ingredients, and additives. Valorization of these materials is multidisciplinary since it involves applying chemical and physical methods to create a desirable modification. This presentation summarizes our research efforts in creating value from dairy waste and byproducts. Upcycling is a guiding philosophy for the work presented here—a combination of processes that convert materials into new ones of higher quality and increased functionality. The upcycling strategies are illustrated under 4 scenarios: 1) converting lactose streams into sweeteners via heterogeneous catalysis; 2) extraction and fractionation of milk phospholipids with switchable solvents; 4) converting ice cream wastewater into functional peptides through subcritical hydrolysis; and 4) converting ice cream waste into biochar and crude oil via hydrothermal liquefaction. Illustrating upcycling in dairy streams has significant potential for improving circularity in the dairy industry.
Animal Behavior and Well-Being Symposium: Hot Topics in Calf Management--Welfare Considerations from Birth to TransportSymposiumAnimal Behavior and Well-Being6/26/2023 9:30t89138ListenPresentation2150Cow-calf separation: Public acceptance and scientific evidence.1M. A. G. von Keyserlingkcow-calf contact public attitudes nurse cowsM. A. G. von Keyserlingk1, D. M. Weary11University of British Columbia, Vancouver, BC, CanadaEarly cow-calf separation is standard practice on most dairy farms around the world. However, a growing body of evidence of public discomfort with this practice, undermining the dairy industry’s social license. Proponents of early separation argue that artificial rearing improves health, prevents the development of abnormal behavior in calves and results in improved milk production. During this presentation, we review the latest available evidence on public acceptability of cow-calf separation and discuss reasons why this practice fails to resonate with societal values. We also summarize the findings of 2 recent systematic reviews that synthesized the available research on the effects of prolonged cow calf contact on 1) acute responses of cows and calves to separation at different times, and long-term effects on calf behavior, welfare and productivity (calf growth and cow milk yield) and 2) cow and calf health, including calf scours, Cryptosporidiosis, Johne’s disease, pneumonia, passive transfer, mortality, and the dam’s udder health. We conclude that there is little evidence that early separation improves the health of dairy cows or calves, or that this practice improves whole-lactation milk yield. Indeed, the available evidence indicates that a period of extended cow-calf contact can have positive effects on calf behavior and growth. We also highlight areas requiring further research to help farmers interested in adopting prolonged cow-calf contact systems.
Animal Behavior and Well-Being Symposium: Hot Topics in Calf Management--Welfare Considerations from Birth to TransportSymposiumAnimal Behavior and Well-Being6/26/2023 9:30t88107ListenPresentation2151Calf housing and social impacts.2E. K. Miller-Cushondairy calf social housing social behaviorE. K. Miller-Cushon11University of Florida, Gainesville, FLHousing practices for calves vary widely in the dairy industry today and an understanding of dairy calf behavior is driving changes to refine calf rearing. Calf management influences early life experiences, having implications for behavioral development, cognition and response to novelty, and abnormal behaviors. Social housing supports the development of social bonds between calves and eases adaptation to novel social groups. Social housing is particularly beneficial when introduced early, with behavioral benefits of social housing evident in the first weeks of life. Social housing also influences the development of both feeding patterns and competitive behavior. Cumulative effects of calf social housing on social and feeding behaviors may mediate longer-term effects on behavior and performance and there remains a need to examine these effects in adulthood. Beyond influences on social development, socially reared dairy calves are less reactive to novelty and may have improved ability to navigate management transitions. Social housing, in addition to other aspects of environmental complexity, also relates to the development of abnormal oral behaviors. While cross-sucking is a concern in socially housed calves, the duration of individual abnormal oral behaviors is greatest in individually housed calves raised in relatively restrictive environments. Providing opportunities for dairy calves to perform a range of motivated natural behaviors, including social interaction and feeding behavior, is key for calf behavioral development and likely to have long-term welfare implications.
Animal Behavior and Well-Being Symposium: Hot Topics in Calf Management--Welfare Considerations from Birth to TransportSymposiumAnimal Behavior and Well-Being6/26/2023 9:30t88266ListenPresentation2152Transportation impact on preweaned calves.3C. Cramersurplus calves transport welfareC. Cramer11Colorado State University, Fort Collins, COAn important animal welfare concern across the US dairy industry is the transportation of preweaned calves from the source dairy to a calf-raising facility (e.g., calf ranches, heifer raising facilities, veal operations), auction, livestock market, or directly to slaughter. The increased adoption of breeding dairy cows with beef semen has resulted in more surplus calves being transported within the first week of life, garnering additional attention to calf transportation practices. Transportation stressors include limited (if any) access to food and water, commingling, environmental temperature changes, and a variety of handling techniques. Neonates are particularly vulnerable to transportation stressors due to their decreased ability to thermoregulate, underdeveloped immune system, and immature physiologic stress responses. Given that calves in the US are often transported at an average age of 3 d, and in many cases, less than 24 h of age, there is a critical need to address these welfare concerns. In addition to age, fitness for transport is a key welfare consideration; recent data from the US demonstrates that some source dairies transport compromised calves (i.e., dehydrated, diarrhea, navel inflammation, etc.), leading to significant welfare challenges during transportation. Calves arriving at US veal facilities have been reported to be dehydrated, lethargic, hypoglycemic; and/or have poor body condition, navel inflammation, and diarrhea. It is also possible that calves become compromised in transit to their destination. Thus, there is ample opportunity to target decision-making and producer-focused education not only at the source dairy, but at each stage of transportation to address critical welfare concerns. This presentation will summarize relevant research and key welfare issues relative to calf transportation and identify current gaps in knowledge.
Animal Behavior and Well-Being Symposium: Hot Topics in Calf Management--Welfare Considerations from Birth to TransportSymposiumAnimal Behavior and Well-Being6/26/2023 9:30t88297ListenPresentation2153Thermal stress impact on calves.4J. Van Oscold stress heat stress heat abatementJ. Van Os1, K. Reuscher11Department of Animal and Dairy Sciences, University of Wisconsin, Madison, WIAspects of calf welfare, such as the need for social contact and thermal comfort, have the potential for synergy or conflict. Calves expend energy to produce heat and maintain homeothermy at higher ambient temperatures relative to older cattle. Cold stress negatively affects growth performance and health. Mitigation strategies largely focus on nutritional interventions or by limiting heat loss with resources such as bedding or jackets. A yet-undocumented potential strategy to conserve body heat is for calves to huddle together in pair or group housing. Numerous other benefits of social housing have been documented in terms of calf social and cognitive development, welfare, and growth. Conversely, in the warm season, close social proximity could perhaps exacerbate heat stress, but this has not been investigated. Relative to older dairy cattle, less attention has been given to heat abatement strategies for pre-weaned calves. Providing supplemental shade (e.g., shade cloth over outdoor hutches) can reduce environmental heat gain. Strategies to promote heat dissipation include providing fans in indoor housing or increasing the apertures on outdoor hutches to improve air exchange and airflow. In Wisconsin, we conducted studies of calves housed in outdoor hutches, where they are exposed to seasonal extremes. We evaluated how social contact, when calves are housed in pairs of adjacent plastic hutches connected with an outdoor area, interacts with thermal comfort in winter vs. summer. In summer, we additionally investigated the effects of hutch ventilation to mitigate heat stress. Preliminary results show that pair-housed calves prefer to spend most of their time together across weeks of life, regardless of season. In winter, ambient temperature inside the hutch increases more when there are 2 calves vs. 1 calf inside. In summer, hutch ventilation, but not the number of calves, affects the hutch microclimate; furthermore, ventilation reduces calves’ thermoregulatory indicators of heat stress. These findings suggest that pair housing does not conflict with thermal comfort in either winter or summer, further building the case for promoting good calf welfare through social housing.
Animal Behavior and Well-Being Symposium: Hot Topics in Calf Management--Welfare Considerations from Birth to TransportSymposiumAnimal Behavior and Well-Being6/26/2023 9:30n8848ListenDiscussion5
Joint Breeding and Genetics and Lactation Biology Symposium: Genomics and Phenomics of LactationSymposiumBreeding and Genetics6/26/2023 9:30t88075ListenPresentation2165ADSA®-EAAP Speaker Exchange Presentation: Use of milk mid-infrared spectral data in dairy genetics: Past, present and future.1N. Genglermilk components novel traits high-dimensional traitsN. Gengler11University of Liège-GxABT, Gembloux, BelgiumFor 5 decades, major milk components such as fat and protein contents have been routinely predicted using mid-infrared (MIR) spectrometry, a nondestructive analysis technology, based on the absorption of MIR light by milk, associated to the Fourier transform generating whole MIR spectra. The historic use of MIR spectra in animal breeding was until recently restricted to its indirect use through MIR-predicted major milk components. A reason why additional potential for the use of MIR spectra data was overlooked for such a long time, was its unavailability outside used spectrometers. But this bottleneck was resolved and since around 2006, published research has been exploding leading to the present-day increasing availability of novel MIR-based phenotypes based on predictions developed by associating relevant reference data and corresponding MIR spectra. Key factors affecting the quality of predictions were identified and animal breeders have today access to many MIR-based phenotypes. These does not only include direct fine milk composition traits as fatty acids, but also indirect traits to assess quality of milk and milk products, technological properties, animal health and status, and emissions and interactions with the environment. Current situation is that breeders but also farm advisors, are feeling overwhelmed with many traits. Only slowly industry is taking up the generated opportunities for animal breeding and management. From an animal breeding perspective integrating even only some of these MIR-predicted traits in sustainable breeding goals is currently a challenge. In the future an alternative view on this situation should be considered. As a matter of fact, the high-dimensional MIR spectral data space, defined by the underlying absorbances along the range of wavenumbers but also across lactations and lactation stages, is also describing a global milk phenome. Direct use of MIR data as phenotypes has been proposed. These high-dimensional traits could allow breeders to rapidly assess underlying genomic information, however important theoretical and computational improvements are still needed to deal with them properly in the future.
Joint Breeding and Genetics and Lactation Biology Symposium: Genomics and Phenomics of LactationSymposiumBreeding and Genetics6/26/2023 9:30t89118ListenPresentation2166Phenotypic and genomic modeling of lactation curves: A longitudinal perspective.2H. R. Oliveiramilk production profitability random regression modelH. R. Oliveira1, G. S. Campos1, L. F. Brito11Purdue University, West Lafayette, INLactation curves, which describe the pattern of milk production over time, provide critical insights about animal health, milk production efficiency, and the overall profitability of the dairy industry. Consequently, understanding the longitudinal perspective of lactation curves can help dairy producers optimize management practices, improve milk production efficiency, and reduce animal health risks. Both phenotypic and genomic modeling have been used to study lactation curves, providing valuable information for dairy producers and breeders. Phenotypic modeling involves the analysis of data on milk production collected from individual animals, which can be used to estimate parameters of phenotypic lactation curve models, such as lactation peak and persistency. On the other hand, genomic modeling also incorporates genetic marker information to predict the genetic basis of lactation curves, which allows the identification of genetic variants associated with milk production. Random regression models provide a powerful tool for modeling lactation curves, allowing for the estimation of both genetic and environmental effects on milk production over time. Furthermore, the use of random regression models allows for a more flexible and robust modeling of the lactation curve compared with traditional models based on fixed time points. In this invited talk, we will discuss the importance of the longitudinal perspective in the study of lactation curves and the various statistical and mathematical models used to analyze longitudinal data. We will also highlight the key factors that influence milk production over time, and the potential applications of longitudinal analysis of lactation curves in improving animal health and milk production efficiency. Overall, analyzing the longitudinal perspective of lactation curves will continue to play a crucial role in improving the production efficiency and sustainability of the dairy industry, and the methods and models developed will be applied to other longitudinal traits.
Joint Breeding and Genetics and Lactation Biology Symposium: Genomics and Phenomics of LactationSymposiumBreeding and Genetics6/26/2023 9:30t89572ListenPresentation2167Mitochondrial bioenergetics of extramammary tissues during lactation and in response to heat stress.4A. Skibielproteomics energy metabolism liverA. Skibiel1, M. Zachut2, G. Dahl3, A. Kavazis4, W. Hood41University of Idaho, Moscow, ID, 2ARO Volcani Center, Rishon Lezion, Israel, 3University of Florida, Gainesville, FL, 4Auburn University, Auburn, ALHeat stress has detrimental impacts on agricultural operations by reducing livestock productivity and quality. In the US dairy industry, heat stress results in financial costs that exceed $2 billion. Heat stressed dairy cows produce less milk, and have altered energy metabolism, and higher morbidity and mortality rates, which occur when cows are heat stressed when dry and when lactating. However, gaps in knowledge remain regarding the cellular and molecular mechanisms underlying heat effects on energy metabolism and consequently milk production. Mitochondria produce around 90% of cellular ATP through oxidative phosphorylation, generate precursors for milk synthesis, and modulate the energetic response to stress. Yet, little information exists regarding mitochondrial bioenergetics during lactation and in response to heat stress in dairy cows, particularly for extramammary tissues with supporting roles in milk synthesis. Here, I will focus on our studies in dairy cows exploring hepatic mitochondrial adaptations across lactation and impacts of heat stress on expression of genes and proteins involved in mitochondrial function as well as mitochondrial bioenergetics and structure. Our studies involved observational and experimental approaches, including proteomics analysis of liver tissue from dairy cows that were heat stressed or actively cooled and mitochondria functional assays conducted across a typical lactation and in mid-lactation cows that were heat stressed or normo-thermic. Expression of nuclear genes involved in mitochondrial biogenesis and function were quantified using qRT-PCR. Mitochondrial morphology was assessed through transmission electron microscopy. Mitochondrial respiration using NADH or FADH2-linked substrates was quantified using an electrode-based system to measure mitochondrial oxygen consumption. Results from this work indicate that mitochondrial efficiency is enhanced as milk yield increases during lactation. Additionally, while moderate to high levels of heat stress reduce expression of hepatic mitochondrial proteins involved in energy production, mild heat stress appears to have little direct impact on hepatic mitochondrial function. Further research is necessary to investigate mitochondrial responses to moderate and high heat loads in dairy cows both during the dry and lactating periods.
Joint Breeding and Genetics and Lactation Biology Symposium: Genomics and Phenomics of LactationSymposiumBreeding and Genetics6/26/2023 9:30t88308ListenPresentation2168The microbiome of mammary gland: Implications for udder health and therapeutic potentials.5H. Derakhshanimammary microbiome microbiome therapeutics mastitisH. Derakhshani1, J. C. Plaizier1, H. W. Barkema2, J. De Buck2, E. Khafipour3, M. G. Surette41University of Manitoba, Winnipeg, MB, Canada, 2University of Calgary, Calgary, AB, Canada, 3Cargill Animal Nutrition and Health, Minneapolis, MN, 4McMaster University, Hamilton, ON, CanadaThe advent of culture-independent metagenomics has revolutionized our understanding of the role of commensal microbiota in immune homeostasis and disease susceptibility of humans and animals. In the context of the bovine mammary gland, several studies have linked the composition of milk microbiota to both the physiological status of cows and the farm environment. Factors such as stage of lactation, metabolic status, incidence of clinical and subclinical mastitis, cows’ genotype, and the type of bedding material used on farms have all been related to the composition of milk and teat canal microbiota. The notion of a viable intramammary microbiota, if proven valid, could have important implications for development of novel microbial ecosystem therapeutics for improving mastitis resistance. However, strong debates exist on the permissiveness of the mammary gland for a rich and diverse microbiome, which usually contradicts the very low bacterial biomass detected in milk samples collected from healthy udders. Culture-independent metagenomic approaches alone cannot establish whether the identified microbial communities are viable, and if so, can play a role in udder physiology and mastitis susceptibility. In this presentation, we will provide a snapshot of the current state and limitations of the mammary microbiome research. In addition, we will describe how recent advances in high-throughput culturing and genome sequencing of microbiota has enabled isolation and identification of previously uncultured lineages of the host-associated microbiotas, including strictly anaerobe species isolated from the bovine mammary gland. Particularly, we will discuss how the application of genome mining tools and high throughput functional screening assays could facilitate identification of potential therapeutic targets, including novel probiotic candidates and microbial natural products with potent activities against mastitis pathogens.
Breeding and Genetics Platform Session: Novel Traits, Novel TechnologiesPlatform SessionBreeding and Genetics6/26/2023 14:00t89891ListenPresentation2243Genetic improvement of calf health: Genomics makes it possible.1B. Fessendencalf wellness genomics HolsteinB. Fessenden1,2, A. McNeel1, D. Weigel2, D. Gonzalez-Pena1, N. Vukasinovic3, F. Di Croce31Zoetis Precision Animal Health, Kalamazoo, MI, 2Zoetis Outcomes Research, Kalamazoo, MI, 3Zoetis Precision Animal Health R&D, Kalamazoo, MIHeifer disease and death losses represents a financial cost for dairy producers. Genetic improvement programs that incorporate differences in risk of calf disease and livability have potential to improve profitability of dairy production. To partially address this effect on profitability, a genomically enhanced genetic evaluation for calf health was developed using a single-step genomic BLUP and a univariate threshold animal model. The estimated heritabilities are 0.042, 0.045, and 0.060 for calf respiratory disease, calf scours, and calf livability. An animal’s relative risk for each of the diseases is reported as a standardized transmitting ability (STA). This study was conducted to demonstrate the ability of calf wellness STA to predict calf disease and death incidence using 10,751 Holstein heifers born in 2021 from 10 US commercial herds that recorded at least 2 of the desired outcomes. Heifers were ranked by their STA within herd and birth season then assigned to genetic quartiles based upon this ranking. Calf health events were collected from on-farm herd management software and heifers were assigned as healthy (0) or diseased/died (1) for each event. Statistical analysis was performed using generalized linear mixed model with genetic quartile as a fixed effect and herd and birth season as random effects. Calf wellness prediction quartiles were significantly different for calf disease incidence. The difference between the worst and best genetic quartiles being 1.81% for calf livability, 3.66% for calf scours, and 13.99% for calf respiratory disease, which represents reductions in incidence of 34%, 52%, and 33%, respectively. The differences in the STA between the worst and best quartiles were 11 STA for each trait with the STA standard deviation being 5 for all 3 traits. This demonstrates that improving calf health and livability through genetic selection presents an opportunity for dairy producers to reduce calf disease incidence, herd replacement costs, and improve herd profitability when combined with comprehensive management practices.
Breeding and Genetics Platform Session: Novel Traits, Novel TechnologiesPlatform SessionBreeding and Genetics6/26/2023 14:00t89083ListenPresentation2245Candidate mutation for calf recumbency in Holsteins.2C. D. Dechowcalf recumbency mutation CACNA1sC. D. Dechow1, P. M. VanRaden2, D. J. Null2, A. Al-Khudhair2, M. C. McClure31Pennsylvania State University, University Park, PA, 2USDA Animal Genomics and Improvement Lab, Beltsville, MD, 3ABS Global, DeForest, WIA recessive recumbency haplotype that results in elevated calf mortality but with apparent incomplete penetrance was previously linked to the end of chromosome 16 (78.7 to 80.7 Mbp). The region included 110 unique genes, 13 of which were plausible candidate genes based on association with diseases reported in the Online Mendelian Inheritance in Man database. Genotype analysis indicated that the haplotype was common and traced back to 1952 with a key ancestor born in 1984 (HOUSA1964484, Southwind) identified from chip genotypes as homozygous for the suspect haplotype. Sequence data (30x, Illumina HiSeq pair-ended) from Southwind, an affected calf, and the sire of the affected calf was scanned for candidate mutations. A missense mutation in calcium channel, voltage-dependent, L type, α 1S subunit (CACNA1S) that alters a GGC codon to AGC and facilitates a glycine to serine amino acid substitution at 79,613,592 bp was considered the most promising candidate. The mutation was homozygous in the affected calf and heterozygous in the calf’s sire and Southwind. Sequence data available from the Cooperative Dairy DNA for 299 other Holsteins indicated a 97% concordance with the haplotype and an 89% call rate. The Sorting Intolerant From Tolerant score (range 0 to 0.01) indicated that the mutation was deleterious with a moderate projected impact which may explain the incomplete penetrance. CACNA1S is predicted to have multiple transcripts of 39 to 40 exons with the mutation in exon 30 to 32; the exon amino acid sequence appears to be broadly conserved. CACNA1S enables calcium channel voltage gate activity and is highly expressed in skeletal muscle. In humans, heterozygotes for a CACNA1S mutation may experience periodic paralysis whereas homozygotes may have no ability to stand and can be more severely affected than the recumbency. Mice homozygous for CACNA1S knockout mutations show degenerated muscles, edema, failure of myoblast differentiation by d 13 of embryonic development, and perinatal death. A stand-alone test for the mutation is under development and the mutation is expected to be added to a genotyping array.
Breeding and Genetics Platform Session: Novel Traits, Novel TechnologiesPlatform SessionBreeding and Genetics6/26/2023 14:00t88600ListenPresentation2244Genetic evaluation for stillbirth and pre-weaning mortality.3M. M. Axfordcalf survival calf weaning rate stillbirthM. M. Axford1,2, M. Khansefid1,2, J. Pryce1,21Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, Victoria, Australia, 2School of Applied Systems Biology, La Trobe University, Bundoora, Victoria, Australia, 3DataGene Ltd, Bundoora, Victoria, AustraliaThe welfare of calves is important to both farmers and consumers. Practices that increase the proportion of calves born alive and continue to thrive through to weaning contribute to improved sustainability as they improve animal welfare, improve farm financial performance and reduce environmental waste. Farmers often record whether the calf is alive or dead when noting a calving observation. Stillbirths (SB) are calves recorded as dead at birth or die within 24 h after birth. Pre-weaning mortality (PWM) refers to calves that die after the first day of life but before weaning based on termination data. Both stillbirth and pre-weaning mortality are characterized by low heritability and are binomial in nature. Data collection for these traits is incomplete, compared with traits like milk yield in cows. Despite these challenges, genetic variation can be measured and used to produce breeding tools, such as EBVs, to reduce calf mortality over time. The aim of this study was to compare the performance of various linear models to predict stillbirth and pre-weaning mortality traits in Holstein and Jersey cattle and evaluate their applicability for industry-wide use in the Australian dairy industry. Calving records from 2.78M Holstein and Jersey dams were obtained from DataGene’s Central Data Repository from 1990 onwards. About 7% of calves were recorded as stillborn in the period 2000–2021 (n = 1.74M calvings). Pre-weaning mortality is much lower than stillbirth during the same period at 2% (n = 0.89M calves). Genetic parameters were estimated using bivariate models for stillbirth direct, stillbirth maternal and pre-weaning mortality using calving ease as a covariate. The heritability of calf traits was 1–2% depending on the breed, trait and model. Based on this study, it is possible to measure genetic variance in calf traits as a first step to using genetic selection to increase the proportion of calves born alive and calves weaned. Improved calf and calving recording practices and further research is expected to increase the reliability of genetic predictions.
Breeding and Genetics Platform Session: Novel Traits, Novel TechnologiesPlatform SessionBreeding and Genetics6/26/2023 14:00t88541ListenPresentation2246Feasibility study of genetic evaluation for Johne’s disease in US Holstein cows.4L. C. Novoinfectious disease reliabilities single-step modelL. C. Novo1,2, J. Burcahard2, H. D. Norman2, J. Dürr2, R. Fourdraine3, T. M. McWhorter2, F. Peñagaricano1, K. L. Parker Gaddis2, X. L. Wu21University of Wisconsin-Madison, Madison, WI, 2Council on Dairy Cattle Breeding, Bowie, WI, 3Dairy Records Management Systems, Raleigh, NCParatuberculosis, or Johne’s disease (JD), is an infectious enteric disease in cattle and other ruminants, causing substantial economic loss annually worldwide. This work investigated the feasibility of a national genetic evaluation for Johne’s Disease susceptibility in US Holstein cattle. The data, provided by the Council of Dairy Cattle Breeding, comprised 365,980 Holstein cows from 1,048 herds participating in the voluntary control program for JD between 2002 and 2022 diagnosed with 2 protocol kits: Idexx (IDX) and Parachek (PCK). Only test results from the first 5 parities were analyzed. An animal was considered infected if it had at least one positive result or uninfected otherwise, with an overall incidence of 4.72% of animals. Genotypes of 78,964 SNP markers were extracted for 25,000 animals. Variance components were estimated using 3 models, namely, a pedigree-only threshold model (THR), a single-step threshold model (ssTHR), and a single-step linear model (ssLR). For the threshold models, the Markov chain Monte Carlo simulation consisted of 80,000 iterations with a burn-in period of 15,000 and thinned for every 100th. The heritability estimates of JD susceptibility were low to moderate. The 2 threshold models gave higher posterior heritability estimates (0.11–0.16) than the linear model (0.05–0.09). The average reliability of the estimated breeding values of JD susceptibility based on the 3 models varied from 0.18 (THR) to 0.22 (ssLR) for IDX and from 0.14 (THR) to 0.18 (ssTHR and ssLR) for PCK. Despite no prior direct genetic selection on JD, the estimated genetic trends of JD susceptibility were negative and highly significant (P < 0.0001). Based on these results, we conclude that a national genetic evaluation of JD susceptibility in the US Holstein cattle using ELISA-based tests is feasible, which will reduce the JD infection rate in the long term.
Breeding and Genetics Platform Session: Novel Traits, Novel TechnologiesPlatform SessionBreeding and Genetics6/26/2023 14:00t88391ListenPresentation2247Individual measure of body weight on in-house commercial dairy cattle using a 3D camera system for genetic evaluations and improved management decisions.5J. Lassenbody weight efficiency dairy cattleJ. Lassen1, J. Thomasen1, S. Borchersen11Vikinggenetics, Randers, DenmarkIn this study data on individual body weight measures from the 3D camera-based system CFIT was analyzed. The data are measured on dairy cows in commercial in-house settings. The system was developed to predict body weight based on the curvature of the back of the cow after each milking. A total of 9142 cows were measured in 19 herds across 3 breeds – Jersey (2513 cows), Red Dairy cattle (2813 cows) and Holstein (3816 cows). Mean body weight was higher for Red Dairy cattle (647.9 kg) and Holstein (683.8 kg) than for Jersey (469.6 kg). Repeatability estimates for body weight as a weekly average was 0.83, 0.85 and 0.88 for Jersey, Red Dairy cattle and Holstein respectively. The perspectives in having such records available are huge both for the farmer and for the dairy industry. The records can both be used for improving management in farms on an individual cow level and herd level, but also for genetic evaluation and selection. When selecting for improved efficiency maintenance is a major part of the resource usage complexity and controlled by bodyweight. Changes in body weight are an indicator for the cows wellbeing. The data are currently presented for the farmer for 4 different parameters: 1) dry cow management to know how body weight change has been through the dry period, 2) early lactation body weight change to indicate how well the lactation startup has been, 3) energy balance to maximize probability of a successful insemination and 4) late lactation body weight change to point at cow gaining to much body weight before dry off. The numbers are presented both at an individual cow level as well as means within lactation. These numbers are highly influenced by herd strategy but can still be used to benchmark within breed and across herds.
Breeding and Genetics Platform Session: Novel Traits, Novel TechnologiesPlatform SessionBreeding and Genetics6/26/2023 14:00t88859ListenPresentation2248Estrus expression in dairy cows: Phenotyping, genetic variability, and association with reproductive performance.7J. A. Chascoestrus expression genetic parameters pregnancy successJ. A. Chasco1, R. C. Chebel2, K. A. Weigel1, F. Peñagaricano11University of Wisconsin-Madison, Madison, WI, 2University of Florida, Gainesville, FLDairy cow estrus is marked by acute changes in behavior, such as increased activity, decreased feed intake, and decreased rumination. These behavioral changes can be measured in the field using wearable sensors and other monitoring systems. The main goals of this study were to develop phenotypes for estrus expression, evaluate their genetic variability, and assess their associations with pregnancy success. Data consisted of bi-hourly activity and rumination records collected using automated monitoring devices in 10k lactating cows during 2 years on a large commercial farm. We developed an algorithm that quantifies activity and rumination changes to characterize estrus duration and strength. The identified estrus events were assigned to the corresponding insemination events. The association between estrus traits and pregnancy success was evaluated using alternative logistic regression models, including year-season, lactation, sexed or conventional semen, and estrus traits. The statistical analysis showed that the addition of a detected estrus event (binary variable, yes/no) contributes significantly to explaining pregnancy success, relative to insemination in the absence of a detected estrus. In addition, estrus duration, classified as none, low, intermediate, and long, was significantly associated with the probability of pregnancy success. Similar results were found for activity strength and rumination strength. The estimates for heritability and repeatability were 0.104 ± 0.017 and 0.136 ± 0.009 for estrus duration, 0.134 ± 0.021 and 0.214 ± 0.010 for rumination strength, and 0.125 ± 0.021 and 0.218 ± 0.010 for activity strength. Overall, longer, and more intense estruses were significantly associated with pregnancy success. In addition, estrus traits are heritable, and breeding for improved estrus expression has the potential to boost estrus detection and increase insemination and pregnancy rates without relying on hormonal treatments.
Breeding and Genetics Platform Session: Novel Traits, Novel TechnologiesPlatform SessionBreeding and Genetics6/26/2023 14:00t88143ListenPresentation2249Genome-wide association analysis of white spotting in Montbeliarde-sired crossbred dairy cattle.8B. J. HeinsMontbeliarde coat color crossbreedingB. J. Heins1, K. T. Sharpe11University of Minnesota, Morris, MNThe Montbeliarde is a red pied dairy breed and white faces are a characteristic of the breed. However, crossbred cattle may exhibit a characteristic of a split face trait that may contain more than one color and not a solid white face. The objective of the study was to investigate the genetic architecture of the white face trait in Montbeliarde-sired crossbred dairy cattle. A genome-wide association study was conducted with 150 Montbeliarde-sired crossbred dairy cattle, and cows and heifers were born from 2010 to 2022 at the University of Minnesota West Central Research and Outreach Center dairy herd in Morris, MN. All animals were Montbeliarde-sired; however, the maternal grandsire breed was either Holstein or Viking Red. The cows and heifers were sired by 18 bulls and ranged from 1 to 28 daughters in the herd. Cattle were genotyped with a 50K, 65K, or 150K SNP chip from Neogen (Lincoln, NE) and imputed to 150K. Face color was scored as a 0 (all white face) or 1 (split face) and 39 of the 150 animals (26%) had a split face of more than one color. Quality control and association analysis was with the SNP and Variation Suite v8.9.1 (Golden Helix, Inc., Bozeman, MT) with a minor allele frequency of 0.05 and SNP call rate of 0.6. For significance testing, a P-value of 5 × 10–6 as the significance threshold. The analysis identified 2 SNP on chromosome 22 with a strong signal and 1 SNP on chromosome 1. The top variant (BTA-54082-no-rs; P = 8.78 × 10−10) was mapped to the 32.1404 RSID A>T and the second the top variant (BovineHD2200009163; P = 8.0647 × 10−10) was mapped to the 31.9513 RSID A>G. The BovineHD2200009163 variant was mapped to the melanocyte inducing transcription factor (MITF) downstream of the FERM domain containing 4B (FRMD4B) genes which was linked to BTA-54082-no-rs on BTA22. Most animals with a split face carried the ‘G’ allele and all cattle except 1 carried the ‘A’ allele for solid white face. The MITF gene is involved in cell pigmentation and is the causal locus for white spotting in cattle. The results indicate that the white face in Montbeliarde-sired crossbreds may not be dominant, and the split face may occur because of incomplete dominance.
Breeding and Genetics Platform Session: Novel Traits, Novel TechnologiesPlatform SessionBreeding and Genetics6/26/2023 14:00t88555ListenPresentation2250Environmental factors and genetic parameters for milk fatty acids in Japanese Holstein cattle.9Y. Masudade novo fatty acid milk components preformed fatty acidY. Masuda11Rakuno Gakuen University, Ebetsu, Hokkaido, JapanFatty-acid (FA) content in milk represents the energy balance of milking cows; therefore, the measurement can be used to monitor the animal's health condition. The FA content is now easily predicted by Fourier-transform mid-infrared spectroscopy (FT-MIR) in the dairy herd improvement program in Japan. This study aimed to determine environmental factors for the FA contents and to estimate genetic parameters for the FA traits. Data included 1,448,373 test day records from 211,462 Holstein cows in the 1st lactation, calving in Hokkaido, Japan, between April 2021 and October 2022. Two groups of FA, de novo FA (between C4 and C14) and preformed FA (equal to or greater than C18), were predicted by FT-MIR. The de novo FA percentage (DNF%) and preformed FA percentage (PFF%) was calculated as the ratio of the predicted FA content to the total FA content. The data set was divided by lactation stage, defined as every 30 d in milk (DIM) in each lactation, i.e., DIM 6 to 35 as stage 1, DIM 36 to 65 as stage 2, and so on. Significant environmental factors were determined with the F-test of Type III sum of squares. Variance components were estimated with a simple animal model. For each trait, (co)variances were estimated with a bivariate mixed model for phenotypes between 2 different stages. At all stages, herd-year of calving, year-month of calving, and a regression coefficient on DIM nested within the year-month of calving were significant (P < 0.01). Age of calving and regression on DIM within the age of calving were significant only at stages up to DIM 155. Heritability at stage 1 for DNF% was 0.24, for PFF%, 0.30, and the value decreased up to stage 7 (DIM 215). For both traits, stages 1 and 2 showed lower genetic correlations with later stages, e.g., for DNF%, 0.21 between stages 1 and 5. The genetic correlations of stage 3 or later were high (>0.90) up to stage 7. Further research will focus on genetic relationships between health traits and the FA content up to DIM 65, where the negative energy balance is a major concern.
Breeding and Genetics Platform Session: Novel Traits, Novel TechnologiesPlatform SessionBreeding and Genetics6/26/2023 14:00t88737ListenPresentation2251Genetic parameters of milkability traits derived from automatic milking systems in US Holstein cows.10P. Khanalautomatic milking system milkability genetic parameterP. Khanal1, A. T. H. Utsunomiya1, J. Johnson1, P. Ross1, N. Deeb11STgenetics, Navasota, TXThe number of dairy herds with automatic milking systems (AMS) is increasing rapidly which reduce the need of human involvement in milking process. Study of the genetic architecture of milkability traits are important for dairy producers focusing on precision dairy system. Therefore, the objectives of this study were to estimate the heritabilities and repeatabilities for different milkability traits and to estimate the genetic correlations among different milkability traits from AMS in US Holstein cows. A total of 504,141 daily records of milking speed (MS), maximum milking speed (MMS), harvest rate (HR), box time (BT), number of milkings (NOM) and milking duration (MD) were collected from 2,941 multiparous (n = 1, 2 or 3) lactating cows. Data were recorded by Lely AMS installed at STgenetics research farm at Ohio from 2019 to 2022. The model included the fixed effect of contemporary group, lactation number, lactation stage and milk yield as covariate, as well as random additive genetic effect and permanent environmental effect. Analyses were conducted using LMT software. Univariate and bivariate analyses were implemented to estimate heritabilities and genetic correlation among traits. Pedigree information was used to specify the genetic relationships to estimate the variance components and genetic correlations. The heritability of MS was 0.52 ± 0.05, MMS was 0.56 ± 0.04, HR was 0.40 ± 0.04, BT was 0.44 ± 0.04, NOM was 0.23 ± 0.04 and MD was 0.49 ± 0.05. Repeatabilites were moderate to high for all traits analyzed which ranged from 0.40 ± 0.04 for NOM to 0.88 ± 0.05 for MMS. The genetic correlation between all traits ranged from moderate to high in both directions which ranged from −0.97 ± 0.01 between MS and MD to 0.97 ± 0.01 between MS and MMS. The moderate to high heritabilities of different traits suggested that all the traits studied could be improved by genomic selection. The results from this study could be used to design and refine the selection index for implementation in precision dairy breeding program.
Breeding and Genetics Platform Session: Novel Traits, Novel TechnologiesPlatform SessionBreeding and Genetics6/26/2023 14:00t88382ListenPresentation2252Genomic prediction of breeding values for behavior traits measured in automatic milking systems in Holstein cattle using machine learning methods.11V. B. Pedrosaaccuracy of prediction automatic milking systems deep learningV. B. Pedrosa1, S. Y. Chen1,2, J. S. Doucette3, L. S. Gloria1, J. P. Boerman1, L. F. Brito11Department of Animal Sciences, Purdue University, West Lafayette, IN, 2Sichuan Agricultural University, Chengdu, China, 3Agriculture Information Technology (AgIT), Purdue University, West Lafayette, INIdentifying genomic prediction (GP) models that might provide more accurate breeding values is of great interest when evaluating complex traits such as livestock behavior. In this context, the main objective of this study was to compare the predictive performance of genomic breeding values using deep learning algorithms (DL) and traditional methods for milking refusals (MREF) and milking failures (MFAIL) in Holstein cows measured by automatic milking systems (milking robots). A total of 1,993,509 daily records were collected using 36 milking robot stations for 4,511 genotyped Holstein cows. A total of 57,600 single nucleotide polymorphisms remained after quality control. Four GP methods were considered in this study: 1—Bayesian Lasso (LASSO); 2—Multiple Layer Perceptron (MLP); 3—Convolutional Neural Network (CNN); and 4—Genomic Best Linear Unbiased Prediction (GBLUP). The first 3 methods were implemented using Python (v.3.9), in which the DL methods were estimated using the Keras and Tensorflow packages. The GBLUP method was implemented using the BLUPF90 family package. The accuracy of prediction (MSE) for MREF and MFAIL was 0.349 (0.079) and 0.275 (0.089) for LASSO; 0.374 (0.098) and 0.325 (0.090) for MLP, 0.379 (0.078) and 0.302 (0.091) for CNN, and 0.352 (0.092) and 0.307 (0.090) for GBLUP, respectively. Furthermore, a lower re-ranking of selection was observed in MLP versus CNN methods compared with the other approaches for both MREF and MFAIL. Promising results showed slightly higher accuracies when DL methods were applied. However, the results observed may not be sufficient to justify the use of DL compared with more traditional methods due to the computational demand required and the difficulty of performing GP for non-genotyped animals using DL procedures.
Breeding and Genetics Platform Session: Novel Traits, Novel TechnologiesPlatform SessionBreeding and Genetics6/26/2023 14:00t88451ListenPresentation2253Exploring opportunities to evaluate genomically mid-infrared spectroscopy (MIR)-predicted residual CH4 exploiting correlations to multiple across country evaluation (MACE) traits.12N. Genglerexternal information ssGBLUP evaluation systemH. Atashi1,2, N. Gengler11University of Liège-GxABT, Gembloux, Belgium, 2Shiraz University, Shiraz, IranBreeding has been identified as a potentially promising strategy to reduce methane (CH4) emissions. However, trait definitions and, despite availability of genomic data, setup of such genetic evaluation systems remain important issues. The aim of this study was to demonstrate an optimized computational ssGBLUP setting exploiting correlations to traits evaluated in an international context by INTERBULL through Multiple Across Country Evaluation (MACE). The trait evaluated was Residual CH4 (RCH4) defined on a genetic level as the deviation of MIR-predicted CH4 (MCH4) from Expected CH4 (ECH4) obtained form traits available internationally through MACE. Genetic parameters and EBV for MCH4 were estimated using test-day MCH4 records on 229,465 first-, 151,726 s-, and 90,484 third-parity Walloon Holstein cows. Mean (SD) MCH4 yields were 327 (68), 356 (70), and 358 (72) g/day and mean (SD) h2 estimates for daily MCH4 were 0.12 (0.04), 0.14 (0.05), and 0.13 (0.05), for the first 3 lactations, respectively. For 1,129 bulls with at least 30 daughters (727 genotyped), EBV for 305-d MCH4 for each lactation (and average of first 3 lactations) were regressed on published EBV of MACE evaluated milk, fat and protein yields, derived fat and protein percentages, and linear type traits. EBV of ECH4 were defined as predictions combing the MACE evaluated traits using the obtained regression equations. Correlations between EBV of 305-d MCH4 and ECH4 ranged from 0.57 to 0.61 in the first 3 lactations and was 0.60 for the averaged 3 lactation EBV of 305-d MCH4. Linear type traits including body depth, chest depth, bone quality, teat placement, udder support and udder texture showed significant association to MCH4. An innovative evaluation setup is possible considering direct MCH4 data and, as external information, EBV for ECH4 combined in a bivariate ssGBLUP exploiting the indirect extra information provided by correlated traits that are available for sires based on daughters found internationally. EBV of RCH4 can be predicted by subtracting ssGBLUP recomputed 305-d EBV for ECH4 from EBV for MCH4.
Joint NMC (National Mastitis Council) and ADSA Lactation Biology Symposium: Unlocking the Potential of the Bovine Mammary Gland--Recognition of the Contribution of ADSA Fellow Mike AkersSymposiumLactation Biology6/26/2023 14:00t89200ListenPresentation2272Physiological regulation of lactogenesis and early lactation: Implications for milk and colostrum production.1T. B. McFaddenlactation lactogenesis milkT. B. McFadden11University of Missouri, Columbia, MOThe mammary gland is a truly remarkable organ. As the final stage of successful reproduction in mammals, lactation has proven to be a highly successful adaptation and reproductive strategy. Indeed, the Cenozoic Era, spanning the past 65 million years to the present, has been dubbed the Age of Mammals. As befits the wide range of mammalian species, mammary glands and milk vary tremendously in function and composition. Thus, lactation physiology presents a rich tapestry through which to explore evolutionary biology and function. In terms of biological limits, modern dairy animals continue to raise the ceiling of perceived limits to productivity. At the start of my career, training under Mike Akers at Virginia Tech in the late 1980s, we spoke of cows producing 30,000 lbs of milk in a lactation as a reach goal. Yet, over the past several years the world’s top cows have produced over 75,000 lbs in a single lactation. Across all of this variation, many of the key regulatory features of lactogenesis and lactation are common among mammals and these have been described by researchers such as Mike Akers, among many others. The aim of this presentation is to review some of the range of lactation physiology, the core regulatory features, and opportunities to improve milk composition and productive efficiency, with emphasis on contributions by Dr. Akers and his collaborators.
Joint NMC (National Mastitis Council) and ADSA Lactation Biology Symposium: Unlocking the Potential of the Bovine Mammary Gland--Recognition of the Contribution of ADSA Fellow Mike AkersSymposiumLactation Biology6/26/2023 14:00t88400ListenPresentation2273Foundational studies on the role of nutrition on prepubertal mammary growth and development.2K. Sejrsenmammary growth nutrition epithelial cells heifers IGF-1K. Sejrsen1, S. Purup1, M. Vestergaard11Aarhus University-Viborg, Department of Animal and Veterinary Sciences, Tjele, DenmarkObservations of a positive relationship between body weight at calving and milk yield suggested that age at calving can be reduced without negative effect on milk yield if weight at calving is maintained. This was investigated in several experiments, including studies using identical twins in US and Denmark. Surprisingly the high feeding level required to lower age at puberty and obtain a normal weight at calving resulted in a dramatic reduction in subsequent milk yield. This was supported in subsequent Danish experiments. Scrutiny of the data indicated that the effect mainly was due to the high feeding level in the early part of the rearing period coinciding with the period of allometric prepubertal mammary development. A later study confirmed that high feeding level reduced growth of mammary parenchyma before puberty but not after. The results also showed a positive relationship between circulating level of growth hormone and prepubertal mammary growth. A significant relationship with prolactin disappeared after correction for growth hormone. The importance of growth hormone for prepubertal mammary growth was supported by a positive effect of exogenous growth hormone. However, a role of circulating levels of growth hormone in mediating the effect of level of nutrition is questionable because GH receptors are absent in mammary tissue and IGF-1 – the main mediator of GH action - is increased not decreased by increasing level of nutrition. Furthermore, the response of serum on primary cell cultures depends on IGF-1 and not GH content. So, why is prepubertal mammary growth decreased not increased by high feeding level. This is largely still an open question but using primary cell cultures from parenchymal tissue has added some insight. Adding mammary parenchymal extract from heifers fed high feeding to the primary cells stimulate cell proliferation less than extract from heifers fed moderate feeding level despite a higher content IGF-1. Evidence suggest that inhibitory effect of locally produced IGFBP-3 is involved, but a role for other locally produced factors cannot be excluded.
Joint NMC (National Mastitis Council) and ADSA Lactation Biology Symposium: Unlocking the Potential of the Bovine Mammary Gland--Recognition of the Contribution of ADSA Fellow Mike AkersSymposiumLactation Biology6/26/2023 14:00t88872ListenPresentation2274Nuances of pre-pubertal mammary gland development and the role of nutrition.3H. L. M. Tuckermammary development myoepithelial mammary epitheliumH. L. M. Tucker11Novus International Inc, Saint Charles, MOThe prepubertal period establishes the foundation of the mammary gland structure for a heifer. At the macro level the mammary gland is separated into parenchyma and the mammary fat pad that will eventually merge. At the micro level there are many cell types and structural proteins that eventually develop to support production of milk. The integration of parenchyma into the mammary fat pad results in numerous coordinated cellular interactions that must occur during growth and development of the gland. These cells and proteins are heavily influenced by hormones deriving from the ovaries despite occurring before estrus onset. When heifers are ovariectomized, mammary gland mass decreases resulting in increased estrogen receptor 1 positive cells, change in number and morphology of myoepithelial cells, and decrease in proliferating cells. Ovariectomized heifers also have an abundance of change in the extracellular matrix where fibronectin is higher while laminin is lower. With an ovariectomy, the disruption of the complicated web of interactions between different hormones makes it difficult to pinpoint specific hormonal actions. More specifically, when estrogen is blocked during the prepubertal period a reduction in size of the overall gland results, coinciding with a reduction in protein expression of estrogen receptor 1 and number and size of myoepithelial cells. The stromal tissue is influenced by increased collagen deposition and an increase in number of putative epithelial stem cells observed. Moreover, there is still the added complication of systemic versus local influences of hormones that are difficult to distinguish. Beyond the influence of hormones on the mammary gland, nutrition can also elicit an effect. Studies have shown through elevating different nutrients the macro level of the mammary gland can be influenced, which results in an impact on the micro level of the gland. With a wide range of feeding practices during the prepubertal period across the industry the influence of nutrition is of importance for the future productive life of the cow.
Joint NMC (National Mastitis Council) and ADSA Lactation Biology Symposium: Unlocking the Potential of the Bovine Mammary Gland--Recognition of the Contribution of ADSA Fellow Mike AkersSymposiumLactation Biology6/26/2023 14:00t89071ListenPresentation2275Contributions of the mammary physiologist to the mastitis researcher.5B. D. Engerintramammary infection inflammation pathophysiologyB. D. Enger11Department of Animal Sciences, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OHMastitis is considered to be the most common and expensive disease in the US and global dairy industries. Significant advancements over the past 50 to 70 years have markedly reduced the occurrence and the negative physiological and financial consequences of mastitis. Many of the key advancements that have resulted in better prevention, treatment, and an understanding of mastitis have arisen from key contributions of mammary gland physiologists. Central among these contributions is the mammary physiologist’s unique knowledge of mammary tissue architecture and cell type organization, particularly how the heterogeneous tissue and cell types work in concert to accomplish the functional role of milk synthesis and secretion. Joint efforts by mammary physiologists and mastitis researchers have elucidated how milk secretion and composition are changed during mastitis, which is primarily a result of alterations in epithelium integrity and cellular competency. The exploitation of the compositional changes has been fruitful, allowing for the development of improved diagnostic approaches to identify affected cows and assess treatment outcomes from both a disease and physiology-based perspective. Histological evaluations by mammary physiologists have improved the immunologist’s and mastitis researcher’s understanding of the dynamics of immune cell recruitment and clarified the spatial localization of the recruited immune cells in tissue compartments. Joint efforts have also been successful identifying how the teat canal and teat sphincter prevent mastitis, which has improved equipment and management decisions aimed at maintaining the key defense mechanisms of the mammary gland. Continued efforts and collaborations will be important as key knowledge gaps remain regarding the pathophysiology of mammary gland inflammation and advancements are needed to determine how to better influence the immune response to desired outcomes. A better understanding of the interplay between physiology and mammary gland host defense can improve animal health and welfare and reduce the deleterious impacts of mastitis on mammary gland productivity.
Joint NMC (National Mastitis Council) and ADSA Lactation Biology Symposium: Unlocking the Potential of the Bovine Mammary Gland--Recognition of the Contribution of ADSA Fellow Mike AkersSymposiumLactation Biology6/26/2023 14:00t88510ListenPresentation2276Understanding mammary physiology and histology: A story told in pictures.6R. Akersmammary gland research lactationR. Akers11Virginia Tech, Blacksburg, VAHow do you decide a research direction or more narrowly a research question? What sparks your interest or your scientific curiosity? Maybe you need to ask, am I actually curious at all? In the end, what motivates you to be in this discipline, even in this symposium, at this moment in time? Distilled and concentrated, all our sequential professional actions are the latest in a line of questions posed and corresponding answers each of us had to conjure. I will describe some of twists and turns that I have taken in my career. What were the some of the rocks that I overturned and what led me to those particular stones. It has to be clear that like all other academics or scientists, any success that I have had rests on the efforts of my former teachers and mentors, in particular Dr. William Heald and Dr. Alan Tucker, and the many colleagues and students I have known. Without each of you, there would be no career in lactation biology to review. As a discipline, we all stand on the shoulders of those who came before us. It is often, rightly noted that many of the central questions in our branch of lactation biology, have not actually changed. Rather the tools and approaches to attempt to answer the questions have evolved. It is often repeated that a picture is worth a thousand words. Images have been an important part of my career and I will share some of those that have punctuated research over the years.
Joint NMC (National Mastitis Council) and ADSA Lactation Biology Symposium: Unlocking the Potential of the Bovine Mammary Gland--Recognition of the Contribution of ADSA Fellow Mike AkersSymposiumLactation Biology6/26/2023 14:00n8987ListenDiscussion, followed by Reception7
Ruminant Nutrition Symposium: Improving Rumen Fermentation Through Altering Rumen MicrobiotaSymposiumRuminant Nutrition6/26/2023 14:00t88268ListenPresentation2301The rumen microbiome and its function—Predators within and their implication in intraruminal recycling of microbial protein.1Z. Yurumen protozoa rumen viruses intraruminal recycling of microbial proteinZ. Yu1, M. Yan11The Ohio State University, Columbus, OHMicrobial protein accounts for > 80% of the protein metabolizable by dairy cows. Intraruminal recycling of microbial protein decreases the metabolizable protein reaching the abomasum and small intestines and thus is an important barrier for nitrogen utilization efficiency. Although proteolytic bacteria participate in intraruminal recycling of microbial protein, rumen protozoa are considered the major culprit as they directly engulf microbial cells and degrade the cellular protein. Recent genomic studies have identified the genes encoding the “digestive enzymes” of rumen protozoa, while transcriptomic studies confirmed the expression of these genes. Besides confirming the “guilt” of rumen protozoa in lysing microbial cells and degrading microbial protein, the genomic and transcriptomic information also identified protozoal digestive enzymes as targets for specific inhibition of rumen protozoa to decrease intraruminal recycling of microbial protein. In addition to rumen protozoa, rumen viruses, especially those of bacteria (i.e., bacteriophages), can infect and then lyse their host from inside by their lytic cycle, increasing the bacterial protein available for degradation by proteolytic bacteria. Therefore, rumen bacteriophages likely also contribute to the intraruminal recycling of microbial protein. In a recent metagenomic study, we developed a global rumen virus database by collecting and analyzing nearly 1,000 rumen metagenomes. We found diverse rumen viruses including phages infecting rumen bacteria, methanogens, and protozoa. Most of the species that can be infected by rumen bacteriophages belong to the phylum Bacteroidetes and Firmicutes, the most abundant phyla of the rumen microbiome, and lytic phages represent a high proportion of the rumen phages. These phages probably contribute significantly to the intraruminal recycling of microbial protein. Preliminary analysis also showed an association of the rumen virome with feed efficiency and methane emissions. Future research on intraruminal recycling of microbial protein should include rumen viruses.
Ruminant Nutrition Symposium: Improving Rumen Fermentation Through Altering Rumen MicrobiotaSymposiumRuminant Nutrition6/26/2023 14:00t87866ListenPresentation2302New biochemical pathways for forming short-chain fatty acids during fermentation in rumen bacteria.2T. Hackmannrumen bacteria fermentationT. Hackmann11University of California, Davis, Davis, CAFermentation is a major type of metabolism and carried out by over 2,300 species of bacteria. Though fermentation is widespread, the biochemical pathways underpinning it are not always clear. Pathways are written in textbooks and other resources, but they are based on study of a few model bacteria. Recent work suggests textbook pathways do not apply to many bacteria, and new pathways await discovery. In one study, we searched genomes of bacteria from the cattle rumen, and we found 44% of them did not encode textbook fermentation pathways. For example, 8% of them encoded a pathway for forming acetate not previously known in bacteria. In subsequent studies, we have found biochemical evidence for new pathways. In propionibacteria, for example, we confirmed the existence of a pathway for forming acetate previously unknown in bacteria. The pathway involves 2 enzymes, succinyl coenzyme A:acetate CoA-transferase and succinyl-CoA synthetase. The enzymes are common in bacteria, but not previously recognized as having this role in fermentation. Similar studies have confirmed new steps in pathways for forming propionate and butyrate. Discovering these new steps and pathways provides new targets for manipulating fermentation, which will improve animal productivity.
Ruminant Nutrition Symposium: Improving Rumen Fermentation Through Altering Rumen MicrobiotaSymposiumRuminant Nutrition6/26/2023 14:00t89835ListenPresentation2303Microbiome-guided strategies to improve cattle production.4P. Fangastrointestinal tract microbiota biomarkerP. Fan1, K. Jeong2,31Department of Animal and Dairy Sciences, Mississippi State University, Starkville, MS, 2Department of Animal Sciences, University of Florida, Gainesville, FL, 3Emerging Pathogens Institute, University of Florida, Gainesville, FLTrillions of microorganisms inhabit the gastrointestinal tract (GIT) of animals, forming a dense and diverse microbial ecosystem. The GIT commensal bacteria co-evolve with the host and exert numerous functions influencing animal digestion, metabolism, immunity, and behavior. The aim of this presentation is to highlight the roles of “sensor” and “motor” of GIT microbiota played in the mutualistic relationship and propose potential strategies of using microbial features as biomarkers for animal breeding and early prediction and as direct targets to improve cattle performance. Our previous finding showed a significant impact of host genetics on the abundance of butyrate-producing bacteria in the hindgut gut of cattle throughout life, which were correlated with cattle weight gain and plasma IgG level, and identified specific host SNPs in genes related to metabolism and immunity associated with these bacteria. Integrating the GIT microbiota feature in cattle breeding is also supported by evidence from other studies reporting the genetic effects on rumen microbiota and interactions with feed efficiency and methane production. Besides, we observed distinct bacteria-bacteria co-occurrence networks between healthy and diarrheic calves and isolated beneficial bacteria from healthy calves that inhibited the pathogens, suggesting microbiota from diarrhea-resistant could be a potential source for probiotic development. In addition, a dramatically higher abundance of antimicrobial resistance genes in GIT of newborn calves compared with adult calves as well as antimicrobial resistant bacteria in colostrum were detected in both our and other studies, indicating a necessity to optimize calf diet and management to develop healthy GIT microbiota. Future research should evaluate the efficiency of using microbiota features for genetic selection and phenotype prediction and exploit the causative effects of specific commensals on cattle physiology.
Ruminant Nutrition Symposium: Improving Rumen Fermentation Through Altering Rumen MicrobiotaSymposiumRuminant Nutrition6/26/2023 14:00n8894ListenDiscussion5
Breeding and Genetics Symposium: Breeding for Resilience in Dairy AnimalsSymposiumBreeding and Genetics6/27/2023 9:30t88780ListenPresentation2412Getting to grips with resilience: Toward large-scale phenotyping of this complex trait.1N. C. Friggensresilience modelling proxiesN. C. Friggens1, G. Lenoir2, M. Ithurbide31INRAE, Palaiseau, France, 2AXIOM, Azay-sur-Indre, France, 3INRAE, GenPhySE, Université de Toulouse, Castanet Tolosan, FranceThis paper will discuss the issues involved, and review recent work, in phenotyping resilience, i.e., an animal’s ability to respond to and recover from environmental disturbances. As there is no single direct measure of resilience several proxy measures have been proposed for use in population level phenotyping. These are frequently estimates of perturbations in performance trajectories, which can be quantified in different ways. For such proxies to be of value they need to have been shown to be related to the accumulated consequences of a good resilience. These accumulated consequences may be measures such as productive longevity, total number of recorded disease events, etc. The rationale for this, and limitations, are discussed. Further, given that there is no single direct measure of resilience there are recent initiatives advancing the state-of-the-art in deriving resilience measures from multivariate analyses of time-series measures of multiple indicators. Examples are presented using functional PCA coupled with hierarchical clustering. Finally, prospects for inclusion in selection programs are discussed.
Breeding and Genetics Symposium: Breeding for Resilience in Dairy AnimalsSymposiumBreeding and Genetics6/27/2023 9:30t89305ListenPresentation2413When, why, and how to breed for disease resilience in livestock.2A. Doeschl-Wilsondisease resilience breedingA. Doeschl-Wilson1, P. W. Knap2, M. Ghaderi-Zefreh1, R. Pong-Wong11The Roslin Institute and R(D)SVS, University of Edinburgh, Easter Bush Estate, Scotland, UK, 2Genus-PIC, Schleswig, GermanyInfectious diseases are a major threat to sustainable production of high-producing animals such as dairy cattle. Breeding for increased disease resilience has been a research focus for many years, but effective implementation into practical breeding programs is still lacking as this complex genetic trait is extremely difficult to estimate. Here we investigate how future breeding programs may benefit from recent research on disease resilience. We consider 2 alternative existing definitions of individual disease resilience as either a reaction-norm of host performance on environmental pathogen burden, or as the animal's capacity to resist or recover from the perturbation caused by an infection. We investigate the corresponding data requirements for accurately estimating individuals’ genetic merit for disease resilience and the potential implications on individual and herd health and performance. In particular, we demonstrate that in the case of infectious diseases, herd disease resilience is more than the sum of the resilience of its herd members, but also depends on host traits affecting pathogen transmission. We conclude that the most promising break-throughs in genetic improvement of disease resilience rely on technological innovations such as automated data generation, and on methodological developments for analysis.
Breeding and Genetics Symposium: Breeding for Resilience in Dairy AnimalsSymposiumBreeding and Genetics6/27/2023 9:30t89320ListenPresentation2414Genetics of heat tolerance in dairy cattle.4F. Peñagaricanofetal programming heat stress temperature-humidity indexF. Peñagaricano11University of Wisconsin-Madison, Madison, WIHeat stress negatively impacts the performance of dairy cows, causing huge economic losses to the dairy industry. The first objective of this study was to reveal the genetic basis of thermotolerance in Holstein cows. Multi-trait repeatability test day models with random regressions on a function of temperature-humidity index values were used for the analyses. Heritability estimates for milk production and conception under heat stress were around 20% and 3%, respectively, suggesting that the ability of a dairy cow to produce and conceive under heat stress is influenced by genetic factors, and hence it could be improved by genetic means. Notably, genetic correlations between general and thermotolerance additive genetic effects were negative, indicating an unfavorable relationship between cows’ ability to either produce milk or conceive under thermo-neutral versus thermo-stress conditions. Therefore, the continued selection for greater productivity and fertility ignoring heat tolerance will result in even greater susceptibility to heat stress. Whole-genome scans identified genomics regions that harbor genes directly implicated in the cellular response to stress, heat shock protein binding, regulation of DNA repair, and oxidative stress. Our second objective was to examine the effects of intrauterine heat stress on the epigenome of the offspring. Intrauterine insults, such as thermal stress, can induce permanent changes in the structure, physiology, and metabolism of the offspring. This phenomenon is known as fetal programming and could have significant implications on food animal production. Our results showed that in utero heat stress alters the DNA methylation profile of fetal liver and mammary gland, and programs their morphology in postnatal life. These epigenetic changes may contribute to the poorer performance of in utero heat stressed calves. Overall, our findings contribute to a better understanding of the genetic and epigenetic basis underlying dairy cattle performance under heat stress.
Breeding and Genetics Symposium: Breeding for Resilience in Dairy AnimalsSymposiumBreeding and Genetics6/27/2023 9:30t89836ListenPresentation2415Gene editing for improved health and resiliency.5T. Sonstegardgene editing disease resistance heat toleranceT. Sonstegard11Acceligen, Eagan, MNGenome editing in the genetic stocks of food animals has tremendous potential as a breeding method best-suited to introduce traits not readily available for intensive selection in commercial breeding populations, especially those affecting disease resistance and adaptation to climate. To date, gene editing has been used to alter prolactin receptor and produce heat-tolerant, registered Angus for commercial production of semen and embryos that rapidly allows beef production improvement in the tropics. More recently, genome alterations based on rationale design have been deployed and tested to demonstrate genetic improvement of resistance to porcine reproductive and respiratory syndrome virus and bovine viral diarrhea virus in swine and cattle, respectively. This presentation will highlight the results of these new traits to breed healthier commercial animals that will eventually change global market dynamics of livestock production.
Breeding and Genetics Symposium: Breeding for Resilience in Dairy AnimalsSymposiumBreeding and Genetics6/27/2023 9:30n8824ListenDiscussion6
Dairy Foods Symposium: Continued Challenges in Controlling Dairy SpoilageSymposiumDairy Foods6/27/2023 9:30t89878ListenPresentation2416Understanding next-generation dairy spoilage bacteria.1T. S. Obergpaucilactobacillus wasatchensis gas production non-starter lactic acid bacteria (NSLAB)T. S. Oberg11Utah State University, Logan, UTDefects in aged cheese continue to be a problem in the industry even with advances in cheese production technology, starter and adjunct culture selection, and modern microbial isolation and identification technologies. One reason is the difficulty in growing and isolating the causative microorganisms of these defects so that we can understand the mechanisms they utilize for growth, which can generate defects in cheese. Recently, Paucilactobacillus wasatchensis, a novel heterofermentative non-starter lactic acid bacteria (NSLAB) which causes late gas defects in commercially aged cheese has been identified. This bacterium grows very slowly under normal laboratory testing protocols and, hence, would go undetected utilizing most NSLAB isolation methodologies. Whole-genome sequencing of Pa. wasatchensis identified several potential strategies that the bacteria can use to grow and thrive in an aged cheese including the ability to grow on ribose as the sole carbon source, the ability to ferment gluconate, and the presence of several amino acid decarboxylases. In vitro testing and challenge studies have validated these pathways and shown that Pa. wasatchensis can cause late gas defects in cheese through the production of CO2 even when the typical hexose sugars generally implicated in gas production are not present. These studies have shown that Pa. wasatchensis can be useful as a type strain for the study of hard-to-grow microorganisms present in cheese and can increase our understanding of their source, how these organisms thrive in aged cheese, and how modern dairying and manufacturing processes can unintentionally increase the risk of problem products.
Dairy Foods Symposium: Continued Challenges in Controlling Dairy SpoilageSymposiumDairy Foods6/27/2023 9:30t88852ListenPresentation2417Sources, transmission, and tracking of sporeforming bacterial contaminants in dairy systems.2N. Martinspores subtyping trackingN. Martin11Cornell University, Ithaca, NYSporeforming bacteria are pre- and post-pasteurization contaminants in dairy systems. At the farm, spores transfer from soil, water, manure and other sources into raw milk primarily at the point of milking. In processing facilities, spores may persist for long periods of time in equipment or in the environment, where they can subsequently contaminate dairy products. Implications of spore contamination include premature spoilage in fluid milk and cheese, reduced specification compliance in dairy powders and ingredients, and represent a biological barrier to shelf-life extension for reaching new markets. Molecular subtyping for sporeforming bacteria in dairy systems represents a key tool for tracking and eliminating sources of spore contamination. In particular, sequencing of the rpoB gene has been used successfully for tracking spore contaminants throughout the dairy continuum. Here we explore case studies for the successful implementation of rpoB subtyping to reduce spore contamination in dairy products, best practices for developing baseline spore subtyping data, and digital tools that amplify the impact of this subtyping data.
Dairy Foods Symposium: Continued Challenges in Controlling Dairy SpoilageSymposiumDairy Foods6/27/2023 9:30t89961ListenPresentation2418Moo-deling the Dairy-verse: Using computer modeling to get more out of our testing results.3A. Trmcicspoilage computer modeling digital dairyA. Trmcic11Milk Quality Improvement Program, Cornell University, Ithaca, NYThe age of Industry 4.0 is upon us, and the dairy industry is moving forward with the rest of the world towards a more digitalized and automated future. With this move the volume of data that are being generated and the speed at which they are being generated is increasing exponentially. While the majority of these data are still being used for day-to-day activities by the Dairy Industry, there is an added value in them that is potentially being lost because using the data from the past can help us predict the future. This symposium will cover how these generated data can be used to build computer models that can be used by the Dairy Industry as support tools in decision-making. This symposium will cover spoilage prediction computer models that were developed in recent years for application in fluid milk, yogurt, and cheese manufacturing. The speaker will present on the process of development, validation and use of these prediction models, as well as how these models might impact the interaction the consumers have with our dairy products. The key goal of this symposium is to introduce the benefits of computer modeling and open the door to future innovations in the industry captured under the common term Digital Dairy.
Dairy Foods Symposium: Continued Challenges in Controlling Dairy SpoilageSymposiumDairy Foods6/27/2023 9:30t89890ListenPresentation2419The application of protective cultures for yeast and mold control in fermented dairy products.4S. Neuensbioprotection yeast moldS. Neuens11Chr. Hansen Inc, Milwaukee, WIBioprotection is the art of using natural microbial food cultures to inhibit unwanted contaminants—preventing food spoilage or improving food safety. The process of fermentation has been used from ancient times to the present day as a natural way of preserving and protecting the quality of foods. Chr. Hansen takes this a step further by identifying and selecting the best of the good bacteria to supply as commercial food cultures with bioprotective effect under the brand FRESHQ to the dairy industry. These cultures are used to enhance the inhibition of yeast and mold growth in fermented dairy products throughout shelf life. This presentation will focus on the application of bioprotective cultures for yeast and mold control in fermented dairy products. Explore how these cultures work in fermented dairy applications. Reveal the Chr Hansen’s team of scientists’ discovery of the main mechanism responsible for delaying the growth of yeast and mold. And further, provide a framework on how Chr Hansen works with dairy processors to not only demonstrate the effect of bioprotective cultures but to show the value of using such a product. The application of food cultures with bioprotective effect is becoming more widespread, and for good reason. Fermentation-enabled bioprotection, such as Chr Hansen’s FRESHQ, helps fight spoilage to extend shelf life, reduce the need for artificial preservatives, cut down waste and enable consumers to get the most out of the foods they buy.
Dairy Foods Symposium: Continued Challenges in Controlling Dairy SpoilageSymposiumDairy Foods6/27/2023 9:30n8873ListenDiscussion5
Extension Education Symposium: Leading Extension Programs on Dairy Farms--Tribulations, Changes, and SuccessesSymposiumExtension Education6/27/2023 9:30t89150ListenPresentation2432Championing the science of behavioral change in dairy extension.1N. Silva-del-Rioextension education behavioral change new practice adoptionN. Silva-del-Rio11Veterinary Medicine Teaching and Research Center, Tulare, CAAre extension educators being effective change leaders? Stakeholder adoption of novel technologies or practices can be disappointing, even after solid research and well-orchestrated extension efforts support the efficacy and economic sustainability of these practices. On the contrary, well-designed advertising campaigns seem effective at changing consumers’ behaviors. So, what makes change difficult? In this interactive presentation, we will study the social and psychological principles behind behavioral change. Participants will learn how to apply those principles in dairy production systems. Case studies will demonstrate how to lead change by overcoming physical barriers (path), designing effective action plans (rider), and engaging the emotional self (elephant).
Extension Education Symposium: Leading Extension Programs on Dairy Farms--Tribulations, Changes, and SuccessesSymposiumExtension Education6/27/2023 9:30t88112ListenPresentation2433Dairy food safety training: Checking the box versus improving operational efficiencies.2C. Stevensonfood safety training designC. Stevenson11North Carolina State University, Raleigh, NCThe cost-versus-benefit analysis of dairy foods safety training programs is an ongoing consideration for dairy foods businesses. Food safety training is a costly business activity required by regulatory and third-party auditing entities. Such training requirements vary from introductory training for operators to more advanced training for managers. The design of food safety training also takes various forms such as slide decks, computer-based training, on-the-job training, etc. Whereas some organizations implement all their training in-house, others often leverage third-party training companies and university specialists’ services. No matter the cost, design, or provider, it is worthwhile to question the impacts of the food safety training program on the company’s day-to-day food safety program performance as well as its organizational culture of food safety. This presentation will highlight several studies of the impacts of different food safety training programs implemented at dairy foods companies. These studies include the following: (1) a comparison of the effects of training program delivery methods on food safety program performance across 70 dairy processing plants: (2) an analysis of behavioral psychology as it pertains to operators’ experiences of training programs and their knowledge, performance, and attitudes about food safety, as well as (3) characteristics of dairy food safety training programs that lead to greater knowledge gains and conversion of knowledge into practice. The outcome of this presentation will be increased awareness about how training program design, cost, and delivery method impact overall food safety program performance.
Extension Education Symposium: Leading Extension Programs on Dairy Farms--Tribulations, Changes, and SuccessesSymposiumExtension Education6/27/2023 9:30t88130ListenPresentation2434Assessing the impact of dairy extension programs with stakeholders.3L. Holdendairy extension assessment educationL. Holden11The Pennsylvania State University, University Park, PAEducation and training is a little like a jigsaw puzzle with assessment being that final piece that completes the picture. Extension educators provide a wide range of programs and materials for dairy stakeholders including education for industry professionals, dairy farm owners, managers and employees. Understanding the impact of that education is critical not only for adding value to our end-users but also for continuing to develop even greater learning opportunities. The Penn State Extension Dairy Team has developed and delivered a variety of programs: training for Dairy Advisory Teams, customized producer educational programs, a Women in Dairy Conference, hands-on training at the farm for employees, and a variety of workshops, webinars and online courses. This session will highlight key aspects of some of these programs as well as the corresponding assessment data gathered following program delivery. Examples of “successes and struggles” for teams and data about impactful learning take-aways will be shared. So if you are a brand new extension educator or a seasoned veteran, come and join in the discussion. A better understanding of our stakeholders needs, through program evaluation, focus group data, pre-post or reflective appraisal approaches helps to complete the “jigsaw puzzle” of learning and makes our path forward for learning in the future more successful.
Extension Education Symposium: Leading Extension Programs on Dairy Farms--Tribulations, Changes, and SuccessesSymposiumExtension Education6/27/2023 9:30t88096ListenPresentation2435On-farm translational research and outreach through academic–extension–industry partnerships.4D. Douphratepartnerships research safetyD. Douphrate11Texas A&M University, College Station, TXDairy farming is among the most dangerous occupations and accounts for a disproportionately large percentage of all injuries in livestock-related agriculture. The US dairy industry continues to shift to a large-herd production model due to economies of scale. This shift has led to a higher risk of fatalities, injuries and work-related musculoskeletal disorders (MSD) due to task specialization, increased work demands and hazards. Owners and managers of growing farms are confronted with numerous human resource challenges which can compromise the health and safety of farm workers. Additionally, dairy owners are increasingly dependent on front-line supervisors to effectively manage a larger non-English-speaking workforce with novice workers who have minimal livestock experience before working on large-herd farms. Owners are increasingly seeking supervisors who demonstrate effective management and leadership skills, especially in relation to worker health and safety. Much research effort has been directed at developing safety management systems for large enterprises; however, there is a lack of development, implementation and evaluation of safety management systems for smaller enterprises, especially dairy farming operations. Despite increasing herd sizes with increasing numbers of hired workers, over 95% of dairy farms in the US remain private, family-owned operations. These small enterprises often have limited resources and lack formalization of safety management. This symposium presentation will outline translational research and outreach efforts to address dairy worker health and safety issues through academic, extension, and industry partnerships. Past research will be presented, as well as examples of partnerships with transdisciplinary researchers, dairy producers, extension specialists, and industry associations. Modern dairy farm human resource challenges will also be discussed, as well as methods to overcome these challenges to conduct research that can be translated into practice.
Extension Education Symposium: Leading Extension Programs on Dairy Farms--Tribulations, Changes, and SuccessesSymposiumExtension Education6/27/2023 9:30n8883ListenPanel Discussion5
Joint Reproduction, Physiology and Endocrinology, and Ruminant Nutrition Symposium: Mechanisms Linking Transition Health, Nutrition, and Fertility of Dairy CattleSymposiumReproduction6/27/2023 9:30t89099ListenPresentation2460Nutritional strategies to improve the health and fertility of dairy cows.1B. J. Bradfordreproduction longevity transitionB. J. Bradford11Michigan State University, East Lansing, MIThe importance of nutrition in supporting health and fertility has been recognized at least since the discovery of essential nutrients in the early 1900s. However, the optimal nutritional program for dairy cattle to enable a healthy transition to lactation, return to cyclicity, conception, and successful implantation of the conceptus remains imprecise at best. Large retrospective studies have provided strong evidence that transition disorders—not only infections but also metabolic diseases—are associated with poor subsequent fertility. Likewise, cows that lose substantial body condition in early lactation have poor reproductive efficiency, perhaps in part due to diseases underlying the loss in condition, but likely also due to endocrine and metabolite impacts of rapid tissue mobilization. These associations suggest that dietary strategies which reduce transition disorders and promote dry matter intake in early lactation should contribute to greater reproductive success. Both prepartum and postpartum dietary strategies and feed supplements have been evaluated for impacts on reproduction, and several meta-analyses have attempted to integrate these studies to generate stronger evidence for impacts of specific nutrients. Compelling results in the literature include the positive impacts of controlled energy diets in the weeks leading up to parturition and beneficial associations between early lactation protein balance and fatty acid intake with reproductive efficiency (reduced time to pregnancy). More specifically, omega-3 fatty acids fed around the time of breeding may have beneficial impacts on conceptus viability as well as maternal tolerance of the conceptus. To more clearly define impacts of specific nutrients (especially micronutrients) on longevity and reproductive outcomes, appropriately powered studies are needed; both automated feeding systems for individual animal treatment and very large pen-level studies provide opportunities to address this gap. Nutritional strategies that optimize health and reproductive outcomes can substantially impact dairy profitability and these topics warrant more research focus.
Joint Reproduction, Physiology and Endocrinology, and Ruminant Nutrition Symposium: Mechanisms Linking Transition Health, Nutrition, and Fertility of Dairy CattleSymposiumReproduction6/27/2023 9:30t89309ListenPresentation2461Direct and indirect effects of trace mineral nutrition on health and fertility of dairy cows.2E. S. Ribeiromicronutrient transition period reproductionE. S. Ribeiro1, B. Mion1, L. Ogilvie1, B. Van Winters1, G. Madureira1, J. F. W. Sprícigo11Department of Animal Biosciences, University of Guelph, Guelph, Ontario, CanadaTrace minerals (TM) serve as cofactors of metalloenzymes required for several biological processes such as gene expression, protein synthesis, and oxidative balance. Because of insufficient concentration in most common feedstuff, dietary supplementation of Co, Cu, Mn, Se, and Zn is recommended to optimize health and performance in dairy cows. Multiple sources of TM are available for dietary supplementation and are mainly classified into 3 classes: inorganic salts of TM (STM), inorganic hydroxy TM (HTM), and organic TM (OTM). They differ in their chemical composition and bonding, stability and solubility in the digesta, microbial utilization and toxicity, and bioavailability for gut absorption, which can cause both pre- and post-absorptive effects. A supplementation method that improves rumen fermentation and digestibility can improve energy and nutrient intake and indirectly benefit health, especially during transition when feed intake is reduced. Moreover, greater bioavailability can result in enhanced TM status and directly benefit immunity, antioxidant capacity, and overall health. Improvements in transition health benefits reproduction indirectly. Nonetheless, the role of TM on biology of cells in the ovary, uterus, and developing conceptus allows direct effects of TM supplementation on fertility. We recently examined the effects of complete replacement of STM (Co, Cu, Mn, and Zn sulfates and Na selenite) by OTM (Co, Cu, Mn, and Zn sulfates and Na selenite) in both pre- and postpartum diets of 273 individually fed cows. The replacement strategy changed the systemic distribution of Co and Se, increased prepartum feed intake, reduced ruminal activity and enhanced neutrophil function during transition. In multiparous cows, OTM increased postpartum feed intake. In primiparous cows, it reduced milk yield, increased postpartum BCS, and hastened resumption of ovarian cyclicity. In addition, OTM reduced incidence of lameness and metabolic problems, and improved development of preimplantation conceptuses. No differences in incidence of other transition health problem and in reproductive performance were observed.
Joint Reproduction, Physiology and Endocrinology, and Ruminant Nutrition Symposium: Mechanisms Linking Transition Health, Nutrition, and Fertility of Dairy CattleSymposiumReproduction6/27/2023 9:30t89834ListenPresentation2462Impact of dry matter intake and rumen-protected amino acids during the transition period to optimize uterine health and fertility.4F. C. Cardosomethionine lysine dry matter intake PMNF. C. Cardoso1, A. R. Guadagnin11University of Illinois at Urbana-Champaign, Urbana, ILThe depth and duration of negative energy balance (NEB) and negative protein balance (NPB) during the transition period are highly related to dry matter intake (DMI). Formulating and delivering appropriate diets that limit total energy intake to requirements but also provide proper intakes of all other nutrients [including the indispensable amino acids (IAA) Met and Lys] before calving can help lessen the extent of NEB and NPB after calving. Supplementation of rumen-protected methionine (RPM) during the transition period improved uterine immune function through improved glandular morphology, increased neutrophil infiltration after calving, and discovery of neutrophil extracellular trap formation in bovine endometrial tissue. Cows supplemented with rumen-protected lysine (RPL) had decreased liver oxidative stress (SOD1, superoxide dismutase 1) and acute phase response (SAA3, serum amyloid A3) and reduced gene expression of NFKB1 (nuclear factor kappa B1) leading to increased proinflammatory IL1B postpartum, likely indicating improved immune activation when cows consumed RPL, a necessary component of early postpartum health. Prepartum supply of RPL altered uteroplacental metabolism and glucose transport. Additionally, we reported on the association of pre- and postpartum DMI, body weight (BW), body condition score (BCS), milk yield and milk composition, and days to first ovulation with cytological endometritis at 15 (CYT15) and 30 DIM (CYT30). A second objective was to understand the association of vaginal discharge with CYT15 and CYT30 and performance. Simple regression analyses demonstrated linear associations of increased DMI, particularly postpartum, with decreased uterine PMN percentage and lower vaginal discharge score. Additionally, increased units of vaginal discharge score and increased percentage units of uterine PMN were linearly associated with decreased milk yield. CYT15 was associated with lower DMI from 4 wk before calving until 4 wk postpartum and was associated with lower milk yield. In conclusion, the association of vaginal discharge with cytological endometritis was variable and dependent on the day of evaluation. Providing RPM and RPL during the transition period impacts dairy cows’ health and uterine environment.
Joint Reproduction, Physiology and Endocrinology, and Ruminant Nutrition Symposium: Mechanisms Linking Transition Health, Nutrition, and Fertility of Dairy CattleSymposiumReproduction6/27/2023 9:30t88362ListenPresentation2463Effects of omega-3 fatty acid supplementation on the reproduction system in cows and bulls.5U. Moallemomega-3 fatty acids reproductive systemU. Moallem11Department of Ruminants Science, Agriculture Research Organization, Volcani Institute, Rishon LeZion, IsraelMammals can synthesize all of the essential fatty acids (FA), except those belonging to the omega-3 (n-3) and omega-6 (n-6) families, which should be supplied in the diet. Common feedstuffs are rich in n-6 FA, whereas the supply of n-3 FA in the intensive dairy industry is mainly limited to flaxseed and fish oils. The n-3 FA are involved in many biological processes, such as the reproductive and immune systems, and therefore their dietary supplementation in dairy cattle is of special interest. In a series of studies, we investigated the rate and total infiltration of n-3 fatty acids into the ovarian compartments in cows, and sperm in bulls, and consequently their physiological effects. Interestingly, selective-uptake mechanism of the n-3 FA has been demonstrated in the ovary compartments, as well as in bull sperm. For example, the content of eicosapentaenoic (EPAn-3), which originated from fish oil, was high in oocytes, but was not found in the follicular fluid. On the other hand, docosapentaenoic acid (DPAn-3), which is synthesized de novo from shorter n-3 FA, accumulated only in oocytes. We also found that a specific time period is required for the infiltration of dietary n-3 FA into the target tissues; this was particularly salient in bulls, but also applies to cows. The incorporation of these unique FA into the reproductive system exerts some positive effects on fertility. The intensity, duration, timing, and pattern of hormones’ secretion around estrus were influenced by n-3 supplementation. In addition, we performed ovum pick-up, in vitro maturation, and oocyte fertilization, and found a higher cleavage rate in cows supplemented with n-3 FA. In bulls, the enrichment of sperm with n-3 FA improved the survival and quality of fresh and freeze–thawed semen. Furthermore, we found that the beneficial effects obtained for the reproductive system in cows and bulls from feeding n-3 FA can be achieved with the supplementation of α-linolenic acid (ALA) from flaxseed. In conclusion, dietary n-3 FA are incorporated into the compartments of the reproductive system in cows and bulls, and exert several beneficial effects.
Dairy Foods: Milk Protein and Enzymes Committee Symposium: High Milk Protein Foods Innovation OpportunitiesSymposiumADSA Dairy Foods Milk Protein and Enzymes Symposium6/27/2023 14:00t88151ListenPresentation2491High milk protein foods, sensory and consumer insights.1M. A. Drakeconsumer insights milk protein beveragesM. A. Drake1, D. M. Barbano21North Carolina State University, Raleigh, NC, 2Cornell University, Ithaca, NYProtein-rich foods, including beverages and bars, continue to enjoy high consumer demand. The perceived importance of milk protein versus other types of protein has decreased with consumers in recent years. There is increased competition from plant and animal free protein sources. However, milk proteins have unique flavor, functional and nutritional properties that align with consumer desires and provide opportunities for innovation. Consumers desire convenient and credible sources to know more about milk protein and need effective messaging to reduce their vulnerability to incomplete information and misinformation. Qualitative and quantitative studies of consumer insights will be discussed.
Dairy Foods: Milk Protein and Enzymes Committee Symposium: High Milk Protein Foods Innovation OpportunitiesSymposiumADSA Dairy Foods Milk Protein and Enzymes Symposium6/27/2023 14:00t89028ListenPresentation2492High-protein ice cream: Processing and chemistry.2S. Rankinice cream protein structureS. VanWees1, S. Rankin1, R. Hartel11University of Wisconsin-Madison, Madison, WIPreference for better-for-you desserts has expanded the ice cream category to include reduced-calorie, low-sugar, and high-protein alternatives. Fortification of ice cream with protein-rich ingredients presents several challenges in manufacturing unique frozen desserts with acceptable functional attributes. Commercially available high-protein frozen desserts are being manufactured to provide intended nutritional benefits, yet are routinely plagued with poor texture, flavor character, and storage stability. Work within this realm demonstrates that each step of the manufacturing process affects the structure, thus functional behavior of finished frozen desserts. While proteins are known to provide several key benefits, such as mix viscosity, emulsifying capacity and improved foam structure, more recent work demonstrates that proteins, especially at higher levels can negatively affect the multiphase structure of ice cream. Research suggests that the source of protein, the hydration state and history of the protein ingredient, and the intrinsic properties of the protein influence the development of fat, ice, and air structures, as well as the stability of these dispersed phases during distribution and storage. Our work proposes a novel paradigm for frozen dessert structure based on assessments from temperature-cycled storage on ice crystal size and foamability/foam stability as affected by proteins. Dispersions of milk protein were affected by rehydration, solubilized solids and particle size distributions, and the dilatational viscoelasticity of the protein-stabilized air interface may help predict air cell stability during abusive storage. Frozen desserts made with globular whey proteins may be more resistant to foam destabilization caused by storage abuse compared with those made with caseins due to the increased dilatational viscoelasticity. Investigations on composition, microstructure, and interfacial properties on stability of frozen foams also inform the causes and mechanisms of shrinkage in frozen desserts; therefore, it is imperative to utilize the physicochemical attributes of protein to facilitate the design of high-quality, better-for-you frozen desserts.
Dairy Foods: Milk Protein and Enzymes Committee Symposium: High Milk Protein Foods Innovation OpportunitiesSymposiumADSA Dairy Foods Milk Protein and Enzymes Symposium6/27/2023 14:00t88605ListenPresentation2493Innovations in high-protein food bars and preventing unwanted hardening.4D. J. McMahonprotein bars hardeningD. J. McMahon11Utah State University, Logan, UtahHigh-protein food bars are often manufactured using combinations of whey protein isolate (WPI), partially hydrolyzed WPI, and/or milk protein isolate as the major dairy protein source. Other functional ingredients depending on the target market include solid vegetable oil, various sugar alcohols, glycerin, fiber, hydrocolloids and emulsifiers. This presentation covers changes that occur during storage of high protein food bars, mechanisms proposed as the cause of hardening. An understanding of how proteins interaction with the surrounding water and sugar alcohol cosolvents can be used to prevent unwanted bar hardening.
Dairy Foods: Milk Protein and Enzymes Committee Symposium: High Milk Protein Foods Innovation OpportunitiesSymposiumADSA Dairy Foods Milk Protein and Enzymes Symposium6/27/2023 14:00t88747ListenPresentation2494Muscle protein synthesis in response to dairy protein fractions, whole protein-dense foods, and resistance exercise.5N. M. M. P. de Hartmuscle protein synthesis exercise whole protein-dense foodsN. M. M. P. de Hart11The University of Utah, Salt Lake City, UTStimulation of muscle protein synthesis is necessary for maintaining muscle mass. Protein from different dairy sources affects the magnitude of protein synthesis and further enhanced when combined with resistance exercise. The interplay between dietary protein and exercise has emerged over the years with a specific focus on protein fractions such as whey and casein. On the contrary, whole protein-dense foods are less understood but investigating these foods are necessary to advance practical approaches to promote maintenance of muscle mass since most people consume mixed macronutrient protein-dense whole foods and not solely isolated protein fractions. An overview of the current understanding of muscle protein synthesis in response to protein feeding and in combination with resistance exercise will be discussed.
Joint AAVI (American Association of Veterinary Immunologists) and ADSA Animal Health Symposium: Harnessing Novel Molecular Technologies to Address Challenges in Livestock ProductionSymposiumAnimal Health6/27/2023 14:00t88706ListenPresentation2507Single-nuclei transcriptomics as a tool to address adipose tissue dysfunction in dairy cows.2C. Strieder-Barbozatranscriptome adipocyte metabolic diseaseC. Strieder-Barboza1,21Department of Veterinary Sciences, Davis College of Agricultural Sciences and Natural Resources, Texas Tech University, Lubbock, TX, 2School of Veterinary Medicine, Texas Tech University, Amarillo, TXA robust body of literature supports the central role of adipose tissue (AT) dysregulation in the development of metabolic disease in periparturient dairy cows. Yet, gaps of knowledge about mechanisms underlying AT dysfunction remain. Our group uses single-cell RNA sequencing analysis (scRNaseq) to identify distinct cell (sub)types involved in the subcutaneous (SAT) and visceral (VAT) AT dysfunction and metabolic disease pathogenesis in dairy cows. Single-cell-RNaseq allows an in-depth characterization of cellular diversity by providing the transcriptional profile of individual cells, including what genes are expressed, at what expression level, and how they vary across thousands of cells within a heterogeneous sample. A limitation of scRNaseq in AT is that mature adipocytes are missing in data sets as they are too large to be sorted by microfluidics. To overcome this, we developed methods to perform single-nuclei RNaseq (snRNaseq) from cryopreserved AT samples. Our novel snRNaseq work identified vast cellular diversity in SAT and VAT of dairy cows, including distinct subtypes of adipocytes (AD), adipocyte progenitor cells (APC), endothelial cells (EC), macrophages (MAC), and mesothelial cells (ME). We found that ME are a VAT-exclusive cell type, and that the abundance of APC, EC, and MAC varies between SAT and VAT in dairy cows. Our most recent snRNaseq data indicate that subclinical ketosis affects the transcriptome of APC, EC, and AD populations in a depot-dependent manner in VAT and SAT of early lactation dairy cows by altering the expression patterns of genes associated with extracellular matrix remodeling, anti- and pro-inflammatory responses, and adipogenic regulation. These findings point to a network of cell subpopulations regulating depot-specific AT function in metabolic disease. The discovery of novel molecular and cellular targets and a better understanding of the mechanisms linking depot-specific AT dysfunction to metabolic disease provided by snRNaseq can help with the development of potential depot- or cell-specific preventive and therapeutic interventions to improve health in periparturient dairy cows.
Joint AAVI (American Association of Veterinary Immunologists) and ADSA Animal Health Symposium: Harnessing Novel Molecular Technologies to Address Challenges in Livestock ProductionSymposiumAnimal Health6/27/2023 14:00t89876ListenPresentation2508Connecting the dots: Immune status understanding using single-cell sequencing approaches.3J. E. Wiardasingle-cell scRNA-seq mastitisJ. E. Wiarda1,2, J. M. Trachsel1, A. L. Shircliff1, J. B. Stasko1, S. K. Sivasankaran1,3, J. D. Lippolis1, E. J. Putz1, M. R. Ackermann1, C. K. Tuggle3, C. L. Loving11National Animal Disease Center, ARS, USDA, Ames, IA, 2Oak Ridge Institute of Science and Education, Oak Ridge, TN, 3Iowa State University, Ames, IATraditional “bulk” assessment of gene expression via RNA sequencing captures overall patterns of transcriptional activity but fails to define cellular or spatial dynamics that influence functional outcomes related to immune status. High-resolution transcriptomics have revolutionized understandings of livestock immune status by resolving gene expression to the level of individual cells via single-cell RNA sequencing (scRNA-seq) and small-area tissue space via spatial transcriptomics (STomics). Blood and milk are routinely obtained via minimally invasive procedures and are thus ideal for assessing livestock immune status. scRNA-seq was used to dissect cellular compositions of blood and milk from cattle with chronic mastitis, revealing an abundance of granulocyte clusters in milk and lymphocytes in blood that contributed to distinct immune landscapes. While scRNA-seq reveals immune status in cells isolated from blood and milk, delineating how immune cells function within an organized tissue landscape is complicated because spatial context of cells is lost via scRNA-seq. To establish spatial organization of cells recovered from immunologically complex tissues, scRNA-seq and STomics data sets recovered from pig intestinal tissues containing Peyer’s patches were integrated. Data set integration allowed prediction of cellular locations within transcriptionally and morphologically distinct intestinal regions, revealing 2 biologically-relevant routes of immune cell activation and differentiation that were highly organized according to spatial locations. However, as scRNA-seq and STomics become common practice in research, we must also be cognizant of and overcome obstacles related to both technology- and species-specific limitations, including transcript capture efficiency, capture granularity, genome annotation, sample-assay compatibility, sampling capacities, operating costs, data analysis, and interpretation of results. Nevertheless, scRNA-seq is useful for gaining insight into livestock immune status through study of underlying cellular dynamics, while integration of scRNA-seq and STomics creates even greater potential for understanding immune dynamics within organized tissue space.
Joint AAVI (American Association of Veterinary Immunologists) and ADSA Animal Health Symposium: Harnessing Novel Molecular Technologies to Address Challenges in Livestock ProductionSymposiumAnimal Health6/27/2023 14:00t89892ListenPresentation2509A single-cell atlas of bovine skeletal muscle reveals mechanisms regulating intramuscular adipogenesis and fibrogenesis.5X. Fuadipogenesis fibrogenesis fibro/adipogenic progenitor intramuscular adipose tissue single-cell RNAseqL. Wang1, P. Gao1, C. Li1, Q. Liu1, Z. Yao2, Y. Li1, X. Zhang1, J. Sun2, C. Simintiras1, M. Welborn3, K. McMillin1, S. Oprescu4, S. Kuang4, X. Fu11School of Animal Science, Louisiana State University Agricultural Center, Baton Rouge, LA, 2Department of Computer Science, Old Dominion University, Norfolk, VA, 3School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, 4Department of Animal Sciences, Purdue University, West Lafayette, INBackground: Intramuscular fat (IMF) and intramuscular connective tissue (IMC) are often seen in human myopathies and are central to beef quality. The mechanisms regulating their accumulation remain poorly understood. Here, we explored the possibility of using beef cattle as a novel model for mechanistic studies of intramuscular adipogenesis and fibrogenesis. Methods: Skeletal muscle single-cell RNaseq was performed on 3 cattle breeds, including Wagyu (high IMF), Brahman (abundant IMC but scarce IMF), and Wagyu/Brahman cross. Sophisticated bioinformatics analyses, including clustering analysis, gene set enrichment analyses, gene regulatory network construction, RNA velocity, pseudotime analysis, and cell-cell communication analysis, were performed to elucidate heterogeneities and differentiation processes of individual cell types and differences between cattle breeds. Experiments were conducted to validate the function and specificity of identified key regulatory and marker genes. Integrated analysis with multiple published human and non-human primate data sets was performed to identify common mechanisms. Results: A total of 32,708 cells and 21 clusters were identified, including fibro/adipogenic progenitor (FAP) and other resident and infiltrating cell types. We identified an endomysial adipogenic FAP subpopulation enriched for COL4A1and CFD (log2FC = 3.19 and 1.92, respectively; P < 0.0001) and a perimysial fibrogenic FAP subpopulation enriched for COL1A1 and POSTN (log2FC = 1.83 and 0.87, respectively; P < 0.0001), both of which were likely derived from an unspecified subpopulation. Further analysis revealed more progressed adipogenic programming of Wagyu FAP and more advanced fibrogenic programming of Brahman FAP. Mechanistically, NAB2 drives CFD expression, which in turn promotes adipogenesis. CFD expression in FAP of young cattle before the onset of intramuscular adipogenesis was predictive of IMF contents in adulthood (R2 = 0.885, P < 0.01). Similar adipogenic and fibrogenic FAP were identified in humans and monkeys. In aged humans with metabolic syndrome and progressed Duchenne muscular dystrophy (DMD) patients, increased CFD expression was observed (P < 0.05 and P < 0.0001, respectively), which was positively correlated with adipogenic marker expression, including ADIPOQ (R2 = 0.303, P < 0.01; and R2 = 0.348, P < 0.01, respectively). The specificity of Postn/POSTN as a fibrogenic FAP marker was validated using a lineage-tracing mouse line. POSTN expression was elevated in Brahman FAP (P < 0.0001) and DMD patients (P < 0.01) but not in aged humans. Strong interactions between vascular cells and FAP were also identified. Conclusions: Our study demonstrates the feasibility of beef cattle as a model for studying IMF and IMC. We illustrate the FAP programming during intramuscular adipogenesis and fibrogenesis and reveal the reliability of CFD as a predictor and biomarker of IMF accumulation in cattle and humans.
Joint AAVI (American Association of Veterinary Immunologists) and ADSA Animal Health Symposium: Harnessing Novel Molecular Technologies to Address Challenges in Livestock ProductionSymposiumAnimal Health6/27/2023 14:00t89759ListenPresentation2510Multi-OMICs integration opens a new bridge to knowledge gaps in regulatory mechanisms underlying bovine mastitis.6E. M. Ibeagha-Awemumulti-OMICs approach DNA methylation/ncRNA/mRNA transcriptome regulatory networks of mastitisE. M. Ibeagha-Awemu1, M. Wang1,2, M. Laterrière3, D. Gagné3, F. Omonijo1, N. Yang2, N. Bissonnette11Sherbrooke Research and Development Centre, Agriculture and Agri-Food Canada, Sherbrooke, Québec, Canada, 2Département des sciences animales, Université Laval, Québec, Québec, Canada, 3Quebec Research and Development Centre, Agriculture and Agri-Food Canada, Québec, Québec, CanadaBovine mastitis, regarded as the most common disease of dairy animals, is multifaceted and multifactorial, involving the interaction of various factors and biological processes. Subclinical mastitis accounts for a larger share of the economic losses associated with mastitis, due to its higher incidence rate and persistence. Extensive single-OMICs studies have provided clues of the molecular mechanisms underlying mastitis through the identification of associated genomics alterations (SNPs, QTLs), differential transcriptomics (mRNAs, miRNAs, cirRNAs, lncRNAs), epigenomics (DNA methylation, histone modifications), proteomics and metabolomics, etc. These single-OMICs data sources only provide insights as to which biological processes they individually impact. However, they are limited in their ability to capture the interactions and relationships between different biological processes and thus, cannot provide a comprehensive view of the molecular mechanisms underlying mastitis. To address these limitations, the multi-OMICs approach has emerged as a promising tool for gaining a deeper understanding and elucidation of the complex biological systems and potential causative molecular mechanisms underlying various conditions. The multi-OMICs approach has been applied in various fields, including human disease, agriculture and environmental science. Applying multi-OMICs approaches to integrate a range of high dimensional data sets at multiple layers, including DNA methylation, mRNA and non-coding RNA (miRNA, snoRNA, lncRNA) transcriptomes and QTL data, we and others have revealed DNA methylation-ncRNA-gene networks and identified key regulatory pathways involved in mastitis. This approach has provided a more comprehensive view of the biological processes implicated in the host response to mastitis pathogens and has enhanced and extended our current understanding of the complex regulatory systems of subclinical mastitis, which can inform the development of new strategies for managing mastitis (e.g., breeding for mastitis resistance, new diagnostic and treatment methods).
Joint AAVI (American Association of Veterinary Immunologists) and ADSA Animal Health Symposium: Harnessing Novel Molecular Technologies to Address Challenges in Livestock ProductionSymposiumAnimal Health6/27/2023 14:00n8852ListenDiscussion7
Ruminant Nutrition Symposium: Advances in Fatty Acid NutritionSymposiumRuminant Nutrition6/27/2023 14:00t89131ListenPresentation2559Best practices in fatty acid analysis.1K. J. HarvatineCLA biohydrogenation lipidsK. J. Harvatine1, T. C. Jenkins2, S. P. Alves31Penn State University, University Park, PA, USA, 2Clemson University, Clemson, SC, 3University of Lisbon, Lisbon, PortugalFatty acid (FA) analysis has become routine in many dairy nutrition experiments but is challenging due to the diversity in sample types, FA of interest, and goals of projects. The presentation will overview the most commonly used procedures and highlight key issues and best practices. Methyl-ester derivatives are commonly prepared, but procedures vary in approach and chemistry. Direct methylation is more common in feeds, digesta, fecal, and tissue samples as it ensures more complete lipid extraction while extraction followed by methylation is more common in milk as it reduces loss of shorter chain FA and artifacts. Multiple internal standards from different classes (FAME, FFA, TG) are recommended and allow calculation of FA concentration and methylation efficiency. The stringency of methylation protocols can be increased by increasing reagent concentrations, reaction time, or temperature, but care must be taken to minimize oxidation and isomerization. Gas chromatography with flame ionization detection is the most common approach and is highly repeatable and linear, but column selection, column wear, and temperature programs influence results. Fatty acid recovery must be determined and optimization of integration setting should not be overlooked. Multiple inject may be required to separate or quantify some peaks. Advances in columns and mass spectrometry provide additional opportunities for identification of FA commonly found in samples from ruminants. Ruminant samples can contain hundreds of peaks and attempting to identify every peak can become extremely time-consuming and overwhelming. Considering the hypothesis and goals of the experiment are very important. Lastly, results must be converted to FA for reporting. One major issue is that some samples and derivation procedures create artifacts that can be up to half of the total peak area. Artifacts can be removed using solid phase extraction and is necessary if artifacts co-elute with FA. In conclusion, FA analysis is complex but robust procedures are available. Selection and execution of the right procedures for each experiment are important for robust hypothesis testing and increasing repeatability across laboratories.
Ruminant Nutrition Symposium: Advances in Fatty Acid NutritionSymposiumRuminant Nutrition6/27/2023 14:00t88381ListenPresentation2560Seventy years of research on ruminal biohydrogenation. A critical review.2P. G. Toralfatty acid lipid rumenP. G. Toral1, G. Hervás1, P. Frutos11Instituto de Ganadería de Montaña (IGM), CSIC-University of León, Grulleros, León, SpainOur knowledge about ruminal biohydrogenation (BH) has improved enormously since this metabolic process was empirically confirmed in 1951. Until the 1990s, advances in BH research were modest, due in part to analytical limitations in the identification of fatty acid isomers. Poor understanding of the implications of BH for animal performance and nutritional quality of ruminant-derived products did not contribute either. For years, BH was mostly perceived as a process to be avoided for increasing the post-ruminal flow of unsaturated fatty acids. Two milestones changed this perception and aroused great interest in analyzing BH intermediates: in 1987, in vitro anticarcinogenic properties of conjugated linoleic acids (CLA) were described; and in 2000, the inhibition of milk fat synthesis by trans-10 cis-12 CLA was confirmed. Articles on BH grew linearly between both years, tripling the number of publications in the literature. In the 2000s, research on this topic grew exponentially, reaching a plateau in the 2010s. Numerous BH metabolites have been described both in small and large ruminants, and the major deviation from the common pathway (i.e., the trans-10 shift) is relatively known. However, less well-characterized alterations exist. In addition, expectations placed on this area of research have not always been materialized. Indeed, the exhaustive description of new BH intermediates (e.g., using isotopic tracers) has not been coupled with research on their actual biological effects. Furthermore, BH seems no longer perceived as a metabolic niche inhabited by few bacterial species with highly specific metabolic capability, but we have failed to elucidate which microbial groups are actually involved in the process and the basis for alterations in BH pathways (i.e., changes in microbial populations or their activity). Answering these questions would have relevant practical implications in animal science. In this review we summarize the state-of-the-art on ruminal BH, including a critical review of the achievements and failures accumulated over these decades, as well as the future approaches from the perspective of dairy research.
Ruminant Nutrition Symposium: Advances in Fatty Acid NutritionSymposiumRuminant Nutrition6/27/2023 14:00t87602ListenPresentation2561Odd- and branched-chain fatty acid metabolism: Food abundance and human physiology.4J. T. Brennabranched-chain fatty acids yak human nutritionJ. T. Brenna11University of Texas at Austin, Austin, TXDairy products are the major sources of odd- and branched-chain fatty acids [(O)BCFA] in the diets of persons in North America. In the US cow’s milkfat contains about 2% BCFA. The mean human dietary BCFA intakes in the US exceed 500 mg/d compared with less than 100 mg/d for the well-studied omega-3 long-chain polyunsaturated fatty acids. We established that BCFA are major components of the first solid meal of the prenatal (fetal) humans via oral intake of amniotic fluid-borne vernix caseosa particles, where BCFA averages 30%. Our objective is to review the body of recent evidence indicating that BCFA are key underconsumed nutrients for human gut health. Approximately 90% of branched fat swallowed as a component of vernix caseosa disappears in the human fetal GI tract, presumably absorbed by the fetal enterocytes. BCFA appearing in the meconium, the material accumulating the rectum throughout gestation, are dominated by longer chain (C16–26) BCFA with no detectable BCFA below C16. The BCFA are present in human milk at levels lower than in cow’s milk. When human fetal or adult-like enterocytes are treated with BCFA as free fatty acids, they are taken up and rapidly incorporated into membrane phospholipids to 30–60% depending on structure. When administered in place of linoleic acid rich oils, they reduce the incidence of necrotizing enterocolitis in a neonatal rat model of the disease. In so doing, they increase the inflammatory cytokine IL-10 and shift the nascent microbiota toward organisms that contain high levels of BCFA in their membranes. The BCFA in California sea lion vernix develop mid-way through gestation, where they are found in vernix, stomach contents, amniotic fluid, plasma and meconium of fetal sea lions, all paralleling humans. Among ruminant milks, milks of yaks (Bos grunniens or Poephagus grunniens) are richest in BCFA, especially in the “half-lactating” yak where BCFA concentrations average 5.3%. Yak manure is particularly rich in BCFA, averaging almost 15% BCFA. Peoples of the Qinghai-Tibetan plateau rely on yak milk and dairy products as staples, consuming at the extremes 3,500–5,000 mg of BCFA per day.
Ruminant Nutrition Symposium: Advances in Fatty Acid NutritionSymposiumRuminant Nutrition6/27/2023 14:00t88232ListenPresentation2562Oxylipids: Mediators of the inflammatory process from initiation to resolution.5G. A. Contrerasoxylipids lipolysis inflammation initiation resolutionG. A. Contreras11Department of Large Animal Clinical Sciences, Michigan State University, East Lansing, MIOxylipids (oxylipins) are lipid mediators of inflammation derived from the oxygenation of ω-3, -6, and -9 PUFA. Oxylipids’ biosynthesis starts with PUFA release from phospholipid membranes or lipid droplets into the cytoplasm by lipolytic enzymes (phospholipases and lipases). Next, enzymatic and non-enzymatic oxidation yield oxylipids. Generally, arachidonic (AA) and linoleic (LA) acids-derived oxylipids are crucial for inflammation’s initiation stages. As the inflammatory process progresses, these ω-6 metabolites are “degraded” to epoxides, ketones, and other intermediate lipids by enzymes activated during different stages of inflammation resolution. Many of these oxylipids trigger the resolution of inflammation. As an example, LA's first oxidation products are HPODEs that are rapidly reduced to HODEs by glutathione peroxidases, followed by a dehydrogenation to oxoODEs (ketones) by hydroxy fatty acid dehydrogenase. In contrast to AA and LA-derived oxylipids, oxidation products of ω-3 PUFA, including ALA, EPA, and DHA, are considered pro-resolving. Given the number of chemical reactions involved in oxylipids biology, their profile is dynamic and varies by tissue. For example, during periods of intense lipolysis, such as parturition, the oxylipid content of adipose tissues is more dependent on the activity of hormone-sensitive lipase than on phospholipases. Consequently, the oxylipid profile of fat depots reflects on the PUFA profile of their triglyceride rather than their phospholipids. In contrast, in sites with an active bacterial infection, such as the mammary gland during mastitis, the oxylipid profile highly depends on immune cells’ membrane phospholipid fatty acid content. Notably, not all oxylipids synthesized in tissues appear in circulation, and therefore a careful interpretation of plasma lipid mediator content is warranted. Nutritional and pharmacological interventions can modulate oxilipid profile in tissues and circulation. Although increasing the production of pro-resolving oxylipins may improve inflammatory disease recovery, it may impair physiological processes that rely on rapid and robust inflammatory responses.
Ruminant Nutrition Symposium: Advances in Fatty Acid NutritionSymposiumRuminant Nutrition6/27/2023 14:00n8891ListenDiscussion6
ADSA-INRAE International Partnership Symposium: Milk--From Production to Effect on Human Health | The Latest Results of INRAE in Rennes in the PEGASE and STLO Research UnitsSymposiumADSA/INRAE International Partnership Symposium6/28/2023 9:30n8829ListenIntroduction to symposium (Dupont and Everett)1
ADSA-INRAE International Partnership Symposium: Milk--From Production to Effect on Human Health | The Latest Results of INRAE in Rennes in the PEGASE and STLO Research UnitsSymposiumADSA/INRAE International Partnership Symposium6/28/2023 9:30t88004ListenPresentation2600The structure of dairy products at different length scales drives the mechanism of digestion and the nutrient bioavailability.2D. Dupontdigestion food structure nutrientD. Dupont1,21INRAE, Rennes, France, 2Institut Agro, Rennes, FranceRecent findings have demonstrated that the food matrix structure is one of the key drivers to control the fate of food in the digestive tract and, consequently, the kinetics of nutrient release. As an example, using the pig as a model of human, we have demonstrated that, at identical composition, differences in dairy product macrostructure (milk vs acid or rennet gels) lead to differences in gastric emptying, protein hydrolysis in the gut and amino acid bioavailability. Compared with dairy gels, milk goes quickly through the stomach to reach the small intestine where protein will be rapidly and extensively degraded. This generates a fast and intense peak of plasma amino acids. When macrostructures are identical, differences at the microscopic scale can also have a strong impact on dairy product digestion. For instance, the structure of infant formula (IF) has been shown to dramatically influence the hydrolysis of milk protein. Infant formulas were designed at INRAE’s dairy platform and their in vivo digestion by piglets investigated. First, IF1 was a control IF with vegetable oil and milk proteins at the interface of the lipid droplet. In IF2, lipid droplets were stabilized by milk phospholipids to recreate a structure close to that of the milk fat globule. Finally, IF3 was also stabilized by milk phospholipids and 60% of the vegetable oil was replaced by milk fat. Piglets were fed 28 d with one of the 3 IFs and then slaughtered. Concentration of milk proteins in the jejunum and ileum was higher for IF3 whereas IFNg secretion was increased suggesting an improved intestinal immune system maturation such as observed in sow suckling piglets. Finally, the nature of IF was shown to drastically affect the intestinal microbiota composition of piglets. The structure of dairy products can therefore be considered as a lever to control the kinetics of nutrients release during digestion and fulfil the nutritional needs of specific populations such as elderly people, athletes, obese etc.
ADSA-INRAE International Partnership Symposium: Milk--From Production to Effect on Human Health | The Latest Results of INRAE in Rennes in the PEGASE and STLO Research UnitsSymposiumADSA/INRAE International Partnership Symposium6/28/2023 9:30t88070ListenPresentation2601Hormonal and nutritional regulations of lactation persistency in dairy cows.3M. Boutinaudapoptosis proliferation cell exfoliationM. Boutinaud1, C. Gaillard1, L. Herve1, F. Dessauge1, L. Delaby1, P. Lacasse2, V. Lollivier11INRAE, Institut Agro, PEGASE, 35590 Saint Gilles, France, 2AAFC, Sherbrooke R&D Centre, CanadaIn dairy cows, it is believed that the decrease in milk production after the peak of lactation is largely caused by mammary epithelial cell loss. However, the physiological regulations of lactation persistency in dairy ruminants are not entirely elucidated. Therefore, several experiments were conducted to assess the effects of hormonal and nutritional challenges on milk production and the mammary tissue. In a first experiment, the effect of the long-term inhibition of prolactin release was assessed at early lactation with cows receiving or not daily injections of quinagolide for 8 wk. The prolactin inhibition induced a faster decline in milk production (−14%) associated with a reduction in cell proliferation and an increase in apoptosis in the mammary tissue. Another experiment was conducted to observe the effects of sex steroids. Multiparous cows were either ovariectomized or sham-operated around 60 d in milk and followed for 52 weeks. Ovariectomy slowed the decline of milk yield (+10%) and thus, improved lactation persistency. This effect was accompanied with modifications of apoptosis/proliferation balance in the mammary tissue and a reduction of mammary epithelial exfoliation into milk. The effects of feeding level were also investigated in 2 experiments. In the first experiment, dairy cows were assigned to a basal diet or a severe feed restriction from 2 wk before calving to wk 11 postpartum. The negative effect of feed restriction on milk yield (−38%) was accompanied with a higher level of apoptosis in the mammary gland without effect on cell proliferation but affecting the total amount of DNA in the tissue. A second experiment, a moderate feed restriction of cows at early lactation for 4 weeks, decreased milk yield (−8%) without affecting the apoptosis/proliferation balance but increasing mammary epithelial cell exfoliation into milk. Altogether, these experiments confirmed that the regulation of lactation persistency in the dairy cows is related to changes in the number of mammary cells through either the regulation of apoptosis/proliferation balance but also through the rate of mammary cell exfoliation into milk.
ADSA-INRAE International Partnership Symposium: Milk--From Production to Effect on Human Health | The Latest Results of INRAE in Rennes in the PEGASE and STLO Research UnitsSymposiumADSA/INRAE International Partnership Symposium6/28/2023 9:30t87942ListenPresentation2602Breeding factors of dairy cows, milk lipolysis, and consequences on semi-hard cheese and fresh cream.4C. Hurtaudmilk lipolysis dairy productsC. Hurtaud1, L. Bernard2, A. Thierry3, G. Garric3, M. Harel-Oger3, C. Cebo41PEGASE, INRAE, Institut Agro, Saint-Gilles, France, 2Université Clermont Auvergne, INRAE, VetAgro Sup, UMR Herbivores, Saint-Genes-Champanelle, France, 3STLO, INRAE, Institut Agro, Rennes, France, 4Université Paris-Saclay, INRAE, AgroParisTech, GABI, Jouy-en-Josas, FranceMilk lipolysis is defined as the hydrolysis of triglycerides. Short-chain fatty acids released in milk are responsible for rancid flavor that is unacceptable for consumers. In addition, the presence of partial glycerides impairs milk functional properties. Milk lipolysis represents an important criterion to assess the quality of milk. Within the framework of the ANR-19-CE21–0010 LIPOMEC project, we aimed thus to establish breeding and feeding strategies that ensure stable milk quality, and to characterize the effects of milk susceptibility to spontaneous lipolysis (SL) induced during milk transformation. Feed restriction in dairy cows induced SL, with higher value in evening milk. We therefore studied the impact on SL i) of milking intervals: 10–14, 14–10, and 12–12, and ii) of milking frequency, on 2 groups of cows that produced milk that was susceptible or not to SL before the experiment was started, by applying once, twice or 3-times-a-day milking. Regarding milking intervals, more SL was observed in the evening milk for 10–14 interval and in the morning milk for 14–10. A small but not significant increase in evening milk was observed for the 12–12 interval. Regarding milking frequency, SL was significantly lower with once-a-day milking, and higher with 3-times-a-day milking, with a larger increase for milks susceptible to SL. Regarding transformation, we compared the changes in lipolysis during processing operations for milk susceptible or not to SL. The processing steps (milk transport, transfer by pumping, heat treatment, skimming and cold maturation before renneting) induced an overall increase, which was significantly greater for susceptible milks. The most impactful steps were skimming and cold maturation. However, the differences induced were not significantly sensorially perceived, according to the results of triangle tests performed in the 2 mo-matured cheeses and in 2 mo-stored fresh creams. Taken together, our results demonstrate that farming practices such as feeding level, milking interval or milking frequency significantly affect the level of SL in milk and the level of induced lipolysis during milk transformation.
ADSA-INRAE International Partnership Symposium: Milk--From Production to Effect on Human Health | The Latest Results of INRAE in Rennes in the PEGASE and STLO Research UnitsSymposiumADSA/INRAE International Partnership Symposium6/28/2023 9:30t88127ListenPresentation2603Eco-design approaches for developing sustainable processes: New opportunities for the dairy sector.6G. Gesan-Guiziouecodesign processing food manufacturingG. Gesan-Guiziou11UMR STLO, INRAE, Institut Agro Rennes-Angers, UMR STLO, INRAE, Institut Agro Rennes-Angers, 35000, Rennes, FranceMore than 70% of all agricultural goods currently produced in the European Union are transformed into manufactured food products, and this trajectory is set to intensify as food manufacturing processes increasingly integrate the multiple fractionation, assembly and formulation steps required to propose a vast array of food products with specific properties. This increasing rate of food processing in addition to the increasing complexity of food manufacturing forces the food industry to address its impact on the environment. This talk presents the main approaches for ecodesigning food manufacturing processes. The first approach, based on minimizing material flows (particularly energy and water) within the process, either via modifications to operating conditions or via a redistribution or reuse of the flows within the process, is widely implemented at the industrial level. The second approach, based on comparative environmental assessment of either different processes or different scenarios for a particular process that is then iteratively improved, is starting to be used. This approach typically employs life cycle assessment to single out the most environment-negative processes and unit operations to help guide process engineers toward an improved design. New approaches based on modeling, simulation-optimization ecodesign approaches are also emerging. Only these approaches integrate the notion of compromise between different technological, economic and environmental objectives (minimizing key process-related quantities, i.e., inputs (water, energy and chemicals), environmental impacts and the related costs, while maximizing productivity and product properties) by co-optimizing conflicting objectives, and tease out the optimal solutions. These approaches will be illustrated with examples taken from the dairy sector, and explicitly discussed with respect to the potential rewards and challenges of their respective application.
ADSA-INRAE International Partnership Symposium: Milk--From Production to Effect on Human Health | The Latest Results of INRAE in Rennes in the PEGASE and STLO Research UnitsSymposiumADSA/INRAE International Partnership Symposium6/28/2023 9:30t88071ListenPresentation2604Variation factors of milk calcium content in dairy cows and cellular mechanisms of milk calcium secretion.7A. Boudondairy cows feeding system milk compositionA. Boudon1, M. Boutinaud1, C. Hurtaud11PEGASE, INRAE, Institut Agro, 35590, Saint-Gilles, FranceMilk calcium (Ca) content has long been considered to be determined by milk protein content, with a strong influence of genetics of cows. Milk mid-infrared spectrometry analyses allowed showing a high heritability of milk Ca contents and a genetic correlation between this parameter and protein contents. This review of INRAE results aimed to illustrate that environmental factors also induce variations in milk Ca content. A survey based on the collection of 200,000 individual milk samples in the major areas of milk production in France showed that calendar month and cow feeding strategy affected milk Ca content, which dropped in the spring during grazing turnout and was lower when cows were fed fresh and conserved grass rather than corn silage. Complementary experimental studies clearly showed that the stage of lactation, which is an identified cause of milk Ca content variation, only explained a limited part of this variability. Thanks to a meta-analysis, based on experiments comparing diets in cows with similar stage of lactation, we showed a specific effect of diets on milk Ca content. Total, soluble and colloidal calcium contents of milk and ratio between milk Ca and protein contents were lower when diets were based on pasture rather than on corn silage, with intermediate values with diets based on grass silage or hay. Lower milk Ca contents with grass-based diet were not explained by an increased dietary cation anion difference. For some other environmental factors influencing milk Ca content, such as digestible protein and net energy balance or day length, we could observe parallel variations of milk Ca and casein contents. Milk Ca variations may be related to variations of the expression of mammary genes involved in calcium secretion pathways. Even though we observed a huge increase in knowledge in the regulation of Ca secretion in milk these last 15 years, the underlying mechanism for environmental milk Ca variation remain to be elucidated.
ADSA-INRAE International Partnership Symposium: Milk--From Production to Effect on Human Health | The Latest Results of INRAE in Rennes in the PEGASE and STLO Research UnitsSymposiumADSA/INRAE International Partnership Symposium6/28/2023 9:30t88187ListenPresentation2605Milk microbiota: Potential allies for mammary gland health.8S. Evenmilk microbiota mammary health probioticsC. Goetz1, L. Rault1, M. Boutinaud2, C. Citti3, H. Falentin1, J. Guinard-Flament2, P. Germon4, M. Mariadassou5, D. Morgavi6, X. Nouvel3, Y. Le Loir1, S. Even11STLO, INRAE, Institut Agro, Rennes, France, 2PEGASE INRAE, Institut Agro, Saint Gilles, France, 3IHAP, Université de Toulouse, INRAE, ENVT, Toulouse, France, 4ISP, INRAE, Université de Tours, Nouzilly, France, 5Université Paris-Saclay, INRAE, MaIAGE, Jouy-en-Josas, France, 6Université Clermont Auvergne, INRAE, VetAgro Sup, UMR Herbivores, Saint-Genes-Champanelle, FranceBovine mastitis has long been thought to be the result of a host-pathogen interaction; however, the microbiota is now considered as a key player of this infectious disease process. This talk presents an overview of our research on the role of milk and mammary gland microbiota on mammary health and the opportunities it offers for a more sustainable management of dairy cows' health. The role of milk and mammary gland microbiota on mammary health was first highlighted by exploring these relationships either before or after mastitis events, i.e., some time from the infectious episode. Teat cistern microbiota (collected in foremilk) was found to be related to the history of animals with regard to mastitis. Besides, using changing from twice- to once-daily milking (ODM) to trigger an udder perturbation in initially healthy quarters of cows, a temporal relationship was reported between initial teat cistern microbiota and the immune response and mastitis development following transition to ODM. To identify determinants of milk microbiota composition, cows with different scores of susceptibility to mastitis were used to explore the microbiota in various body sites throughout lactation. The microbiota from milk, mouth, nose and vagina were specific and evolved throughout lactation. Interestingly, an important intra-animal sharing of microbes between anatomic sites was reported, whereas inter-animal microbial sharing was limited, suggesting a host regulation of bovine microbiota, including a slight role of the score of susceptibility to mastitis on milk microbiota. Within mammary gland microbiota, lactic acid bacteria (LAB), used as probiotic, showed promise for mastitis prevention. In vitro, LAB were able to compete with pathogens for epithelium colonization and exhibited immunomodulatory properties. A promising LAB candidate was recently evaluated in vivo through the assessment of its microbiological, immune and physiological impact on the mammary gland, following post milking application on teat skin. The safety of such topical application was confirmed, opening up an avenue for the development of new prophylactic strategies.
ADSA-INRAE International Partnership Symposium: Milk--From Production to Effect on Human Health | The Latest Results of INRAE in Rennes in the PEGASE and STLO Research UnitsSymposiumADSA/INRAE International Partnership Symposium6/28/2023 9:30t88436ListenPresentation2606Interfacial self-organization in droplets of dairy protein mixes: From skin formation to powder functional properties.10L. Lanottedrying proteins skin formationL. Lanotte11UMR STLO, INRAE, Institut Agro Rennes-Angers, 35000 Rennes, FranceMilk powders are nowadays highly added-value goods, whose demand continuously increases, driven by world population growth and globalization. The specificity of dairy powder end-users, as in the case of infant formulas and supplements for athletes, requires a tight control of functional and nutritional properties. This crucial question is still far from being resolved since the most employed technique for powder production, i.e., the spray drying, does not favor a direct insight into the mechanisms governing the droplet sol-gel transition at the industrial scale. Over the past decade, we implemented a multiscale approach to investigate the drying dynamics in mixes of dairy proteins (i.e., whey proteins and casein micelles), which represent fundamental components of milk. Coupling complementary techniques (e.g., profile visualization, microscopy, mass measurements), the evaporation steps have been characterized first in droplets of single classes of proteins and then in mixtures. Our outcomes revealed that the intrinsic signature of whey protein and casein micelle molecular characteristics on the structure of the so-called skin, leading to the formation of smooth and hollow dry particles in the first case and wrinkled ones in the latter. Interestingly, the study of protein mixtures highlights a behavior typical of polydisperse colloidal systems, consisting of the gradual accumulation of the smaller macromolecules, i.e., whey proteins, at the surface (smaller-on-top). Under certain experimental conditions, this auto-stratification conferred to whey proteins a predominant impact on dry particle shape. Surprisingly, these results have been confirmed also by tests performed using a pilot monodisperse dryer despite the significantly different drying time scale. The next studies will focus on more complex dairy systems to further shed light on the milk drying process and possibly provide a predictive method for tuning powder functional properties starting from sample composition and environmental conditions.
ADSA-INRAE International Partnership Symposium: Milk--From Production to Effect on Human Health | The Latest Results of INRAE in Rennes in the PEGASE and STLO Research UnitsSymposiumADSA/INRAE International Partnership Symposium6/28/2023 9:30t88217ListenPresentation2607Variations in milk lactose content and the mechanisms underlying in dairy cows.11J. Guinard-Flamentmilk lactose variations dairy cowJ. Guinard-Flament1, A. Hamon1, N. Decoopman1, M. Boutinaud1, C. Gaillard1, C. Hurtaud1, M. Gelé2, L. Mériaux3, S. Dufour4, H. Larroque5, S. Lemosquet11PEGASE, INRAE, Institut Agro, Saint-Gilles, France, 2IDELE, Paris, France, 3EILYPS, Pacé, France, 4Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, Canada, 5GenPhySE, Université de Toulouse, INRAE, ENVT, Castanet-Tolosan, FranceLactose has not often been the subject of specific research as it is rarely included in milk payment systems. However, milk lactose content has been proposed as a potential indicator of udder health and metabolic disorders in dairy cows. Since these data are easy and quick to collect in dairy farms at a large scale and at a moderate price (MIR analysis), it is of interest to better understand its variations in milk to use it as an indicator. Lactose is synthesized from blood glucose in the mammary epithelial cells. It is the main osmotic agent in milk and determines the amount of water transferred from the blood compartment into the mammary tissue lumen. Thus, its synthesis and secretion largely explain the volume of milk produced by the animals and, for this reason, its content in milk varies little compared with milk fat and protein contents. The lactose content in milk is the result of 3 main mechanisms: 1) the regulation of the metabolic activity of the mammary gland for the synthesis of milk constituents, mainly based on the quantity of glucose taken up by the udder and its partition between the intra-cellular metabolic pathways, 2) the regulation of the osmotic pressure of milk related to the relative concentration of the different osmotic agents in milk (lactose, Na+, K+, Cl, proteins, citrate), and 3) the integrity of the mammary epithelium which, if altered, is accompanied by passive transfers of soluble molecules (lactose, minerals) between the alveolar lumen of the udder and the blood (and vice versa). The aim of this review will be to discuss the mechanisms underlying variations in milk lactose content regarding variations reported in commercial dairy farms in the west of France and in Canada. In particular, it will highlight the interactions between the factors of variation, whether these factors are intrinsic or extrinsic to the animals in relation to the rearing conditions (feeding, milking, and health).
ADSA-INRAE International Partnership Symposium: Milk--From Production to Effect on Human Health | The Latest Results of INRAE in Rennes in the PEGASE and STLO Research UnitsSymposiumADSA/INRAE International Partnership Symposium6/28/2023 9:30t88359ListenPresentation2608How could a breakthrough innovation in cheese technology be accepted by the consumer?12G. Garriccheese technology innovation consumersM. Harel-Oger1, C. Martin2, S. Marette3, J. Chamberland4, G. Garric11INRAE, INRAE, Institut Agro Rennes-Angers, UMR1253 STLO, Rennes, France, 2INRAE, Centre des Sciences du Goût et de l'Alimentation, CNRS, INRAE, Institut Agro, Université de Bourgogne, F-21000 Dijon, France, 3Université Paris Saclay, Université Paris-Saclay, INRAE, AgroParisTech, Paris-Saclay Applied Economics, 91120 Palaiseau, France, 4STELA, Department of Food Sciences, STELA Dairy Research Center, Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec, QC G1V 0A6, Canada, 5INRAE, INRAE, Institut Agro Rennes-Angers, UMR1253 STLO, Rennes, FranceTraditional cheese technology first consisted in draining a coagulated milk to generate a curd that was eventually salted and ripened. From’Innov was suggested as a new simplified cheesemaking concept based on decoupling cheese texture development and aroma production. The production of flavor molecules is conducted externally, in fermented dairy matrices that are added in the cheese milk prior coagulation. Subsequent works generated the knowledge to modulate functional properties of From’Innov cheese, and the concept was also duplicated in the dry form (Valo’From) for large-scale export. The From’Innov concept has many advantages for dairy processors: it is an agile process (1 line for all products of a plant), adaptable to demand (1 “ripened” cheese is made in 5 d), and is more efficient than a conventional process (−25% energy and fluids, and margins increased by 50% per kg of cheese produced). However, one question remains: are consumers ready for this breakthrough innovation? A consumer test (142 participants) was carried out to compare, under blind conditions, the hedonic appreciation (HA) and willingness to pay (WTP) of 2 soft bloomy-rind cheeses obtained by the From’Innov process (one mild and one with more intense aroma) with a commercial product obtained in a supermarket: l’Ortolan Milleret cheese dairy (Bourgogne-Franche-Comté, France). From’Innov cheeses had a lower score for HA and WTP (P < 0.01). It was even further reduced when it was explained to consumers that these 2 cheeses were obtained using an innovative process. On the other hand, when consumers knew that the new process was more energy-efficient and that new cheeses contained −25% salt and fat, WTP increased and became very close to that of commercial cheese (P > 0.05). Consumers are therefore sensitive to the benefits of From’Innov for health and efficiency. Future work is still required to understand how this process could find its place in a mature cheese market to increase the offer for cheese having a lower environmental impact and better nutritional quality.
ADSA-INRAE International Partnership Symposium: Milk--From Production to Effect on Human Health | The Latest Results of INRAE in Rennes in the PEGASE and STLO Research UnitsSymposiumADSA/INRAE International Partnership Symposium6/28/2023 9:30n8832ListenDiscussion14
Joint CSAS (Canadian Society of Animal Science) and ADSA Production, Management, and the Environment Symposium: Mitigation Strategies to Achieve Dairy Net ZeroSymposiumProduction, Management and the Environment6/28/2023 9:30t88930ListenPresentation2646Towards a net zero dairy future in Canada.1F. JacksonDairy Net Zero greenhouse-gas emissions life cycle analysisF. Jackson11Dairy Farmers of Canada, Ottawa, ON, CanadaDairy farmers are motivated to run their farms in the most efficient and sustainable way possible – to succeed as a business, and because it’s the right thing to do. The DFC’s recently launched net-zero goal aligns with the Canadian government’s commitment to achieve net-zero GHG emissions across Canada by 2050 and is also aligned with many business and global commitments such as Pathways to Dairy Net Zero led by the Global Dairy Platform. The presentation will review DFC’s most recent life cycle analysis, the strategy toward net zero and their recently launched best management guide.
Joint CSAS (Canadian Society of Animal Science) and ADSA Production, Management, and the Environment Symposium: Mitigation Strategies to Achieve Dairy Net ZeroSymposiumProduction, Management and the Environment6/28/2023 9:30t88545ListenPresentation2647Could nutrition have a meaningful impact on reducing the carbon footprint of milk?2A. N. Hristovcarbon footprint milk greenhouse gasA. N. Hristov11The Pennsylvania State University, University Park, PADepending on the production system, the carbon footprint of milk (CFM) has been estimated at as low as 0.75 to as high as 1.21 and even over 5.0 kg of CO2 equivalents/kg energy-corrected or fat- and protein-corrected milk, with the general trend being for lower CFM in intensive vs. extensive production systems. The allocation of the major greenhouse gases (GHG) to emission sources (i.e., enteric fermentation, manure management, feed production) also depends on the production system and varies among and within regions. Consequently, the role of nutrition in GHG and CFM mitigation would, to a large extent, depend on the production system. A recent comprehensive analysis of published data recommended several nutritional strategies that can reduce absolute or relative (per unit of product) enteric methane emissions in ruminants by 12 to 32%. It can be estimated that in extensive, pasture-based dairy production systems where ≥ 80% the GHG can be from enteric fermentation, a 30% reduction in enteric methane emissions, with an effective feed additive such as the methane inhibitor 3-nitrooxypropanol, would result in 25% overall reduction in CFM; for comparison, in intensive dairy production systems (where the share of enteric methane emissions may be < 50% of the total GHG), the effect of that same mitigation practice on CFM would be about 13%. Limited research has shown additivity of the mitigation effect of some nutritional strategies; if confirmed (these interactions need to be further studied), simultaneous implementation of 2 or more practices may increase the reduction in CFM from the above examples to 40 and 20%, respectively. Important questions that have not been adequately addressed are the persistence of the effect of nutritional GHG mitigation strategies over full lactation or multiple lactations and the effects of diet on manure composition and GHG emissions. In conclusion, nutritional approaches alone can have a significant mitigation impact on CFM, but that impact can be considerably greater if they are integrated, particularly in intensive dairy production systems, with manure- and animal management-related mitigation practices.
Joint CSAS (Canadian Society of Animal Science) and ADSA Production, Management, and the Environment Symposium: Mitigation Strategies to Achieve Dairy Net ZeroSymposiumProduction, Management and the Environment6/28/2023 9:30t88682ListenPresentation2648Accelerating the discovery, regulatory approval, and adoption of feed additives that reduce enteric methane emissions from livestock.3J. W. McFaddenfeed additive livestock methaneJ. W. McFadden11Cornell University, Ithaca, NYMethane is a climate pollutant that contributes to global warming. In 2021, the Global Methane Pledge set a target to reduce global methane emissions 30% by 2030, relative to 2020 levels, to limit global warming to 1.5°C by 2030, while enhancing public health and agricultural productivity. Methane from livestock agriculture represents ~40% of global methane emissions. Although cattle are part of a natural carbon cycle, reducing enteric methane production from ruminants using feed additives has potential to lower global methane emissions, while enhancing the conversion of dietary energy to meat or milk production. To define efficacy and safety of methane-reducing feed additives, we must consider impacts on enteric and manure methane and nitrous oxide emissions, nutrient digestibility and partitioning, rumen fermentation and microbiome, N retention, health and fertility of the animal, and meat and milk composition. Long-duration feeding trials are needed to ensure animal safety and consistent efficacy over time. If methane reduction fades with time, we must consider co-supplementation or replacement strategies with alternatives to ensure persistence. Our understanding of mode of action, especially for plant-based additives, is poor but necessary to define. We must do better to define methane reduction within the framework of energetic utilization in different planes of nutrition, physiological states, and environments. Because no one additive is likely to be a global solution, we must ramp up studies that examine how additives reduce enteric methane emissions across different production systems. Attention needs to focus on alternative modes of delivery for such approaches. Methodological standards that validate enteric methane monitoring and efficacy are required. In parallel, we must scrutinize technology through proper life cycle assessment and evaluate scalability. Enhancing efficiency in the developing world cannot be ignored. To meet this call for action, we must encourage international engagement, infrastructure development, academic-industry partnerships, and consumer education efforts.
Joint CSAS (Canadian Society of Animal Science) and ADSA Production, Management, and the Environment Symposium: Mitigation Strategies to Achieve Dairy Net ZeroSymposiumProduction, Management and the Environment6/28/2023 9:30t88254ListenPresentation2649The future of breeding programs: Redefining sustainability.5C. M. Richardsongenetics sustainability environmentC. M. Richardson1, J. J. Crowley2, P. R. Amer21AbacusBio International Ltd, Edinburgh, UK, 2AbacusBio Ltd, Dunedin, New ZealandReducing emissions is vital to improve sustainability and industry leaders have set emission goals to either reduce gross emissions, lower emissions intensity, or reach net-zero. However, additional traits should also be measured and compared in terms of their impact on the broader definition of sustainability. In addition to environmental impact, a sustainable breeding objective must consider profit, animal welfare, farmer well-being, and social responsibility. Traits to be considered include direct emissions (e.g., nitrogen and methane), production efficiency (e.g., feed efficiency, growth), closer to biology reproduction and fertility (e.g., oestrous strength and semen quality), health (e.g., calf and transition cow health) and welfare traits (e.g., polled). Many of these novel traits require labor intensive or expensive phenotyping, resulting in small data sets and low reliability estimated breeding values. Opportunities exists to overcome this limitation by utilizing international collaboration to combine international, developing inexpensive and easy-to-measure proxy traits, and expanding novel phenotype reference population using female driven reference population and young stock and males. Non-economic values can be estimated that quantify the impact a trait has on societal perspective (e.g., farmer preference) or environmental impact (methane emissions), and combined with economic weights to calculate aggregate weights for each trait. While validation techniques are still uncertain, the United Nations Sustainable Development Goals may be applied to determine the improvement in sustainability due to genetic selection. This approach allows for various perspectives of sustainability, such as in the developed vs developing world, to be considered. Number and quality of relevant phenotypes are currently the main limiting factor. As confidence continues to grow in the opportunity to improve sustainability through genetic selection, substantial new investment will be required both in phenotyping activities, but also into novel breeding structures and scheme designs that can maximize the value and impact of these phenotype.
Joint CSAS (Canadian Society of Animal Science) and ADSA Production, Management, and the Environment Symposium: Mitigation Strategies to Achieve Dairy Net ZeroSymposiumProduction, Management and the Environment6/28/2023 9:30t88241ListenPresentation2650Development of genomic evaluation for methane efficiency in Canadian Holsteins.6H. Sweettmethane emissions genomic evaluation single-step evaluationH. Oliveira1,2, S. Narayana1, A. Fleming1, H. Sweett1, S. Shadpour3, F. Malchiodi4, J. Jamrozik1, G. Kistemaker1, P. Sullivan1, F. Schenkel3, B. Van Doormaal1, C. Baes3,5, F. Miglior1,31Lactanet Canada, Guelph, ON, Canada, 2Purdue University, West Lafayette, IN, 3University of Guelph, Guelph, ON, Canada, 4Semex, Guelph, ON, Canada, 5University of Bern, Bern, SwitzerlandRising methane emissions and their impact on the global temperature change has become an increasing concern. Although the dairy industry is not the sole source of increasing global methane emissions, it has the potential to mitigate this increase and contribute to climate cooling. In 2016, methane was the largest contributor to the milk carbon footprint at 48%, mainly due to enteric fermentation. Dairy cattle produce, on average, 150 kg of methane per lactation and these emissions can represent a loss of 4% to 7% gross energy intake for the animal. As such, using genetics to select for cows with reduced methane emissions is a strategy that can combat global warming and improve the efficiency of the dairy industry. In April 2023, Lactanet launched genomic evaluations for Methane Efficiency using mid-infrared (MIR) spectroscopy data. Research based out of the University of Guelph using a machine learning algorithm has shown great accuracy of predicting individual animal methane emissions for milk-recorded cows using milk MIR spectral data. Lactanet developed methane predictions using methane data collected from research herds in Canada through 2 research projects, the Efficient Dairy Genome Project and the Resilient Dairy Genome Project, and milk spectral data collected via our milk recording services. Predicted methane had a genetic correlation with collected methane of 0.85 and a heritability of 0.23 (0.01). Lactanet’s genomic evaluation for Methane Efficiency was developed using a 4-trait single-step genomic evaluation for predicted methane for the Holstein breed, including milk, fat and protein yields as energy sinks. Methane Efficiency is defined as genetic Residual Methane Production in 120–185 DIM of the first lactation, independent of Milk, Fat and Protein via a linear regression approach. The average reliability of Methane Efficiency for genotyped young bulls and heifers is over 70%. Methane Efficiency is an important selection tool, allowing dairy producers to achieve an expected 20% to 30% reduction in methane emissions from their herd by 2050, without negatively affecting production.
Joint CSAS (Canadian Society of Animal Science) and ADSA Production, Management, and the Environment Symposium: Mitigation Strategies to Achieve Dairy Net ZeroSymposiumProduction, Management and the Environment6/28/2023 9:30t87993ListenPresentation2651ADSA®-EAAP Speaker Exchange Presentation: How to mitigate methane and ammonia emissions at the farm level with innovative approaches.8P. J. Galamadairy emissions housingP. J. Galama1, A. Kuipers11Wageningen Livestock Research, Wageningen, Gelderland, the NetherlandsComplying with intensive societal discussions, the Dutch Dairy chain has set goals for 2030 to increase the sustainability on the topics of climate, welfare, grazing, biodiversity, environment, new business model and land based farming. Also, a coalition of several Dairy organizations have set management goals about dilution of manure, grazing and protein in ration together with the Ministry of Agriculture to reduce the nitrogen losses, especially ammonia emission. The potential to reduce ammonia and greenhouse gas emissions with these management measures and investment in housing systems like floor types to separate feces and urine, daily removal of manure from the barn, different freewalk housing systems, Cow-toilet and air extraction systems will be shown. The challenge is to design a cow barn that improves animal welfare, manure quality and reduces emissions. These indicators were studied in case control studies with groups of 16 cows at research station Dairy Campus. The Cowtoilet is an automatic urinal that cows use voluntarily in a concentrate feeder. It collects 35% of the urine production and reduced the ammonia emission by around 35- 45%. A permeable plate on a slatted floor improves the walkability of the cows and collects all the urine underneath the floor. The ammonia emission can be reduced between 35 and 50% by acidification of the urine, flushing the plates with the urine or by spraying 20 L water per cow per day on the floor in combination with a urease inhibitor. A freewalk housing system with woodchips bedding material decreased the ammonia emission with 32% but did increase methane emission with 30%. A new development is a freewalk system with sand bedding that separates the urine by drains at the bottom of the bedding. The feces are picked up by a bedding cleaner behind the tractor. The data of 12.000 dairy farmers using the Annual Nutrient Cycle Assessment tool (ANCA) were analyzed and show the importance of fertilizing, feeding and housing systems on the emissions of ammonia and greenhouse gasses. It illustrates that low emissions of ammonia can go hand-in-hand with low emissions of greenhouse gasses.
Joint CSAS (Canadian Society of Animal Science) and ADSA Production, Management, and the Environment Symposium: Mitigation Strategies to Achieve Dairy Net ZeroSymposiumProduction, Management and the Environment6/28/2023 9:30t89223ListenPresentation2652The key role of forage and manure management to achieve net-zero targets.9J. GambleNet-zero manure management forageJ. Gamble11USDA-ARS-PSRU, St. Paul, MNDairy forage and manure management directly influence on-farm biogenic carbon (C) storage and emissions and are therefore key considerations for achieving net-zero greenhouse gas (GHG) emissions. However, in-field changes in biogenic C such as soil organic C (SOC) or flux-based net ecosystem C balance (NECB) are not commonly or consistently included in C footprint or life cycle GHG inventories of agricultural systems. This presentation will discuss the impacts of forage crop and manure management on changes in SOC and NECB in the Upper Midwest US; examine how critical C cycling feedbacks between manure and soil impact these outcomes; and highlight the importance of including these changes into broader assessments of GHG emissions and soil sustainability.
Joint CSAS (Canadian Society of Animal Science) and ADSA Production, Management, and the Environment Symposium: Mitigation Strategies to Achieve Dairy Net ZeroSymposiumProduction, Management and the Environment6/28/2023 9:30t89087ListenPresentation2653Embracing the challenge: Net zero and beyond.10G. Dicknet-zero greenhouse gas emissions barn designG. Dick1,21Dicklands Farms, Chilliwack, BC, Canada, 2Dicklands Biogas LP, Chilliwack, BC, CanadaLast year Dairy Farmers of Canada (DFC) unveiled a goal to reach net-zero greenhouse gas (GHG) emissions from farm-level dairy production by the year 2050. In this presentation we will discuss one farm’s steps toward reaching this target. Topics discussed will included increasing efficiency through genetic progress and nutrition. An overview of the development, design, planning and construction of an integrated biogas and nutrient recovery facility. On farm opportunities for conversion to other energy sources from diesel. Introduction of a new barn design for the capture of methane from enteric fermentation. As well as on farm carbon capture methods and sequestration options. This presentation will show that to go beyond Net Zero there are many, many steps to be taken. However, with careful planning and an understanding of the end goal it can be achieved.
Joint CSAS (Canadian Society of Animal Science) and ADSA Production, Management, and the Environment Symposium: Mitigation Strategies to Achieve Dairy Net ZeroSymposiumProduction, Management and the Environment6/28/2023 9:30n8860ListenPanel - Achieving Net Zero Roundtable12
Joint Growth and Development and Physiology and Endocrinology Symposium and Platform Session: From Fetus to Weaning – The Microbiome and Its Impact on Immune DevelopmentSymposiumGrowth and Development6/28/2023 9:30t89321ListenPresentation2641Gut-microbiome-organs system axes: The role of short-chain fatty acids and probiotics.1S. P. Lernermicrobiota short-chain fatty acids probioticsS. P. Lerner11Chr. Hansen, Inc, Milwaukee, WIThere is a large and continually increasing body of evidence that the gut microbiota plays an essential role in the physiologic health and mental well-being of humans, animals, and birds. Via actions that are dependent upon an initial production of short-chain fatty acids (acetate, butyrate, and propionate) in the intestinal tract of their hosts, the microorganisms of the microbiota indirectly, but significantly, impact the function of a multitude of organs systems, including, but not limited to, the digestive, pulmonary, hepatic, adipose, and central nervous systems. There is tremendous evidence from studies of germ-free and humanized mice that healthful benefits can be transferred to unhealthy individuals by transplanting the intestinal microbiota from a healthy donor. In production animal model systems, fecal transplantation from healthy donor sows and the use of microbiota-altering probiotic supplements have been shown to significantly ameliorate the actions of industry-plaguing respiratory and reproductive viruses and thereby reduce mortality and morbidity in pig flows. Finally, we’ve seen that the most successful individuals in a pen of broiler chickens had a demonstrably greater proportion of short-chain-fatty-acid-producing microorganisms in their microbiota compared with that found in the least successful individuals in the same pen. With the ever-present push to improve the efficiency of food production and adopt sustainable agricultural solutions, it is incumbent upon us to gain a better understanding of the remarkable role played by a balanced and robust microbiota in achieving those objectives.
Joint Growth and Development and Physiology and Endocrinology Symposium and Platform Session: From Fetus to Weaning – The Microbiome and Its Impact on Immune DevelopmentSymposiumGrowth and Development6/28/2023 9:30t88568ListenPresentation2642Tyndallized Lactobacillus helveticus supplementation improves gut structure and function in dairy calves around weaning.2M. F. Olmedagut permeability inflammation weaningM. F. Olmeda1, L. R. Cangiano1,3, C. Villot2, E. Chevaux2, B. K. McNeil1, T. J. DeVries1, M. A. Steele11Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada, 2Lallemand Animal Nutrition, F-31702 Blagnac, France, 3Department of Animal and Dairy Sciences, University of Wisconsin–Madison, Madison, WIThe objective of this study was to evaluate the impact of tyndallized Lactobacillus helveticus supplementation on gut structure and function of Holstein bull calves exposed to an abrupt weaning model, consisting of a stepdown from milk replacer (MR) over 4d (d35–42). A total of 44 newborn bull calves were randomly assigned to 1 of 2 treatments: Control (CON, n = 22) fed a premix containing a carrier with no paraprobiotic, and tyndallized Lactobacillus helveticus (TLH, n = 22) fed a premix providing 2 × 109 cfu/d/calf of TLH. Calves received 6 L/d of MR (150 g powder/L) split over 3 meals, which was increased to 9 L/d one week after arrival. Treatments were added to the MR at morning and evening feedings at a rate of 2.5 g of premix/feeding and fed until d42. Starter feed was offered ad libitum starting on d28. On d43, a subset of 19 calves were euthanized. Intestinal tissues were sampled at the proximal and distal jejunum, and the ileum to evaluate the surface area (SA). Blood samples were taken on d35, 42, 49, and 56 to evaluate serum amyloid A (SAA) during and after the weaning period. Gut permeability was measured on d34 and 40 by analyzing blood samples taken during 10 h of orally dosed lactulose, D-mannitol, and chromium-EDTA markers. Data were analyzed using a generalized linear mixed model in SAS with fixed effect of treatment, day, its interaction, and the random effect on group. There were no changes observed in the intestinal tissue SA with TLH supplementation (P = 0.84). A treatment by day interaction was observed in serum SAA concentrations (P = 0.03), wherein TLH had lower concentrations of SAA on d35, 42, and 49. No differences in gut permeability markers were detected between treatments, but the Lactulose:Mannitol ratio was lower and lactulose and chromium AUC were higher for the postweaning period compared with preweaning (1.02 vs. 1.26 µg/mL, P < 0.01; 60.36 vs. 68.40 µg/mL, P = 0.05; 2356 vs. 2925 mg/mL, P < 0.01 on d34 and 40, respectively). In conclusion, the abrupt weaning model increased intestinal permeability, and TLH administration may help regulate the inflammatory response following weaning.
Joint Growth and Development and Physiology and Endocrinology Symposium and Platform Session: From Fetus to Weaning – The Microbiome and Its Impact on Immune DevelopmentSymposiumGrowth and Development6/28/2023 9:30t89354ListenPresentation2643Immunomodulation strategies to control respiratory disease in preweaned calves.3J. L. McGillbovine respiratory disease innate immunity preweaned calvesJ. L. McGill11Iowa State University, Ames, IABovine respiratory disease is the second leading cause of preweaned heifer mortality, and the leading cause of weaned heifer mortality. Young calves are highly susceptible to infection due to their immature immune system. Although maternal immunity protects calves in the early weeks after birth, this protection is not always effective against respiratory pathogens. As maternal immunity wanes, the calf’s own adaptive immune system is naïve, leaving them highly susceptible to infection. The incidence of bovine respiratory disease has remained static for the last several decades, despite the widespread availability of therapeutics and vaccines, underlining the need for improved interventions strategies. The innate immune system is appealing as a target for novel therapeutic or preventative strategies. It is broadly specific and can therefore provide protection against multiple pathogens. The innate immune system acts quickly, responding within minutes to hours, rather than the days required by the adaptive immune system. In very young calves, the adaptive immune system may not be fully matured; however, the innate immune system is active and primed for protection. This talk will discuss our recent work on development of strategies to enhance innate immune function in young calves, including in-feed supplements such as phytogenic additives and postbiotics, nutrition approaches and the development of intranasal or systemic immunostimulant treatments to prime the innate immune system in calves during periods of high risk.
Joint Growth and Development and Physiology and Endocrinology Symposium and Platform Session: From Fetus to Weaning – The Microbiome and Its Impact on Immune DevelopmentSymposiumGrowth and Development6/28/2023 9:30t88909ListenPresentation2644IgG transport kinetics and histological features in the postnatal bovine intestine are maximized during very early life.4R. Hiltzcolostrum immunoglobulin G absorption neonatal calfR. Hiltz1, D. Vine1, D. R. Barreda1, A. H. Laarman11University of Alberta, Edmonton, Alberta, CanadaThis abstract is part of the ADSA-Graduate Student Competition: Production (PhD Oral)
Bovine calves are immunologically naïve at birth, requiring passive immunity transfer through colostral immunoglobulin (Ig) absorption. Knowledge regarding location and kinetics of Ig transport is limited. This study focused on the effect of time and colostrum feeding on IgG vesicle abundance and IgG transport kinetics in bovine small intestine within 24 h of life. Holstein-Angus calves (n = 36) were assigned to one of 5 harvest times in the postnatal period (1.5, 6, 12, 18, or 24 h) and were either fed colostrum (6C, 12C, 18C, and 24C) or not fed (1.5NC and 24NC). At harvest, a blood sample was taken for serum IgG analysis; segments of duodenal, proximal and distal jejunal, and ileal tissue were sampled and preserved for histology analysis, via periodic-acid-Schiff stain, or mounted in Ussing chambers containing Kreb’s buffer. Mucosal buffer was spiked with 120 mg/mL IgG and 10 mg/mL biotinylated IgG (B-IgG); serosal appearance of B-IgG was measured for 4 h. Tissue was analyzed for PAS-positive vesicle density and size. Statistics were analyzed using a 2-way (Ussing flux, histology) or a one-way (serum IgG) ANOVA in R (version 4.2.2) with a Tukey post-hoc adjustment. Serum IgG peaked at 12C (1,314 mg/dL IgG, P < 0.001) and remained constant at 18C and 24C. B-IgG flux was highest for 6C calves in all tissue segments except proximal jejunum (duodenum 11.4 ± 9.85; prox. jejunum 0.755 ± 12.8; dist. jejunum 18.6 ± 8.52; ileum 13.2 ± 4.17mg/mL/hr/cm2). Distal jejunum had the highest absorption of any tissue, and was highest in 6C calves (6C 18.6 ± 8.52; 12C 3.22 ± 6.19; 18C −0.43 ± 4.46; 24C 5.45 ± 5.05; 24NC 4.41 ± 4.94 mg/mL/hr/cm2). Histologically, vesicle density was highest in 12C calves (P < 0.001; 6hr 9.59 ± 0.42, 12hr 13.58 ± 0.59, 18hr 4.3 ± 0.46, 24hr 7.8 ± 0.46, 24NC 1.2 ± 0.31 vesicles/villi); maximal vesicle density was in the jejunum (P < 0.001; duodenum 0.8 ± 0.19, prox. jejunum 9.17 ± 0.40, dist. jejunum 11.1 ± 0.48, ileum 8.02 ± 0.37 vesicles/villi). Vesicle size increased in fed calves (P < 0.001) and tended to increase with postnatal time (P = 0.055). The B-IgG flux indicated maximal IgG absorption occurred at 6 – 12hrs of life; increased vesicle number indicated IgG absorption was highest in the jejunum sections of the small intestine.
Joint Growth and Development and Physiology and Endocrinology Symposium and Platform Session: From Fetus to Weaning – The Microbiome and Its Impact on Immune DevelopmentSymposiumGrowth and Development6/28/2023 9:30t89818ListenPresentation2645Early-life microbiome: Modulator of immunity and health.5N. Malmuthugemicrobiome immunity neonatesN. Malmuthuge11Agriculture Agri-Food Canada, Lethbridge, AB, CanadaThe pioneer microbiota colonizing the neonatal gut primes the developing immune system and stimulates long-term immune memory. The immune memory stimulated by the gut microbiota during neonatal period (birth to weaning) can only be restored if interventions are done before weaning. In addition, the neonatal gut microbiota has recently been linked to immune responses generated following immunization, suggesting that early-life microbiota is vital for the active and passive immunity of the host. Therefore, microbial perturbations (dysbiosis) during early life lead to neonatal infections and long-term microbiome-linked pathologies. In calves, the diversity and density of gut microbiota are affected by various factors such as the calving method, colostrum and milk feeding, antibiotics, water feeding, and housing. Moreover, variations in the gut microbial communities have been linked to enteric infections in neonatal calves. Omics-based studies mining host-microbe interactions in the gut at the molecular level reported that beneficial microbiota such as lactobacillus and bifidobacteria are associated with the expression of genes and regulatory molecules (microRNA) involved in immune responses in calves. These studies together suggest that pioneer microbiota play a vital role in modulating immunity and health in calves. As a result, microbial interventions have become one of the highly sought-after areas in livestock research, including dairy calves. Prebiotics, probiotics, and fecal matter transplantation/fresh rumen liquid inoculant are popular interventions tested in neonatal calves. However, our understanding of the impact of such interventions on immune priming and immune memory is lacking in calves. Therefore, an in-depth understanding of the immuno-modulatory role of the early-life microbiome is essential to improve the health of calves by supporting the establishment of healthy/beneficial gut microbiota.
Ruminant Nutrition Symposium: Dairy Nutrition to Improve Feed Utilization--Recognizing the Contributions of ADSA Fellow Dr. Bill WeissSymposiumRuminant Nutrition6/28/2023 14:00n8897ListenWelcome remarks1Maurice Eastridge
Ruminant Nutrition Symposium: Dairy Nutrition to Improve Feed Utilization--Recognizing the Contributions of ADSA Fellow Dr. Bill WeissSymposiumRuminant Nutrition6/28/2023 14:00t88089ListenPresentation2757How understanding variability in feedstuffs improves feeding practices.2W. P. Weissvariation compositionW. P. Weiss1, N. R. St-Pierre11Ohio State University, Wooster OHSoftware used to formulate diets do not incorporate variability in nutrient composition of feeds and requirements. Formulating diets using mean composition of ingredients to meet the mean inputs of a pen is suboptimal. The best dietary safety factors (SF) depend on economics and on the variability in both requirements and nutrient composition. Accurate estimates of true variation in nutrient composition can be used to derive best SF. Good data are available on the total variation in feed nutrients such as minerals and crude protein, but total variation includes that caused by the observer (sampling and analytical variation) and true variation. Based on limited data, observer variation comprised 40 to 70% of the total variation in nutrient composition of feeds and TMR. For many feeds, observer variation exceeded true variation, making a good population mean more accurate than a single sample. For feeds such as forages and many byproducts, multiple samples within a farm are needed to estimate true variance. This number can then be used when formulating a diet. For example, if the true SD for CP in distillers grains is known, reducing the entered CP by 1 SD unit ensures that ~67% of the time the distillers grains will provide at least as much CP as expected. Assuming good TMR making techniques, the variation in nutrient composition of a TMR should be less than the variation in its ingredients. Mathematical techniques exist to estimate SD of a TMR based on ingredient true variation and inclusion rates. With this information, one can determine the inclusion rate of an ingredient with high variation (which are often inexpensive) that will not adversely affect TMR variation. We have essentially no information on variability of nutrients calculated for the total diet (e.g., NEL and MP). Because multiple components go into calculating these nutrients, variation is likely less than what is observed for feed-based nutrients. Because NEL and MP are nutrients most likely to limit milk production, accurate estimates of their variation would allow for more accurate energy and protein SF which should reduce feed costs and increase efficiency.
Ruminant Nutrition Symposium: Dairy Nutrition to Improve Feed Utilization--Recognizing the Contributions of ADSA Fellow Dr. Bill WeissSymposiumRuminant Nutrition6/28/2023 14:00t88840ListenPresentation2758Improvements in diet formulation and evaluation of energy for dairy cattle.3P. J. Kononoffnet energy of lactation feed digestionP. J. Kononoff11University of Nebraska-Lincoln, Lincoln, NEThe net energy system estimates the intake of useable energy and allows comparison to the requirements of maintenance, growth, and production yielding insightful estimates of allowable production. Methods to measure or predict energy in dairy feeds have undergone evolution after the OARDC energy equation was outlined 40 years ago. This summative representation has evolved to its current use by predicting net energy for lactation (NEL) from the chemical feed fractions and pairs this information with derived digestion coefficients and subtracts the aggregate from metabolic fecal components. The NEL values of feeds in NASEM (2021) are not fixed but derived from the energy content from the digestible portion of NDF, CP, fatty acids, and starch with remaining material being described as residual organic matter. NEL represents energy of the total diet and not a sum of individual feeds. Methods to account for more feed-based sources of variation and associative animal effects have been investigated and identified. In parallel with these, adjustments in animal requirements have kept in pace with experimental observations. These include a 25% increase in maintenance energy, a more dynamic estimate of energy needed to support fetal growth, likely a result of genetic improvements, an increase in the conversion of NEL from 0.64 to 0.66. Supporting all of these advancements is use of simplistic but laborious digestion experiments which may vary in design in interpretation and novel experimental designs. Future advances in the NEL system should attempt to shed light on variable efficiencies of nutrient use. Recent interest and attention related to cattle nutrition and the environment has spurred application of methods to measure losses of energy which vary in application, accuracy, and precision; all of which will affect consideration of integration into future energy systems. In the future the NEL system will undoubtedly be enhanced with improved measure of nutrients and growing understanding of their availability and effects on the body.
Ruminant Nutrition Symposium: Dairy Nutrition to Improve Feed Utilization--Recognizing the Contributions of ADSA Fellow Dr. Bill WeissSymposiumRuminant Nutrition6/28/2023 14:00t89019ListenPresentation2759Dairy nutrition to improve feed utilization—Recognizing the contributions of ADSA Fellow Dr. Bill Weiss beyond prevention of metabolic diseases: Feeding transition dairy cows for optimal performance.5A. Tebbepostpartum nutrition metabolizable protein and energy supply diet and parity interactionsA. Tebbe11Purina Animal Nutrition LLC, Shoreview, MNHigh producing dairy cows are metabolically challenged during the transition period. This is because rapid increases in nutrient requirements for fetal growth, colostrum synthesis, and high milk solids yield often surpass metabolizable intake from the diet. When dietary supply fails to meet demands, cows mobilize nutrients from internal stores including bone, muscle or adipose tissues to meet requirements. However, transition cows can still experience a high incidence of metabolic diseases due to a lack of or excessive nutrient mobilization from body stores. Minimizing the incidence of metabolic diseases is key to improving cow health, and increasing peak milk and milk yield over an entire lactation. Thus, most nutritional research with transition cows has focused on strategies to prevent metabolic diseases (e.g., hypocalcemia, acidosis, ketosis). Most nutritional strategies have focused on the prepartum cow, and these strategies (e.g., controlled energy diets, negative DCAD diets) are commonly implemented on commercial dairies. Less research on the postpartum period is available, but as average herd size increases, grouping and feeding postpartum cows separately to improve health and production will become more common. Current postpartum research suggests increasing metabolizable protein concentration and improving amino acid balance of the postpartum diet improves milk solids yield. Increasing dietary energy in the postpartum period has had mixed results depending on the source (i.e., fat vs. starch), fermentability of the starch source, and fatty acid profile. Production responses when manipulating the postpartum diet may also depend on the prepartum diet composition and parity. Understanding the interactions of diet, parity, and the supply of nutrients between pre- and postpartum diets will be important to optimizing transition cow health and production.
Ruminant Nutrition Symposium: Dairy Nutrition to Improve Feed Utilization--Recognizing the Contributions of ADSA Fellow Dr. Bill WeissSymposiumRuminant Nutrition6/28/2023 14:00t88267ListenPresentation2760Mineral absorption and how that impacts mineral requirements.6J. Goffmacrominerals absorption homeostasisJ. Goff11Iowa State University, Ames, IAMacrominerals include the cations Ca, Mg, Na, and K and the anions Cl, P, and S. The requirement for absorbed mineral is the sum of tissue demands for maintenance, lactation, pregnancy and growth. The amount of mineral to be supplied by the diet to reach these absorbed mineral requirements is affected by the relative availability of the form of the mineral in the diet. Various sources of mineral will have differing coefficients for absorption. Most minerals utilize 2 methods of crossing the intestinal epithelial barrier. Specific ionized mineral transporter proteins/channels facilitate absorption of these minerals. The 2nd mechanism is by passive diffusion down a concentration and / or electrical gradient into the interstitial space below the absorptive epithelium and into the blood. The blood concentrations of the macrominerals are often tightly controlled and the homeostatic mechanisms in place to maintain a stable concentration of one mineral can affect the absorption or excretion of another mineral. The relative amounts of the minerals in the blood have a large impact on blood acid-base balance as well. The trace minerals, Cu, Zn, Mn, Fe, Co, Se, and I also have specific carrier mechanisms. More important to trace mineral absorption in ruminants is the negative impact the rumen environment has on solubility and bioavailability of trace minerals. Specific examples of each of the above mineral considerations will be presented for discussion.
Ruminant Nutrition Symposium: Dairy Nutrition to Improve Feed Utilization--Recognizing the Contributions of ADSA Fellow Dr. Bill WeissSymposiumRuminant Nutrition6/28/2023 14:00n8893ListenDiscussions, with reception to follow7