| Ruminant Nutrition 6: Calves and Heifers | Oral | Animal Health | 2025/06/25 10:45:00 | t93934 | Watch | 1551 | Does fiber make a healthy gut? The case of providing forage for calf diarrhea. | 1 | G. D. Plaugher | health,hay,social housing | G. D. Plaugher1, I. L. B. Fernandes1, B. J. Bone1, M. C. Cantor1 | "In this randomized control trial, we evaluated the effects of feeding pelleted hay to pair-housed dairy calves on diarrhea characteristics (severity, duration, and cases). Holstein heifer calves (n = 32 pairs; 64 calves) were paired (5 ± 3 d of age) and randomly assigned in blocks of 4 to a control (CON; no hay) or treatment (HAY; pelleted timothy). All calves received 7.4 L/d of milk replacer (22% CP, 20% fat). Three trained observers with an interobserver agreement of κ = 0.90 recorded fecal score (0 = solid, 1 = loose, 2 = loose and sifts through bedding, 3 = watery) until 30 d of age to assess for diarrhea. Pairs with diarrhea had at least one calf with a fecal score = 2 for 2 consecutive days, or a score = 3 for 1 day. Severe diarrhea was a fecal consistency = 3 for at least 3 d in a pair. A case of diarrhea ended after resolution of diarrhea for 4 consecutive days. We used simple logistic regression models to assess the association of HAY with the odds of diarrhea severity, adjusting for pair average serum total protein (STP) and pair average birthweight (BWT), and season. We used multinomial logistic regression models to assess the association of HAY with the odds of diarrhea duration (0, ≤4 d, or ≥5 d) and number of diarrhea cases (0, 1, 2+), adjusting for STP, BWT, season, and antibiotic treatment for diarrhea, with block as a random effect. We had 27 pairs with diarrhea (14 = HAY, 6 = severe; 13 = CON, 10 = severe). Control calves were 5.05 times more likely to have a severe case of diarrhea than HAY calves (odds ratio [OR] 5.05; 95% CI 1.45–17.60; P = 0.01). There was no association of HAY with the odds of diarrhea duration (OR 0.33; 95% CI 0.09–1.20; P = 0.09) or multiple cases of diarrhea (OR 3.8; 95% CI 0.85–16.99; P = 0.08). We suggest that offering timothy hay pellets reduces the severity of diarrhea in pair-housed dairy calves." |
| Ruminant Nutrition 6: Calves and Heifers | Oral | Ruminant Nutrition - Calves and Heifers | 2025/06/25 10:45:00 | t94113 | Watch | 1552 | Evaluating the microbiome profile of neonatal calves supplemented with galacto-oligosaccharide using shotgun metagenomics. | 2 | K. A. Ike | calf,galacto-oligosaccharide,shotgun metagenomics | K. A. Ike1, D. P. Casper1,2, U. Y. Anele1, M. F. Scott3 | "Galacto-oligosaccharide (GOS) is a prebiotic derived from whey. This study investigated the effect of GOS inclusion rates on gut microbiome of neonatal calves using shotgun metagenomics. Eighty-eight newborn Holstein bull calves, aged 2 to 5 d, were blocked based on their initial body weight and randomly assigned to 1 of 4 treatments using a randomized complete block design. The treatments consisted of a 22:20 (crude protein:fat) amino acid-balanced milk replacer (MR) supplemented with GOS at levels of 0 g/d (control), 2 g/d, 4 g/d, and 8 g/d. Calves were fed 0.283 kg of MR in 1.9 L MR twice daily for the first 14 d. From d 15 to d 35, the MR amount increased to 0.43 kg in 2.84 L per feeding, given twice daily. From d 36 to d 42, calves received 0.43 kg in 2.84 L once daily, followed by weaning. The GOS supplementation rate remained consistent despite the increase in milk volume. Fecal samples were taken rectally on d 40 before weaning and stored at −80°C until they were sent out for metagenome sequencing. Quality control of the reads was done using FastQC, and taxonomic classification was performed using Kraken2. Statistical analysis of the microbial abundance data was done using EdgeR. Bacillota (firmicutes) phylum was dominant across all treatments. Calves receiving 4 g/d had the highest relative abundance for Bacillota (firmicutes) phylum and the lowest for Bacteroidota phylum. The relative abundance of Lachnospiraceae family was higher in calves fed 2, 4, or 8 g/d compared with 0 g/d. Calves fed 4 g/d had higher relative abundance for the Atopobiaceae family, whereas calves supplemented with 2 g/d had higher relative abundance of the Coriobacteriaceae family. Compared with 0 g/d, calves fed 2, 4, or 8 g/d were differentially lower (false discovery rate <0.05) for Shigella, Clostridium, and Campylobacter genera and Escherichia coli, which are known to cause diarrhea in calves. Salmonella was also differentially lower for calves fed 4 g/d. Supplementation with GOS also differentially lowered several viruses, including Tunavirus strains (bacteriophages). Results from this study suggest that GOS helped to shape gut microbiome, reduce pathogenic burdens, and promote microbial homeostasis." |
| Ruminant Nutrition 6: Calves and Heifers | Oral | Ruminant Nutrition - Calves and Heifers | 2025/06/25 10:45:00 | t93897 | Watch | 1553 | Effect of calcified marine algae in calf starter, intake, and age on growth and rumen development in dairy calves. | 3 | A. M. E. Hoving | rumen development,calcified marine algae,rumen | A. M. E. Hoving1,2, S. M. Kientz2, S. G. Sayles2, A. H. Laarman2 | "Calcified marine algae (CMA) is used as a rumen buffer in cows, but effects on preruminant calves are unknown. The aim was to study effects of CMA in calf starter on growth and rumen development. Calves (n = 24) were individually housed, blocked by body weight, and randomly assigned in a 2 × 2 factorial arrangement of treatments. Starter was buffered with either 2.4% inorganic sources (limestone, bicarbonate, magnesium oxide; CT) or 1.25% CMA and 1.27% inorganic sources (limestone; CA). Daily, all calves were assessed for clinical health and received 6 L of milk replacer. Weaning transition occurred from d 49 to 63. Starter was fed ad libitum from d 15; intake was measured daily and body weight weekly. On d 51, rumen pH was measured continuously using an indwelling bolus. Harvest occurred either at 70 d of age (AGE) or whenever cumulative CS intake reached 50 kg (INT). At harvest, digesta and full and empty rumen and abomasum were weighed. Feces and rumen digesta were taken on d 42, 56, and 70 and at harvest. Data were analyzed in R using the LMER package and ANOVA test including diet and harvest point as fixed effect and arrival day as random effect. Before provision of calf starter at 15 d, CA calves had more sick days than CT (P < 0.01). After calf starter provision, there were no differences in sick days (P = 0.10). Rumen pH tended to be lower in CA groups (P = 0.07), but fecal pH was unaffected (P = 0.29). There were no differences among treatment groups of either total rumen or fecal VFA concentration (P = 0.11; P = 0.11). Empty rumen weight was higher for INT compared with AGE (P < 0.01), with no differences in digesta weight (P = 0.84). Full abomasum weight was higher for INT (P = 0.02), and CA-INT had higher abomasum weight than CA-AGE (P < 0.01). Rumen papillae length was shorter in CA calves (P = 0.04); papillae width was unaffected (P = 0.91). Despite more sick days before calf starter intake, CMA did not decrease calf starter intake (P = 0.49) or growth (P = 0.12). Further work is needed to evaluate how CMA may affect calf productivity depending on health status, but CMA may delay rumen development." |
| Applied Nutrition Platform Session: Leveraging High Oleic Soybeans for Dairy Cow Profitability | Platform Session | Ruminant Nutrition | 2025/06/23 09:00:00 | t95661 | Watch | 1168 | Critical knowledge to get the most from high oleic soybeans. | 2 | L. Davis | high oleic soybean,roasting,expelling | L. Davis1 | "Numerous studies published in the 1990s consistently showed that feeding dairy cows roasted soybeans compared with raw soybeans or soybean meal led to increased milk yield and fat-corrected milk. Heat treatment, including roasting, increases rumen undegradable protein (RUP) and particle size reduction of the whole roasted soybean improves digestibility in the small intestine. Subsequent research into the total rumen unsaturated fatty acid load (RUFAL) identified that diets high in RUFAL can disrupt ruminal fermentation and milk fat synthesis, causing practicing nutritionists to limit oilseeds in the ration. The introduction of high oleic soybean varieties that replace much of the polyunsaturated fatty acids with oleic acid, a monounsaturated fatty acid, reduces the risk of milk fat depression and has created new interest in feeding higher levels of roasted or expelled soybean products from high oleic soybeans. Optimal roasting methodology, including time and temperature, as well as steeping and cooling times have been refined. Further processing that includes extrusion and expelling can increase RUP levels beyond those achieved with roasting alone and can reduce the fat content of the finished product when that is warranted. Quality control measurements such as protein dispersibility index (PDI), Ross assay, or multi-step in vitro protein evaluation (MSPE) methods are tools that can help optimize the end product." |
| Applied Nutrition Platform Session: Leveraging High Oleic Soybeans for Dairy Cow Profitability | Platform Session | Ruminant Nutrition - Lipids | 2025/06/23 09:00:00 | t93507 | Watch | 1169 | Effects of feeding a diet with high oleic soybean oil on milk and enteric methane production in lactating cows. | 3 | B. Bae | gas facemask,milk fat,oleic acid | B. Bae1, J. Kim1,2, K. Park1,2, H. Hu1, M. L. Eastridge3, C. Lee1,2 | "Feeding fat enriched with oleic acid showed positive effects on milk production in the literature. In various in vitro studies, oleic acid was effective in mitigating methane production. The objective of this study was to determine the effects of a diet with high oleic soybean oil on milk and enteric methane production. The study was conducted with 8 mid-lactation Holstein cows in a crossover design. Cows were randomly assigned to one of 2 treatments within each block: a diet supplemented with fatty acids (FA; 2% of dietary DM) enriched with saturated FA (28% C16:0, 55% C18:0, and 7% C18:1; CON), or the CON diet supplemented with high oleic soybean oil (8% C16:0, 4% C18:0, and 77% C18:1; HOSO) by replacing the saturated FA. Each period consisted of 14 d of diet adaptation and 7 d of sampling for lactation performance. We developed a facemask system and used to collect enteric gas samples for individual cows every 3 h in a 24 h cycle over 3 d. All data were analyzed using PROC MIXED of SAS, with period and cow within block as random effects and treatment as a fixed effect. Dry matter intake and BW were not affected by treatments. Milk yield was not affected but numerically greater (44.4 vs. 42.3 kg/d; P = 0.13) for HOSO compared with CON. Therefore, milk yield per DMI tended to be greater (P = 0.09) for HOSO. Milk protein and lactose yields did not differ between treatments. Milk fat concentration (3.92 vs. 4.48%) and yield (1.70 vs. 1.88 kg/d) were lower (P < 0.01) for HOSO compared with CON. Although ECM did not differ, cows on HOSO had lower ECM per DMI (1.43 vs. 1.48; P = 0.04) compared with CON. No differences in enteric methane production (357 g/d) and methane production per DMI (11.6 g/kg) were found between HOSO and CON. In conclusion, feeding high oleic soybean oil may increase milk yield and feed efficiency, but decrease milk fat yield, suggesting that energy utilization will differ between feeding different types of FA. In addition, feeding high oleic soybean oil had no effect on methane production." |
| Applied Nutrition Platform Session: Leveraging High Oleic Soybeans for Dairy Cow Profitability | Platform Session | Ruminant Nutrition - Lipids | 2025/06/23 09:00:00 | t94512 | Watch | 1170 | Interaction of soyhulls and increasing fat with high oleic soybean products on milk production and fatty acid profile in dairy cows. | 4 | M. Ibrahim | high oleic soybean,soyhull,milk fat | M. Ibrahim1,2, P. Doane3, K. J. Harvatine1 | "Supplementing fats in dairy diets is crucial to meet energy needs and maintain optimal milk fat yield in dairy cows. We hypothesized that increasing dietary fat from different high oleic soybean (HOSB) feeds in combination with increasing diet digestibility with soyhulls would increase milk fat yield. Eighteen multiparous Holstein cows (DIM = 135 ± 21) were used in an incomplete Latin square design with 21-d periods. Treatments were a 2 × 3 factorial of soyhulls and soybean sources. Soyhulls were fed at 10% of DM replacing corn silage and alfalfa haylage. Soybean sources were a mixture of normal and heat-treated solvent-extracted meal (CON), expeller HOSB meal (EXP), and roasted HOSB (RSB). The RSB were fed at 10% of DM and others were fed to supply equal CP and similar RUP. Data were analyzed in JMP Pro 18 and the model included the random effects of cow and period and the fixed effects of soyhulls, soybean source, and their interaction. There was no interaction between soyhulls and soybean type (P > 0.05). Soyhulls increased DMI (2.8 kg/d, P < 0.001) and milk (2.9 kg/d, P < 0.001) and milk protein (105 g/d, P < 0.001) yield and decreased milk fat (0.3 units, P < 0.001) compared with CON. Roasted HOSB decreased milk protein compared with CON (0.14 units; P < 0.01) but soybean source did not change DMI or milk and milk fat or protein yields (P > 0.05). The concentration of <16C FA in milk fat was decreased by both EXP and RSB (P = 0.03), although the yield of de novo FA was not changed (P = 0.12). The concentration of 16C FA was decreased in EXP and RSB compared with CON (26.3, 29.1, 32.4; P < 0.001). Yield of 16C FA was reduced 85 g/d in RSB (P < 0.001), but EXP was not different from CON. Concentration and yield of >16C FA in milk fat were increased 68 and 163 g/d in EXP and RSB compared with CON (P < 0.001). In conclusion, increasing dietary fat from HOSB increased milk preformed FA yield and decreased C16 FA and protein concentration, but had no effect on milk and milk fat yield and DMI. Soyhulls increased DMI, milk and milk protein yield and decreased milk fat concentration." |
| Applied Nutrition Platform Session: Leveraging High Oleic Soybeans for Dairy Cow Profitability | Platform Session | Ruminant Nutrition | 2025/06/23 09:00:00 | t95662 | Watch | 1171 | Integrating scientific insights into feeding high oleic soybeans to dairy cows. | 6 | A. M. Bales | oleic acid,soybean,milk fat | A. M. Bales1,2, A. L. Lock1 | "High oleic acid soybeans (HOSB) are a feed ingredient that hold promise for improving the performance of dairy cows. This is due to their high oleic acid (OA) content, a fatty acid (FA) we have previously demonstrated to increase FA digestibility and milk production responses in high-producing dairy cows. The unique OA content (75%–80% total FA) of HOSB makes it an attractive alternative to conventional soybeans, cottonseed, and some FA supplements. Notably, HOSB can be produced regionally in the USA by dairy and soybean producers, making it an attractive option. With the recent publication of research evaluating HOSB, there has been significant growth in the use of HOSB in lactating dairy cow diets. In this review we will provide a summary of recent research with HOSB and share examples of on-farm impacts of feeding HOSB. These industry examples will discuss how to utilize HOSB as a protein and FA-rich feed ingredient, decisions regarding diet formulation with HOSB, and processing methods of HOSB. Our previous research has demonstrated that feeding roasted and ground HOSB into the diet can enhance milk and milk component yields when compared to both a non-FA supplemented control and raw HOSB diets. Recent research investigated the potential benefits of incorporating specific dietary ingredients with HOSB to further increase milk production responses. These studies demonstrated that both dietary acetate and supplemental palmitic acid could improve milk fat yield with HOSB; as well as emphasizing that production responses to different dietary 18-carbon FA (stearic vs. OA) will vary. Additionally, we examined the impact of high oleic expeller meal and the potential of this product as a quality protein source with a reduced supply of OA. The outcomes of these studies provide valuable insights into the potential and limitations of HOSB feeding, enabling dairy farmers and nutritionists to make informed decisions regarding its optimal dietary utilization. The challenge and opportunities will be to effectively apply this knowledge in feeding and management of today’s high-producing dairy cows. Further research will undoubtedly continue to develop and improve our understanding of this unique opportunity with OA that HOSB offers for optimizing milk production responses in a profitable and sustainable manner." |
| Applied Nutrition Platform Session: Leveraging High Oleic Soybeans for Dairy Cow Profitability | Platform Session | Ruminant Nutrition | 2025/06/23 09:00:00 | n9331 | Watch | | Panel Discussion with Lunch | 7 | | | | |
| Joint Ruminant Nutrition and Animal Health Platform Session: NC2040—The Gut as a Gateway; What We Know, What We Don’t, and Where We’re Going | Platform Session | NC2040 Platform Session | 2025/06/25 13:30:00 | t95667 | Watch | 1597 | Progress in the gut: What we know about “gut health” | 1 | G. B. Penner | barrier function,immune response,permeability | G. B. Penner1, C. A. Bertens1, J. R. Aschenbach2 | "“Gut health” is a poorly defined term generally used to indicate adequate functionality of the gastrointestinal tract (GIT) and its associated microbiota. The term “gut health” became gradually popular in the scientific literature only around the beginning of the current millennium and was initially coined regarding humans and monogastric animals. The later advent of gut health studies in ruminants was built on existing research that evaluated aspects of GIT functionality, focusing primarily on ruminal adaptation such as strategies to promote papillae growth to support increased absorptive surface area and adaptation of the ruminal microbiota. Much of this research was performed in dairy calves around weaning and beef and dairy cattle during dietary changes and when fed highly fermentable diets. Collectively, these studies highlighted that increasing diet fermentability generally increased the capacity for short-chain fatty acid (SCFA) absorption with changes in functional activity and enlargement of the epithelial surface. Others evaluated mechanisms for SCFA transport, highlighting that absorption includes SCFA-/HCO3- exchange such that the absorption of SCFA- results in the release of HCO3-, helping to stabilize ruminal pH. Likewise, dietary adaptation altered the metabolic pathways involved in SCFA absorption, suggesting increased cholesterol synthesis in addition to ketogenesis. As cattle with ruminal acidosis often had an acute-phase protein response, barrier function properties of the ruminal epithelium were evaluated and partly integrated with studies on the immune system. Later, a focus on hindgut acidosis emerged, leading to the characterization of GIT permeability as an indicator for barrier function and more focused research evaluating GIT immune responses. It is now generally accepted that regions within the small intestine are more permeable than pregastric and large intestinal regions, and that nutritional challenges appear to affect postruminal permeability to a greater extent. Ongoing research efforts are needed to understand factors that promote maintenance of GIT barrier function, and research should expand to include other components of barrier function such as mucus, antimicrobial peptides, and immunoglobulin secretion. Emerging research has focused on the immune-related responses of the GIT to evaluate cell populations, immune pathways induced in response to nutritional challenges, and responses when other organ systems become infected, supporting the concept of the gut-brain axis." |
| Joint Ruminant Nutrition and Animal Health Platform Session: NC2040—The Gut as a Gateway; What We Know, What We Don’t, and Where We’re Going | Platform Session | NC2040 Platform Session | 2025/06/25 13:30:00 | t94599 | Watch | 1606 | Gut health in ruminants: Where to from here? | 10 | A. H. Laarman | ruminal acidosis,hindgut acidosis,immune response | A. H. Laarman1, K. C. Krogstad2, J. S. Osorio3 | "Supporting high-yield dairy production requires energy-dense diets that, because of their rapid fermentability, create an acidotic pressure, especially in the rumen. Subacute ruminal acidosis, in particular, has long been linked to compromised fiber digestibility, reduced ruminal barrier integrity, and lower productivity in dairy cattle. In past decades, much research has focused on minimizing lipopolysaccharide release and mitigating rumen pH depression. In so doing, the hindgut also becomes at risk, as energy-dense diets can increase post-ruminal starch flow, causing excessive hindgut fermentation and disrupting barrier function in the hindgut. Consequently, rumen acidosis itself has come to be seen as a more holistic complex involving the entire gastrointestinal tract, whereby rumen pH, hindgut pH, and immune response all play roles in the adverse productivity effects seen in dairy cattle. Seen as a complex disorder that is more than just depressed rumen pH, ruminal acidosis requires a more holistic response in our diet formulations and nutritional programs. We must improve our understanding of how nutrition, management, and stress influence rumen tissue structure, hindgut barrier function, immunophenotype, and inflammatory tone. For instance, recent research demonstrated that the immunophenotype of the rumen wall is a tolerant and resilient structure that exhibits a differential response to lipopolysaccharides from different microbial species, highlighting the need for improved understanding of not only the microbial response but also the cow response and their interaction. Going forward, the microbe-immune interface is likely to play an important role in tailoring diets for high-producing dairy cows, enhancing rumen fermentation and buffering in the rumen while supporting the immunological responses of the cow." |
| Joint Ruminant Nutrition and Animal Health Platform Session: NC2040—The Gut as a Gateway; What We Know, What We Don’t, and Where We’re Going | Platform Session | NC2040 Platform Session | 2025/06/25 13:30:00 | t94319 | Watch | 1598 | Evaluating the effects of fat and colostrum supplementation in milk replacer on gut permeability, hematology, and performance of non-replacement calves. | 2 | L. Pisoni | non-replacement calves,milk replacer fat supplementation,colostrum supplementation | L. Pisoni1, C. Wang2, D. J. Seymour1,3, J. Mergh Leão4, A. Keunen5, D. L. Renaud2, M. A. Steele1 | "This study aimed to investigate the impact of fat and colostrum supplementation in milk replacer (MR) on gut permeability, hematology, and performance in non-replacement calves during the first 28 d after arrival at a calf-rearing facility. At arrival, 48 calves (n = 24 Holstein and n = 24 Holstein × Angus) were allocated to 1 of 3 treatments: (1) low-fat (LF; n = 16) received 6 L of MR (26% CP, 17% fat) from d 1 until d 28; (2) high-fat (HF; n = 16) received 6 L of MR (26% CP, 24% fat) from d 1 until d 21, then transitioned to LF MR until d 28; and (3) extended colostrum (EXT; n = 16) received 6 L of MR (26% CP, 24% fat) supplemented with 140 g of colostrum replacer from d 1 until d 21, then transitioned to LF MR until d 28. All calves were fed MR twice daily and had ad libitum access to water and solid feed. Body weight (BW) and solid feed intake were recorded weekly. Blood samples were taken on d 1, 7, 14, 21, and 28, and gut permeability tests using Cr-EDTA as a marker were performed on d 7, 14, 21, and 28. Data were analyzed using a repeated measure linear regression model in SAS with calf as a random effect and treatment, time, and their interaction as fixed effects. Calf BW, average daily gain, and solid feed intake did not differ (P = 0. 15, P = 0.74, and P = 0.40, respectively) between treatments. However, crossbred calves had greater BW (63.5 kg ± 1.18 vs. 59.17; P = 0.01) compared with Holstein calves. White blood cell (WBC) count was greater in HF calves compared with LF calves (2.21 × 109/L ± 0.042 vs. 2.05 × 109/L ± 0.043; P = 0.03), whereas EXT calves showed intermediate values. Gut permeability was not different (P = 0.26) between treatments. However, Cr-EDTA concentrations showed a 3.5-fold reduction from wk 1 (866.6 ppb) to wk 28 (245.4 ppb). In conclusion, no differences were observed when supplementing colostrum in MR, whereas MR fat supplementation increased WBC without influencing gut permeability or performance in non-replacement male calves." |
| Joint Ruminant Nutrition and Animal Health Platform Session: NC2040—The Gut as a Gateway; What We Know, What We Don’t, and Where We’re Going | Platform Session | NC2040 Platform Session | 2025/06/25 13:30:00 | t94544 | Watch | 1599 | Effects of starch inclusion level in a starter diet for milk-fed beef-on-dairy calves on growth performance and gastrointestinal health. | 3 | L. Rivas | fecal score,liver abscess,scours | L. Rivas1, P. A. Lancaster1, W. E. Brown2, R. L. Larson1, R. Amachawadi1 | "Beef-dairy cross calves have twice the liver abscess prevalence as native beef calves, which may be related to early feeding management strategies. The objective of this study was to compare different starch levels in a starter diet on growth performance and gastrointestinal health in beef-dairy cross calves at weaning. Castrated male beef-dairy cross calves (n = 20) were randomly assigned to a high- or low-starch starter grain (44 vs. 24% starch, respectively; n = 10/treatment) fed ad libitum from d 10 of age, and refusals were weighed once daily. Milk replacer was offered twice daily at 3.8 L/d and was increased to 5.7 L/d on d 10 until d 40, then stepped down 1.9 L/d per week until weaning on d 54. Calves were weighed on d 10, 40, 51, 54, and 80. Feces were assigned a categorical score 5×/week, and days of electrolyte therapy were recorded as a measure of scours incidence. Body weight and starter DMI were analyzed with a linear mixed effects model including fixed effects of treatment and day, and random effect of calf. Fecal scores were analyzed with a mixed effects logit model, and days of electrolyte therapy were assessed with a simple linear model. All analyses were done using R v 4.4.1. Preweaning BW increased with time (P < 0.01; 52.4 ± 2.66 kg on d 10 vs. 75 ± 2.63 kg on d 54), but there was no evidence of difference between treatments (P = 0.29). Starter DMI revealed a significant time × treatment interaction. There was no evidence of differences in starter DMI on d 40 when milk stepdown began (P > 0.05), but low starch had greater starter DMI at weaning on d 54 than high starch (P < 0.01; 1.96 vs. 1.65 ± 0.07 kg/d). There was no evidence of differences (P > 0.05) between treatments for ADG, fecal score, or days of electrolytes during the preweaning period. There was no evidence of differences between treatments (P = 0.88) in postweaning DMI or BW, but postweaning DMI and BW increased with time (P ≤ 0.054). In conclusion, low starch increased starter DMI during the milk stepdown phase; otherwise starch content of the starter grain had minimal effects on intake, growth, and gastrointestinal health." |
| Joint Ruminant Nutrition and Animal Health Platform Session: NC2040—The Gut as a Gateway; What We Know, What We Don’t, and Where We’re Going | Platform Session | NC2040 Platform Session | 2025/06/25 13:30:00 | t93372 | Watch | 1600 | Intestinal integrity and inflammatory markers in neonatal beef × dairy calves exposed to Salmonella infection. | 4 | K. Migl | beef × dairy calves,inflammation,diet | K. Migl1, R. Santos1, K. M. Holzapfel1, S. Gade1, L. M. Kluppel1, M. Cruz-Penn1, F. Rosa1 | "Dairy farmers have been increasing the output of dairy × beef crosses calves, also known as beef-on-dairy calves. Although beef-on-dairy calves are managed similarly to replacement heifers, whether their diet should be adjusted to improve long-term health and performance remains unclear. In this light, this study aimed to assess the gut health status of beef-on-dairy calves either fed or deprived of colostrum while experiencing enteric infection. Newborn beef × dairy calves were randomly assigned to either a colostrum-deprived or a colostrum-fed group (n = 12/group), with the latter receiving 2.8 L of pooled colostrum via oral gastric tube within 6 h after birth. Colostrum quality was 26% on the Brix scale. At 8 d of age, a subset of calves in each group were orally inoculated with Salmonella Typhimurium. Inoculated calves were euthanized, and intestinal samples were collected at 72 h post-inoculation, whereas non-inoculated calves were euthanized, and intestinal samples were collected at 23 d of age. Ileum samples were subjected to total RNA extraction, gene expression analysis via RT-qPCR, and histological assessments. Data were analyzed using PROC GLIMMIX (SAS 9.4) with group as the fixed effect and calf within group as the random effect. At 72 h post-inoculation, the colostrum-fed inoculated calves had a tendency (P = 0.07) for greater CLDN1 expression relative to the control inoculated calves. However, CLDN4 did not differ between groups. At 23 d of age, the non-inoculated colostrum-fed group had a tendency (P = 0.07) for greater NFKB expression compared with the non-inoculated colostrum-deprived calves. In contrast, TNFA and IL10 did not differ between groups. Qualitative histological assessments revealed epithelial necrosis, villi blunting, and absence of goblet cells in the ileum of colostrum-deprived calves relative to colostrum-fed calves at 72 h following Salmonella infection. Beef-on-dairy calves deprived of colostrum and under systemic inflammation had epithelial damage. Further investigations are needed to understand the influence of feeding practices on the intestinal health of beef-on-dairy calves." |
| Joint Ruminant Nutrition and Animal Health Platform Session: NC2040—The Gut as a Gateway; What We Know, What We Don’t, and Where We’re Going | Platform Session | NC2040 Platform Session | 2025/06/25 13:30:00 | t93521 | Watch | 1601 | Characterizing ruminal T lymphocytes in lactating dairy cows. | 5 | L. C. Vandevoorde | immunology,rumen,gamma-delta | L. C. Vandevoorde1, I. G. Moussiaux1, K. C. Krogstad1 | "The rumen is the largest component of the mature bovine digestive tract, but we know little of its immune system and immune functions. Previous research has demonstrated that rumen tissue is heavily populated with immune cells, most being T lymphocytes. We conducted 2 experiments to evaluate ruminal T lymphocyte phenotypes in rumen tissue. The first experiment included 3 ruminally cannulated Holstein dairy cows in an observational experiment. The second experiment included 6 ruminally cannulated cows in a replicated 3 × 3 Latin square experiment to assess the effect of increasing dietary starch on ruminal immune cell phenotypes. The levels of starch used in experiment 2 were low (20%), medium (25%), and high (30%). In experiment 1, blood and rumen tissue T lymphocyte proportions were analyzed in JMP with a 2-tailed t-test. In experiment 2, rumen immune cell phenotypes were analyzed with a mixed model, which included the fixed effect of starch concentration and the random effects of square and cow within square. Rumen evacuations were conducted during each experiment to facilitate rumen papillae harvest. The papillae were then subject to a tissue digestion and cell isolation procedure. The flow cytometry panel included CD45+ (leukocytes), CD3+ (T lymphocytes), CD4+ (helper T cells), and TCRN-24+ (γδ T cells). The cows in experiment 1 were clinically healthy, consuming 26.0 ± 3.44 kg/d of DMI and producing at 50.6 ± 12.99 kg/d of milk (mean ± SD). We observed that CD3+ cells constituted 60.8% ± 10.10% (mean ± SEM) of all ruminal CD45+ cells compared with 32.9 ± 10.10% in blood (P = 0.01). The TCRN24+ cells were the most prominent subset of T lymphocytes in rumen tissue and were enriched compared with blood (36.4% ± 5.3% vs. 4.3 ± 5.3%; P = 0.02). The CD4+ were not enriched in the rumen compared with blood (3.5% ± 1.2% vs. 6.0 ± 1.2%; P = 0.18). We observed a TCRN24+CD4+ population in the rumen that was absent in blood (17.9% ± 3.6% vs. 0.3 ± 3.9%; P = 0.04). In experiment 2, starch concentration did not affect T lymphocyte proportions (P ≥ 0.25), but TCRN24+ were the most prominent subset in rumen tissue. Our data demonstrate that rumen papillae contain γδ T lymphocytes, which may aid in rumen tissue regulation, maintenance, and function." |
| Joint Ruminant Nutrition and Animal Health Platform Session: NC2040—The Gut as a Gateway; What We Know, What We Don’t, and Where We’re Going | Platform Session | NC2040 Platform Session | 2025/06/25 13:30:00 | t93714 | Watch | 1602 | Optimizing starch concentrations in low-forage diets. | 6 | I. G. Moussiaux | starch,digestibility,low-forage diet | I. G. Moussiaux1, K. C. Krogstad1 | "Forage quality and availability will be challenged due to fluctuating weather patterns. Optimizing low-forage diets may enhance farm resilience when forage is limited. Our objective was to determine the optimal dietary starch concentration in low-forage diets. We hypothesized that increasing dietary starch in a low-forage diet (12.5% forage NDF [fNDF]) will increase milk yield, reduce milk fat yield, and increase milk fat depression related milk fatty acids. Starch was increased by adding more corn grain and reducing soybean hulls. Six multiparous Holstein cows (29–92 DIM) were assigned to treatments containing (1) 20% starch (LS), (2) 25% starch (MS), or (3) 30% starch (HS) in a replicated 3 × 3 Latin square design, with 21-d periods. The diet compositions were 34, 30, and 27% NDF for LS, MS, and HS respectively. The CP was 18% for each diet. Statistical models included random effects of square and cow within squares. We assessed the linear (L) and quadratic (Q) effects of dietary starch concentrations. Rumen pH and fecal pH were unaffected (5.84, 5.78, 5.87; L, P = 0.48; Q, P = 0.43). Plasma Hp, an inflammatory biomarker, was also not affected by starch (L, P = 0.93; Q, P = 0.14). Starch did not affect DMI (37.12, 35.72, 36.40 kg/d; L, P = 0.33; Q, P = 0.12) or milk yield (48.9, 47.4, 49.9 kg/d; L, P = 0.53; Q, P = 0.16). Increasing starch linearly reduced milk fat percentage (3.98, 3.72, 3.34%; L, P = 0.04; Q, P = 0.25) and tended to quadratically reduce milk fat yield (1.91, 1.55, 1.63 kg/d; L, P = 0.05; Q, P = 0.08). Short-chain fatty acids C6:0, C8:0, C10:0 (L, P ≤ 0.03; Q, P ≤ 0.31) and trans-10, cis-12, C18:2 (0.006, 0.009, 0.03%; L, P < 0.01; Q, P = 0.45) were significantly affected. Milk protein percentage tended to linearly decrease with increasing starch (3.45, 3.35, 3.24%; L, P = 0.07; Q, P = 0.87), whereas milk protein yield remained unchanged (1.67, 1.58, 1.60 kg/d; L, P = 0.16; Q, P = 0.15). Increasing starch quadratically reduced ECM (52.84, 46.98, 48.95 kg/d; L, P = 0.09; Q, P = 0.05). Reduced starch concentration increased milk fat yield and energy-corrected milk yield in low-forage NDF rations." |
| Joint Ruminant Nutrition and Animal Health Platform Session: NC2040—The Gut as a Gateway; What We Know, What We Don’t, and Where We’re Going | Platform Session | NC2040 Platform Session | 2025/06/25 13:30:00 | t93737 | Watch | 1603 | Assessing an ex vivo assay with gastrointestinal tissue sections to investigate mucosal immune responses in dairy calves. | 7 | P. O. McDonald | explant,mucosal immunology,scours | P. O. McDonald1, L. K. Mamedova1, B. J. Bradford1 | "Scours remain a leading cause of calf morbidity and mortality, leading to steep economic losses for producers each year. Mucosal immunity along the gastrointestinal tract is therefore essential for maintaining calf health. Our objective was to evaluate whether challenging intestinal tissue explants ex vivo would lead to quantifiable immune responses. Sections (25 mm2) of ileum and mid-jejunum from male dairy calves (n = 3; 8–10 d old) were collected at harvest and placed mucosal side up in a 24-well plate containing biopsy pads and prewarmed medium. To simulate scours, explants were stimulated with either control (medium only), bovine rotavirus (TCID50, ~1.8 × 107 per well) or Escherichia coli (1 × 107 per well; field isolate). The plate was incubated at 37°C with 5% CO2 for 2 h. Explants were then placed in Trizol for RNA isolation and medium collected for cytokine analysis. Transcript abundance was determined by qPCR for TNF and IL6 relative to RPS9 (reference gene). Supernatants were analyzed with a bovine multiplex ELISA for cytokines and chemokines. Data were analyzed (SAS GLIMMIX) with the fixed effects of stimulant, tissue location, and their interaction and the random effect of calf. Pathogenic stimulation increased mRNA abundance (P < 0.05) of TNF (undetected in 7/18 samples) and IL6 (undetected in 2/18 samples) above control, but was not significantly affected by pathogens, tissue locations, or their interaction (all P > 0.40). Both tissue segments had detectable net release (P < 0.05) of the following proteins: IL1b, IL6, IL10, MIP1a, MCP1, MIP1b, and VEGFa. Only ileal explants had measurable net release of IFNg, IL1a, IL17a, IL36a, and TNF. Ileal segments had or tended to have greater release of IFNg (P = 0.03), IL1a (P = 0.04), IL6 (P = 0.08) IL10 (P = 0.07), IL17a (P = 0.03), IL36Ra (P = 0.01), MIP1b (P = 0.049), TNF (P = 0.06), and VEGFa (P < 0.01). Despite this evidence of immune activity in the explants, main effects of stimulant and the interaction with tissue location were not significant for any cytokine. These results demonstrate that intestinal explants, particularly from the ileum, generate measurable secretion of cytokines. Responses to bacterial and viral enteric pathogens were not detected in this small pilot study." |
| Joint Ruminant Nutrition and Animal Health Platform Session: NC2040—The Gut as a Gateway; What We Know, What We Don’t, and Where We’re Going | Platform Session | NC2040 Platform Session | 2025/06/25 13:30:00 | t94130 | Watch | 1604 | Effects of a synbiotic on gastrointestinal permeability and performance in peak milk cows during feed restriction. | 8 | V. L. Daley | synbiotic,intestinal permeability,somatic cells | V. L. Daley1, C. M. K. Bradley1, T. L. Crews1, O. N. Genther-Schroeder1 | "The objective of this study was to evaluate the effects of a synbiotic on total-tract gastrointestinal permeability (TTP), animal health, and performance in peak-lactation cows using a feed restriction (FR) model. Multiparous Holstein cows (n = 24), housed in a freestall barn with Calan gates, were assigned a treatment (trt) based on previous 305-d milk yield (MY) and expected calving date in a completely randomized design. Treatments consisted of a control (CON) or a synbiotic group (SYN, 14 g/d Bacillus subtilis spores and yeast products on a DM basis, Amulet) mixed into TMR and fed from 28 d before calving to the end of the FR challenge (89 ± 9 d postpartum). For the FR challenge, all cows (74 ± 9 DIM, 51 ± 10 kg/d MY) were moved to tiestalls, and fed and milked 3×/d for 14 d. The study included an ad libitum period (AL, d 1 to 5), followed by a FR period (FR, d 6 to 9) targeting 50% of the average daily DMI from the AL period, and a refeeding period (RE, d 10 to d 14) targeting 110% of AL DMI. The TTP was measured during the AL and FR periods (d 3 and 6) by comparing plasma Cr recovery from cows orally dosed with 1.5 L of 180 mM Cr-EDTA. All cows were fitted with a jugular catheter on d 2 for blood collections that were taken daily from d 2 to 13 for metabolites and inflammatory markers, and at 0, 2, 4, 8, 12, 18, and 24 h post-dosing of Cr-EDTA to estimate the area under the curve (AUC). Two mixed models were fitted to the data to include fixed effects of trt, time or period, their interactions, and the random effect of cow within trt. No negative health issues were detected during the FR challenge. Both DMI and ECM were similar between trt (P > 0.05). We found that FR reduced MY (P < 0.01, 18% decrease) and increased serum NEFA (P < 0.01, 70% increase) and BHB (P < 0.01, 30% increase). Further, FR increased TTP compared with AL (AUC: P < 0.01, 16% increase) but was not affected by trt (P > 0.05). Serum haptoglobin was similar between groups (P > 0.05). Cows fed SYN tended to have lower milk SCS (P = 0.09) than CON. Overall, SYN may prevent milk SCS increase during stress in peak milk cows." |
| Joint Ruminant Nutrition and Animal Health Platform Session: NC2040—The Gut as a Gateway; What We Know, What We Don’t, and Where We’re Going | Platform Session | NC2040 Platform Session | 2025/06/25 13:30:00 | t94163 | Watch | 1605 | The effects of an intramammary LPS challenge in early-lactation cows fed a direct-fed microbial on performance, systemic inflammation, and gastrointestinal tract permeability. | 9 | C. Bertens | probiotic,inflammation,mastitis | C. Bertens1, D. Paulus-Compart2, C. Stoffel2, N. Hogan3, A. Facciuolo4, G. B. Penner1 | "This study evaluated the effects of a direct-fed microbial (DFM) on DMI, milk yield, systemic inflammation, and regional gastrointestinal tract (GIT) permeability following an intramammary lipopolysaccharide (IMM-LPS) challenge. Lactating Holstein cows (n = 34, 56 d in milk [DIM]) with somatic cell count (SCC) <250,000 cells/mL were used, including 15 that were ruminally cannulated. Cows received either 28 g/d of DFM (a blend of probiotics, postbiotics, and exogenous enzymes; DFM) or no DFM (PLB) for 26 d before being challenged with nothing (CON) or IMM-LPS (200 µg of Escherichia coli O111:B4 LPS; LPS) on d 27 into both rear quarters (DFM-LPS, n = 8; DFM-CON, n = 9; PLB-LPS, n = 8; PLB-CON, n = 9). Post-challenge observation included 3 phases (d 1 to 5 [CHAL], d 6 to 10 [REC1], and d 11 to 15 [REC2]) to assess DMI, milk yield, regional GIT permeability (using a bolus dose of Cr-EDTA into the rumen and Co-EDTA into the abomasum followed by blood sampling for calculation of area under the curve [AUC]), and blood markers. The effects of DFM, LPS, time, and the 2- and 3-way interactions were tested using GLIMMIX. We found that DMI decreased by 30%, 11%, and 9%, and milk yield decreased 50%, 24%, and 9% from d 1 to 3 for LPS relative to CON (LPS × day, P < 0.01). The DMI decreased by 12%, 3%, and 2% in CHAL, REC1, and REC2, respectively, for LPS compared with CON (LPS × phase, P < 0.01). The LPS cows had 18% less milk in CHAL, 3% less in REC1, and 1% less in REC2 than CON (LPS × phase, P < 0.01). Exposure to IMM-LPS increased rectal temperature over CON by 2.8°C 6 h post-challenge (LPS × hour, P < 0.01). Plasma haptoglobin was increased by 642-, 41-, and 5-fold (P < 0.01), on d 1, 7, and 12 for LPS over CON, and milk SCC increased by 1,868-, 11-, and 2-fold (P < 0.01) for LPS relative to CON in CHAL, REC1, and REC2. On d 1, the Cr and Co AUC were 24% (LPS × phase, P < 0.01) and 28% (LPS × phase, P < 0.01) lower for LPS than CON, respectively. On d 6 the Co AUC was 33% lower for LPS than CON, but Cr AUC did not differ on d 6 or 11, and Co AUC did not differ on d 11. The IMM-LPS challenge induced local and systemic inflammation that persisted longer than reduced DMI and milk yield. Total and post-ruminal GIT permeability may transiently decrease in response to IMM-LPS, but the DFM used may not attenuate the response." |
| ADSA Dairy Foods Division International Partnership Program (IPP) Symposium: The Netherlands Food Valley—Protein and Lipid Functionalities for Future Dairy Products | Symposium | ADSA International Partnership Program Symposium - Invitation Only | 2025/06/25 09:30:00 | t93822 | Watch | 1542 | Reassembled casein micelles as a model system to study casein micelles. | 11 | Z. Fan | reassembled casein micelles,casein micelle structure,casein micelle gelation | Z. Fan1, E. Bijl1, K. A. Hettinga1 | "Casein micelles are complex colloidal particles with essential functional and nutritional roles in milk and dairy products. The casein micelle structure is important for dairy product manufacturing, as the gelation of casein micelles is a key step in producing dairy products such as cheese and yogurt. Therefore, understanding the structure and behavior of casein micelles is critical. However, casein micelles exhibit natural variation in casein composition, post-translational modifications, mineral content, and size, making them a difficult system to study. For example, although the casein composition of casein micelles has been linked to their rennet coagulation properties, the precise relationships and underlying mechanisms remain inconclusive. To address these challenges, we need a model system that is easier to control and study, such as reassembled casein micelles (RCM). The RCM are casein micelles assembled in vitro by slowly mixing purified caseins and milk salts under controlled conditions (typically 37°C and pH 6.7). By making reassembled casein micelle, we can isolate a single variable and study how it affects casein micelle structure and behavior. Additionally, by modifying the structure of RCM, we can connect their structural variations to functional properties, such as gelation. This presentation will demonstrate how RCM have been used to investigate the effects of casein composition and modifications on casein micelle formation and structure, as well as the connection to gelation." |
| ADSA Dairy Foods Division International Partnership Program (IPP) Symposium: The Netherlands Food Valley—Protein and Lipid Functionalities for Future Dairy Products | Symposium | ADSA International Partnership Program Symposium - Invitation Only | 2025/06/25 09:30:00 | t93830 | Watch | 1543 | Recombinant milk proteins for the development of high-quality dairy alternatives. | 12 | E. Bijl | caseins,precision fermentation,gelation | E. Bijl1, A. De Groot1, Z. Fan1, R. Bouma1, A. E. Thiel1, L. M. C. Sagis1, K. A. Hettinga1 | "The consumer demand for dairy alternatives has been rapidly growing in the past decades. Concerns about sustainability and animal welfare of traditional milk production are 2 important motivations for an increasing percentage of consumers to replace animal-based proteins with plant-based protein sources. Unfortunately, current plant-based analogs of dairy foods on the market have sensory and techno-functional shortcomings. An emerging alternative is the use of genetic engineering to produce dairy proteins during the process called “precision fermentation.” For this process, recombinant DNA technology is used to insert protein genes into fast-growing host organisms such as bacteria, yeast, and fungi. This way, recombinant dairy proteins, such as β-LG, caseins, or lactoferrin, can be produced. A significant advantage of recombinant-produced proteins is that they have, in contrast to plant-based proteins, similar or even an improved composition and structure compared with the original animal-based dairy proteins. Using these ingredients therefore allows for a fine-tuned modulation of dairy product quality. We are currently working on research projects involving these recombinant proteins to develop microbial-based alternatives for dairy ingredients and products with a specific focus on the role of caseins. We used highly purified casein fractions obtained from bovine and microbial-based sources. Foaming and emulsifier properties were investigated by determining the properties of the air-water and oil-water interfaces using oscillating drop tensiometry. In addition, the assembly of these caseins into casein micelles increases the application for dairy products, such as cheese and yogurt, as the coagulation properties of casein micelles shape the structure of these products. We therefore determined how renneting, acid gelation and gastric clotting of casein micelles assembled in vitro differ from native casein micelles. By understanding structure-formation-stability-function relationships between caseins and reassembled casein micelles, we can tailor these to optimize functionality for high-quality alternatives for dairy ingredients and products. Simultaneously, this increased understanding allows us to translate these insights back to regular dairy products." |
| ADSA Dairy Foods Division International Partnership Program (IPP) Symposium: The Netherlands Food Valley—Protein and Lipid Functionalities for Future Dairy Products | Symposium | ADSA International Partnership Program Symposium - Invitation Only | 2025/06/25 09:30:00 | n9298 | Watch | | Panel Discussion | 13 | | | | |
| ADSA Dairy Foods Division International Partnership Program (IPP) Symposium: The Netherlands Food Valley—Protein and Lipid Functionalities for Future Dairy Products | Symposium | ADSA International Partnership Program Symposium - Invitation Only | 2025/06/25 09:30:00 | t93352 | Watch | 1536 | Tailoring digestion of dairy proteins through processing to obtain specific structures. | 2 | K. A. Hettinga | milk protein,structure,digestion | K. A. Hettinga1 | "Milk proteins, as one of the major protein sources in the Western diet, are nutritionally important, but also have numerous other physiological effects. When consuming milk proteins, these are usually present in a specific product structure that may modulate the physiological effects. Processing of milk changes the physicochemical properties of milk proteins and the properties of the resulting dairy product structure. These changes will subsequently have consequences for digestibility. Postdigestion, this may lead to different digestion products being present in the intestine, having both nutritional and immunological consequences for the consumer. The impact of milk processing on protein functionality depends on both structure and composition of the dairy matrix as interactions among proteins, as well as between proteins and other milk components, will occur. For example, the presence of β-LG during heating changes aggregation among proteins, but also the presence of minerals and lipids modulates process-induced changes to milk proteins. These process-induced changes are known to impact the formation of dairy structures (e.g., yogurt, cheese), and may also impact dairy structures during digestion (e.g., gastric clot formation). The physiological consequences of these process-induced effects on dairy product structure have been studied using both in vivo and in vitro approaches, with the integration of data from both types of studies giving novel insights into the health impact of processing on dairy products. In this presentation, I will therefore discuss the effect of industrial processes on milk protein properties and the effect of dairy structures, showing how this will impact digestion of dairy products and the nutritional and immunological consequences thereof. This knowledge can be used for tailoring digestion of dairy products by using specific processes." |
| ADSA Dairy Foods Division International Partnership Program (IPP) Symposium: The Netherlands Food Valley—Protein and Lipid Functionalities for Future Dairy Products | Symposium | ADSA International Partnership Program Symposium - Invitation Only | 2025/06/25 09:30:00 | t93789 | Watch | 1537 | The genetic background of bovine and goat milk composition in relation to functional properties. | 3 | H. Bovenhuis | milk,genetic,composition | H. Bovenhuis1, R. Gonzalez-Prendes1,3, Y. Liu1, E. Bijl2, R. P. M. A. Crooijmans1 | "Milk is a unique product rich in essential nutrients, including vitamins, minerals, amino acids, and fatty acids. Significant differences exist among individual cows and goats in milk composition, partly due to genetic factors. Historically, these genetic differences have been utilized to tailor milk composition for specific dairy products. For instance, selection for increased fat content was driven by demand for butter, while selection for protein content was influenced by cheese production. Over time, this selective breeding resulted in distinct breeds and, in some cases, differences in breeding goals within the same breed across different countries. Extensive research has established that milk protein variants influence manufacturing properties. Variants of kappa-casein have been linked to milk's renneting time, while β-LG variants affect the fouling rate of heating equipment. The availability of whole genome sequence data presents exciting opportunities for identifying additional milk protein variants. Beyond these qualitative genetic differences in milk protein variants, more recent studies have revealed substantial quantitative genetic variation in milk protein composition. Similarly, genetic factors play a significant role in variations in milk fatty acid composition, mineral content, and oligosaccharides. Several genes and genomic regions with a major influence on detailed milk composition have been identified. Despite its potential, this genetic variation remains largely untapped, while insights at the DNA level offer interesting possibilities for the production of specialized dairy products." |
| ADSA Dairy Foods Division International Partnership Program (IPP) Symposium: The Netherlands Food Valley—Protein and Lipid Functionalities for Future Dairy Products | Symposium | ADSA International Partnership Program Symposium - Invitation Only | 2025/06/25 09:30:00 | t93657 | Watch | 1538 | Goat milk caseins: Insights into their compositional variability and technofunctionality compared with cow milk caseins. | 5 | S. Breunig | goat milk,casein micelle,milk gelation | S. Breunig1,2, H. Bovenhuis3, R. P. M. A. Crooijmans3, P. Keijzer2, K. A. Hettinga1, E. Bijl1 | "Goat milk products often exhibit different properties than cow milk products, for example during gelation. As casein micelles are key structural elements for many dairy products, studying goat milk casein micelles and their techno-functional properties is essential to improve our understanding of goat milk and products thereof. We studied the compositional variation of goat caseins in individual milk samples with regard to casein composition, casein micelle size, protein content, and salt composition, which are interconnected. The occurrence of certain genetic goat casein variants thereby impacts the overall casein composition and casein micelle size. The interaction between these different parameters is complex, especially because goat milk casein is highly polymorphic. Furthermore, the interplay between these parameters is not always similar to cow casein micelles and is therefore important to investigate. Despite differences in casein composition, micelle size, and hydration between goat and cow caseins the internal structure of casein micelles was found to be similar using small-angle neutron scattering (SANS). Gelation properties such as gel strength and coagulation time of raw goat and cow milk also only differ slightly. The gelation properties of heated cow and goat milk, however, are changed significantly due to heat-induced aggregation of whey proteins and caseins. However, these heat-induced changes are more severe for cow milk gels. We show that this difference is due to greater heat-induced changes on cow than goat casein micelles. We furthermore investigated whether this is mainly influenced by differences in casein or whey fractions in both types of milk. Differences in the gel structure formed from raw and heated goat and cow milk were also observed using spin-echo SANS. This approach showed that heat-induced differences in gel structure are mainly due to changes in the compactness of casein aggregates formed during gelation. In this presentation, we will thus cover novel insights into goat caseins and their variation, their similarities to cow caseins, as well as some of the key differences that appear to be relevant for techno-functional properties." |
| ADSA Dairy Foods Division International Partnership Program (IPP) Symposium: The Netherlands Food Valley—Protein and Lipid Functionalities for Future Dairy Products | Symposium | ADSA International Partnership Program Symposium - Invitation Only | 2025/06/25 09:30:00 | t93659 | Watch | 1539 | Dairy innovations and their relevance for immune health. | 6 | J. Garssen | immune health,dairy,processing,raw milk | B. van Esch1,2, T. Baars1, M. Diks1, P. Dekker3,4, K. A. Hettinga3, R. Kort5, J. Garssen1,2 | "Epidemiological studies have shown an inverse relation between raw cows' milk consumption and the development of allergies. This protective effect seemed to be abolished by milk processing. In recent years we confirmed the epidemiological findings on asthma and food allergy by showing causality. Current research is aiming at mild-thermal and non-thermal processing techniques and the relevance for immune health. Pathogen-controlled raw milk was collected from a biodynamic dairy farm. For kefir, raw milk (Raw Milk Company, the Netherlands) was fermented with a defined freeze-dried starter culture. Allergy modulating effect of raw milk was assessed in murine models for allergic asthma and food allergy and a proof-of-concept provocation trial in infants allergic to cow milk. Kefirs made from either raw or heated milk were investigated for bacterial and fungal microbiota composition, and the allergy modulating effect. Raw milk reduced allergic symptoms in models for asthma and food allergy. Effects were preserved after skimming but abolished after pasteurization. Bioactive proteins in the whey fraction are partly responsible for the effects. The allergy protective effect of raw milk was lost around 65°C. We demonstrated that raw unprocessed cow milk has a lower allergenic potential than processed milk. The latter was confirmed in allergic children who tolerated raw cow milk up to 50 mL without showing any allergic symptoms. In kefir made from either raw or heated milk, we identified variants identical to those in the starter culture. In raw milk kefir, specific variants of Lactococcus lactis and the yeasts Pichia and Galactomyces could be identified. The number and intensity of peptides drastically increased after fermentation. Heating negatively affected the diversity of the peptide composition in kefir. Raw milk kefir suppressed the acute allergic skin response in a murine food allergy model. These effects coincided with higher percentages of activated Th1 cells and IFNg production. Raw and low temperatures processed cow milk reduced allergic symptoms in experimental models for food allergy and allergic asthma pointing toward a generic immune effect of unprocessed cow milk. Nonthermal processing techniques such as fermentation are promising tools for producing a safe dairy product with preserved health benefits." |
| ADSA Dairy Foods Division International Partnership Program (IPP) Symposium: The Netherlands Food Valley—Protein and Lipid Functionalities for Future Dairy Products | Symposium | ADSA International Partnership Program Symposium - Invitation Only | 2025/06/25 09:30:00 | t93705 | Watch | 1540 | Functional properties and sensory perception of dairy-based products. | 8 | E. Scholten | cheese,ice cream,milk fat | E. Scholten1, G. Sala1 | "Controlling the sensory experience of food products is essential to increase food liking. Different sensory attributes create a specific mouthfeel, which is governed by structure that the different ingredients create through a variety of interactions. The structure provides certain macroscopic rheological (mechanical) properties and lubrication aspects, important for many different sensory attributes, such as hardness, springiness, adhesives, creaminess, and so on. Understanding the link between the specific organization of the structural elements at smaller length scales and the textural properties on a macroscopic scale is essential to influence sensory perception. In this presentation, we will discuss the link between structure and texture of different dairy products. For example, in the case of cheese, we will discuss the role of different enzymes on the textural evolution related to protein hydrolysis and the creation of the casein network and accompanying interactions. The specific structural characteristics drive a variety of different sensory attributes, both during the first bite and during oral processing. In the case of heated gels, we will discuss how specific ingredients and additives, such as fat and salt alter the structure of the gels at different pH values and conditions, and how this is linked to different textural characteristics, such as the fracture properties and melting behavior, and how these are related to sensory perception. In ice cream, we show how dairy fat controls the complex structure in terms of the overrun, the serum phase properties, and the ice crystal network, and how this is linked to different quality attributes in ice cream, such as mechanical and melting properties. These properties depend on both the formation of partially coalesced fat globules at the air-water interface and the formation of a continuous fat network in the lamellae present between the air cells. Such knowledge provides an understanding of structure-texture relationships, which can then also be used for ingredient flexibility. We will briefly discuss how this knowledge can also be used for product reformulation, and the design of sugar and fat-reduced ice cream or dairy-free cheese." |
| ADSA Dairy Foods Division International Partnership Program (IPP) Symposium: The Netherlands Food Valley—Protein and Lipid Functionalities for Future Dairy Products | Symposium | ADSA International Partnership Program Symposium - Invitation Only | 2025/06/25 09:30:00 | t94225 | Watch | 1541 | Effects of prepartum dam characteristics on colostrum and heifer calf development. | 9 | Y. P. Wang | epigenesis,maternal effects,dam-calf relationships | Y. P. Wang1, E. Saccenti2, A. Lammers1, J. Arts1, R. M. Bruckmaier3, E. E. A. Burgers1,4, R. M. A. Goselink4, J. J. Gross3, M. Reichelt1, B. Kemp1, A. T. M. van Knegsel1 | "The objective of this study was to evaluate the relationships between dairy dams and their heifer calves by first analyzing the effects of prepartum metabolic and milk characteristics of dams on their heifer calves, and second, analyzing the role of colostrum yield and composition in the dam-calf relationships. Holstein Friesian dairy dams (n = 62) were monitored from 4 wk before conception until calving. Heifer calves from those dams were monitored from birth until the first 100 DIM of their first lactation. Dam variables were classified according to the 4 life stages: preconception and the 3 trimesters of gestation. Calf variables were classified according to the 3 life stages: weaning, rearing, and first 100 DIM. Dam and heifer variables were analyzed one-by-one in a regression model per life stage. Higher milk lactose in dams during the preconception period and the first 2 trimesters of gestation was related to higher BW in calves during rearing and first 100 DIM. Higher BCS in dams during the third trimester of gestation was related to lower concentrations of lactoferrin, IGF-1, and transforming growth factor-β2 in colostrum, which were further related to lower plasma nonesterified fatty acid concentration in calves during weaning. Greater prepartum dry matter intake and energy balance in dams were related to higher natural antibody (NAb) levels in dam colostrum which were further linked to higher NAb levels in calf plasma during weaning and rearing. In conclusion, the greatest percentage of relationships occurred when dams and heifers were both lactating, compared with weaning and rearing life stages in calves. Colostrum composition played a role in the relationship between dam milk yield and energy status with calf BW and immune variables." |
| ADSA Southern Branch Platform Session: Novel Approaches and Technologies for Monitoring Milk Quality | Symposium | ADSA Southern Branch Symposium | 2025/06/25 09:00:00 | t94457 | Watch | 1500 | Early mastitis detection using modern technologies on dairy farms. | 1 | S. Paudyal | mastitis,technology,detection | S. Paudyal1 | "Mastitis remains a significant challenge in dairy farms, adversely affecting milk yield and quality, and increasing culling rates. Despite extensive research, mastitis prevention and treatment remain a major challenge in modern dairy farms. Traditional diagnostic methods, such as microbiological culture and SCC evaluation, involve milk-appropriate sampling and laboratory analysis. Although cow side tests have been available, they often lack the accuracy needed for reliable detection. The advent of modern tools and precision dairy technologies has revitalized the focus on mastitis detection. Early detection is crucial for minimizing the risk of chronic illness and enabling timely treatment and recovery. Daily monitoring of cow level parameters provides an opportunity to identify the deviations that are associated with the induction of mastitis events, thus presenting opportunities for early detection in subclinical stages. Numerous studies have explored various tools for this purpose. Although some tools directly monitor milk characteristics and components (e.g., electrical conductivity, somatic cells, and milk leucocyte differentials), technologies assessing cow health (e.g., rumination sensors, monitoring milk fat and protein components) are also extensively explored for their use in monitoring udder health. This presentation will summarize research findings on novel tools for monitoring udder health and detecting diseases in dairy cattle. As prevention and treatment of mastitis are dependent on the type of pathogen-associated, we further explore the opportunity and challenges associated with identification of pathogen groups causing mastitis events based on noninvasive parameters obtained in dairy farms. This will also set the stage for discussions on advanced analytics and the development of modern sensor and image-based tools for evaluating mastitis detection algorithms, which are continually evolving." |
| ADSA Southern Branch Platform Session: Novel Approaches and Technologies for Monitoring Milk Quality | Symposium | ADSA Southern Branch Symposium | 2025/06/25 09:00:00 | t94499 | Watch | 1501 | Decades of infrared thermography research without farm applications: Why mastitis detection has not reached the real world, and why it still may. | 2 | T. L. Wells | dairy cattle,infrared thermography,artificial intelligence | T. L. Wells1, A. R. Rivers1 | "Mastitis is a prevalent and economically significant disease in dairy cattle, leading to lower milk production, decreased milk quality, and increased treatment costs. Detecting mastitis early is crucial for effective treatment, but traditional diagnostic methods such as SCC testing and bacterial culture are expensive, time-consuming, and impractical for large dairy farms. For years, researchers have studied infrared thermography (IRT) as a noninvasive way to detect mastitis by measuring temperature changes in the udder caused by inflammation. More recently, artificial intelligence (AI) and deep learning (DL) have been used to analyze IRT images. However, despite decades of research, IRT is still not used in dairy production. We examine the approaches that have been taken to thermal imaging and why they have failed for reasons such as environmental factors, poor standardization, and spatial and interanimal variability. Past studies have also had statistical issues with experimental design, sample size, validation sets, and data leakage. This review looks at past research on IRT for mastitis detection and suggests ways to overcome these challenges with emerging technologies and new experimental designs. With the right improvements, IRT combined with AI could become a reliable tool for farmers, helping them detect mastitis early, improve cow health, and reduce economic losses." |
| ADSA Southern Branch Platform Session: Novel Approaches and Technologies for Monitoring Milk Quality | Symposium | Animal Health | 2025/06/25 09:00:00 | t93438 | Watch | 1502 | Validation of a rapid on-farm culture system for group classification of clinical mastitis-causing pathogens. | 3 | F. G. Guardado Servellon | udder health,selective therapy,dairy cattle | F. G. Guardado Servellon1, D. L. Renaud1, B. J. Paredes Osorio2, T. J. DeVries3, K. L. Spence1, R. Couto Serrenho1 | "The objective of this diagnostic accuracy study was to compare the use of a rapid test tube system (MD; MastDecide, Quidee GmbH, Homberg, Germany) to aerobic milk culture for group classification of mastitis pathogens in dairy cows. A total of 204 milk samples from cows with clinical mastitis (CM) were collected across 60 dairy herds in Ontario, Canada. Clinical mastitis was diagnosed by the presence of abnormal milk or udder changes. Samples were collected by producers and transported to the University of Guelph on the day of collection. Each sample was tested via MD (gram-positive, gram-negative, or “no growth”) and via aerobic milk culture followed by MALDI-TOF (reference method, RM). The MD and RM results were interpreted at 14 and 24 h after incubation, respectively. An additional assessment regarding accuracy of intramammary antibiotic (IMM AB) treatment decisions (gram-positive: to treat; gram-negative and “no growth” samples: not to treat) was performed. Test performance characteristics (overall accuracy, sensitivity [Se], specificity [Sp], positive [PPV] and negative [NPV] predictive values) as well as Cohen’s kappa coefficient (κ) were calculated. The RM results were classified as gram-positive (n = 107, 52.5%), gram-negative (n = 20, 9.8%), “no growth” (n = 51, 25.0%), other pathogens (n = 21, 10.3%), and mixed growth (gram-positive and negative; n = 5, 2.6%). The RM results for other pathogens and mixed growth were removed for the calculation of test performance characteristics. The Se of the MD test was 58% (95%CI: 47%–67%), 40% (19%–64%), and 61% (50%–72%) for gram-positive, gram-negative, and “no growth,” respectively. The Sp of the MD test was 73% (63%–81%), 84% (78%–89%), and 75% (66%–82%) for gram-positive, gram-negative, and “no growth,” respectively. The PPV and NPV of the MD test were 68% (57%–78%) and 63% (54%–72%) for gram-positive, 22% (10%–39%) and 93% (87%–96%) for gram-negative, and 62% (50%–73%), 74% (65%–82%) for no growth, respectively. The overall test accuracy for Gram group analysis was 57%, with a κ of 0.30. Regarding IMM AB treatment, the MD test yielded a correct decision relative to the RM for 65% of the cases. Using this on-farm test as a primary guide in CM AB treatment decisions should be approached with caution, as the risk of false negatives may potentially compromise cure of CM cases." |
| ADSA Southern Branch Platform Session: Novel Approaches and Technologies for Monitoring Milk Quality | Symposium | Animal Health | 2025/06/25 09:00:00 | t94596 | Watch | 1503 | Early genomic predictions for mastitis resistance and somatic cell score association with udder health parameters in Jersey cows. | 4 | T. J. Almand | genomics,mastitis,Jerseys | T. J. Almand1, E. B. Oliveira2, H. F. Monteiro1, D. Bruno3, E. Okello1,4, F. S. Lima1 | "Epidemiological studies suggest that Jersey cows generally exhibit a lower incidence of mastitis than Holsteins. However, mastitis remains a significant concern for Jersey cows, indicating that further understanding of the associations of genomic resistance to mastitis (GZMAS) and genomic somatic cell score (GSCS) with mastitis may inform effective management strategies. This study investigated the associations between GZMAS, GSCS, SCC score, and the incidence of clinical and subclinical mastitis in Jersey cows. We hypothesized that cows with higher genomic resistance to mastitis (high GZMAS) and lower predicted somatic cell scores (low GSCS) would experience reduced incidences of clinical and subclinical mastitis, particularly during critical lactation phases. The study included Jersey cows (n = 2,952) with at least 200 DIM and available genomic data. The GZMAS and GSCS traits were categorized into terciles (T1 = lowest, T3 = highest), with comparisons focused on 2 extreme groups: low resistance/high SCC (T1T3, n = 384) and high resistance/low SCC (T3T1, n = 413). Mixed models in JMP (SAS) were used for data analysis using herd and cow ID as random effects. No significant differences in SCC at the previous lactation dry-off were observed (T3T1 = 58.0 ± 20.7 vs. T1T3 = 92.2 ± 23.4, P = 0.78); however, high resistance/low SCC cows had a lower incidence of subclinical mastitis at dry-off (T3T1 = 5.3 ± 1.6% vs. T1T3 = 14.1 ± 1.8%, P = 0.003). At the first test date, these cows exhibited lower SCC (T3T1 = 86.2 ± 22.5 vs. T1T3 = 201.4 ± 25.2, P = 0.001) and reduced subclinical mastitis incidence (T3T1 = 6.4 ± 1.7% vs. T1T3 = 18.3 ± 1.9%, P < 0.001). By 150 DIM, high resistance/low SCC cows had a lower clinical mastitis. incidence (T3T1 = 1.3% ± 1.3% vs. T1T3 = 10.1% ± 1.5%, P = 0.001), fewer clinical cases per cow (T3T1 = 0.05 ± 0.02 vs. T1T3 = 0.21 ± 0.03, P = 0.001), and fewer subclinical cases per cow (T3T1 = 0.55 ± 0.06 vs. T1T3 = 1.31 ± 0.07, P = 0.001). These findings underscore the potential of genomic selection for mastitis resistance and SCS in guiding targeted mastitis control strategies in Jersey cows." |
| ADSA Southern Branch Platform Session: Novel Approaches and Technologies for Monitoring Milk Quality | Symposium | Animal Health | 2025/06/25 09:00:00 | t94051 | Watch | 1504 | Milk and milk spectra: A rich opportunity for mastitis prediction. | 5 | D. Lin | Fourier-transform infrared spectroscopy,milk components,machine learning | D. Lin1, J. A. A. McArt1 | "Milk Fourier-transform infrared (FTIR) spectra show potential for mastitis prediction, but much remains to be understood about whether they outperform milk yield, SCC, and its predicted milk components (e.g., major components, fatty acids, and metabolites) in a feasible prediction timeframe. In this study, we developed a machine learning framework integrating milk-related features (milk yield and SCC) and milk spectra-related features (4 types of milk major components, 10 types of milk fatty acids, 3 types of metabolites, and milk spectra) for upcoming mastitis prediction, leveraging 2,703 proportional milk samples in the healthy group (n = 475; no adverse health events) and 2,819 proportional milk samples in the mastitis group (n = 441; diagnosed solely with clinical mastitis), collected from a dairy farm in New York. Each cow was sampled once per day, generating a longitudinal dataset tracking individual cows over time. To capture temporal patterns, we constructed 30 separate predictive models based on subgroups from 30 distinct time periods before the diagnosis date (−30 d to −1 d). To mitigate DIM-related confounding, we applied a data-balancing strategy, ensuring an equal distribution and sample size of healthy and mastitis samples within each subgroup. Additionally, we removed subgroups with fewer than 10 mastitis samples and excluded samples collected at DIM 0 to reduce physiological variation. From 8 to 6 d before mastitis diagnosis, prediction accuracy increased significantly across all features, with average accuracy improving from 0.42 to 0.69 in regression-based models and from 0.52 to 0.66 in random forest-based models before stabilizing. During this period, the average accuracy of regression-based models using milk spectra improved significantly from 0.37 to 0.81, while random forest-based models showed an increase from 0.52 to 0.75. This improvement was greater compared with other features, such as milk yield (from 0.37/0.54 to 0.66/0.66, regression and random forest, respectively), SCC (from 0.37/0.54 to 0.64/0.64), milk major components (from 0.39/0.50 to 0.65/0/65), milk fatty acids (from 0.55/0.51 to 0.58/0.61), and metabolites (from 0.48/0.39 to 0.58/0/54). Beyond 5 d before diagnosis, while milk spectra remained superior to SCC and its predicted components, its prediction accuracy was no longer consistently higher than that of milk yield (−5 d: 0.81/0.73 vs. 0.78/0.76; −4 d: 0.80/0.70 vs. 0.82/0.80; −3 d: 0.78/0.69 vs. 0.82/0.78; −2 d: 0.77/0.70 vs. 0.82/0.81; −1 d: 0.78/0.71 vs. 0.81/0.80; milk spectra vs milk yield; regression and random forest, respectively). Quantitative analysis confirmed that feature differences between healthy and mastitis groups emerged around 8 d before diagnosis, with milk yield divergence increasing as diagnosis approached. These results highlight the opportunity to use milk-related and milk spectra-related features to predict mastitis earlier, enabling timely interventions and improving farm efficiency." |
| ADSA Southern Branch Platform Session: Novel Approaches and Technologies for Monitoring Milk Quality | Symposium | Animal Health | 2025/06/25 09:00:00 | t94541 | Watch | 1505 | Application of machine learning algorithms to predict mastitis events using milk electrical conductivity, rumination time, and water intake parameters. | 6 | B. Shrestha | accuracy,machine learning,random forest classifier | B. Shrestha1, R. Neupane1, N. Fagundo1, S. Paudyal1 | "The objective was to evaluate the potential of using milk electrical conductivity (EC), rumination time (RT) and water intake (WI) to develop machine learning based algorithms to predict mastitis events in dairy cattle. This retrospective study was conducted on data collected on an organic dairy farm in central Texas. The final dataset consisted of 925,302 data points, which were collected from 898 dairy cows monitored from 2022 to 2024, with 26,332 event-days labeled as mastitis based on events reported from herd management software (Dairy Comp 305), including 5 d before and after the event as individual events. Daily records of RT (min/d), and WI (L/d) were collected using SmaXtec sensor boluses placed in the rumen of the cows after calving on their first lactation. Electrical conductivity data were retrieved from Afimilk milking system on the dairy. Two different machine learning algorithms: random forest classifier (RF), and AdaBoost classifier (AB) with 5-fold cross validation (80% training, 20% test) were tested using Sklearn Python module to predict the mastitis events using EC, RT, and WI variables individually and in specific combinations using accuracy and precision metrics. The RF model demonstrated better metrics (accuracy %, and precision %) when including all predictor variables (EC, RT, and WI) in the model (71% ± 0.1% and 64% ± 0.1% vs. 60% ± 0.01% and 51% ± 0.2%, for RF, AB respectively). Models using the combination of EC and RT together had 71% ± 0.1% and 57% ± 0.1% versus 67% ± 0.01% and 56% ± 0.9% values for accuracy and precision for RF and AB, respectively. Models utilizing RT and WI together had accuracy and precision of 70% ± 0.1% and 61% ± 0.1% versus 60% ± 0.01% and 36% ± 8.8% for RF and AB, respectively. Models containing EC and WI together had accuracy and precision of 61% ± 0.1% and 54% ± 0.3% versus 61% ± 0.01% and 52% ± 0.6% for RF and AB, respectively. Finally, models utilizing EC only as a predictor had accuracy and precision values 68% ± 0.01% and 57% ± 0.6% versus 68% ± 0.01% and 56% ± 0.5% for RF and AB, respectively. These findings suggest that RF model utilizing all 3 variables (EC, RT, and WI) could be used to detect mastitis." |
| ADSA Southern Branch Platform Session: Novel Approaches and Technologies for Monitoring Milk Quality | Symposium | Animal Behavior and Well-Being | 2025/06/25 09:00:00 | t94552 | Watch | 1506 | Multitask contrastive learning for efficient training of small image sets for individual cow recognition across different behavior poses. | 7 | A. A. C. Alves | animal monitoring,contrastive learning,livestock identification | J. Hooker1, B. B. de Medeiros1, C. Saha1, T. Abdulrahman1, A. A. C. Alves1,2 | "The development of scalable computer vision models for livestock monitoring is often constrained by the need for large, annotated datasets. This study evaluated the effectiveness of multitask contrastive learning (MTCL) for identifying individual Holstein cows from small reference datasets collected under different behaviors and angles. A total of 21 lactating cows were housed in a freestall barn in Winterville, Georgia, where 3 overhead cameras captured RGB images at 10-s intervals. An object detection model (YOLOV7) was trained with 3,120 annotated images to classify 4 behaviors (feeding, lying, drinking, standing). From this set, a random subset was cropped according to labeled bounding boxes and annotated for animal ID, generating a dataset of 557 images (26 ± 8 per animal). We used this dataset to train 2 identification models: (1) a baseline ResNet50-based classifier and (2) an MTCL model, expanding the baseline architecture to a triplet network to learn both cow identification and pairwise similarity. A data augmentation strategy was used for the baseline model to partially mitigate the small image set problem. The MTCL model was trained with 10,000 image pairs sampled from the small dataset to optimize contrastive and cross-entropy losses. To create the testing set, behavior classes and corresponding IDs were manually annotated for an hour (0900–1000 h) across 3 cameras, one day after the training set period. YOLOv7 inferences on the testing set were used to automatically generate cropped images for cow identification models. Behavior detection accuracy in the testing set ranged from 94.75% (standing) to 99.83% (lying down), with sensitivity ranging from 89.00% to 100%. For individual cow identification, MTCL consistently outperformed the baseline model, achieving accuracy between 93.3% (left camera) and 97.4% (right camera). In contrast, the baseline model performed poorly (<25% accuracy, F1 <0.1) on all behavior poses and angles. The most challenging position for MTCL was standing behavior, with accuracy as low as 89%. Results show that MTCL enhances cow identification across behaviors, supporting robust livestock monitoring with small datasets." |
| ADSA Southern Branch Platform Session: Novel Approaches and Technologies for Monitoring Milk Quality | Symposium | Animal Behavior and Well-Being | 2025/06/25 09:00:00 | t94214 | Watch | 1507 | AI-powered heat stress scoring in individual dairy cow using computer vision and YOLOv11. | 8 | R. Neupane | artificial intelligence,computer vision,dairy | R. Neupane1, B. Shrestha1, S. Muppa2, P. Allena2, N. Rodriguez3, J. Velez3 | "The objective was to develop and validate an AI-driven system utilizing computer vision to quantify heat stress in dairy cattle by analyzing behavioral indicators such as drooling, and open-mouth breathing. A total of 140 cows were selected from a dairy farm in Central Texas and evaluated for panting score by 2 independent observers with Cohen’s Kappa value of 0.68 which served as the gold standard. Video footage of study cows was collected using a standard RGB camera (GoPro Hero 9) on 4 d in July 2024. Python pipeline using Os and OpenCV modules were used to extract individual frames from video, and used naive YOLOv11 model for cow detection and following that Segment Anything Model (SAM) for cow image segmentation. The image labeling and annotation was done in RoboFlow, capturing varying lighting conditions and time periods, images preprocessing (resizing and contrast adjustment) and augmentation (flip, and rotation) to generate additional training images (3×). Another object detection YOLOv11 model was trained and employed to detect and segment the muzzle-nose region, followed by the extraction of foam and mucus features. The muzzle-nose detection model achieved a precision of 0.7655, recall of 0.6622, and a mean Average Precision (mAP) of 0.6971 at an IoU threshold of 0.50 (mAP@50), while the foam-mucous detection model had a precision of 0.632, recall of 0.222, and a mAP@50 of 0.224, highlighting the need for further optimization. Heat stress classification was performed using grayscale intensity histograms, and statistical features such as mean and standard deviation of pixel intensities. Based on the value of mean grayscale pixel intensities (AVG), the corresponding heat stress levels were assigned (low [AVG <50], moderate [50 ≤ AVG <100], and severe [AVG ≥100]), which achieved an overall classification accuracy of 82%, macro average precision of 56% and macro average recall of 71%. To conclude, we developed and demonstrated an automated heat stress scoring system that reduces reliance on subjective manual observation, provides a scalable solution for real-time cow monitoring. Future work will focus on refining detection models, expanding dataset diversity, and integrating real-time deployment for on-farm applications." |
| ADSA Southern Branch Platform Session: Novel Approaches and Technologies for Monitoring Milk Quality | Symposium | Production, Management, and the Environment | 2025/06/25 09:00:00 | t95580 | Watch | 1508 | FT-MIR spectra as management tool for milk processability. | 9 | S. Franceschini | mid-infrared spectra,pattern detection,management tool | I. Alexakis1, S. Franceschini1, C. Nickmilder1, J. Leblois2, V. Wolf3, HoliCow Consortium22, H. Soyeurt1 | "Milk Fourier transform mid-infrared (FT-MIR) spectra are widely used by the DHIA to select cows based on spectral predictions from milk. However, these spectra remain underused as a management tool for farmers. In the NWE Interreg project HoliCow, 41 million spectra were aggregated from 39 breeds across 6 European countries, enabling the FT-MIR prediction of 26 traits related to milk composition and technological properties. An unsupervised learning approach was then applied to identify patterns in these spectral predictions, focusing on milk technological traits such as laboratory butter yield, cheese yield, and coagulation properties. A specific computational method was developed to manage the large dataset in hierarchical clustering. The dataset was divided into subsets, which were clustered iteratively. At each step, ~95% of the variability was retained from the previous subset and merged into the subsequent subset to process the entire dataset efficiently. The results from each subset were merged, and a final hierarchical clustering was performed on 38,400 centroids. Among the 6 clusters identified, 3 were particularly noteworthy when compared using MIR-based predictions. One cluster exhibited superior aptitude for butter production, characterized by a high butter yield. Another cluster showed the greatest potential for cheese and yogurt production, with improved coagulation properties (i.e., higher curd firmness and coagulation speed), higher cheese yield, and increased yogurt DM content. The third cluster demonstrated a well-balanced transformation potential, performing well across butter, cheese, and yogurt production. Moreover, multiple algorithms were tested to predict cluster membership based on the 26 predictors. Among these models, random forest achieved the highest overall accuracy in both cross-validation and validation (0.84), effectively capturing the complexity of the dataset. So, these predictions could be used to guide management on a routine basis and improve the milk quality at individual level to produce dairy products." |
| Animal Health Symposium: Interspecies Crossover of Highly Pathogenic Avian Influenza into Dairy Cattle | Symposium | H5N1 Platform Session | 2025/06/23 09:00:00 | t95456 | Watch | 1128 | Combating the complex ecology of highly pathogenic avian influenza virus: Inoculation to application in lactating dairy cattle. | 1 | B. Arruda | | B. Arruda1, A. L. Baker1, M. B. Palmer1, P. Boggiatto1, C. Souza1, B. Trindade1, G. C. Zanella1, A. Campos1, K. Lantz2, M. Torchetti2, P. J. Gorden3, K. Sarlo Davila1 | "Influenza A viruses (IAV) remain the most common cause of pandemics. Highly pathogenic avian influenza A (HPAI) strains belonging to the H5NX subtype have pandemic potential and the ecology of currently circulating H5N1 viruses has become increasingly complex due to factors previously not documented. This presentation will provide information on the complex ecology of IAV including HPAIV, viral traits that promote infection and transmission, the factors that influence virus-host interactions and expression of clinical disease, and pathology. The molecular, serologic, and pathology results from 6 inoculated lactating dairy cows and 2 convalescent lactating dairy cows and the application of this data to the field and vaccine evaluation will be discussed." |
| Animal Health Symposium: Interspecies Crossover of Highly Pathogenic Avian Influenza into Dairy Cattle | Symposium | H5N1 Platform Session | 2025/06/23 09:00:00 | t94481 | Watch | 1135 | Transmission of highly pathogenic avian influenza H5N1 to calves fed unpasteurized milk from experimentally infected cows. | 11 | K. M. Sarlo Davila | transcriptomics,immunology,influenza | K. M. Sarlo Davila1, A. L. Baker1, P. M. Boggiatto1, M. V. Palmer1, E. J. Putz1, S. C. Olsen1, G. C. Zanella1, A. Campos1, A. Buckley1, B. Arruda1 | "Highly pathogenic avian influenza (HPAI) was confirmed in dairy cattle in Texas on March 25, 2024, by the US Department of Agriculture (USDA) National Veterinary Services Laboratories (NVSL) in response to a multi-state investigation into milk production losses. Infectious virus and viral RNA were consistently detected in milk from affected cows. The amount and duration of virus shed in milk from inoculated mammary quarters point to milk as a primary source of virus spread within and between dairy herds. Pasteurization has been shown to inactivate the virus in milk; however, domestic cats consuming raw milk from affected cows developed fatal systemic influenza infection. To determine if HPAI could be transmitted to calves fed unpasteurized milk from virus positive lactating cows 4 Holstein calves of approximately 7 to 11 wk old were fed 0.95 L of unpasteurized milk from experimentally inoculated cows twice a day via bucket. Calves developed clinical signs including nasal discharge, mild fever, mild lethargy, loose stool, and slightly increased respiratory effort for 5–6 d. Viral RNA was consistently detected in nasal swabs from all 4 calves from 2 DPI through 4 DPI, with consistent detection persisting after calves were transitioned to being fed milk from non-inoculated cows. Infection was confirmed by viral RNA detected in nasal swabs, lung lesions, antigen and RNA detection in lung, multiple lymph nodes and pharyngeal tonsil, and seroconversion." |
| Animal Health Symposium: Interspecies Crossover of Highly Pathogenic Avian Influenza into Dairy Cattle | Symposium | Breeding and Genetics | 2025/06/23 09:00:00 | t93880 | Watch | 1136 | Frequency and treatment of highly pathogenic avian influenza A (H5N1) in high, average, and low immune responder cows. | 12 | S. C. Beard | immune response,dairy,genetics | S. C. Beard1, M. E. Carson1, B. Mallard2,3, M. Lohuis1,3, F. Malchiodi1,3 | "Avian influenza A (H5N1) was first identified in 1959, but it was not until 2020 that a new variant, termed highly pathogenic avian influenza (HPAI), emerged. Initially detected in wild and domestic birds in Europe, it spread to North America in 2021. In 2024, HPAI A (H5N1) outbreaks spread to dairy cattle, presenting significant health challenges and industry instability. Semex’s Immunity+ is a genetic breeding solution designed to enhance broad-based disease resistance in dairy cattle by identifying bulls and cows with superior immune response. This selective breeding approach has led to significant reductions in disease incidence, including but not limited to mastitis, pneumonia, and lameness, contributing to improved herd health and increased profitability for producers. The objective of this study was to evaluate the relationship between Immunity+ genomic estimated breeding value (GEBV) and the probability of requiring treatment for HPAI A (H5N1) over a 12-mo period. Treatment records and Immunity+ GEBVs were collected for 15,386 cows from 6 large commercial dairy farms in the United States that experienced HPAI outbreaks. Cows were classified as “High,” “Average,” and “Low” responders based on their Immunity+ GEBV. A binomial logistic regression and ANOVA was conducted to assess the association between immune response GEBV and HPAI treatment probability. Odds ratios and marginal means were estimated to quantify treatment likelihood. Differences in treatment probability among response groups were evaluated using Tukey’s adjustment for multiple comparisons. Results indicated that cows classified as “Low” responders had a significantly higher probability of requiring treatment for HPAI compared with those classified as “High” responders (P = 0.02, odds ratio = 1.16). It is probable that high responders were equally exposed to HPAI A (H5N1), but did not develop signs severe enough to require treatment, suggesting greater resistance to disease. These results indicate that genetic selection for immune responsiveness can significantly reduce HPAI A (H5N1) treatment rates in commercial dairy cattle herds, providing a sustainable strategy for enhancing herd health, reducing disease burden, and mitigating the economic impact of outbreaks of HPAI in dairy production systems." |
| Animal Health Symposium: Interspecies Crossover of Highly Pathogenic Avian Influenza into Dairy Cattle | Symposium | H5N1 Platform Session | 2025/06/23 09:00:00 | t94311 | Watch | 1137 | Factors associated with risk of clinical signs of highly pathogenic avian influenza infection and impacts on productivity in lactating dairy cattle. | 13 | L. Olthof | highly pathogenic avian influenza (HPAI),H5N1,disease | L. Olthof1, K. C. Krogstad2, B. J. Bradford1 | "As highly pathogenic avian influenza (HPAI) spreads in US dairy herds, substantial uncertainty remains regarding mode(s) of transmission and net impacts on cattle health and productivity. Therefore, the objectives of our study were to identify factors associated with risk of HPAI diagnosis on-farm among lactating cows and quantify subsequent productivity of HPAI+ vs. HPAI− cows. We utilized herd management data from a farm in Michigan (47.4 ± 0.2 kg/d ECM, 1.58 ± 0.04 SCS) that experienced an HPAI outbreak in May 2024. Over 13 d, 20.4% of the herd’s lactating cows (693/3,391) exhibited clinical symptoms and were treated for HPAI. Univariate analysis (GLIMMIX) demonstrated greater risk of diagnosis for multiparous vs. primiparous cows (odds ratio [OR] 1.81; 95% CI 1.49–2.20); pregnant vs. not (OR 1.34; 1.13–1.59); post-peak vs. <100 DIM (OR 1.51; 1.26–1.80); and greater milk yield (OR 1.012 per kg/d; 1.003–1.022). Multivariate modeling retained only parity and the quadratic effect of DIM (both P < 0.01) as risk factors, with peak risk for lactation 5 and 186 DIM. Impacts of HPAI+ diagnosis in the same lactation were assessed with data from 9 test days through January 2025 in a model that included parity, the quartic fit of DIM, and repeated measures within cow. At 25 d after onset, HPAI+ cows produced 14.8 ± 0.44 kg/d (P < 0.001) less ECM and SCS increased 1.91 ± 0.08 units (P < 0.001) relative to HPAI− cows. Although SCS no longer differed at 98 d post-onset, ECM yield remained significantly different through 224 d after the outbreak (−4.24 ± 0.71 kg/d, P < 0.001). Primiparous cows had less ECM reductions than multiparous cows (−2.21 ± 0.65 vs. −7.16 ± 0.73 kg/d for parity 1 vs. 3, P < 0.001). Fat and protein concentrations increased subtly for 2 and 4 mo post-onset, respectively. In summary, primiparous appear to have been somewhat protected from clinical HPAI and suffered fewer production losses than multiparous cows. Milk production was impaired for more than 7 mo after HPAI onset, far longer than impacts on SCS." |
| Animal Health Symposium: Interspecies Crossover of Highly Pathogenic Avian Influenza into Dairy Cattle | Symposium | Extension Education | 2025/06/23 09:00:00 | t93730 | Watch | 2210 | Enhancing dairy industry preparedness: A collaborative outreach approach to managing highly pathogenic avian influenza (HPAI) in California. | 14 | N. Silva-Del-Rio | highly pathogenic avian influenza (HPAI),dairy industry outreach | N. Silva-Del-Rio1, R. Branco Lopes2, D. R. Bruno3, B. M. Karle4, R. A. Black5, M. Lema6, M. Payne7,8 | "The highly pathogenic avian influenza (HPAI) outbreak has posed a significant challenge for California’s dairy industry. To support dairy producers and the allied industry, several outreach efforts were organized by UC Cooperative Extension (UCCE). A webinar series, held from September–Dececember 2024 in partnership with the California Milk Advisory Board and the California Dairy Quality Assurance Program, featured updates from the California Department of Food and Agriculture (CDFA), HPAI overview (e.g., clinical signs, transmission routes, preliminary epidemiological findings), treatment strategies, dairy producers’ and veterinarians’ perspectives on HPAI’s management, financial assistance programs, and research updates. Each session averaged 1 h and included a Q&A session. In a parallel effort, UCCE launched a 3-location workshop series in Northern California, focusing on preventive practices, as the outbreak had not yet reached this region. The in-person workshops attracted 80 attendees, including producers and allied industry. Our assessment of knowledge gained was informal, based on direct conversations with attendees after the event. All participants we spoke with indicated an increase in understanding of the topic. We selectively targeted the dairy producers that attended those meetings for follow-up conversations; but we were less interactive with allied industry participating in the meetings. The team also developed written outreach materials (one magazine article, one newsletter article, and 3 fact sheets) to provide timely information to dairy producers. A formal needs assessment evaluating the impact of these educational efforts is underway. Additionally, the team is part of the Extension Collaborative on Immunization Teaching and Engagement (EXCITE) initiative. Within EXCITE, the H5N1 program aims to increase dairy producers’ knowledge of HPAI’s impact on human health and promote immunization of dairy workers. The team has collaborated with local and state Human Health Services (HHS) to gather information on rural vaccination clinics and their efforts in disease prevention and dairy producer education. As part of this initiative, a pilot program was launched in January 2025 in one county, with UCCE, the Farm Bureau, and HHS collaborating on a vaccination clinic. In summary, UCCE approached HPAI outreach efforts as a One Health issue, ensuring the protection of both animal and human health through collaborative and multi-disciplinary efforts within California’s dairy industry." |
| Animal Health Symposium: Interspecies Crossover of Highly Pathogenic Avian Influenza into Dairy Cattle | Symposium | H5N1 Platform Session | 2025/06/23 09:00:00 | t95152 | Watch | 1139 | Impact of HPAI and its role in strengthening biosecurity practices in dairy farming. | 15 | Z. Rodriguez | highly pathogenic avian influenza (HPAI),H5N1,dairy cattle,economic impact | Z. Rodriguez1 | "The recent outbreak of highly pathogenic avian influenza (HPAI) H5N1 in cattle has highlighted the vulnerabilities of the dairy sector to the entrance of emerging infectious diseases and reinforced the need for proactive preparedness against novel and endemic threats. While many aspects of the disease remain under study, the experience acquired from over a year of dealing with HPAI H5N1 in cattle has provided valuable insights into its prevention and impact. To better inform HPAI H5N1’s preparedness, and develop cost-effective prevention and control strategies, is imperative to quantify its impact on animal productivity. These insights help farmers and advisors make informed decisions on disease management, treatments, and resource allocation while guiding policymakers in designing policies, subsidies, and compensation mechanisms to mitigate economic losses. Furthermore, recognizing HPAI H5N1’s impact may also empower farmers to adopt stronger preventive measures. Typically, biosecurity measures applied in dairy farms have been highly inconsistent across operations as they depend on multiple factors, such as farmer’s risk preconceptions, posing a challenge to disease management efforts. While farm-to-farm transmission requires further study, strengthening biosecurity and updating them based on research findings is the most sensitive approach to reduce disease spread and enhance industry resilience. This presentation will focus on 2 key aspects: HPAI H5N1’s productive and economic impact and farmers’ willingness to adopt stricter biosecurity measures." |
| Animal Health Symposium: Interspecies Crossover of Highly Pathogenic Avian Influenza into Dairy Cattle | Symposium | H5N1 Platform Session | 2025/06/23 09:00:00 | t95645 | Watch | 1129 | The impact of influenza A H5N1 virus infection on dairy production and its risks to public health. | 2 | D. G. Diel | influenza A,dairy cow,mastitis,economic impact,food safety, | D. G. Diel1,2, F. Pena-Mosca3, M. Nooruzzaman1, E. Frye1,2, N. H. Martin4, M. MacLachlan1, S. D. Alcaine2, P. S. B. de Oliveira1, M. Zurakowski2, M. K. Koeve1, R. Ivaneck1, M. Prarat-Koscielny5, Z. R. Lieberman6, W. L. Leone1,2, F. Elvinger1,2 | "The spillover of highly pathogenic avian influenza (HPAI) H5N1 virus into US dairy cattle poses significant challenges to the industry and potential public health risks. We investigated an HPAI H5N1 outbreak’s impact on dairy cattle and evaluated virus stability in dairy products. In an affected herd of 3,876 adult cows, 20.0% exhibited clinical disease lasting 3 wk, while herd seroprevalence reached 89.4%, with 76.1% of infections being subclinical. Clinically affected cows demonstrated a 6-fold higher mortality risk and 3.6-fold increased risk of premature herd removal, with milk production losses averaging 900 kg per cow during the 60-d post-outbreak period. Economic losses, including decreased milk production, mortality, and early herd removal, averaged $950 per affected cow, totaling approximately $737,500 for the herd. Analysis of virus stability in raw milk showed effective inactivation (5–6 log reduction) under standard pasteurization and most thermization conditions, except at 50°C for 10 min. In raw milk cheese studies, virus survival was pH-dependent; infectious virus persisted through cheese making and aging for up to 60 d at pH 6.6 and 5.8 but was inactivated during cheese making at pH 5.0. These findings, confirmed in commercial raw milk cheese samples, demonstrate substantial production and economic impacts while highlighting the effectiveness of thermal treatments and the potential use of thermization of milk pH control in cheese making for ensuring dairy product safety." |
| Animal Health Symposium: Interspecies Crossover of Highly Pathogenic Avian Influenza into Dairy Cattle | Symposium | H5N1 Platform Session | 2025/06/23 09:00:00 | t93422 | Watch | 1130 | H5N1 through the lens of time: Before, during, and after the outbreak in dairy cattle. | 4 | G. A. Wager-Jones | H5N1 outbreak,automated body condition score (BCS),disease recovery monitoring | G. A. Wager-Jones1,2, J. Hague1, K. Lotspeich1, C. Hamilton1, M. Fujiwara1 | "The study assessed variation in milk yield (MY) and body condition score (BCS) during an H5N1 outbreak. A total of 1,032 observations from 172 cattle were collected between October 15 and December 2 across 6 dates. The first confirmed infection was on October 19. The MY data came from farm software, while BCS was assessed via images. Data included lactation number and days in milk (DIM). The BCS was classified as under-conditioned (UC) (<2.5), normal-conditioned (NC) (2.5–3.5), or over-conditioned (OC) (>3.5). Two robust linear mixed models addressed data non-normality. Fixed effects included BCS category, date, and their interaction, with cows as a random effect. The model explained 74% of MY variation, with 29% attributed to fixed effects. Interaction effects showed MY changes over time by BCS. On October 22, UC and OC cows had no significant MY changes. By October 28, UC cows showed a significant MY drop (−15.5 lb, t = −4.5, P < 0.001), whereas OC cows had a non-significant reduction (−8.2 lb). By November 11, MY decline persisted in UC cows (−8.8 lb, t = −2.5, P = 0.014) but remained minor in OC cows (−3.8 lb). By December 2, MY losses stabilized (−3.5 lb for OC, −5.1 lb for UC). A separate model analyzed BCS, explaining 90.7% of its variation, with 7% due to fixed effects. Post-outbreak, BCS dropped 0.03 on October 28 (t = −2.4, P < 0.05) but recovered, increasing by 0.05 on November 11 (t = 3.4, P < 0.001), 0.06 on November 18 (t = 3.8, P < 0.001), and 0.11 on December 2 (t = 7.0, P < 0.001). H5N1 had no immediate effect, but MY and BCS declined from October 28. The BCS recovered, but MY continued decreasing until December 2. The UC cows suffered the most severe MY losses, likely due to metabolic stress, whereas OC cows experienced a milder, temporary decline. Both groups produced less milk post-infection. Continuous BCS monitoring may aid recovery, especially for UC and OC cows." |
| Animal Health Symposium: Interspecies Crossover of Highly Pathogenic Avian Influenza into Dairy Cattle | Symposium | H5N1 Platform Session | 2025/06/23 09:00:00 | t95627 | Watch | 2240-SPOT | Influenza A virus sialic acid receptor distribution in the bovine mammary gland across physiological states. | 5 | P. H. Baker | avian influenza,H5N1,mammary gland,sialic acid receptor | P. H. Baker1, L. M. Glendenning2, M. X. S. Oliveira3, B. A. Cobb2, B. D. Enger3, S. N. Langel1 | "Highly pathogenic avian influenza (HPAI) A (H5N1) virus emerged in lactating dairy cattle in March 2024, causing mastitis, economic losses, and infections in other farm animals and workers. Influenza A virus (IAV) initiates infection by binding to terminal sialic acid (SA) residues on oligosaccharide chains of host cell surface glycoproteins. Human-adapted IAV strains typically recognize α2,6-linked SAs, which are predominant in the upper respiratory tract, while avian IAV strains preferentially bind α2,3-linked SAs, commonly found in the intestinal tract of birds and the lower respiratory tract of humans. Recently, both α2,6- and α2,3-linked SAs were found to be expressed in the mammary glands of lactating cows; however, little is known about their distribution across different physiological states. Using lectin histochemistry, we compared α2,6- and α2,3-linked SA distribution in the mammary glands of prepubertal dairy calves, pregnant dairy heifers (6.5- and 8.5-mo gestation), and lactating cows. Each group expressed both SA α2,6, the preferred receptor for human and swine IAVs, and importantly, SA α2,3, which is favored by avian IAVs. Notably, mammary glands of pregnant heifers exhibited the highest expression of SA α2,3, with predominant expression within the alveolar lumens. These findings suggest that SA α2,3 expression may vary with reproductive life stage, raising the possibility that pregnant heifers may be susceptible to H5N1-induced mastitis and could serve as a viral reservoir before entering the lactating herd. Future studies will assess the susceptibility of mammary epithelial cells from pregnant heifers to H5N1 and examine whether their secretions interact with the virus in ways that promote or inhibit infection." |
| Animal Health Symposium: Interspecies Crossover of Highly Pathogenic Avian Influenza into Dairy Cattle | Symposium | H5N1 Platform Session | 2025/06/23 09:00:00 | t93797 | Watch | 2232-SPOT | Insights from a single outbreak: Cow-level risk factors associated with HPAI in lactating Holstein cows. | 6 | A. Rico | H5N1,avian influenza,highly pathogenic avian influenza (HPAI) | A. Rico1,2, N. Blaine3, A. Lago4, N. Silva-del-Rio1,2 | "Highly pathogenic avian influenza (HPAI) H5N1 (clade 2.3.4.4b) has spilled into dairy cattle populations. Seven months after the initial outbreak, many unknowns remain. This study aims to identify cow-level factors (e.g., days in milk [DIM], milk yield, parity, pregnancy) that may increase susceptibility to H5N1 infection using on-farm records. We enrolled 3,281 Holstein lactating cows from a commercial herd with 12 pens, mainly housing pregnant cows from a sister facility. The outbreak peaked in late May. Cow information, including DIM, milk yield, parity, reproductive status, and pen allocation, was extracted from herd records as of May 1, 2024. Cases were defined as cows with “flu” recorded in their health history by August 31, 2024. Comparable pens were identified via cluster analysis. Associations between cow-level factors and case risk were assessed using chi-square and t-tests. A 1:1 matched cohort (98 pregnant, 98 non-pregnant) was used to analyze pregnancy effects. A nested case-control study was analyzed using conditional logistic regression, while a cohort-based case-control study (pregnant cows in comparable pens) used mixed-effects logistic regression with pen as a random variable. The significance level was 0.05. The overall case risk was 16.2%. In the descriptive study (n = 3281), DIM, milk yield, and days carrying calf were not significantly different between cases and non-cases (P > 0.05), while pregnancy, parity, and pen allocation were (P < 0.05). Risk varied across pens (7–27%) and among comparable pens (7%–24%). In the second study (n = 196), non-pregnant cows had a 4% risk, while pregnant cows had an 18% risk (OR = 4.9; 95% CI: 1.6, 14.9). In the final study (n = 1,546), only parity was a significant risk factor; first-parity cows had a 9% risk, while multiparous cows had an 18% risk (OR = 2.1; 95% CI: 1.5, 2.8). Key findings: (1) similar pens had varying risk levels, (2) pregnant lactating cows had higher case risk than non-pregnant ones, and (3) among pregnant cows, first-parity cows had lower risk than multiparous cows." |
| Animal Health Symposium: Interspecies Crossover of Highly Pathogenic Avian Influenza into Dairy Cattle | Symposium | H5N1 Platform Session | 2025/06/23 09:00:00 | t94177 | Watch | 2233-SPOT | Multiple gastrointestinal microbial virulence genes are increased in rectal swab samples from lactating dairy cows of HPAI-positive farms. | 7 | S. R. Fensterseifer | coinfection,bird flu,H5N1 | S. R. Fensterseifer1, A. M. Lange2, E. A. Galbraith2, R. P. Arias1, S. Busato1, S. Son2, M. R. King2 | "Highly pathogenic avian influenza A (HPAI H5N1) virus has been detected in dairy cows in the United States since March 2024. Although the mortality rate has been low in cows compared with its devastating effects in poultry, the full impact of HPAI infections on cow health remains unclear. Coinfections with multiple microbes and increased pathogen loads have been shown to exacerbate disease severity, contribute to complications, and affect viral shedding and replication. This study aimed to investigate if lactating dairy cows from HPAI-positive (HPAI+) and non-positive (NoHPAI) commercial dairy farms had any differences in key microbial virulence genes associated with gastrointestinal (GI) disease. Rectal swab samples were taken from lactating dairy cows in 4 HPAI+ farms within 1 mo of infection (n = 113 cows, 2.88 ± 0.13 lactations, 162.9 ± 10.3 DIM) and compared with 19 NoHPAI farms (n = 571 cows, 2.51 ± 0.06 lactations, 110.4 ± 4.2 DIM) in similar geographical regions. A qPCR panel was used to quantify common GI microbial virulence and marker genes. Kruskal–Wallis, followed by Mann–Whitney pairwise comparisons, and chi-squared tests were performed to detect differences in gene quantity and frequency, respectively, between HPAI+ and NoHPAI cows. Cows from HPAI+ farms had increased (P < 0.001) quantities of total E. coli ZnT and E. coli marker O157, as well as the E. coli virulence genes eaeA (P = 0.01), enteroaggregative stable toxin EAST1 (P < 0.001), and Shiga toxin 1 (P = 0.016) compared with cows from NoHPAI farms. Clostridium perfringens α toxin gene cpa and Salmonella were also higher (P < 0.001) in cows from HPAI+ farms compared with NoHPAI. Eimeria bovis and Aspergillus flavus were detected in rectal swabs from HPAI+ and NoHPAI cows, but no differences (P ≥ 0.929) in gene quantities were found. In conclusion, cows from HPAI+ farms had increased GI loads of pathogenic E. coli, C. perfringens, and Salmonella, which may elevate disease risk and exacerbate existing health issues. Insight into HPAI coinfection highlights the need for further research to develop strategies that promote cow health during outbreaks." |
| Animal Health Symposium: Interspecies Crossover of Highly Pathogenic Avian Influenza into Dairy Cattle | Symposium | H5N1 Platform Session | 2025/06/23 09:00:00 | t94230 | Watch | 2234-SPOT | Effects of highly pathogenic avian influenza H5N1 infections on dairy operations. | 8 | R. G. S. Bruno | highly pathogenic avian influenza (HPAI),dairy,cow | D. R. Bruno1, C. Stenkamp-Strah2, B. Melody3, R. G. S. Bruno4, J. Lombard2 | "In 2024, highly pathogenic avian influenza (HPAI) H5N1 was detected for the first time in US dairy cattle in Texas. H5N1 has now been confirmed in dairy herds in 17 states. This study examined the impact an H5N1 outbreak has on herd health and productivity, specifically evaluating milk production, disease duration, and herd removal, utilizing records from affected Jersey and Holstein herds in California, Colorado, and Michigan. Farm data from these herds, including treatment records, were retrieved from DC305. Herd sizes ranged from 1,000 to 6,000 cows. During the outbreak, farm employees administered treatment to cows displaying clinical signs of H5N1, including abnormal milk, reduced feed intake, decreased rumination, mild respiratory symptoms (e.g., clear nasal discharge, labored breathing), lethargy, dehydration, and altered stool consistency. Descriptive statistical analysis was used to summarize herd-level disease patterns, treatment frequencies, mortality rates, and production losses. Records show that approximately 60% of cows exhibiting clinical signs were treated only once, while the remaining affected cows received multiple treatments. The highest treatment rate occurred between d 6–8 after the first cows displaying clinical signs were treated. Based on treatment records, disease duration at the herd level lasted between 10 and 45 d. Mortality rates varied by farm, with H5N1-related herd removal ranging from 0% to 15%, depending on herd size. Affected dairies experienced a 10% to 50% decline in milk production (10 to 45 lb per cow), and a minimal to 3-fold increase in bulk tank somatic cell counts compared with pre-outbreak levels. Subsequent lactation milk production levels are being evaluated as the H5N1–affected cows reach this point in time. These findings underscore the substantial impact of H5N1 on dairy herd health and productivity. Early detection, intervention, and preventive management strategies are critical for mitigating the disease's effects and maintaining herd sustainability." |
| Animal Health Symposium: Interspecies Crossover of Highly Pathogenic Avian Influenza into Dairy Cattle | Symposium | H5N1 Platform Session | 2025/06/23 09:00:00 | n9318 | Watch | | Discussion | 9 | | | | |
| Applied Nutrition Symposium: Milk Pricing Dynamics and Strategies for Enhancing Milk Fat Production | Symposium | Applied Nutrition Symposium: Milk Pricing Dynamics and Strategies for Enhancing Milk Fat Production | 2025/06/23 13:30:00 | t95659 | Watch | 1269 | Balancing dietary amino acids for optimum milk fat synthesis and implications of dietary fatty acids. | 1 | M. E. Van Amburgh | | M. E. Van Amburgh1, A. C. Benoit1 | "With the implementation of genomic selection, the genetic capacity for milk fat and protein synthesis has dramatically increased. For milk fat, the rate of change is nearly exponential, given the selection pressure on genes and alleles such as SCD1 and DGAT1. These changes are analogous to creating a new genotype similar to reevaluating new generations of growing swine to match the EAA supply to the protein accretion rate of the animal. Data from cell culture and in vivo experiments have demonstrated interactions between AA and fatty acid (FA) supply on milk fat synthesis and yield. To highlight a few, Lys has been shown to facilitate the upregulation of FABP and SREBP1, which in turn upregulates enzymes such as ACS, ACC, and FAS, enhancing de novo FA synthesis. Met and Leu have also been shown to be involved in the upregulation of SREBP1, whereas Arg increased de novo and mixed FA synthesis through increased expression of ACC, SCD, and DGAT1. Elongation of the FA carbon chain requires FAS and data has demonstrated the role of His, Lys, Ser, and Cys in the expression and activity of the enzyme system, also suggesting that FAS has a requirement for both EAA and NEAA. In addition, there are interactions with the amount and profile of FA supplied to the cow. The general recommendation is to feed moderate levels of total FA and a balanced ratio of individual FA similar to balancing for EAA. To achieve increased FA synthesis, the requirements of EAA at a metabolizable level are generally much greater than have been historically supplied. Using the approach of Higgs et al., the grams per Mcal of ME provides a more precise approach for achieving the supplies required to increase the expression of these enzymes. For example, supplying at least 1.19 g metabolizable Met and His/Mcal ME, and 3.2 g metabolizable Lys/Mcal ME provides adequate levels of those EAA to achieve increased milk fat synthesis. It is also important to consider dietary sources of substrates that enhance ruminal butyrate production, as butyrate is used in significant quantities to synthesize FA and triglycerides on a molar basis. To realize the genotypic capabilities of high-producing dairy cattle to yield more milk fat, nutrient supplies need to increase concomitant with the change in capacity." |
| Applied Nutrition Symposium: Milk Pricing Dynamics and Strategies for Enhancing Milk Fat Production | Symposium | Applied Nutrition Symposium: Milk Pricing Dynamics and Strategies for Enhancing Milk Fat Production | 2025/06/23 13:30:00 | t95665 | Watch | 1270 | Optimizing milk fat: Aligning dairy nutrition with genetic progress. | 2 | A. L. Lock | Key Words: de novo,milk fat,palmitic acid | A. L. Lock1, J. M. dos Santos Neto1 | "With the growing emphasis on milk components and driven by shorter generational intervals, genetic selection for milk fat has increased exponentially in the past decade. This has prompted questions about whether nutrition can keep pace with the rapid genetic progress in milk fat. To address this, we must improve our understanding of how the mammary gland makes milk fat, the precursors it requires, and the mechanisms to provide them. We will present recent research that underscores the latest advancements in these areas. Milk fat contains triglycerides with fatty acids (FA) from de novo (<16 carbon FA) and preformed (>16 carbon FA) sources. Mixed FA (16-carbon FA) can be derived from both sources. A balance of de novo and preformed FA incorporation into milk triglycerides is needed for maintenance of milk fat fluidity. A common dietary approach to increase milk fat yield is by increasing the supply of mixed and preformed FA to the mammary gland. Consistent evidence from the literature underscores the effectiveness of palmitic acid-enriched diets in increasing milk fat yield. Moreover, it emphasizes that responses to different dietary 18-carbon FA will vary. Recent studies have explored the use of oilseeds, with high-producing dairy cows consuming whole cottonseed and roasted high oleic acid soybeans showing promising results. Additionally, sodium acetate supplementation increases milk fat yield by increasing de novo and mixed FA yield. This approach may not be practical in a commercial setting, but it shows the potential for improving milk fat yield by increasing de novo FA substrate supply to the mammary gland. Previously, studies in the literature primarily focused on strategies to increase milk fat yield by enhancing substrates for de novo FA or dietary FA for preformed FA. Recent research, however, has emphasized the importance of increasing the supply of both sources to the mammary gland and the important role played by C16:0. In summary, given rapid increases in genetic selection for milk fat, recent research underscores the need to develop dietary strategies that target increased yields of both de novo and preformed FA in the mammary gland. This approach is crucial to ensure long-term, sustained increases in milk fat production." |
| Applied Nutrition Symposium: Milk Pricing Dynamics and Strategies for Enhancing Milk Fat Production | Symposium | Applied Nutrition Symposium: Milk Pricing Dynamics and Strategies for Enhancing Milk Fat Production | 2025/06/23 13:30:00 | t95666 | Watch | 1271 | The economics of butterfat production. | 3 | N. R. St-Pierre | | N. R. St-Pierre1 | "Until 2000, US milk was paid based on butterfat and solids nonfat. The price support system used underpaid butterfat while overpaying solids nonfat. The 2000 Farm Bill reformed the pricing system using end-product pricing. From then on, butterfat price has been calculated from the unregulated wholesale price of butter. This led to an increase in domestic butterfat price. Questions remain regarding the economics of butterfat production. At the onset, one must separate strategic vs. tactical butterfat production. Strategic production is what would be produced without any stimulants to fat production. Strategic butterfat only needs to consider the nutritional costs associated with a unit of butterfat output. Based on NRC (2001), one pound of butterfat requires 4.25 Mcal of NEL, 0.17 lb of MP, 1.13 lb of effective NDF (eNDF), and 0.38 lb of non-effective NDF (neNDF). The software Sesame uses hedonic pricing to extract the average cost of these 4 nutrients across all feedstuffs traded in a given market. From 2015 to the end of 2024, the average, minimum, and maximum implied prices per unit in the US have been: $0.10/Mcal NEL ($0.06 to $0.18); $0.30/lb of MP ($0.10 to $0.60); $0.05/lb of eNDF (−$0.04 to $0.10); and −$0.05/lb neNDF (−$0.20 to $0.10). During the same period, butterfat price averaged $2.54/lb (minimum $1.32, maximum $3.71, SD $0.56). Therefore, during this 10-year span, one pound of butterfat has generated an average of $2.54 in additional gross income, required an average of $0.52 in nutrient costs, resulting in an average of $2.02 in net income. Importantly, the price paid for butterfat always exceeded the cost of the required nutrients. The economics of strategic butterfat production is simply a no-brainer. Tactical butterfat is a very different proposition. First, the butterfat response varies not only by the stimulant under consideration (e.g., palmitic acid, methionine analog, and so on), but also by breed, stage of lactation, parity, and other unknown factors. That is, there is uncertainty in the response to the stimulant for a given herd. Decision making under uncertainty must go beyond calculating the average benefits. A detailed example will be provided for palmitic acid supplementation." |
| Applied Nutrition Symposium: Milk Pricing Dynamics and Strategies for Enhancing Milk Fat Production | Symposium | Ruminant Nutrition | 2025/06/23 13:30:00 | n9313 | Watch | | Panel Discussion and Reception | 4 | | | | |
| Breeding and Genetics Symposium: Joint ADSA-Interbull Session—Creating Carbon-Friendly Cows and Leveraging Omics to Improve the Sustainability of Dairy Production | Symposium | Breeding and Genetics | 2025/06/23 13:30:00 | t94136 | Watch | 1223 | Breeding for more sustainable dairy cows. | 1 | F. Peñagaricano | feed efficiency,methane emission,resilience | F. Peñagaricano1 | "Sustainability, defined as meeting the needs of the present without compromising the ability of future generations to meet their own needs, is the balance between the economy, society, and the environment. Achieving a sustainable dairy farming is paramount to address the major challenges facing humankind, including food security, energy use, biodiversity, climate change, and the environmental footprint of human activity. Three components play a crucial role in dairy farm sustainability: feed efficiency, methane emissions, and resilience. Feed accounts for more than 50% of total production costs, and hence, improving feed efficiency increases farm profitability and reduces the environmental impact of milk production. Enteric methane is a major source of greenhouse gas emissions from dairy farming. Methane also represents a loss of gross energy intake, energy that could otherwise be available for milk production. Therefore, reducing methane emissions from dairy cattle provides multiple benefits, including reducing the environmental impact of dairy farming and improving production efficiency. Resilience can be defined as the capacity to maintain performance or bounce back to normal functioning after a perturbation. These perturbations are associated with any factor that can cause a dairy cow to be stressed, such as diseases, temperature changes, or management alterations. Improving cow resilience is critical to safeguard the long-term sustainability of the dairy industry. Overall, the success of dairy farming can be seen as the ability of cows to produce milk, while minimizing environmental impact, as well as enhancing cows’ health and welfare, within socially acceptable standards. Genetic selection is arguably a critical tool to achieve these sustainable goals." |
| Breeding and Genetics Symposium: Joint ADSA-Interbull Session—Creating Carbon-Friendly Cows and Leveraging Omics to Improve the Sustainability of Dairy Production | Symposium | Breeding and Genetics | 2025/06/23 13:30:00 | t94598 | Watch | 1224 | Advancing dairy sustainability through feed-efficient genetics and genomics: Research insights and applications. | 2 | J. R. Johnson | feed efficiency,residual feed intake,sustainability | J. R. Johnson1, N. Deeb1, P. Khanal1, P. Ross1 | "As the dairy industry faces increasing pressure to optimize resource use and minimize its environmental footprint, the need for innovative, scientifically sound, and economically feasible solutions to enhance feed efficiency is more urgent than ever. Genetic selection, powered by recent advances in genomics, has already transformed breeding to enhance productivity, reproductive efficiency, and longevity. Now, as a result of significant private and public funding to capture individual animal feed intake at scale, genetic selection indices for feed efficiency—with particular emphasis on residual feed intake (RFI)—have emerged, offering a lasting and cumulative solution to enhance feed efficiency. Residual feed intake, which accounts for variation in feed intake independent of maintenance and productivity, enables producers to identify animals that use feed more efficiently, reducing feed costs and carbon emissions without compromising productivity. Moreover, RFI selection can be integrated with other traits to improve feed efficiency while simultaneously enhancing key attributes such as milk or meat production. With the rapid adoption of RFI in current selection programs, the industry is entering a new era of dairy farming where sustainability and profitability go hand in hand. This presentation will draw on extensive progeny data from a large-scale research program alongside commercial farm data to explore collaborative research findings and discuss implications of RFI selection on animal health, productivity, and sustainability. By examining on-farm data we will provide insights into how RFI selection is being applied to Holstein heifers and cows and how producers are leveraging genetic tools to optimize feed efficiency, reduce feed cost, and lower the carbon footprint of their operations. The findings will also demonstrate how these efforts contribute to broader sustainability goals in dairy production and play a crucial role in mitigating agriculture's environmental impact." |
| Breeding and Genetics Symposium: Joint ADSA-Interbull Session—Creating Carbon-Friendly Cows and Leveraging Omics to Improve the Sustainability of Dairy Production | Symposium | Breeding and Genetics | 2025/06/23 13:30:00 | t93547 | Watch | 1225 | Sustainable breeding for feed-efficient cows with lower methane emissions. | 3 | B. Heringstad | environmental impact,feed efficiency,genetic parameter | B. Heringstad1,2, K. A. Bakke2 | "To meet future challenges and reduce climate impact according to national goals, we need to include feed efficiency and methane emissions in the dairy cattle breeding goals. Collecting phenotypes for these traits in dairy cattle is challenging, expensive, and requires significant time and labor. However, access to reliable phenotypes for the goal traits on a sufficient number of animals is crucial for success. Recording of individual feed intake and methane emissions is now established in research and commercial herds across many countries, and international initiatives and collaboration are in place to expand the reference populations for genomic evaluations. In Norway, large-scale phenotyping of methane emissions and feed intake of Norwegian Red cows is established in collaboration with 14 commercial dairy herds. All cows are genotyped and housed in freestalls with automatic milking systems. Equipment to measure individual roughage intake (https://biocontrol.no) and GreenFeed units (www.c-lockinc.com) for measuring methane emissions are in place. The growing database of high-quality phenotypes of key parameters makes it possible to increase knowledge and develop the tools needed for a successful implementation of breeding feed-efficient and climate-friendly cows. Results so far indicate substantial genetic variation for methane emission, roughage intake, dry matter intake, and different measures of feed efficiency in the Norwegian Red breed. The estimated heritability of daily methane, dry matter intake, and body weight ranged from 0.18 to 0.57 and the genetic correlations among these traits were between 0.66 and 0.81. Our project has also enabled new knowledge on genetic variation in the cow’s response to methane-mitigating feed additives. More knowledge is needed on the genetic associations to important traits, and further research is required to examine which trait definitions would be better for successful implementation in the breeding program." |
| Breeding and Genetics Symposium: Joint ADSA-Interbull Session—Creating Carbon-Friendly Cows and Leveraging Omics to Improve the Sustainability of Dairy Production | Symposium | Breeding and Genetics | 2025/06/23 13:30:00 | t93831 | Watch | 1226 | Development of a greenhouse gas index to reduce enteric emissions in Holsteins. | 4 | F. Malchiodi | sustainability,methane,genomic | F. Malchiodi1, C. Richardson2, S. G. Narayana3, A. Fleming3, C. F. Baes4, F. Miglior1,4 | "Genetic selection offers a cost-effective, long-term strategy for reducing greenhouse gas (GHG) emissions in dairy cattle, enhancing sustainability with each generation. With a focus on genetic advancements in specific traits, such as methane production, selection indexes that integrate both economic performance and environmental impact can be developed. Several countries are incorporating emissions-related traits into national selection indexes, with successful adoption varying based on industry-specific objectives and constraints. Canada has introduced the world’s first national methane breeding value system for dairy cattle (methane efficiency) based on enteric methane production adjusted for milk, fat, and protein yield. Successfully validated using both domestic and international data, this genomic evaluation has demonstrated its efficacy in accurately identifying genetic variation associated with methane reduction, confirming its potential as a valuable tool for mitigating emissions in dairy cattle. In addition to methane efficiency, traits related to body size, longevity, and feed efficiency have been identified as having independent effects on overall system-wide emissions. These traits have been incorporated into an overall sustainability index, which reduces emissions by 168 kg CO2e per cow per year for each standard deviation increase in the index. Results suggest that the most effective breeding approach involves integrating a direct methane trait alongside increased emphasis on environmentally impactful traits. This sustainability-focused index was incorporated into the Lifetime Performance Index (LPI) in April 2025, reflecting the dairy industry’s commitment to profitability, sustainability and environmental stewardship." |
| Breeding and Genetics Symposium: Joint ADSA-Interbull Session—Management of Genetic Diversity for Future-Proofing Dairy Cattle Breeding | Symposium | Breeding and Genetics | 2025/06/23 09:00:00 | t94550 | Watch | 1111 | Identifying genetic diversity within indigenous and highly commercialized breeds for improved performance and future preservation. | 1 | H. J. Huson | genetic diversity,indigenous,breed-specific haplotype | H. J. Huson1 | "Natural and artificial selection has diversified cattle into existing breeds and populations that are uniquely adapted to a variety of environments and specialized for different production measures. Genetic diversity provides the foundation for this phenotypic plasticity within cattle and is important for their long-term sustainability. Simply stated, genetic diversity is the biological variation within a species resulting from genetic variation. Yet diversity within dairy cattle is much more complex than calculating allele frequencies. Breeds such as the Holstein, Jersey, Brown Swiss, Ayrshire, and Guernsey have experienced intense selection pressure to be recognized as top producing dairy breeds. That selection pressure has increased levels of inbreeding and reduced genetic diversity within each breed, yet each breed now possesses unique, conserved haplotypes associated with their productivity that the industry capitalizes on. Therefore, in these highly commercialized breeds, genetic diversity must be maintained to mitigate inbreeding depression while also conserving the breed-specific haplotypes that make them renowned dairy cattle. In contrast, less restricted breeding of indigenous cattle populations increases their genetic diversity, making them more adaptable to changing environmental conditions, yet their worth for production is often undervalued due to limited selection for production. The demands of changing environments including climate, disease, and management practices, necessitate the preservation and informed use of genetic diversity in dairy cattle. This means that highly selected regions of the genome within commercialized breeds as well as broad diversity across breeds, especially that of indigenous populations which are locally adapted to a wide variety of environmental variables, should all be preserved. As geneticists, it is our responsibility to identify genetic diversity to inform breeding practices and germplasm preservation. We need to adapt and improvise our methods to look beyond the simple and see the value of complexity to best inform management practices." |
| Breeding and Genetics Symposium: Joint ADSA-Interbull Session—Management of Genetic Diversity for Future-Proofing Dairy Cattle Breeding | Symposium | Breeding and Genetics | 2025/06/23 09:00:00 | t93945 | Watch | 1112 | Genetic resilience and the dynamics of inbreeding and diversity in dairy breeding. | 2 | C. Maltecca | genetics,inbreeding,diversity | C. Maltecca1, F. Tiezzi2, J. B. Cole3, J. Jiang1, L. Ma4, C. F. Baes5 | "Dairy breeding programs have been remarkably successful in increasing production levels over the past decades, whereby the focus is now increasingly shifting toward improving health, efficiency, product quality, and fertility. Given the nature of dairy selection, mating related animals is inevitable, and while the significant genetic improvements achieved through intense directional selection have so far outweighed any possible negative effects of increased homozygosity, the long-term consequences of this selection strategy remain uncertain. This includes challenges related to managing inbreeding and ensuring the overall sustainability of consistent selective pressure. In dairy populations, there is a fragile balance between the accumulation of homozygosity, the elimination of harmful genetic variants, and the introduction of new genetic variation. Traditional breeding practices, which typically involved longer generation intervals, may have historically helped limit the spread of harmful variants and preserve genetic diversity. However, the adoption of genomic selection, which significantly shortens breeding cycles, has the potential to disrupt this balance. This has in recent years raised concerns about increased inbreeding load and the possible spread of detrimental mutations. Less attention has been given to the unquantified risk of a reduced genetic resilience, the population’s ability to adapt and thrive in changing environments. To effectively manage these risks, it is crucial to deepen our understanding of the molecular basis of inbreeding depression, to quantify the current existing capacity to purge harmful variants within breeding populations and to attain a more atomic understanding of the overall genomic diversity of the global dairy herd. In addition to improving how we characterize genetic variation; it is paramount that we develop a more comprehensive insight into the dynamics of genetic variation recruitment and conversion within the context of modern selection practices and under different environmental conditions." |
| Breeding and Genetics Symposium: Joint ADSA-Interbull Session—Management of Genetic Diversity for Future-Proofing Dairy Cattle Breeding | Symposium | Breeding and Genetics | 2025/06/23 09:00:00 | t94698 | Watch | 1113 | Harnessing indigenous African breeds for sustainable dairy production: Opportunities for crossbreeding to accelerate genetic improvement. | 3 | N. Mapholi | African indigenous cattle breed,digital genomic tool,adaptation attribute | N. Mapholi1, L. T. Nesengani1, M. G. G. Chagunda2, J. E. O. Rege3, I. Houaga1,2, O. Opoola2, C. Banga1,4, E. M. Ibeagha-Awemu5, R. Mrode6, A. Djikeng1,2 | "The African dairy sector has long been central to poverty alleviation, food, and nutritional security. While commercial dairy production in Africa is limited to a few countries, milk production from Africa’s ruminant systems, mostly cattle, but also goat, sheep, and camel, is deeply embedded in livestock production systems in the continent. Across different countries in Africa, dairy contributes significantly to the agricultural GDP. For example, its contribution is 30% in Tanzania, 4.6% in South Africa, and 44% in Kenya. The different levels of contribution across countries are related to the variable farming structures and production practices across the continent, including the utilization of indigenous breeds. Within the high diversity of indigenous ruminant breeds in Africa, some cattle breeds (e.g., East African Zebu, Boran, Kenana, Butana, Ankole, Gudali, and White Fulani cattle) with potential as commercial dairy or dual-purpose animals have demonstrated promising milk production potential under harsh conditions, and are generally found in regions where the dairy industry makes large contributions to agricultural outputs. On the other hand, indigenous breeds such as the Nguni in Southern Africa have often been associated with low milk production of approximately 5.5 kg/d. Despite their exceptional adaptability to the harsh local conditions, most indigenous African cattle breeds are generally characterized by low milk production potential. Consequently, efforts such as targeted selective breeding, cross breeding (e.g., formation of Mpwapwa breed) with exotic breeds and, recently, the use of genomics have been made to improve milk production while leveraging on the adaptation attributes of indigenous breeds. Some of the genomic approaches attempted include the use of digital genomic tools to improve productivity and profitability in smallholder dairy systems, and these have achieved notable success in sub-Saharan Africa. Notwithstanding the general lack of performance and pedigree data for use in breeding programs, efforts have also been made to utilize genomic information to improve milk production in crossbred cattle in East Africa. Results from this endeavor reported the accuracy range of 0.28 to 0.41 suggesting that there is potential to achieve significant improvements in dairy production through the implementation of genomic selection of young bulls in crossbred small-holder cattle populations. Indigenous cattle breeds, therefore, hold the promise to sustainable dairy production on the African continent. Achievement of this goal would, however, need to be underpinned by investments in high level technologies such as genomics and large-scale recording of phenotypic data. This is where the African Animal Breeding Network will play an important role through its flagship pillars, multi-country genetic evaluation, and professional development. Closing the dairy productivity gap in Africa represents a significant driver toward ensuring resilient and climate smart livestock systems in Africa." |
| Breeding and Genetics Symposium: Joint ADSA-Interbull Session—Management of Genetic Diversity for Future-Proofing Dairy Cattle Breeding | Symposium | Breeding and Genetics | 2025/06/23 09:00:00 | t94389 | Watch | 1114 | Genomic- versus pedigree-based inbreeding: 2 sides of the same coin. | 5 | N. P. P. Macciotta | inbreeding,genomic,diversity | N. P. P. Macciotta1, D. Lourenco3, D. Vicario2, L. Degano2, I. Misztal3, A. Cesarani1 | "The management of inbreeding in dairy cattle population represents a key point for the conservation of genetic diversity and for the development of the future cow. The level of inbreeding of a livestock population depicts its genetic history and gives clues for managing its future. Inbreeding coefficients have been traditionally calculated using the pedigree (INB_PED). This is considered as the expected inbreeding, and it relies on accurate and depth pedigrees that are not always available. Genomic technologies allow for the calculation of different metrics that represent the genomic inbreeding (INB_GEN) i.e., the realized inbreeding. The comparison between the different measurements offers the opportunity to consider inbreeding from different perspectives: for example, the genomic inbreeding can be calculated either at whole genome or chromosome level. In this study INB_GEN and INB_PED are compared in different cattle breeds, either dairy or dual purpose, with different levels of selection. The INB_GEN was calculated both from the genomic relationship matrix and from the runs of homozygosity (ROH). The temporality of inbreeding phenomena was investigated through the ROH lengths. Relationships between inbreeding and contribution of the animal to the genomic relationship matrix were also investigated." |
| Breeding and Genetics Symposium: Joint ADSA-Interbull Session—Management of Genetic Diversity for Future-Proofing Dairy Cattle Breeding | Symposium | Breeding and Genetics | 2025/06/23 09:00:00 | t94190 | Watch | 1115 | Managing genetic diversity: Strategies for sustainable livestock improvement. | 6 | C. F. Baes | homozygosity,genetic diversity,livestock improvement | C. F. Baes1, G. Condello1, J. B. Cole2, C. Maltecca3, R. E. Jahnel1, F. Malchiodi1,4, B. Makanjuola1, P. Stothard5, F. S. Schenkel1, F. Miglior1,6 | "Genomic selection has increased selection accuracy and reduced generation intervals, thereby greatly accelerating genetic improvement in dairy cattle. Simultaneously, an increase in the rate of homozygosity has been concomitantly observed. The much-debated concerns about inbreeding depression, reduced genetic variance, and the expression of harmful recessive alleles have further intensified given this rapid increase. Sustaining long-term genetic progress within breeding programs is critical to ensuring adaptability to changing environments, and maintaining animal health and fertility. Using existing genomic evaluation infrastructure, potential methods for identifying detrimental haplotypes can be investigated, mating programs that optimize genetic progress while minimizing inbreeding rates can be explored, and the integration of genomic diversity metrics into selection indices developed. The widespread use of genomically derived metrics, such as runs of homozygosity and effective population size estimates, can provide deeper insights into the accumulation of homozygosity and its phenotypic consequences. In the US and Canada, national genomic surveillance systems are being developed to track and manage genetic defects, ensuring sustainable breeding strategies. Furthermore, genetic diversity conservation efforts such as germplasm repositories and crossbreeding strategies may offer opportunities for safeguarding variation. Finally, genome editing, selective introgression of beneficial alleles, and other advances in precision breeding present additional opportunities to maintain diversity. Through the integration of genomic technologies, mating strategies, and conservation efforts, balanced livestock breeding programs can be developed. A proactive approach to the management of genetic diversity will improve long-term adaptability, economic viability, and environmental resilience in dairy cattle populations." |
| Dairy Foods Symposium: Health Benefits of Cheese | Symposium | Dairy Foods: Health Benefits of Cheese | 2025/06/24 09:00:00 | t93982 | Watch | 1337 | The health benefits of cheese. | 1 | K. Ricklefs-Johnson | cheese,dairy foods,cardiometabolic | K. Ricklefs-Johnson1 | "Cheese, a dietary staple across various cultures, offers numerous health benefits that extend beyond its rich and diverse flavors. Historically, cheese has been valued as a concentrated form of milk with the added advantage of an extended shelf life. It served earlier generations as an energy-dense and nutritious food source. Despite the higher levels of sodium and saturated fat compared with other dairy products, a growing body of evidence suggests that cheese consumption may be linked to a reduced risk of type 2 diabetes (T2D) and a lower risk of stroke. This discrepancy between the expected and observed health impacts of cheese may be attributed to the unique physical structure and composition of proteins, vitamins, and minerals in cheese, known as the dairy matrix. Moreover, cheese is a rich source of essential nutrients, including high-quality protein, bioactive peptides, amino acids, fats, fatty acids, and vitamins A, D, and B12, as well as minerals. The contributions of these nutrients to bone health, muscle function, and cardiovascular wellness are well established. Specifically, calcium and vitamin D are crucial for maintaining bone density and preventing osteoporosis. The protein content in cheese supports muscle repair and growth, while dairy’s unique fatty acids and bioactive peptides may help reduce inflammation and regulate blood pressure. The goal of this presentation is to examine recent scientific research that continues to substantiate the value of cheese consumption as part of a healthy diet, discuss the potential health benefits of cheese consumption in relation to chronic diseases and explore the concept of the dairy matrix and how the unique composition of proteins, vitamins, and minerals in cheese may contribute to its health benefits." |
| Dairy Foods Symposium: Health Benefits of Cheese | Symposium | Dairy Foods: Health Benefits of Cheese | 2025/06/24 09:00:00 | t93623 | Watch | 1338 | Cheese as a unique matrix: Bioaccessibility and bioavailability of nutrients. | 2 | S. Zhou | cheese,vitamin K,bioavailability | S. Zhou1, A. Brodkorb2, J. J. Sheehan2, E. R. Gibney1, E. L. Feeney1 | "Epidemiological evidence now supports that cheese may be beneficial to cardiovascular health. Cheese is a particular example of the dairy food matrix, containing proteins and bioactive compounds that may benefit cardiovascular health despite its high saturated fat content. A key emerging factor is vitamin K (VK), which is involved in blood coagulation and bone and cardiovascular health. Two main forms exist: phylloquinone (K1) from plants and menaquinones (K2, MK4–13) from bacterial fermentation. A source of VK, and especially K2, cheese can vary considerably in VK across different varieties. This is due to multiple factors, including milk source, fermentation processes, and starter cultures. Bovine feeding can affect K1, and we previously reported significantly greater vitamin K1 in Irish Cheddar cheese derived from pasture feeding, vs. Cheddar derived from Total Mixed Ration (TMR) feeding, from a controlled animal feeding trial. It is unknown whether cheese from different feeding systems can result in differences in human VK status. This study investigated the bioavailability and bioaccessibility of vitamin K in pasture-derived and TMR-derived Cheddar cheese. Plasma and serum samples from a 6-wk human intervention study (120 g/d pasture-fed Cheddar cheese [GF-CC; n = 33] vs. TMR-fed Cheddar cheese [TMR-CC; n = 27]) were analyzed for markers of vitamin K status: dephosphorylated, uncarboxylated matrix Gla protein (dp-ucMGP; MyBioSource), undercarboxylated osteocalcin (ucOC), and carboxylated osteocalcin (cOC), via competitive enzyme immunoassay (Takarabio, France). Vitamin K bioaccessibility was investigated using an in vitro digestion model (INFOGEST 2.0). Total and individual VK vitamers (VK1, MK-4, MK-7, MK-9) were analyzed using HPLC-FLD (Agilent Technologies). The TMR-CC group had greater total VK and MK-9, whereas GF-CC had higher K1 and MK-4 versus TMR-CC (both P < 0.05). Despite these differences, results indicated similar improvements in VK status in both intervention groups after consumption. Follow-up in vitro digestion studies of the cheeses from different feeding systems suggest greater bioaccessibility of K1 and MK-4 from GF-CC (P < 0.05), which may have contributed to these findings." |
| Dairy Foods Symposium: Health Benefits of Cheese | Symposium | Dairy Foods: Health Benefits of Cheese | 2025/06/24 09:00:00 | t94543 | Watch | 1339 | Enhancing the bioactive properties of cheese. | 3 | R. A. Ibáñez | cheese,proteolysis,bioactive peptides | R. A. Ibáñez1 | "Due to combined action of native milk enzymes, addition of rennet, and microbial activity from starter and nonstarter lactic acid bacteria, intact caseins (CN) are hydrolyzed into peptides and free amino acids. In recent years, the occurrence of low-molecular weight peptides presents in cheese (i.e., 2–20 amino acid residues) has brought the attention of dairy food scientists from both academia and industry. These peptides have the potential to exhibit physiological responses in human metabolism, which may include antimicrobial, antihypertensive, immunomodulatory, antioxidant, opioid and other activities. These compounds, named bioactive peptides (BP), typically accumulate during cheese ripening, and may require extended time to achieve a significant biological activity. Release is strongly affected by a combination of several factors, including genetic variants of CN, cheese manufacture protocols, ripening conditions and extent of proteolysis. The fate of BP in cheese can also be influenced by gastrointestinal digestion after consumption and must be bioavailable to exhibit a physiological response. Several approaches aimed at improving the bioactive properties of cheese have been proposed, which typically rely on modulating cheese proteolysis (e.g., accelerated ripening). Modifications to typical manufacturing approaches have also been proposed as alternative methods to increase the bioactive properties of cheese. Therefore, cheese is a food product that can be used as a carrier of natural compounds that can positively impact upon human health." |
| Dairy Foods Symposium: Health Benefits of Cheese | Symposium | Dairy Foods: Health Benefits of Cheese | 2025/06/24 09:00:00 | t94696 | Watch | 1340 | Incorporation of health and wellness ingredients in cheese: Challenges and opportunities. | 5 | J. J. Jaeggi | cheese,health,ingredients | J. J. Jaeggi1 | "Consumers in the United States enjoy cheese in many ways. Whether as part of a food system or eaten plain, consumption has increased over the past several years. Cheese is a reliable source of essential nutrients such as calcium, phosphorus, protein, vitamin A, vitamin B12, and zinc. Some cheese may contain probiotic cultures and bioactive peptides, a derivative of protein hydrolysis in cheese. Cheese manufacturing techniques or even varieties can be made to reduce fat, sodium, or carbohydrate intake in addition to optimizing protein and calcium contents. Cheese provides the perfect vehicle in which to incorporate various ingredients to augment health and wellness. Adding nutraceuticals to cheese during the manufacturing process has been tested and, in some instances, fully commercialized. Use of prebiotics such as inulin or other plant-based fiber can help increase satiety by limiting caloric intake. The addition of plant-based phytosterols, n-3 fatty acids, antioxidants, and many other options are possible. However, adding ingredients to cheese can result in a multitude of challenges, with ingredient cost being among the biggest. Ingredients can come in many shapes and sizes including particulates, powders, water, or oil soluble materials. Ingredients are typically added to milk fat, milk, or cheese curd before salting or hooping. Manufacturing considerations such as ingredient loss into the whey resulting in processing issues, allergen concerns, or cross contamination of equipment or brines are a concern for large-scale production or conversion facilities. However slight modifications in manufacturing techniques or facilities designed specifically for the manufacture of these nutraceutical cheeses can be successfully used to reduce ingredient costs and minimize manufacturing losses. Historically, consumers have not been willing to pay the added cost per kilogram needed to manufacture cheeses with health and wellness ingredients, but with the aging of our society, there is a chance the timing may be favorable." |
| Dairy Foods Symposium: Health Benefits of Cheese | Symposium | Dairy Foods: Health Benefits of Cheese | 2025/06/24 09:00:00 | n9374 | Watch | | Development of Tools to Improve the Microbiological Safety of High-Risk Cheese Varieties | 6 | Sarah Engstrom | | | |
| Dairy Management Inc. Symposium: Advances in Membrane-Filtration Ingredients—Technology and Applications | Symposium | Dairy Management Inc. Symposium: Advances in Membrane Filtration Ingredients- Technology and Applications | 2025/06/23 13:30:00 | t93768 | Watch | 1235 | Protein ingredients for high-protein beverages: Insights and applications. | 1 | M. A. Drake | consumer perception,protein beverage,heat stability | D. M. Barbano1, M. A. Drake2 | "Milk proteins have unique flavor, functional, and nutritional properties that align with consumer desires and provide opportunities for innovation. A simple ingredients deck is desirable to today’s consumer, and dairy protein functionality can be utilized to exclude undesirable ingredients (stabilizers, thickeners) from protein beverages. Heat stability (protein aggregation and gelation) remains an ongoing challenge for both extended shelf life and shelf stable milk and milk protein beverages. Removal of lactose and low molecular weight soluble solids increases heat stability of milk proteins. Consumer perception of protein beverages and the role of milk components on protein beverage stability will be addressed." |
| Dairy Management Inc. Symposium: Advances in Membrane-Filtration Ingredients—Technology and Applications | Symposium | Dairy Management Inc. Symposium: Advances in Membrane Filtration Ingredients- Technology and Applications | 2025/06/23 13:30:00 | t95626 | Watch | 1236 | Innovations in protein ingredients for high-protein yogurt manufacturing. | 2 | J. K. Amamcharla | ingredient functionality,acid gel,protein interaction | J. K. Amamcharla1 | "Milk-derived ingredients such as milk protein concentrate (MPC) and isolates are widely utilized for their nutritional and functional benefits in various dairy and food products. These ingredients provide functional benefits such as thickening, gelling, and emulsification. These properties are influenced by protein concentration and interactions between proteins, including casein-casein, casein-whey protein, and whey protein-whey protein interactions. Whey proteins, which make up approximately 20% of the total proteins in milk, are globular proteins highly susceptible to denaturation followed by aggregation during processing. This denaturation exposes sulfhydryl and/or disulfide residues, leading to intra- or intermolecular crosslinking, which can alter functionality. By controlling these interactions, the final functionality of MPC can be customized. In this study, selective modifications, such as fibrillation or pre-aggregation of whey proteins, were applied to produce MPC suitable for a wide range of applications. Ingredients like MPC and NDM, in which whey proteins were selectively converted to fibrils or soluble aggregates, were produced and characterized in terms of acid gelation and other functional characteristics. The MPC with fibrillated whey proteins demonstrated significantly higher viscosity, and acid gels made with this ingredient resulted in firmer gels compared with control MPC. In a separate study, nonfat dry milk (NDM) containing whey protein fibrils was developed using microfiltration and ultrafiltration to produce fibrillated skim milk, which was then spray-dried to create fibrillated NDM. Reconstituted fibrillated NDM also showed improved viscosity, emulsification, and foaming capacity. These findings suggest that selective modifications of whey proteins can enhance the functionality of milk protein powders, making them suitable for various formulations. These whey protein-functionalized ingredients can reduce the need for non-dairy additives and can be classified as clean-label ingredients." |
| Dairy Management Inc. Symposium: Advances in Membrane-Filtration Ingredients—Technology and Applications | Symposium | Dairy Management Inc. Symposium: Advances in Membrane Filtration Ingredients- Technology and Applications | 2025/06/23 13:30:00 | t94026 | Watch | 1237 | Membrane filtration in cheese production. | 3 | S. Govindasamy-Lucey | ultrafiltration,microfiltration,mozzarella cheese | S. Govindasamy-Lucey1 | "There is growing interest in manufacturing cheese from concentrated milk as this increases plant productivity and output. Low concentration factor ultrafiltration (LCF-UF) has been extensively used by the cheese industry, to standardize protein content and reduce seasonal variations in composition and cheese properties/yield. When protein levels in cheese milk are <4%, only minor modifications in the cheesemaking recipe are needed. Low concentration factor microfiltration (LCF-MF) is also becoming popular and has similar benefits to LCF-UF but also removes whey (serum) proteins before cheesemaking. This allows the cheese milk to be standardized to a specific casein (CN) content while removing whey proteins as milk-derived whey (value-added ingredient). Using MF to deplete most whey proteins in cheesemilk does not impact the nutritional profile and more characteristic cheese ripening is observed. We have been exploring cheese milks with CN levels between 4% and 10% made with both UF and MF. Use of higher protein levels requires modifications to address the rapid rennet coagulation process, such as reducing the coagulation temperature and precise selection of the optimum cutting time (as well as a faster cutting cycle). Membrane filtration results in milk that has a higher proportion of insoluble calcium as a percentage of total calcium. Preacidification with different types of acids, or carbon dioxide, can help to partially demineralize milk, along with use of a lower pH at whey drainage. However, fat losses after cutting can prove to be a significant issue with highly concentrated milk. Fat losses in low-moisture, part-skim mozzarella cheeses made from high CN cheesemilk (~9%–10% CN) can be decreased by use of pre-acidification and low pressure homogenization of the cheesemilk, as well as by using a pressed-block process instead of pasta-filata style (to avoid further fat losses in the cooker/stretcher). While concerns remain regarding the impact on cheese quality by the use of concentrated milk, these approaches will become more popular for commodity type cheeses due to the increased yield, more consistent quality, as well as greatly increased factory output." |
| Dairy Management Inc. Symposium: Advances in Membrane-Filtration Ingredients—Technology and Applications | Symposium | Dairy Management Inc. Symposium: Advances in Membrane Filtration Ingredients- Technology and Applications | 2025/06/23 13:30:00 | t94791 | Watch | 1238 | Novel membranes for valorizing dairy coproduct streams. | 4 | J. Hestekin | | J. Hestekin1 | "Dairy processing relies heavily on membranes, but the challenge of fouling necessitates harsh cleaning methods. This project aims to overcome this hurdle by employing an innovative and eco-friendly approach to develop specialized zwitterionic membranes. These membranes will be utilized for producing milk protein concentrates and potentially fractionate dairy proteins. Zwitterionic materials, known for their antifouling properties, have shown promise in various applications. However, many existing materials are not suitable for industries involving human consumption, such as food and pharmaceuticals. In this project, we will synthesize and test a nanocellulose zwitterionic membrane for ultrafiltration performance. The utilization of biocompatible zwitterionic materials will address the pervasive issue of protein fouling, a significant challenge in dairy product processing. The nanocellulosic membrane has been shown to make “slit” membranes so may be able to have better fractionation capabilities than polysulfone membranes currently used in the dairy industry. This innovation has the potential to revolutionize protein extraction from dairy products, ensuring higher efficiency and reduced waste." |
| Dairy Management Inc. Symposium: Advances in Membrane-Filtration Ingredients—Technology and Applications | Symposium | Dairy Management Inc. Symposium: Advances in Membrane Filtration Ingredients- Technology and Applications | 2025/06/23 13:30:00 | t94559 | Watch | 1239 | Protein interactions in whey protein phospholipid concentrate manufacturing. | 5 | G. Ozturk | whey protein phospholipid concentrate (WPPC),protein interaction,milk fat globule membrane (MFGM) | G. Ozturk1 | "Whey protein phospholipid concentrate (WPPC) is a by-product of whey protein isolate production and serves as a source of various bioactive compounds that benefit human health. Our recent findings demonstrated that WPPC contains elevated levels of milk fat globule membrane (MFGM) proteins, which account for 23% of the total relative protein; phospholipids constitute 20% of the total fatty acid pool, whereas whey proteins comprise 40% of the total relative protein. These bioactive compounds derived from WPPC have significant potential as innovative ingredients, underscoring the necessity of meticulously isolating and characterizing these components. However, previous research indicates that WPPC production may involve heat-induced complex formations between whey proteins and MFGM. Thus, it is critical to investigate the changes that occur within the WPPC matrix during thermal treatment. In this study, we conducted 2 pilot-scale WPPC in-house trials using Cheddar cheese whey, which included one processed from raw milk with a single batch pasteurization and another produced from high-temperature, short-time (HTST) milk undergoing a second HTST treatment. Post-production analysis included dynamic light scattering measurements, confocal laser scanning microscopy, Fourier-transform infrared (FTIR) spectroscopy, and reduced and non-reduced SDS-PAGE to examine the insoluble proteins of MFGM dissolved in various reagents. We also quantified β-lactoglobulin through the processing to understand the unfolding and aggregation of β-lactoglobulin. This comprehensive evaluation described how the different treatments impact the interactions between whey proteins and MFGM, along with the formation of insoluble aggregates at the fat surface. By understanding the alterations in whey proteins resulting from these thermal treatments, we aim to enhance the efficiency of isolating valuable compounds such as MFGM proteins, whey proteins, and phospholipids, all of which possess considerable nutritional and economic significance." |
| Donald C. Beitz Recognition Symposium: 50-Plus Years of Dairy Science Research | Symposium | Don Beitz Recognition Symposium | 2025/06/24 13:30:00 | t93455 | Watch | 1433 | Don Beitz and colleagues’ contribution to our understanding of transition cow hypocalcemia and other mineral challenges and strategies for prevention. | 1 | J. P. Goff | hypocalcemia,milk fever,transition cow | J. P. Goff1 | "Shortly after becoming a faculty member at Iowa State University (ISU), Don Beitz started working on all problems of transition cows. One of those problems involved hypocalcemia in dairy cows. Beitz collaborated with colleagues and students at Iowa State on this problem and began a long and fruitful collaboration with the Metabolic Disease Unit at the USDA, ARS, National Animal Disease Center (NADC) as well. The original low calcium diets for prevention of milk fever were performed at Iowa State University. How those diets worked to prevent milk fever was discovered through determination of blood parathyroid hormone concentrations and blood 1,25-dihydroxyvitamin D concentrations. The role phosphorus had on vitamin D metabolism was also discovered in the ISU-NADC collaborations, including experiments demonstrating milk fever could be controlled by reducing diet phosphorus. Various experiments outlining the role of vitamin D in periparturient mineral metabolism were conducted as well as trials testing various vitamin D compounds for their ability to prevent hypocalcemia and milk fever. Iowa State University and NADC became well known for these studies, and the work continues to day." |
| Donald C. Beitz Recognition Symposium: 50-Plus Years of Dairy Science Research | Symposium | Don Beitz Recognition Symposium | 2025/06/24 13:30:00 | t93715 | Watch | 1434 | Advances in understanding fatty liver and ketosis from the work of Don Beitz and his colleagues. | 2 | J. K. Drackley | hepatic lipidosis,ketosis,glucagon | J. K. Drackley1 | "Fatty liver and ketosis are 2 interrelated conditions affecting periparturient dairy cows that are associated with economic losses for the dairy industry. Don Beitz formed an early collaboration with his colleague J. W. Young at Iowa State University, which Beitz continued after Young’s retirement. Early work sought to establish in vivo models of ketosis, using a combination of phlorizin treatment (to stimulate glucose loss in urine) and 1,3-butanediol (a ketone body precursor) in steers. Results showed that many metabolic aspects of lactation ketosis could be reproduced in steers. This led to a model in which fatty liver and ketosis were induced in early lactating cows by modest feed restriction (to 80% of energy requirements) coupled with supplementation of 1,3- butanediol. Several studies sought to refine the model and characterized various aspects of cows subjected to the model, including metabolites in blood and liver, glucose kinetics, and gene expression. A major finding in subsequent studies was that injections of glucagon could prevent and treat fatty liver in periparturient cows. Studies characterized this action of glucagon on metabolites and gene expression. Recent collaborations of Beitz have moved into in vitro models of fatty liver. Beitz’s many contributions on ketosis and fatty liver have been foundational for other scientists to continue research into peripartal metabolism and physiology of dairy cows." |
| Donald C. Beitz Recognition Symposium: 50-Plus Years of Dairy Science Research | Symposium | Don Beitz Recognition Symposium | 2025/06/24 13:30:00 | t94524 | Watch | 1435 | Advances in understanding bovine immunology from the work of Don Beitz and his colleagues. | 3 | C. D. Nelson | immunity,vitamin,dairy cattle | C. D. Nelson1 | "Don Beitz mentored several students with his colleagues at the USDA National Animal Disease Center whose focus was bovine immunology. He and his students advanced the understanding of how the plane of nutrition of growing calves altered immune status. For example, their work showed that feeding calves to achieve a growth rate of 1.2 kg/d compared with 0.55 or 0 kg/d resulted in diminished lymphocyte responses but stronger monocyte responses. Another contribution of Beitz and his students was the characterization of immune changes that occur in cows upon infection with Mycobacterium avium subspecies paratuberculosis. Several of his students evaluated the effects of vitamins A, D, and E on bovine immunity using cell-culture and animal experiments. Collectively, their work provided a framework for the mode of action of vitamins in bovine immune cells and a practical foundation for vitamin nutrition of cattle." |
| Donald C. Beitz Recognition Symposium: 50-Plus Years of Dairy Science Research | Symposium | Don Beitz Recognition Symposium | 2025/06/24 13:30:00 | t95701 | Watch | 1468 | The legacy of Don Beitz and his passion for research and teaching and all things dairy, nutrition, biochemistry, and life. | 4 | M. J. VandeHaar | | M. J. VandeHaar1 | "Don Beitz is a distinguished professor of agriculture at Iowa State University with joint appointments in the Departments of Animal Science and Biochemistry-Biophysics. Don grew up on a farm in southern Illinois and earned his BS and MS degrees from the University of Illinois. He then earned his PhD in dairy nutrition and biochemistry from Michigan State University in 1967. Upon graduation, he began his career at Iowa State and never left. His extraordinary career spanning more than five decades has been marked by significant contributions to research, teaching, and service in the fields of animal science and biochemistry. In addition to the areas highlighted by other speakers, Beitz has advanced our understanding of milk fat synthesis, the genetic control of body composition, and the role of diet in human health and cholesterol homeostasis. He has published 300 peer-reviewed manuscripts, taught 350 courses to 16,000 students, and mentored 107 graduate students as major professor as well as numerous undergraduates. Don has been active in ADSA since 1964 and served as president in 2008 to 2009. He has been a staunch supporter of women and minorities in science, and maintained ties to former students with his annual Christmas letters now for 58 years. Don has seen and been part of many changes in dairy science over his career, but some things remained constant: his enthusiasm for basic science and its application, his ability to inspire a love of learning, and his faith and love for family and community. He has been a great example for many of us." |
| Feed Additives to Mitigate Methane Symposium: Recommendations Published in a Journal of Dairy Science Special Issue | Symposium | Feed Additives to Mitigate Methane Symposium: Recommendations Published in a Journal of Dairy Science Special Issue | 2025/06/25 09:00:00 | t93504 | Watch | 1521 | Recommendations for identification and selection of bioactive compounds to develop antimethanogenic feed additives. | 1 | D. R. Yáñez-Ruiz | in silico,docking,in vitro | Z. Durmic1, E. Duin2, A. Bannink3, A. Belanche4, V. Carbone5, M. D. Carro6, M. Crüsemann7, V. Fievez8, F. Garcia9, A. N. Hristov10, G. Martinez-Fernandez11, S. Muetzel5, E. M. Ungerfeld12, M. Wang13, D. R. Yáñez-Ruiz14 | "This work provides technical recommendations and guidelines for research to identify and screen different compounds to reduce enteric methane (CH4) emissions before they can be further assessed in vivo. For the initial identification of anti-methanogenic feed additives (AMFA) candidates, 2 approaches can be used: mechanistic (combining computational tools—in silico—and docking studies, using a modeling technique to predict how target enzymes interact with candidate molecules, and then synthesizing the candidate compounds), and empirical (finding published evidence of specific bioactive effects, by searching different repositories, followed by obtaining bioactive material from the identified source). Although both approaches offer potential to identify a large number of compounds, sophisticated equipment and specific expertise are required for computational/modeling work and extracting bioactive compounds from a biological matrix, respectively, in mechanistic and empirical studies. Once AMFA candidates have been identified, the next step is to evaluate experimentally the anti-methanogenic activity and there is an array of in vitro methodologies that can be used for this purpose (enzymatic assays, pure cultures of methanogens batch cultures and continuous or semi-continuous cultures). We will present and discuss the main aspects to consider when using different approaches, including identifying the target enzymes to study, developing the enzyme material for running inhibition kinetics, culturing conditions and selection of archaeal species to study and the processing of the rumen inoculum used for experiments conducted using batch cultures and fermenters. In addition, critical overarching methodological considerations for all in vitro approaches are (1) appropriate experimental design and statistical tests, (2) selection of doses depending on the nature and mode of action of the AMFA, (3) careful preparation of solid or liquid formats for appropriate delivery of the additives, and (4) when and how to measure CH4 and units to express its production." |
| Feed Additives to Mitigate Methane Symposium: Recommendations Published in a Journal of Dairy Science Special Issue | Symposium | Feed Additives to Mitigate Methane Symposium: Recommendations Published in a Journal of Dairy Science Special Issue | 2025/06/25 09:00:00 | t93763 | Watch | 1522 | Recommendations for testing enteric methane-mitigating feed additives in ruminant studies. | 2 | A. N. Hristov | feed additive,enteric methane mitigation,guideline | A. N. Hristov1, A. Bannink2, M. Battelli3, A. Belanche4, M. C. Cajarville Sanz5, G. Fernandez-Turren5,6, F. Garcia7, A. Jonker8, D. A. Kenny9, V. Lind10, S. J. Meale11, D. Meo Zilio12, C. Muñoz13, D. Pacheco8, N. Peiren14 | "There is a need for rigorous and scientifically based testing standards for existing and new enteric methane mitigation technologies, including antimethanogenic feed additives (AMFA). This review provides guidelines for conducting and analyzing data from experiments with ruminants intended to test the antimethanogenic and animal production and physiological effects of AMFA. Recommendations include study design and statistical analysis of the data, interactions with diet composition, associative effect of AMFA with other mitigation strategies, appropriate methods for measuring methane emissions, production, and physiological responses to AMFA, and effects on animal health and product quality. Animal experiments should be planned based on clear hypotheses and experimental designs must be chosen to best answer scientific questions, with pre-experimental power analysis and robust postexperimental statistical analyses being important requisites. Experimental conditions should be representative of the production system of interest, to ensure that results and conclusions are applicable and practical. To explore additivity and synergism, as well as trade-offs, including relevant manure emissions, AMFA may be combined with other methane mitigation strategies and studied in appropriately designed experiments. Methane emissions can be successfully measured, and efficacy of AMFA determined, using respiration chambers, the sulfur hexafluoride method, and the GreenFeed system. For proper assessment of an AMFA, it is critically important that representative animal production data are collected and reported. In addition, evaluating the effects of AMFA on nutrient digestibility, animal physiology, animal health and reproduction, product quality, and how AMFA interact with nutrient composition of the diet is necessary and should be conducted at various stages of the evaluation process. The authors emphasize that enteric methane mitigation claims should not be made until efficacy of AMFA is confirmed in animal studies designed and conducted considering the guidelines provided in the review." |
| Feed Additives to Mitigate Methane Symposium: Recommendations Published in a Journal of Dairy Science Special Issue | Symposium | Feed Additives to Mitigate Methane Symposium: Recommendations Published in a Journal of Dairy Science Special Issue | 2025/06/25 09:00:00 | t93858 | Watch | 1523 | Feed additives for methane mitigation: Modeling the impact of feed additives on enteric methane emission of ruminants—Approaches and recommendations. | 3 | A. Bannink | feed additive,methane mitigation,modeling | J. Dijkstra1, A. Bannink1, G. Congio2, J. L. Ellis3, M. Eugène4, F. Garcia5, M. Niu6, R. E. Vibart7, D. R. Yáñez-Ruiz8, E. Kebreab9 | "Over the past decade, there has been significant focus on using antimethanogenic feed additives (AMFA) to mitigate enteric methane (CH4) emissions from ruminants. Administered in small quantities, these additives can considerably reduce methanogenesis. Mathematical models are essential for understanding and predicting the quantitative impact of AMFA on enteric CH4 emissions across diverse diets and production systems. This study provides a comprehensive overview of methodologies for modeling the impact of AMFA on enteric CH4 emissions in ruminants, concluding with recommendations for modeling approaches to quantify AMFA’s impact on CH4 emissions. Key considerations encompass the type of models employed (i.e., empirical models including meta-analyses, machine learning models, and mechanistic models), alignment of modeling objectives, data availability, modeling synergies and trade-offs associated with using AMFA, and model applications for enhanced understanding, prediction, and integration into higher levels of aggregation. Based on an evaluation of these critical aspects, recommendations are provided for modeling approaches to quantify AMFA’s impact on CH4 emissions and in support of farm-level, national, regional, and global inventories for accounting greenhouse gas emissions in ruminant production systems. These recommendations emphasize that data quality is critical in modeling approaches, with a strong preference for peer-reviewed sources. Careful evaluation of additive dosage, delivery methods, and transient effects is essential in quantitative analyses. The chosen model and modeling approach should be clearly defined and aligned with specific objectives, while exploring the synergy of diverse modeling methodologies, including machine learning, to improve understanding and predictive accuracy of AMFA’s impact on CH4 emissions in ruminants. An integral, quantitative assessment is advised to evaluate AMFA’s CH4 mitigation effects, considering potential synergies or trade-offs with other greenhouse gas sources." |
| Feed Additives to Mitigate Methane Symposium: Recommendations Published in a Journal of Dairy Science Special Issue | Symposium | Feed Additives to Mitigate Methane Symposium: Recommendations Published in a Journal of Dairy Science Special Issue | 2025/06/25 09:00:00 | t93790 | Watch | 1524 | A guideline to uncover the mode of action of antimethanogenic feed additives for ruminants. | 4 | A. Belanche | methanogens,mitigation,rumen methanogenesis | A. Belanche1, A. Bannink2, J. Dijkstra2, Z. Durmic3, F. Garcia4, F. G. Santos5, S. Huws5, J. Jeyanathan6, P. Lund7, T. A. McAllister8, D. P. Morgavi9, S. Muetzel10, D. W. Pitta11, D. R. Yáñez-Ruiz12, E. M. Ungerfeld13 | "We discuss a set of guidelines of research and knowledge required for understanding the mode of action of antimethanogenic feed additives (AMFA). According to their mode of action, AMFA can be classified into 4 categories: (1) lowering H2 production, (2) inhibiting methanogens, (3) promoting alternative H2-incorporating pathways, and (4) oxidizing methane. Identifying the exact mode of action of AMFA is complex and costly. Thus, we recommend that in-depth research should only be pursued after the effectiveness and safety of an AMFA has been proven. Key research questions that guide the investigation should cover 5 perspectives: (1) microbiology, identifying the targeted microbes and the potential side effects on nontargeted microbes; (2) cell and molecular biochemistry; identifying the active compounds, the subcellular mechanisms of action on the targeted molecules, and the mechanisms of resistance or adaptation to AMFA; (3) microbial ecology, analyzing the effects of AMFA on the metabolic pathways at the microbial community level, including accumulation of fermentation products and AMFA degradation; (4) animal metabolism, studying effects on feed intake, digestibility, absorption, metabolism, excretion, and accumulation of active compounds or their metabolites to assess safety for animals, consumers, and the environment; and (5) cross cutting, describing the modulatory effects of the diet, type of animal, management, and other factors on the mode of action and effectiveness of AMFA. The research proposed and discussed herein implies multidisciplinary and complementary approaches to fully understand the mode of action of AMFA at different depths. It also addresses existing critical knowledge gaps about the consequences of inhibiting rumen methanogenesis on the microbial ecosystem and host animal, which must be understood for the successful adoption of AMFA to mitigate methane emissions from ruminants." |
| Feed Additives to Mitigate Methane Symposium: Recommendations Published in a Journal of Dairy Science Special Issue | Symposium | Feed Additives to Mitigate Methane Symposium: Recommendations Published in a Journal of Dairy Science Special Issue | 2025/06/25 09:00:00 | t93937 | Watch | 1525 | Regulations and evidence requirements for the authorization of enteric methane-mitigating feed additives. | 5 | J. M. Tricarico | intended use,regulatory status,conditions of use | J. M. Tricarico1, F. Garcia2, A. Bannink3, S. S. Lee4, M. A. Miguel4, J. R. Newbold5, P. K. Rosenstein6, M. R. Van der Saag7, D. R. Yáñez-Ruiz8 | "A review of the regulatory and evidence requirements for authorizing feed additives aimed at reducing enteric methane emissions from ruminants was conducted for 7 illustrative jurisdictions. The primary objective was to provide a broad overview and synthesis to help applicants and scientists comply with regulations and understand evidence requirements needed for authorization of antimethanogenic feed additives (AMFA) in Australia, Canada, the European Union, New Zealand, South Korea, the United Kingdom, and the United States. The review also identified differences and similarities in regulations and evidence requirements, which may aid global regulatory harmonization, and provides recommendations for applicants and scientists. Regulations protect animal health, promote food safety, and prevent unsafe practices and misleading claims. These mandatory regulations cover ingredient safety, manufacturing practices, product labeling, and permissible limits for substances. The intended use, or declared purpose for which the additive is authorized, influences its legal classification or regulatory status, and determines conforming evaluation and approval processes. This includes practical aspects of administration like active ingredients, dosage, mixing, and feeding frequency. Each jurisdiction has unique criteria for legally classifying AMFA, making it challenging to meet all legal classifications with a single set of scientific evidence. However, there is consistency in the need for robust evidence for efficacy, safety, and product quality, despite differences in study requirements. The burden of proof is on the applicant to provide all necessary scientific evidence. Applicants and scientists must consult with authorities before designing research trials. Scientists conduct efficacy and risk assessments that inform regulatory decisions and must follow good scientific practices. Collaboration with regulatory agencies can refine legal classifications and improve harmonization. Educating stakeholders about AMFA’s advantages and proper use can encourage correct usage and enhance understanding and transparency." |
| Feed Additives to Mitigate Methane Symposium: Recommendations Published in a Journal of Dairy Science Special Issue | Symposium | Feed Additives to Mitigate Methane Symposium: Recommendations Published in a Journal of Dairy Science Special Issue | 2025/06/25 09:00:00 | t93818 | Watch | 1526 | Feed additives for methane mitigation: How to account for the mitigating potential of antimethanogenic feed additives—Approaches and recommendations. | 6 | A. del Prado | life cycle assessment,emissions trading schemes,emission factors | A. del Prado1,2, R. E. Vibart3, F. M. Bilotto4, C. Faverin5,6, F. Garcia7, F. L. Henrique8, F. F. G. D. Leite5, A. M. Mazzetto9, B. G. Ridoutt10,11, D. R. Yáñez-Ruiz12, A. Bannink13 | "Recent advances in our understanding of methanogenesis have led to the development of antimethanogenic feed additives (AMFA) that can reduce enteric methane (CH4) to varying extents. Here we examine current and emerging approaches used for accounting (or quantifying) of enteric CH4 abatement through the use of AMFA in livestock systems across scales, from the individual animal to the global level. The accounting process for on-farm enteric CH4 emissions with the use of AMFA starts with the ruminant animal, with estimates obtained from simple empirical emission factors or equations, to complex process-based models. However, the enteric CH4 abatement from the use of AMFA per se remains to be fully quantified in most accounting systems and scales. The accounting also needs to consider the AMFA delivery method and the accounting of synergies and trade-offs in greenhouse gas emissions at levels before (e.g., emissions from AMFA production and distribution) and after (e.g., effects on feed efficiency) being offered to the animal to fully assess the impact of AMFA use. The choice of methodology and level of complexity to account for AMFA abatement in livestock systems must be tailored to the targeted scale of analysis, the availability of input data to represent contextualized conditions, and the accounting objectives. In the accounting of AMFA abatement, it is critical to consider the implications of efficacy (results from controlled interventions) versus effectiveness (results from real-world conditions). Assumptions on the additivity of AMFA abatement should follow insights from experimental work, and in the future, from models as these continue to improve the simulation of combined AMFA efficacy and effectiveness. Collectively, the accounting of enteric CH4 abatement by feed additives remains to be fully assessed beyond experimental results to address pragmatism, potential for adoption and societal acceptance." |
| Forages and Pastures Symposium: Building a Resilient Forage Program for Climate Extremes | Symposium | Forages and Pastures | 2025/06/23 13:30:00 | t95440 | Watch | 1240 | Dealing with climate change and extreme weather events is part of forage-management future. | 1 | V. Baron | | V. Baron1, H. W. Chau2 | "Climate change is evidenced by increasing global mean temperature since industrialization due to retention of incoming solar radiation within the atmosphere due to greenhouse gas accumulation. The upward inflection of temperature has been noted post 1960s. Public awareness has increased due to extreme weather events with dramatic impacts on society including agricultural production. Climatic extremes overlay regional and seasonal climate averages and climate change trends. Hot locations become hotter and moist locations become wetter. Extreme weather events are heat waves, intense precipitation, drought, and tropical cyclones. Compound extremes occur when drought and high temperature occur together, but may include wildfires, unexpected rapid snowmelt, and floods, which are outcomes of the extremes. The frequency and uncertainty of extreme weather occurrence will increase as the mean global temperature continues to increase. Increasing air temperature, the main driver, increases the capacity of air to contain water vapor causing greater evapotranspiration from vegetation or bodies of water. Droughts with high temperature reduce soil moisture during crop-sensitive times. Intense rainfall occurs when water vapor carried by air is released over land masses is problematic at rates greater than can be taken up by soil and crops. Seasonal precipitation may shift to winter and not coincide with periods of crop growth. Intensive water extremes lead to frequent and severe droughts and floods, impacting water availability, infrastructure, and ecosystems services. Adaptation to new normal and uncertainty is crucial to sustainable productivity of the land and related ecosystems. Managing forage, feed crops, and pastures through appropriate regional adaptation to temperature, water use efficiency and improving capacity of soils for rapid infiltration and water storage will be important to reduce risk. Designing herd and infrastructure size to use manure effectively with forage crops to prevent nutrient losses may help reduce harmful outcomes." |
| Forages and Pastures Symposium: Building a Resilient Forage Program for Climate Extremes | Symposium | Forages and Pastures | 2025/06/23 13:30:00 | t94826 | Watch | 1241 | Understanding the alternatives and consequences of taking versus not taking action. | 2 | L. Silva | grazing system,livestock production,nutrient cycling,sustainable intensification | L. Silva1 | "Worldwide, forages are the primary source of feed for livestock production systems due to their diversity of adapted species and lower costs of production. Forage-based livestock operations are complex systems across climates, soil types, genetics, and production systems. Therefore, it is essential to properly implement research-based management practices to support stand production and persistence to maintain a healthy stand against challenges related to extreme weather conditions. Over the past decades, climate trends have shown changes in occurrence and an increase of extreme events (e.g., extended droughts) for the continental US area. These events can lead to issues with production, persistence, and health of forage stands, and overall livestock performance in operations. In recent years, there has been an increasing interest in sustainable production intensification on forage-livestock ecosystems aiming to enhance production, feasibility, resilience, and sustainability while reducing environmental footprint of operations. The adoption of improved management strategies (e.g., use of mixtures) support the delivery of multiple ecosystem services including carbon sequestration and improved soil fertility and health. Among strategies to be implemented, proper grazing management using adequate harvest frequency and intensity allows for proper plant regrowth and energy reserve recovery which impacts stand health and persistence over time. In addition, the use of rotational stocking improves nutrient cycling and redistribution of excreta throughout the pastures, allowing for improved forage production and nutritive value. Then, the nutrient return associated with proper and constant input of plant litter, dead material and roots through decomposition in perennial forage stands, improves soil nutrient levels and contributes to the organic matter accumulation. Increasing resilience of forage systems is essential and it requires a holistic approach to assess the conditions of each system while considering its specificities, goals and resources." |
| Forages and Pastures Symposium: Building a Resilient Forage Program for Climate Extremes | Symposium | Forages and Pastures | 2025/06/23 13:30:00 | t94466 | Watch | 1242 | The current situation and impacts in animal and human systems. | 3 | A. F. Brito | dairy,food security,resilience | A. F. Brito1 | "Resilience can be broadly defined as the ability to recover from or adjust to misfortunes or changes. Therefore, cropping systems that rely on management strategies to endure and recover from biotic and abiotic stressors such as pests, diseases, droughts, floods, and extreme temperatures can be considered resilient and more equipped to sustainably generate food. The global population is predicted to reach 9.7 billion in 2050 and could peak at 10.4 billion in the mid-2080s, creating pressures on the society and agriculture sector to increase food production to keep up with the growing demand. Specific to the dairy industry, there will be a need to not only increase milk production but also that of milk fat and protein in response to elevated global demand for dairy products. Ideally, production of milk and milk components should increase with reduced competition for land and greenhouse gas emissions intensity, requiring more productive and environmentally friendly forage cropping systems. Further, the dairy industry, and the livestock sector as a whole, need to tackle the “feed-food competition” question, previously defined as “the tensions and tradeoffs between two alternative uses for edible crops: direct consumption by humans versus feeding livestock.” Several levers have been pointed out to potentially solve the feed-food competition question: (1) decreasing total feed demand, (2) reducing food-competing feed demand, (3) increasing food availability, (4) increasing animal feed efficiency, and (5) increasing system efficiency via circular economy. Using cover crops for forage production and soil health, increasing the reliance on forage legumes to improve animal production and farm N self-sufficiency, and feeding digestible forages are some examples that address the feed-food competition issue and promote food security. In fact, dairy and other animal products are excellent sources of EAA and micronutrients, and together contribute to 18% of global calories and 25% of global protein consumption. In summary, building resilient forage cropping systems concurrently with increased production of milk and milk components are key factors to ensure food security and human health." |
| Forages and Pastures Symposium: Building a Resilient Forage Program for Climate Extremes | Symposium | Forages and Pastures | 2025/06/23 13:30:00 | t94560 | Watch | 1243 | Designer forages for the future: Future trends in forage breeding for climate extremes. | 4 | A. T. Adesogan | designer forage,future forage,forage breeding | A. T. Adesogan1, J. C. Dubeux1, M. O. Wallau1, E. F. Rios1 | "Increasingly unpredictable extreme weather events due to the changing climate include rising temperatures, sea level rise, prolonged and pronounced droughts, as well as frequent flooding. Forage breeders have a repertoire of classical and cutting edge breeding techniques that are being leveraged to produce more heat, drought, flooding, or salinity-tolerant forages. However, future efforts will need to develop forages that exhibit multidimensional resilience and benefits under various stressors. In addition, future varieties must maintain ecosystem services currently offered by existing varieties despite the change in climate. Traditional forage breeding goals such as increasing forage protein concentration and digestibility as well as pest and disease resistance, should be augmented with more precise objectives such as increasing concentration and bioavailability of limiting amino acids, vitamins or minerals in forage-based diets, reducing antinutritive factors, increasing nutritional stability during storage, improving soil health, inhibiting soil nitrification, stimulating root nodulation and nitrogen fixation, bioremediation capacity, carbon sequestration, and water balance, and increasing the concentration of health-promoting components, such as Mucuna L-dopa, which is used to cure Parkinson’s disease, and so on. The ultimate goal should be to develop designer forages that are resilient to multidimensional stressors, more nutritious, easier to digest, less toxic, and more sustainable and health promoting. Achievement of these goals will reduce the need for supplementation with expensive, often imported concentrates, drugs, pesticides and herbicides, and soil amendments, as well as reducing the need to mitigate greenhouse gas emissions from forage-based livestock systems. The power of artificial intelligence to aid hyperspectral remote imaging, data collection and analysis, genetic diversity exploration, and so on should be leveraged to accelerate progress in developing designer forages of the future with multidimensional benefits." |
| Forages and Pastures Symposium: Building a Resilient Forage Program for Climate Extremes | Symposium | Ruminant Nutrition - General | 2025/06/23 13:30:00 | t94234 | Watch | 1244 | Effect of sward type on milk production, intake, and apparent total-tract digestibility of late-lactation dairy cattle. | 5 | M. Dineen | sward type,dairy cow,digestibility | E. Wims1,2, B. McCarthy1, J. P. Murphy1, T. F. O'Callaghan2, M. Dineen1 | "The objective of this study was to investigate the effect of sward type on milk production, intake, and apparent total-tract digestibility of late-lactation dairy cattle. Nine rumen-cannulated Holstein-Friesian cows, averaging 181 ± 12 DIM and 526 ± 37 kg of BW, were randomly assigned to a treatment sequence in a replicated 3 × 3 Latin square design. The treatments were as follows: perennial ryegrass receiving 50 kg of inorganic N/ha/cut (GO); perennial ryegrass-white clover receiving 25 kg of inorganic N/ha/cut (GC); and perennial ryegrass-white clover-plantain receiving 25 kg of inorganic N/ha/cut (GCP). The pasture feeding rates were adjusted daily to yield refusals of 5% to 10% of intake. In addition, all cows received 0.89 kg of DM of a standard dairy concentrate supplement. The study consisted of three 29-d periods, each period consisting of 21 d of dietary adaptation before an 8-d sample collection period. Data were analyzed using a mixed model (PROC MIXED) that included the fixed effects of treatment and period and the random effect of cow. The GC swards consisted of 83% perennial ryegrass and 17% white clover, whereas the GCP swards contained 38% perennial ryegrass, 7% white clover, 50% plantain, and 5% unsown species. Cows fed GCP tended to have lower milk fat concentration (Table 1). There was no effect of sward type on intake. Cows fed GCP had lower apparent total-tract digestibility (Table 1). The results of this study suggest that high inclusion levels of plantain in pasture swards can negatively affect milk production and total-tract digestibility. Table 1 (Abstr. 1244). Effect of sward type on milk production, intake, and apparent total-tract digestibility of late-lactation dairy cattle | Item | GO | GC | GCP | SEM | P-value | | Milk yield, kg/d | 18.2 | 18.0 | 17.8 | 0.87 | 0.92 | | Milk crude protein, % | 3.88 | 3.87 | 3.83 | 0.09 | 0.56 | | Milk fat, % | 4.60 | 4.58 | 4.23 | 0.17 | 0.05 | | Protein plus fat yield, kg/d | 1.53 | 1.50 | 1.41 | 0.06 | 0.13 | | Dry matter intake, kg/d | 19.7 | 19.2 | 19.2 | 0.55 | 0.54 | | Organic matter intake, kg/d | 17.4 | 17.0 | 16.5 | 0.47 | 0.21 | | Apparent TTDMD,1 g/g | 0.76a | 0.76a | 0.69b | 0.004 | <0.01 | | Apparent TTOMD,2 g/g | 0.81a | 0.80a | 0.75b | 0.004 | <0.01 |
1TTDMD = total-tract dry matter digestibility. 2TTOMD = total-tract organic matter digestibility. " |
| Joint ADSA-CSAS Breeding and Genetics Symposium | Symposium | CSAS Symposium | 2025/06/24 09:00:00 | t94220 | Watch | 1323 | Breeding for improved dairy cattle welfare and resilience: Opportunities in the genomics and phenomics era. | 1 | L. F. Brito | | L. F. Brito1 | "Dairy cattle welfare is a critical aspect of sustainable and ethical livestock production, with significant implications for productivity, dairy product quality, consumer perception, and regulatory compliance. Traditional breeding programs have historically prioritized milk production traits, sometimes at the expense of welfare-related characteristics such as disease resistance, longevity, and heat tolerance. However, advances in genomics and phenomics now offer unprecedented opportunities to integrate welfare traits into breeding programs more effectively. As animal welfare is a multifactorial concept based on biological functioning, natural behavior, and affective states, there is a need for large-scale phenotyping of multiple indicator variables on a longitudinal basis. Recent developments in precision phenotyping, facilitated by automated sensors, imaging technologies, and machine learning, provide detailed, real-time data on key welfare indicators. In general, welfare traits in dairy cattle populations are heritable and, therefore, can be improved through direct genetic selection. The integration of genomics and phenomics allows for the development of genomic selection indexes that incorporate welfare traits without compromising productive efficiency. Genetic correlations between welfare-related and production traits must be carefully managed to avoid antagonistic selection responses. Furthermore, leveraging big data from commercial herds and integrating multi-omics approaches can enhance the predictive accuracy of genomic selection models. Furthermore, accounting for genotype-by-environment interactions in breeding and management decisions is crucial for improving dairy cattle welfare. In this context, the primary objectives of this talk are to discuss opportunities for integrating large-scale phenotypic and genomic data to improve dairy cattle welfare. More specifically, I will present examples of novel welfare and resilience traits that can be derived from precision technologies, including automated milk feeders, milking robots, and wearable sensors, as well as the genetic background of dairy welfare traits and strategies for incorporating welfare and resilience traits into dairy cattle breeding programs." |
| Joint ADSA-CSAS Breeding and Genetics Symposium | Symposium | CSAS Symposium | 2025/06/24 09:00:00 | t94323 | Watch | 1324 | Improving welfare through inclusive innovation: The story of WELL-E. | 2 | E. Vasseur | inclusive innovation,animal welfare | E. Vasseur1,3, A. Baniré Diallo2,3 | "The welfare of animals managed by humans is integrally tied to, and ultimately dependent on, the welfare of the humans doing the managing. Any sustainable and effective change is thus dependent on collaborative solutions that address the needs of both the animals and people involved. Our approach relies on the use of IoT, computer vision, and machine learning to improve our ability to detect and monitor changes in animal welfare and longevity earlier than possible with visual methods, and to generate predictions to aid on-farm decision-making, ensuring that resources and efforts are focused on the animals most likely to succeed in the long term. Grounded in industry partnerships, members of the dairy community sit on both the scientific and management committees, where they contribute to research orientations, leading to the co-creation of research projects and initiatives. This collaborative approach not only ensures the applicability and relevance of all research but allows for continuous feedback between the research and industry environments, creating a true digital living laboratory. Launched in 2023, our team has been conducting pilot research on 2 farms and working directly with staff and management to co-develop and pilot new practices and techniques for the management of animal welfare, to be disseminated across Canada and beyond. We work toward major paradigm shifts in both research (changing the way animal behavior and complex states are understood through new analytic techniques) and practice (our research informing major changes in the Canadian Dairy Code of Practice), with the goal of providing practical, long-term solutions for the improvement of animal welfare, while simultaneously addressing real-world problems farmers face along the way. Our collaborative approach promotes the responsible integration of new technologies to the dairy industry and empowers producers to be at the forefront of positive welfare developments, ensuring their sustainability and reinforcing the importance of stakeholder participation in innovative scientific research." |
| Joint ADSA-CSAS Breeding and Genetics Symposium | Symposium | CSAS Symposium | 2025/06/24 09:00:00 | t94427 | Watch | 1325 | Exploring the role of nutrient adequacy in dairy cow health and welfare. | 3 | D. E. Rico | nutrient requirements,dairy cow,welfare | D. E. Rico1 | "It is well known that adequate nutrient balance is a key aspect of optimal production performance of animals; however, its role on behavior, wellbeing, and health of animals is less well understood. Indeed, nutrient requirements of animals are often established based on physiological state and productivity levels, but rarely considering the impact of increased needs due to social or environmental stress. Furthermore, critical periods of a cow’s life, such as early lactation, are associated with increased morbidity and reproductive problems, both leading to increased rates of culling. Interestingly, although negative energy balance and ketosis were historically presented at the probable cause of some of these issues, current research suggests an underlying role of inflammation in peripartal health. For instance, a recent study determined that up to two-thirds of cows with clinical ketosis also suffered from endotoxemia, highlighting a potentially central role of inflammatory status in the health and productivity of cows in early lactation. Importantly, some nutrients with anti-inflammatory effects such as vitamin D3 and long-chain omega-3 fatty acids have been linked to overall health status and to the modulation of inflammation. Although these nutrients are already part of dairy cow diets, their supply may be insufficient for periods of stress, such as early lactation or during heat stress. Key questions remain in this regard, as specific nutrient requirements for periods of stress are currently not well defined in dairy cows. This presentation explores the role of nutrients with potential to modulate animal health and well-being, highlighting focus areas for future research." |
| Joint ADSA-CSAS Breeding and Genetics Symposium | Symposium | CSAS Symposium | 2025/06/24 09:00:00 | t95637 | Watch | 1326 | Identifying a sustainable path forward when looking to the future of dairy farming. | 4 | M. A. G. von Keyserlingk | | M. A. G. von Keyserlingk1 | "The current animal welfare challenges facing the dairy industry must be looked at in the context of the sustainability as the issues are increasingly complex and the solutions will not always be solved by a simple technical solution. Although we have addressed some of the “low hanging fruit,” such as preventing tail docking and using pain mitigation when disbudding calves, many management practices that are known to compromise animal welfare are still common on many farms, such as feeding calves insufficient amounts of milk, providing social housing for calves, lack of access to pasture, lameness and transition cow disease among others. The failure to provide cows access to pasture, early life killing of surplus calves and the immediate separation of the calf from the cow at birth are particularly contentious as they fail to resonate with societal values. Moreover, the growing tension between suggested practices that attempt to address mitigate the environmental foot print of dairy farming and animal welfare are gaining traction in public discussions. A global discussion on how to preserve dairy cattle health and welfare is urgently needed, sparking a debate on what constitutes the ideal dairy system that balances animal productivity, animal welfare and the values of all stakeholders including the citizens who the industry relies on to buy dairy products. In shaping future dairy systems, all stakeholders must be given a voice, from farmers and scientists to policymakers and community members, acting as citizens and consumers, as the industry strives for a sustainable model that is environmentally friendly, economically viable, and socially acceptable. Listening to society and integrating their insights into our day-to-day discussions on what it means to be a good dairy farmer is an important step toward ensuring the industry’s continued evolution such that practices on farms align with ethical and ecological goals." |
| Joint ADSA-CSAS Breeding and Genetics Symposium | Symposium | CSAS Symposium | 2025/06/24 09:00:00 | t93630 | Watch | 1327 | Herd Sustainability Index: Using milk recording data to evaluate dairy herd sustainability. | 5 | J. St John | herd sustainability,herd management,milk recording | J. St John1, M. Séguin1, D. Lefebvre1 | "Producing milk sustainably has been linked to dairy cow longevity (i.e., length of productive life), production measures, and animal health. The Herd Sustainability Index can help evaluate and compare herd sustainability indicators in Canada using milk recording data. This index includes 10 parameters, focusing on 4 primary concepts: (1) longevity and culling, (2) production and feeding, (3) replacement heifers, and (4) health. Parameters used to evaluate cow longevity are (1) cows in third or greater lactation, (2) involuntary culling, and (3) cow mortality rate. Parameters used to evaluate production and feeding are: (1) MUN <5 or >18 mg N/dL (%), (2) management score for milk production (evaluation of genetic potential vs. actual ECM), and (3) Transition Cow Index assesses the transition period’s success (actual vs. expected yield in early lactation). Parameters used to evaluate replacement heifer management are: (1) calf mortality rate 0 to 24 h (%), and (2) age at first calving (months). Parameters used to evaluate health are (1) cows with high BHB, an indicator of ketosis status in the herd, and (2) cows with high SCC. A percentile rank (1–99) is assigned to each of these 10 parameters based on dairy farms’ data across Canada, allowing producers to see their rank for each parameter. The Herd Sustainability Index is calculated as the sum of the percentile rank for the 10 parameters, with equal weight, and herds are reclassified into percentile ranks based on the sum. The Herd Sustainability Index can help producers identify areas to improve and track their improvement over time. Additionally, management strategies from top-ranking farms (75–99 percentile) can be assessed to help identify potential best management strategies. For example, top-ranking farms have been linked to using foot baths and hoof trimming at least three time a year. Overall, the Herd Sustainability Index stems from indicators developed using routine milk recording data to assist producers in evaluating their herd sustainability and can help identify good management practices on-farm." |
| Joint ADSA-CSAS Breeding and Genetics Symposium | Symposium | CSAS Symposium | 2025/06/24 09:00:00 | n9337 | Watch | | ADSA Foundation Scholar in Production: Considering dairy calf behavioral needs to improve lifelong welfare | 6 | E. Miller-Cushon | | | |
| Joint Animal Behavior and Well-Being and Forages and Pastures Symposium: Societal and Production Implications of Pasture Access for Dairy Heifers | Symposium | Platform Session Submissions: Joint Animal Behavior and Well Being with Forages and Pastures | 2025/06/23 09:00:00 | t93819 | Watch | 1140 | The alignment of societal expectations for providing outdoor access to dairy cows and their welfare. | 1 | P. D. Krawczel | welfare,society,outdoor | P. D. Krawczel1,2, A. M. K. Sjöholm1,3, T. Kokkonen1,3, I. Herzon1,4, P. J. Rissanen1, A. O. Vanhatalo1,3 | "One aspect of an animal production system maintaining its social license to operate is ensuring production practices align with societal values. The expansion and intensification of dairy production across much of the western world has contributed to the reduction of grazing, or outdoor access in general, for lactating dairy cows. This is contrary to the public image of idyllic dairy cows grazing on green pastures, which is also often used in media or advertising of dairy products. This misalignment of public perception and the current production practices may result in a loss of public trust. However, simply providing increased outdoor access does not necessarily improve animal welfare either as going outdoors under some circumstances is detrimental to welfare. Reduced biological function, generally from increasingly variable diet, is often one of the main welfare issues and reasons for farmers’ hesitancy to incorporate outdoor access as a routine management strategy. Additionally, increased labor needs may limit outdoor access for cows. Therefore, outdoor access presents an interesting challenge within modern dairy production as it is generally expected by the public, but its role in meaningfully improving dairy cow welfare is not necessarily straightforward. The objective of this review is to address public attitudes toward outdoor access for dairy cows, the challenges and opportunities stemming from providing outdoor access to improve welfare, and how to align these factors to maintain public trust in dairy production. To address public perception, this review will compare and contrast the views of the general public and those of farmers to understand where agreement can be found. Furthermore, possible cultural or farm-based explanations will be explored for regional differences in outdoor access/pasture use. Regarding welfare, this review will explore the factors, including quality of transfer lanes, feed preferences, and heat stress, that can positively or negatively affect the welfare of cows while outdoors. Finally, we will investigate how this collectively fits together to promote understanding the alignment between the factors of outdoor access valued by the public, those valued by farmers, and those that contribute to improved dairy cow welfare." |
| Joint Animal Behavior and Well-Being and Forages and Pastures Symposium: Societal and Production Implications of Pasture Access for Dairy Heifers | Symposium | Platform Session Submissions: Joint Animal Behavior and Well Being with Forages and Pastures | 2025/06/23 09:00:00 | t93641 | Watch | 1141 | Pasture versus confinement for dairy heifers: Testing assumptions about well-being based on interpretations of behavior. | 2 | M. B. Hall | well-being,behavior,heifer | M. B. Hall1, D. Jaramillo2, K. F. Kalscheur1, C. H. Paiva Camisa Nova3, A. DiSalvo4 | "Assessment of animal well-being requires identifying attributes related to an animal’s status. Reduced well-being has been associated with increased sterotypy, vocalization, and cortisol levels. Do these assessments of stress agree with each other? The impact of rearing environment on behavior and hair cortisol levels in growing Holstein heifers (Hf) starting at 4.8 mo of age (standard deviation [SD]: 0.05; body weight 166, SD: 1 kg) and continuing over 2 years was studied. The Hf were raised from May to August on rotationally stocked cool-season pastures supplemented with grain and/or a vitamin and mineral mix (PAS) or raised in a barn and fed a total mixed ration (BARN). The Hf were assigned to one of 8 treatment (Trt) groups: 4 PAS and 4 BARN groups. For reasons unrelated to the study, 1 Hf was removed from each Trt. Before the study and outside of pasture season, all Hf were housed in a barn. Yearly, hair samples were obtained in May before pasturing, June, and August; behaviors were recorded by trained observers every 10 min for 12 h during daylight on 1 d each in June and July. Behavior data were converted to episodes per Hf by dividing observations by number of Hf in a group. Data were analyzed as repeated measures in a model with Trt, sampling date, year, and interactions, and with group as a random variable and the experimental unit. Standard errors in italics are not back transformed (Table 1). For cortisol, May data were used as a covariate but not significant (P = 0.20). Stereotypy was greater for BARN than PAS in both years. Vocalization was greater for PAS in Year 1 and associated with feeding time, and for BARN in Year 2. Hair cortisol was greater for PAS in both years. Hair cortisol measures did not agree or consistently agree with stereotypy and vocalization measures. Corroboration of behavioral measures that align with indicators of animal stress is needed. Table 1 (Abstr. 1141). Results of study | Measure | Stereotypyepisodes/heifer | Vocalization episodes/heifer | Hair cortisol, pg/mg | | Barn year 1 | 2.1 | 0.19 | 4.8 | | Pasture year 1 | 0.09 | 0.99 | 15.4 | | Barn year 2 | 3.3 | 0.40 | 4.4 | | Pasture year 2 | 0.01 | 0.27 | 18.9 | | Standard error | 0.12 | 1.05 | 0.0199 | | P: Trt, Trt × Year1 | <0.01, 0.01 | 0.26, 0.01 | <0.01, <0.01 |
1Trt = treatment. " |
| Joint Animal Behavior and Well-Being and Forages and Pastures Symposium: Societal and Production Implications of Pasture Access for Dairy Heifers | Symposium | Platform Session Submissions: Joint Animal Behavior and Well Being with Forages and Pastures | 2025/06/23 09:00:00 | t94355 | Watch | 1142 | Mitigating heat stress on pasture. | 3 | C. B. Tucker | heat stress,cattle,shade | C. B. Tucker1, K. E. Schütz2 | "Heat stress in dairy cattle influences efficiency, animal welfare, and sustainability. Strategies to reduce heat load will depend on breed, location, housing and production levels. On pasture, a consistent and cost-efficient way to mitigate heat stress is to provide natural or man-made shade. We will review the scientific evidence about how motivated cattle are to access shade. We will discuss how the quality and availability of shade influences use and effectiveness. Proximity of shade to other resources, such as drinking water, are also important considerations. Indeed, access to water also plays a role in mitigating heat stress. Water quality and availability are important considerations in all housing and we will discuss the specific implications on pasture (e.g., grouping around the trough preventing access; challenges of proving functional water sources in daily rotational grazing systems). In addition to shade and water provision, other possible management tools for nonlactating cattle include shifting the time of feeding in rotational grazing systems to reduce heat load. Last, we will discuss when heat mitigation is needed and methods to assess if the strategies employed are effective. We will cover both environmental-related metrics including those that aggregate relevant weather conditions (e.g., temperature, wind, solar radiation, humidity) and animal-based outcomes (e.g., respiration rate, drool, panting). Our review will highlight the existing scientific knowledge about mitigating heat stress in cattle on pasture and where further research is needed." |
| Joint Animal Behavior and Well-Being and Forages and Pastures Symposium: Societal and Production Implications of Pasture Access for Dairy Heifers | Symposium | Platform Session Submissions: Joint Animal Behavior and Well Being with Forages and Pastures | 2025/06/23 09:00:00 | t94372 | Watch | 1143 | Impact of pasture versus confinement rearing on dairy heifer growth and transition period. | 4 | C. H. P. Camisa Nova | heifer development,performance,grazing | C. H. P. Camisa Nova1, D. M. Jaramillo2, M. S. Akins2, K. F. Kalscheur3 | "The goal of raising dairy heifers is optimal growth to calve by 22–24 mo of age while minimizing costs. This study evaluated the effects of raising dairy heifers on pasture (PAST) compared with confinement (CONF) on growth as a heifer, and intake during the transition period. Sixty-two Holstein heifers (5.2 ± 0.45 mo old) were raised under 2 practices: (1) 31 heifers (3 pastures of 8 and 1 pasture of 7 heifers) were rotationally stocked on legume-grass mixed pastures for 5 mo during 2 grazing seasons, and (2) 31 heifers (3 pens of 8 and 1 pen of 7 heifers) were housed and fed grass- and corn silage–based TMR diets. Diets were formulated for heifer growth to reach 94% of mature weight at first calving. Body weight (BW), hip height (HH), withers height (WH), heart girth (HG), body length (BL), and hip width (HW) were taken through the 2 years of the trial. A logistic growth curve {Y = A/1 + exp[−B (t−C)]} was set for each variable and parameters of the model statistically compared between the treatments. During the transition period, BW and body condition score (BCS) were assessed from −21 through 21 d relative to calving (23 ± 0.8 mo old). Dry matter intake (DMI; % BW) was recorded before calving (wk −4 to −1 relative to calving), and data were calculated as percentage of BW for 21 d after calving. There were no differences between treatments for parameters in the logistic growth model for BW, WH, HG, BL, and HW (P > 0.05). For HH, the parameters A (PAST: 144.4 vs. CONF: 141.1 cm, P = 0.032) and B (PAST: 0.1306 vs. CONF: 0.1646 cm, P = 0.044) differed between treatments. This difference may be attributed to the fact that the animal groups were balanced only based on BW, but the groups were similar for HH before calving. During the transition period, BW was similar between the groups (PAST: 625 vs. CONF: 640 kg, P = 0.15) whereas BCS was affected by treatment during the transition period (PAST: 3.34 vs. CONF: 3.47, P = 0.006). For DMI, PAST had greater intake than CONF (2.11 vs. 1.95% BW/d, P = 0.002). Thus, grazing dairy heifers can achieve similar growth at transition as confined heifers, while exhibiting increased DMI before calving." |
| Joint Animal Behavior and Well-Being and Forages and Pastures Symposium: Societal and Production Implications of Pasture Access for Dairy Heifers | Symposium | Platform Session Submissions: Joint Animal Behavior and Well Being with Forages and Pastures | 2025/06/23 09:00:00 | t93402 | Watch | 1144 | Plasma folate and vitamin B12 concentrations of heifers raised indoors or on pasture. | 5 | M. Duplessis | cattle,grazing,cyanocobalamin | M. Duplessis1, M. B. Hall2, D. M. Jaramillo2, K. F. Kalscheur3, C. H. Paiva Camisa Nova4 | "Folates (B9) and vitamin B12 (B12) are involved in protein and energy metabolism. Our objective was to evaluate plasma B9 and B12 concentrations of Holstein heifers raised on pasture and rotationally stocked on cool-season pastures and supplemented with grain with a vitamin and mineral mix (PAS) or raised in a barn and fed a total mixed ration (BARN). Before the start of the study, all heifers were housed in a barn. Heifers (n = 64) weighing 166 [standard deviation (SD): 1] kg were assigned to one of 8 groups at 4.8 (SD: 0.5) months: 4 PAS and 4 BARN groups. A PAS heifer died due to cause unrelated to the study. Plasma samples were collected by caudal venipuncture in May before treatments began (covariate) and in July, 2 mo after treatments began. Plasma B9 and B12 were analyzed by chemiluminescence. The PROC MIXED of SAS was used to separately analyze plasma B9 in May and July with treatment as fixed effect. For July, plasma B9 in May was a covariate. As some samples were below the detection limit of 150 pg/mL for B12, the proportion of samples below the detection limit was analyzed using PROC GLIMMIX of SAS (chi-squared test) with treatments as fixed effect, separately for May and July. Group was the experimental unit. Values are expressed as least squares means ± standard error. In May, plasma B9 averaged 7.19 ± 0.25 ng/mL and did not differ between treatments (P = 0.39). In July, plasma B9 tended to be higher with PAS (7.29 ± 0.24 ng/mL) than BARN (6.59 ± 0.24 ng/mL; P = 0.10). The proportion of heifers with plasma B12 below the detection limit averaged 75 ± 8% in May with no difference between treatments (P = 0.63). In July, the proportion of animals below the B12 detection limit was greater for PAS (63 ± 9%) than for BARN (35 ± 9%; P = 0.03), suggesting that overall plasma B12 for PAS heifers was lower than for BARN. In conclusion, although dry matter intake was not evaluated, our results suggested that the diets plus environment affected plasma B9 and B12 statuses of Holstein heifers. More research should be conducted to confirm these results and evaluate if they have a practical implication." |
| Joint Animal Behavior and Well-Being and Forages and Pastures Symposium: Societal and Production Implications of Pasture Access for Dairy Heifers | Symposium | Breeding and Genetics | 2025/06/23 09:00:00 | t93977 | Watch | 1145 | Milk fatty acids of Holstein cows compared with Holstein, Jersey, Montbéliarde, Normande, and Viking Red crossbred cows in an organic grazing and low-input conventional research dairy herd. | 6 | K. M. Bosley | milk fatty acid,crossbreeding,organic | K. M. Bosley1, L. B. Hansen1, B. J. Heins1 | "There is growing consumer interest in milk with perceived health benefit from fatty acids (FA), which may open marketing opportunities for producers. The objective of the study was to compare milk FA between Holstein (HO; n = 166) and crossbred dairy cattle composed of Montbéliarde (MO), Viking Red (VR), and HO breeds (MVH; n = 516) and Normande (NO), Jersey (JE), and Viking Red (VR) breeds (NJV; n = 233) at the University of Minnesota West Central Research and Outreach Center (WCROC; Morris, MN) low-input and organic dairy herds. Total, de novo, mixed, preformed, and individual FA were from monthly milk samples from Minnesota DHIA (Buffalo, MN) and data were from February 2021 to June 2024. Test date observations were used to fit Legendre polynomial random regression lactation curves to compare 305-d FA. Primiparous and multiparous lactation curves were evaluated separately. Each cow and lactation was required to have 3 test dates. For statistical analysis, fixed effects were breed group, sire breed within breed group, lactation number (first, second, or third and greater), herd (low-input or organic), calving season (spring or fall) nested within herd, test-date month, and the interactions of lactation and breed group, herd and lactation, test-date month and herd, and lactation and test-day month. Random effects were cow nested within breed group and herd and days in milk at test day. The organic herd had higher (P < 0.05) preformed (37.8 vs. 35.3 g/100 g total FA), 18:0 (11.4 vs. 10.6 g/100 g total FA), and 18:1 cis-9 (20.6 vs. 19.6 g/100 g total FA) FA than the low-input herd. Both crossbred (MVH and NJV) groups had higher (P < 0.05) de novo (25.9 and 26.0 vs. 25.4 g/100 g total FA) FA and lower 16:0 (35.2 and 34.7 vs. 35.6 g/100 g total FA) FA than HO. Phenotypic correlations between 305-d FA and average SCS, days open, and survival did not indicate negative impacts of selection for improved FA production. Crossbreeding along with pasture feeding of cows may improve milk FA for potential niche markets." |
| Joint Reproduction and Physiology and Endocrinology Symposium: Physiological Insights into Ovarian Follicle Development—Laying the Foundation for Enhanced Fertility | Symposium | Physiology and Endocrinology | 2025/06/25 13:30:00 | t95555 | Watch | 1607 | The role of the preovulatory follicle in oocyte metabolism and competence for embryo development in cattle. | 1 | S. E. Moorey | follicle-oocyte metabolism,oocyte competence,preovulatory follicle | S. E. Moorey1 | "Oocyte competence for embryo development is greatly influenced by its surrounding microenvironment during oocyte maturation. The physiologically mature preovulatory follicle is the normal, and presumably ideal, microenvironment of the maturing oocyte. Our overarching hypothesis is that the intrafollicular milieu of physiologically mature preovulatory follicles provides the necessary microenvironment to metabolically program oocytes for successful embryo development. Studies by our team have demonstrated that the follicular fluid metabolite milieu differs between preovulatory follicles of greater and lesser maturity and that such differences have direct effects on the oocyte. Numerous follicular fluid metabolites involved in glucose and amino acid metabolism were more abundant in preovulatory follicles of greater versus lesser physiological maturity. Additionally, abundance of transcripts encoding glycolytic enzymes was higher in cumulus cells from follicles of greater maturity, and both ATP and levels of key transcripts in the mitochondrial respiratory chain were higher in oocytes from preovulatory follicles of greater versus lesser maturity. We supplemented in vitro maturing oocytes with follicular fluid from preovulatory follicles of greater or lesser maturity to determine causality of differing follicular fluid milieu on cumulus-oocyte metabolism and oocyte competence for early embryo development. Follicle maturity status had robust effects on cumulus-oocyte complex consumption or production of key metabolites in glucose, purine, and amino acid metabolism pathways during oocyte maturation. We also observed hastened development rate in embryos arising from in vitro-matured oocytes supplemented with lesser-maturity follicular fluid. Furthermore, RNA sequencing of resulting blastocysts suggested more efficient metabolism and Wnt/β-catenin signaling in blastocysts from oocytes matured in preovulatory follicular fluid from greater-maturity follicles. In contrast, transcriptome profiles of blastocysts from oocytes matured in preovulatory follicular fluid from lesser-maturity follicles indicated oxidative stress and dysregulated cell division. These recent findings by our laboratory indicate effects of follicle maturity, and the resulting follicular fluid microenvironment, on the maturing oocyte, which persist throughout early embryo development and hold promise for improving reproductive efficiency in cattle." |
| Joint Reproduction and Physiology and Endocrinology Symposium: Physiological Insights into Ovarian Follicle Development—Laying the Foundation for Enhanced Fertility | Symposium | Reproduction | 2025/06/25 13:30:00 | t93717 | Watch | 1608 | Effect of subclinical ketosis on ovarian functions in dairy cows. | 2 | N. Neeraj | dairy cow,ovarian activity,subclinical ketosis | N. Neeraj1, N. Sun1, R. Duggavathi1 | "Subclinical ketosis (SCK) is a major metabolic disorder in dairy cows. Multiple large-scale studies have reported an association between SCK during early lactation (1–6 wk after calving) and poor reproductive performance during the subsequent breeding period (9–15 wk postcalving). However, the mechanisms of how SCK influences fertility, specifically ovarian functions, are not fully understood. The objective of this study was to evaluate the association between SCK and ovarian functions. We monitored 50 lactating Holstein cows (11 primiparous and 39 multiparous) for SCK during the first 42 d in milk (DIM) using thrice-weekly blood sampling and cow-side blood BHBA testing. The cows were grouped as Healthy (n = 25 cows) with blood BHBA <1.2 mmol/L during 5–42 DIM. The SCK cows (BHBA 1.2–2.9 mmol/L) were grouped as Early SCK (n = 10 cows) and Late SCK (n = 15 cows) if a positive ketosis test occurred during 5–15 and 16–42 DIM, respectively. From 43 DIM onward, daily ultrasonographic examination of the ovarian dynamics and blood sampling were performed for 1 interovulatory period. All statistical analyses were performed using SAS 9.4 (SAS Institute Inc.). Follicular and luteal data were analyzed using one-way ANOVA, PROC MIXED was used to analyze serum glucose and progesterone, and differences between means were evaluated using Tukey’s multiple comparison test. Serum glucose concentrations during the first 42 DIM revealed that Healthy cows had greater (P < 0.0001) mean glucose concentration (2.9 ± 0.1 mmol/L) than Early and Late SCK cows (2.3 ± 0.2 and 2.6 ± 0.1 mmol/L, respectively). Examination of the ultrasound data revealed that the number of follicles at the emergence of the first follicular wave was greater (P < 0.001) in Healthy cows (14.1 ± 0.4) than in Early and Late SCK cows (11 ± 0.5 and 11.7 ± 0.5, respectively). Although the mean largest corpus luteum diameter and peak progesterone concentrations were similar among cow groups, Healthy cows had higher mean serum progesterone concentrations during the first 15 d of the estrus cycle than Early and Late SCK cows (P < 0.05). These data demonstrate a negative association between SCK within 42 DIM and ovarian (follicular and luteal) functions during the subsequent estrous cycle. This is the first study reporting the apparent knock-on effects of SCK on ovarian functions. Hence, frequent monitoring of dairy herds during the first 6 wk of lactation is necessary to optimize reproductive performance, resulting in sustainable dairy production." |
| Joint Reproduction and Physiology and Endocrinology Symposium: Physiological Insights into Ovarian Follicle Development—Laying the Foundation for Enhanced Fertility | Symposium | Reproduction | 2025/06/25 13:30:00 | t94204 | Watch | 1609 | Antral follicle count and dominant follicle size in dairy cattle. | 3 | K. J. Alward | dairy,follicle,antral follicle count (AFC) | K. J. Alward1, A. B. Pollock2, A. D. Ealy2 | "Antral follicle count (AFC) in cattle has been widely used as a marker of response to superovulation protocols and has been positively linked with embryo production in vitro. Dominant follicle (DF) size at the time of ovulation has also been linked to fertility, with cows that ovulate smaller follicles having reduced conception rates. We hypothesized that DF size and follicular fluid (FF) volume are reduced for low-AFC cattle, which may explain differences in fertility and embryo viability. The AFC for a herd of nonsynchronized lactating Holstein cattle (n = 85) was determined via transrectal ultrasonography (TRUS) by a single operator. Cows in the top 25% (30 ± 2 follicles) were classified as high AFC, and cows in the bottom 25% (13 ± 0 follicles) were classified as low AFC. High-AFC (n = 5) and low-AFC (n = 6) cows were balanced by parity and subjected to a presynchronization protocol (GnRH d 0, PGF2α d 7, GnRH d 10) followed by a synchronization protocol (GnRH d 17, PGF2α d 24 and 25, GnRH 32 h later) and DF measurement and FF collection 16 h later on d 27. Cows were subjected to a second synchronization, which began on d 37 (GnRH d 37, PGF2α d 44 and 45, GnRH 32 h later) and DF measurement and FF collection 16 h later on d 47. Follicle size was determined via TRUS, and collection of DF FF was completed via ultrasound-guided transvaginal aspiration. All cows received an epidural nerve block with lidocaine. The perineum was sanitized, and an ultrasound-guided transvaginal aspiration device equipped with a 21-gauge spinal needle and sterile plastic tubing for FF collection was inserted into the vagina. The needle was advanced through the vaginal wall into the DF antrum, and fluid was aspirated into a 5-mL syringe and measured. Data were analyzed with PROC GLM of SAS 9.4 for follicle area and FF volume, with AFC classification as the main effect and collection time as the repeated measure. Recovery of DF FF was 100% for both groups. Neither follicle area (low = 358 ± 69 mm2; high = 235 ± 35 mm2) nor FF volume (low = 2.88 ± 0.66 mL; high = 2.52 ± 0.61 mL) differed by AFC classification (P = 0.15; P = 0.70). We expected to find lower DF size in low-AFC cows as a linkage to reduced fertility outcomes in these animals; however, this indicates that other factors influence fertility outcomes in low-AFC cattle beyond DF size. Future research will increase animal numbers and evaluate hormone concentrations of FF to investigate differences in fertility." |
| Joint Reproduction and Physiology and Endocrinology Symposium: Physiological Insights into Ovarian Follicle Development—Laying the Foundation for Enhanced Fertility | Symposium | Reproduction | 2025/06/25 13:30:00 | t93821 | Watch | 1610 | Risk factors for anovulation in Holstein cows. | 4 | L. Campora | endometritis,lameness,cyclicity | L. Campora1, E. Morrison1, E. Ribeiro1, R. Couto Serrenho1, S. J. LeBlanc1 | "This longitudinal study investigated cow-level risk factors for anovulation to the start of the breeding period. Holstein cows (n = 2,975; 114 ± 8 cows/herd) from 26 herds in Ontario using automated activity monitors as a primary tool for insemination were enrolled. Body condition score (5-point scale) change (ΔBCS) between wk 1 and 8 was categorized into ≤−0.5, −0.25, or ≥0. Metritis was assessed weekly by researchers. Purulent vaginal discharge (PVD; >50% pus) was diagnosed at wk 4, 6, and 8, and endometritis (ENDO; >5% PMN in uterine cytology) was diagnosed at wk 4, forming a 4-level variable based on combinations of PVD at any time and ENDO. Lameness (LAME) was identified in cows with locomotion score ≥3/5 at wk 8. Serum progesterone <1 ng/mL at all of wk 4, 6, and 8 identified anovular (ANOV) cows. A multivariable logistic regression model of ANOV with the explanatory variables above as fixed effects and herd as a random effect was built in R, retaining variables with P ≤ 0.05. Reporting LSM (95% CI), we found that 12% (10%–14%) of cows were ANOV to wk 8. Parity, uterine health, ΔBCS, and lameness were associated with ANOV. Younger cows were more likely to be ANOV using parity 2 as the referent: parity 1 (14.8%; 12%–18.1%), parity 2 (9.6% (7.4%–12.5%); parity 3 (10.8%; 8.7%–13.3%). Metritis was not associated with ANOV. Endometritis, but not PVD alone, was associated with greater prevalence of ANOV than in healthy cows: neither PVD nor ENDO (44% of cows) 9% ANOV (8%–12%); PVD only (16% of cows) 11% ANOV (8%–15%); ENDO only (19% of cows) 14% ANOV (11%–18%); both PVD and ENDO (21% of cows) 16% ANOV (12%–20%). Accounting for the other variables, cows with ΔBCS ≤−0.5 (43% of cows) were more likely to be ANOV (13%; 11%–16%) than cows with ΔBCS −0.25 (37% of cows) (10%; 8%–13%); there was no difference in the 20% of cows with ΔBCS ≥0 (11%; 9%–15%) versus ΔBCS −0.25. Lame cows at wk 8 (6% of cows) were more likely to be ANOV (22%; 15%–24%) than non-lame (11%; 9%–13%). These findings highlight several factors associated with ANOV. Considering ΔBCS without health variables or PVD without ENDO may bias their associations with ANOV." |
| Joint Reproduction and Physiology and Endocrinology Symposium: Physiological Insights into Ovarian Follicle Development—Laying the Foundation for Enhanced Fertility | Symposium | Reproduction | 2025/06/25 13:30:00 | t95438 | Watch | 1611 | Effect of dosage, and interval between equine chorionic gonadotropin administration and ovum pickup on the follicular population, recovery, quality, and in vitro developmental competence of oocytes in Sahiwal cattle. | 5 | M. A. Afzal | ovum pickup (OPU),equine chorionic gonadotropin (eCG),Sahiwal cattle | M. A. Afzal1,2, J. Ali2, M. Saleem3, M. Nawaz4, A. Riaz2 | "This study aimed to optimize the dose of equine chorionic gonadotropin (eCG) and interval between eCG administration and ovum pickup (OPU), and to evaluate the carryover effect of a single eCG dose on subsequent OPU in terms of follicular population, recovery, quality, and in vitro developmental competence of oocytes in Sahiwal cattle. In experiment 1, cattle (n = 28) were divided into 4 groups (n = 7): 0 IU eCG (control), 250 IU eCG, 500 IU eCG, and 750 IU eCG. In experiment 2, cattle (n = 18) received 500 IU eCG and were assigned to 3 groups (n = 6) based on the interval between eCG injection and OPU: 48 h, 60 h, and 72 h. In experiment 3, cattle (n = 6) received 500 IU eCG and underwent 3 OPU every 60 h to assess carryover effect. All cattle were presynchronized with 2 doses of 0.150 mg D-cloprostenol 11 d apart. At 48 h after the second dose, dominant follicle ablation was performed, along with insertion of an intravaginal progesterone device (CIDR). Dosage of eCG was administered 2 d later. On the day of OPU, CIDR were removed and follicles aspirated using ultrasound-guided transvaginal OPU technique. Data were analyzed using SAS proc. GLIMMIX. In experiment 1, medium-sized follicle numbers and oocyte recovery were higher (P < 0.05) in 500 IU (2.57 ± 0.31; 7.28 ± 0.50) and 750 IU (2.28 ± 0.30; 6.00 ± 0.51) groups than in 250 IU (1.28 ± 0.31; 5.00 ± 0.52) and control (0.57 ± 0.29; 4.85 ± 0.52) groups. However, 500 IU was optimal (P < 0.05), as 750 IU did not improve oocyte quality (P > 0.05). In experiment 2, the proportion of medium follicles was higher in the 60-h (32.00 ± 0.72) and 72-h (30.00 ± 0.64) groups (P < 0.05) than in the 48-h group (14.04 ± 0.58). Grade AB and ABC oocytes were higher in the 60-h group (47.61 ± 1.75; 76.19 ± 2.05) than in the 48-h (26.08 ± 1.16; 52.17 ± 1.58) and 72-h (25.00 ± 0.78; 50.00 ± 1.20) groups (P < 0.05). However, in vitro developmental competence was unaffected (P > 0.05) by the interval between eCG and OPU. In experiment 3, a sharp decline (P < 0.05) in follicular population and oocyte quality was observed after the first OPU, indicating no carryover effect of eCG. In conclusion, 500 IU eCG with a 60-h interval before OPU was most effective for ovarian stimulation in Sahiwal cattle, but a single dose was insufficient for repeated OPU." |
| Joint Reproduction and Physiology and Endocrinology Symposium: Physiological Insights into Ovarian Follicle Development—Laying the Foundation for Enhanced Fertility | Symposium | Physiology and Endocrinology | 2025/06/25 13:30:00 | t95619 | Watch | 1612 | Novel mechanisms conferring resistance to regression during luteal development and pregnancy. | 6 | C. H. K. Hughes | corpus luteum,prostaglandin F2α,luteolysis | C. H. K. Hughes1 | "Fertility in the dairy cow is dependent on normal function of the corpus luteum (CL). The CL is a transient endocrine gland that forms following ovulation and produces the progesterone essential to pregnancy maintenance. In the absence of a pregnancy, the CL regresses in response to uterine prostaglandin (PG)F2α, allowing for another ovulation. Interestingly, before d 5 of the bovine estrous cycle, the CL fails to regress in response to PGF2α, whereas after d 5, CL regress when exposed to PGF2α. To evaluate global physiological changes in CL of differing capacity to regress in response to PGF2α, we compared the transcriptome and proteome of CL collected on d 4 and 6 of the estrous cycle. We identified proteins associated with apoptosis and cell death that increased on d 6, whereas a miRNA that targets these proteins, miR-125b-5p, was increased on d 4. Luteal cells were transfected with this miRNA, resulting in resistance to cytokine-induced cell death in culture. In summary, changes in protein expression and alteration of miRNA-mediated repression between d 4 and 6 may make the CL more susceptible to PGF2α-induced cell death. Similarly to changes observed in developing CL, in early pregnancy, there are mechanisms of altered luteal PGF2α responsiveness, but the regulation of these mechanisms is poorly understood. Interferon tau (IFNT) is the primary maternal recognition of pregnancy signal in the cow. During the time of IFNT secretion, the CL of pregnancy is transiently more resistant to the actions of PGF2α than the CL of the cycle. To evaluate the effects of IFNT on luteal function, we infused IFNT into uteri of nonbred heifers 2× per day for 3 d (d 14–17 of the cycle). The CL were collected and RNaseq was performed. Relative to controls, IFNT resulted in changes to mRNA involved in interferon signaling and antiviral response. Interestingly, among these genes were 3 poly(ADP-ribose) polymerase (PARP), PARP9, 12, and 14, which promote DNA damage response and cell survival. In summary, these studies have identified novel candidate genes that could be targeted to develop technology to support fertility in dairy cattle. This project was supported by USDA Agriculture and Food Research Initiative Predoctoral Fellowship no. 2017-67011-26062 to CHKH, Competitive Grant no. 2012-67015-30212 to JLP, and Penn State Department of Animal Science startup funds to CHKH." |
| Milk Protein and Enzymes Symposium: Value-Added Dairy Powders with Specialized Functionality | Symposium | Dairy Foods - MPE Symposium | 2025/06/24 13:30:00 | | Watch | | Panel | | | | | |
| Lactation Biology Symposium: How the Mammary Milieu Affects Udder and Neonatal Health: From Microbes to Antibodies | Symposium | Lactation Biology | 2025/06/23 09:00:00 | n9359 | Watch | | Introduction to Lactation Biology Symposium | 1 | Tom McFadden | | | |
| Lactation Biology Symposium: How the Mammary Milieu Affects Udder and Neonatal Health: From Microbes to Antibodies | Symposium | Lactation Biology | 2025/06/23 09:00:00 | t95655 | Watch | 1255 | Revisiting the potential of protective intramammary infections in dairy cattle. | 2 | P. R. F. Adkins | mastitis,bacteria,heifer | P. R. F. Adkins1 | "An intramammary infection (IMI) is defined as the presence of an infectious organism in the mammary gland. In general, IMI negatively impact both milk quality and quantity and therefore result in major economic loss to the dairy industry. The National Mastitis Council’s mastitis control plan was developed to improve milk quality by reducing IMI associated with contagious and environmental organisms. While it is best practice to work to reduce the prevalence of all IMI, some minor mastitis pathogens have been found to have minimal negative impacts on both somatic cell count and milk yield. Furthermore, beyond a lack of negative effects, some minor mastitis pathogens may provide protection for the gland. For example, previous research has identified that when quarters were infected with minor pathogens, such as Corynebacterium species, infections with major pathogens were significantly lower than in comparable control quarters not infected with minor pathogens. Additionally, others have previously identified that when quarters were infected with Staphylococcus chromogenes, fewer quarters that were challenged by infusion of Staphylococcus aureus became infected compared with uninfected quarters that were similarly challenged with S. aureus. These protective effects may extend beyond the gland, as teat end colonization with S. chromogenes has been associated with a low somatic cell count in early lactation. Possible protective mechanisms of these organisms include bacteriocin production and competitive exclusion. Bacteriocins are bactericidal peptides produced by bacteria to inhibit the growth of similar or closely related bacterial species. Whole-genome sequencing has identified that approximately 20% of non-aureus staphylococcal species have the potential to produce bacteriocins. Further research working to elucidate the protective mechanisms provided by these bacterial species could result in novel mastitis control and prevention strategies." |
| Lactation Biology Symposium: How the Mammary Milieu Affects Udder and Neonatal Health: From Microbes to Antibodies | Symposium | Lactation Biology | 2025/06/23 09:00:00 | t95647 | Watch | 1256 | Mastitis and the milk microbiome: Challenging old assumptions, embracing new insights. | 3 | J. A. Ferronatto | mammary microbiome,mastitis | J. A. Ferronatto1 | "The study of microbial communities has advanced significantly through improved culture-independent molecular techniques, which have revealed the complex roles microorganisms play in both promoting health and causing disease. The bovine mammary gland has historically been considered sterile, with intramammary infections caused by entry of pathogens via the teat canal. This belief is supported by the effectiveness of mastitis control measures, aimed at preventing pathogen entry. But, recent microbiome studies challenge this paradigm, suggesting that the udder may harbor its own microbiota, potentially transforming mastitis into a condition associated with dysbiosis rather than infection. Despite this evidence, the assertion of a stable and functional mammary microbiota is complicated by the inherent risk of contamination in low-biomass samples; minimal external DNA can significantly distort microbiome analyses. Also, the absence of standardized protocols hinders data reproducibility and comparability. Furthermore, there is currently no strong evidence for the existence of an entero-mammary pathway in cows, a mechanism that facilitates immune cell migration and microbial translocation from the gut to the mammary gland in other species. Nonetheless, it has been proposed that the mammary gland could become colonized at or around the time of the first lactation; opening of the teat canal could allow bacterial translocation from environmental or skin-associated microbiota. Thus, early microbial colonization might influence mastitis incidence throughout a cow’s productive life. However, there is currently no strong evidence that calves are born with a pre-established mammary microbiota, as seen in other mucosal sites. If a mammary microbiota is proven to exist, it would prompt reevaluation of mastitis prevention strategies, which have focused on lactating cows, to consider the role of early-life colonization and its long-term effects on udder health. In conclusion, while the hypothesis of a bovine mammary microbiota remains controversial, emerging molecular evidence and new approaches to mastitis control present an exciting opportunity for further research." |
| Lactation Biology Symposium: How the Mammary Milieu Affects Udder and Neonatal Health: From Microbes to Antibodies | Symposium | Lactation Biology | 2025/06/23 09:00:00 | t95663 | Watch | 1257 | Mucosal immunity and antibody trafficking in the dairy cow mammary gland. | 4 | S. Langel | immunoglobulin,mastitis,colostrum | S. Langel1 | "Antibodies are vital components of the adaptive immune system and are transferred passively from mother to offspring via breast milk across all mammalian species, providing critical protection during early life. Milk contains multiple immunoglobulin isotypes—including IgG, IgA, and IgM—in species-specific proportions. Among these, IgA predominates at mucosal surfaces and plays a key role in targeting both pathogenic microbes and commensal organisms in the neonatal gut. Evidence from several species, including rodents and swine, indicates that IgA-secreting plasma cells can migrate from the intestinal mucosa to the lactating mammary gland via the gut–mammary axis, facilitating the secretion of mucosal IgA into milk. Recent findings from our group also support the existence of an intranasal–mammary axis, in which IgA-secreting cells originate in the nasal mucosa traffic to the mammary gland and contribute to the IgA pool in colostrum and milk. In this talk, I will explore the evidence for the gut–mammary antibody axis in dairy cattle and compare it to what is known in other species. I will also discuss its implications for protecting against intramammary infections in heifers and cows, as well as enteric pathogens in calves. Understanding the origins of antibodies in bovine colostrum and milk will be critical for developing therapeutic strategies aimed at boosting protective antibody levels before calving, with the goal of enhancing disease resistance in both the dam and her offspring." |
| Lactation Biology Symposium: How the Mammary Milieu Affects Udder and Neonatal Health: From Microbes to Antibodies | Symposium | Lactation Biology | 2025/06/23 09:00:00 | n9317 | Watch | | Panel discussion - Lactation Biology Symposium | 6 | | | | |
| Milk Protein and Enzymes Symposium: Value-Added Dairy Powders with Specialized Functionality | Symposium | Dairy Foods - MPE Symposium | 2025/06/24 13:30:00 | s11153 | Watch | | Opportunities for Specialized Dairy Powders | | Annie Bienvenue | | | |
| Milk Protein and Enzymes Symposium: Value-Added Dairy Powders with Specialized Functionality | Symposium | Dairy Foods - MPE Symposium | 2025/06/24 13:30:00 | t93782 | Watch | 1429 | Caseinates: From bucket chemistry to specialized nutrition. | 1 | T. Huppertz | milk protein,caseinate,functionality | T. Huppertz1,2 | "In milk, casein is primarily found in the form of casein micelles. However, in the manufacture of caseinates, the micellar structure is disrupted during the acidification and washing process, which removed the micellar calcium phosphate. On neutralization, casein particles are formed, the size, hydration, and other properties depend strongly on the degree of neutralization and the specific cations of the alkali used therefore. Caseinates of monovalent cations, such as Na or K, consist of defined hetero-oligomers of 10 to 12 caseins. Such particles have excellent heat stability and contribute primarily to viscosity by their nonspherical, elongated shape and water-binding. Caseinates of divalent cations, such are Ca, also contain such casein hetero-oligomers, but next to that also aggregates thereof. Viscosity is lower than for sodium caseinate due to reduced water-binding as a result of Ca-binding by caseins and less elongated shapes. Calcium-binding, and the concomitant charge neutralization, can also affect heat stability of caseinates. Overall, salts are critical in determining the properties of caseinates and are not only determined by the type and level of alkali, but also by residual salts in the washed acid-casein curd. These are primarily residual counterions of caseins and strongly determined by both the type of acid used for the acid-induced precipitation of the caseins as well as the pH at which precipitation is carried out. Although initial uses of caseins were often in nonfood applications, such as glues and paints, and later made an entry into basic foods for their water-binding properties and emulsification properties, they have since emerged as critical ingredients in many nutritional products, including medical nutrition products and protein bars. In medical nutrition, particularly Ca-caseinates play a critical role by providing a low-viscous, heat-stable protein sources with a complete amino acid composition that can also be used in conjunction with other protein sources. In protein bars, careful moderation of protein interactions via protein charge is critical to ensure optimal texture formation." |
| Milk Protein and Enzymes Symposium: Value-Added Dairy Powders with Specialized Functionality | Symposium | Dairy Foods - MPE Symposium | 2025/06/24 13:30:00 | t94753 | Watch | 1430 | Multilength scale evaluation of dairy powders, reconstitution, and characteristics of recombined gel structures. | 2 | K. G. Malmos | | K. G. Malmos1, T. V. Sønderby1, A. Afrough3, P. Koch2, P. Andersen2, X. Qi3, C. Gaiani4, T. Vosegaard2, S. Bakalis3, M. Corredig5 | "The spray-drying process is pivotal in the production of dairy powders, designed to remove water while preserving product integrity. We assess the reversibility of water removal by comparing processability of liquid feeds and their respective powders. Although the dehydration process itself is reversible, predrying modifications such as diafiltration induce significant changes in the mineral content. We utilized 31P SS-NMR as a novel approach to probe the dynamics of phosphorus containing casein components indicating diafiltered caseins to have increased mobility. These predrying interventions lead to modifications that persist through drying and impact the final product characteristics. Additionally, we investigated the crystallization behavior of lactose during the shelf life of dairy powders. Our findings indicate that lactose can migrate to the surface, forming crystalline structures that adversely affect the dissolution rate of the powder. We show that incomplete dissolution of powder ingredients results in poor product characteristics (i.e., water retention and brittleness) of acidified gels, whereas the slower process of mineral equilibration between serum and micellar state has limited effect on gel characteristics. This research underscores the importance of understanding predrying modifications, reconstitution state and modifications during storage to optimize the quality and functionality of spray-dried dairy products used for recombined products." |
| Milk Protein and Enzymes Symposium: Value-Added Dairy Powders with Specialized Functionality | Symposium | Dairy Foods - MPE Symposium | 2025/06/24 13:30:00 | t95024 | Watch | 1431 | Understanding the functional performance of milk powders. | 3 | J. C. Brain | milk powder,reconstitution,performance,mechanistic understanding | J. C. Brain1 | "Reconstitution performance is a key feature of many dairy powders from commodity milk powders through to high-value protein powders. Test methods that measure aspects of powder reconstitution often lack the granularity required to drive process improvement and are often designed to replicate the conditions present in a given product application without thought to providing insights into the mechanisms driving functional performance. Fonterra have been involved in the development of several novel test methods that dramatically improve the objectivity and granularity of powder reconstitution tests. These new methods also have the flexibility to allow modification of test protocols to generate data that provides better insights into the mechanisms driving reconstitution performance. Understanding the mechanisms driving reconstitution performance and how they are impacted by the structure and chemistry of the powder can be useful in building insights into how to tailor formulation and processing conditions to target desired functional outcomes. Conditions in the spray dryer are well known to have a strong impact on the solubility of milk powders, with the rate of formation of insoluble material being a function of both concentration and temperature, peaking by orders of magnitude at the intermediate moisture contents that the product experiences as it transits the dryer. Products containing emulsified fat droplets have been shown to be significantly more susceptible to adverse drying conditions than those containing little or no fat, with the volume of insoluble material generated in whole milk powder being significantly higher than for skim milk powder under the same drying conditions. The formation of clustered fat droplets has been the focus of research relating to cream properties, the main causes of which are heat induced aggregation of proteins on the surface of fat globules and shear-induced formation of “homogenization clusters.” The generation of homogenization clusters have been implicated in the increased insolubility of whole milk powder. Building on these insights, Fonterra is improving our understanding of the mechanisms governing milk powder reconstitution, helping to improve performance of existing products and inform development of new products." |
| Milk Protein and Enzymes Symposium: Value-Added Dairy Powders with Specialized Functionality | Symposium | Dairy Foods - MPE Symposium | 2025/06/24 13:30:00 | t95430 | Watch | 1432 | Functionality of high-protein milk powders in specific applications. | 4 | V. Sunkesula | milk protein concentrate (MPC),high-protein food | V. Sunkesula1 | "Milk protein concentrates (MPCs) are widely used in high-protein dairy formulations due to their excellent nutritional value and functional properties. They provide a high-quality source of protein, making them essential for products such as protein-fortified beverages, yogurts, and dairy-based nutritional supplements. However, despite their benefits, MPCs present significant functional challenges, particularly in high-protein applications. Poor solubility, increased viscosity, and heat-induced aggregation lead to undesirable textures, phase separation, and reduced product stability. These issues arise due to strong protein-protein interactions, inefficient hydration, and structural modifications during processing, limiting their broader commercial application. Researchers are developing advanced solutions to address these challenges and enhance MPC functionality. Mineral modification helps minimize aggregation and enhance heat stability, while enzymatic treatments modify protein structures to improve solubility and gelation. Optimizing filtration techniques to alter MPC composition, such as casein to whey protein ratio, would improve their functionality and performance in some applications. Additionally, innovations in emulsification, water-binding, and whipping properties expand MPC applications in dairy and protein-based foods. These advancements enable the production of high-protein dairy products with improved quality, consumer appeal, and market potential." |
| Paul Kindstedt Recognition Symposium | Symposium | Dairy Foods - Paul Kindstedt Recognition Symposium | 2025/06/22 14:00:00 | n9346 | Watch | | Welcome | 1 | Dr. David Barbano | | | |
| Paul Kindstedt Recognition Symposium | Symposium | Dairy Foods - Paul Kindstedt Recognition Symposium | 2025/06/22 14:00:00 | t94376 | Watch | 1001 | Cheese consistency and yield: From milk composition to cheese manufacture. | 2 | J. J. Sheehan | cheese yield,consistency | J. J. Sheehan1 | "Cheese ultimately is the product of the destabilization of casein micelle aggregates into chains and clusters, leading to formation of a 3-dimensional gel concentration of casein with subsequent dehydration and fermentation. Other macro- and micro-constituents (e.g., fat globules, water, minerals, bacteria, and dissolved solutes) are all interspersed within this casein matrix. There are many challenges to achieving optimum cheese yield and consistency during the manufacture process including that of the changing composition of milk. While traditionally changes to milk arose in certain regions due to seasonal production patterns, more recent dynamics include both the direct, and potentially indirect, changes to milk macro- and micro-constituents arising due to dairy breeding programs, as well as more atypical weather patterns with associated changes in herd diet. Similarly, recent changes to farming practices and initiatives driven by sustainability concerns may also affect milk composition and cheese manufacture. Research is currently focused on fingerprinting these changes in milk, in determining their impact on specific cheese manufacture process operations and ultimately on applying data analysis approaches and process control strategies to gain a deeper understanding of how commercial cheese manufacturers may achieve greater control in cheese moisture content and cheese yield management. The output of this research will be considered in the context of current knowledge." |
| Paul Kindstedt Recognition Symposium | Symposium | Dairy Foods - Paul Kindstedt Recognition Symposium | 2025/06/22 14:00:00 | t94589 | Watch | 1002 | Analysis of the physiochemical properties of mozzarella cheese: From melt characteristics to free oil and expressible serum. | 3 | L. E. Metzger | Kindstedt,mozzarella | L. E. Metzger1 | "A cornerstone of Dr. Kindstedt’s research program was the development and application of practical analysis methods for cheese and dairy products. The unique feature of Dr. Kindstedt’s work was the clever utilization of simple, readily available laboratory equipment to evaluate and characterize critical physiochemical properties of cheese that provided insight into the impact of manufacturing parameters on cheese characteristics. Some examples of this work are (1) the application of helical viscometry for the analysis of mozzarella cheese stretch characteristics; (2) free oil measurement to predict the melt and browning characteristic of mozzarella cheese; and (3) expressible serum analysis to determine the ripening rate and optimal age for shredding and baking. These practical analysis methods played a central role in the understanding of the impact of manufacturing parameters on the functionality of mozzarella cheese and were critical for the rapid increase in production of mozzarella cheese between 1985 and 2005 when per capita consumption of mozzarella cheese doubled." |
| Paul Kindstedt Recognition Symposium | Symposium | Dairy Foods - Paul Kindstedt Recognition Symposium | 2025/06/22 14:00:00 | t94511 | Watch | 1003 | The life of a pasta filata mozzarella scientist. | 4 | S. Govindasamy-Lucey | pasta filata,mozzarella cheese,functionality | S. Govindasamy-Lucey1 | "Dr. Paul Kindstedt is one of the best-known scientists that have investigated the properties of mozzarella cheese. Mozzarella, especially the low-moisture, part-skim version, is the most popular cheese made in the US and over the past 30 years has also became a globally important cheese variety. Its popularity is due to its widespread use in pizzas. Dr. Kindstedt undertook systematic studies on the impact of manufacturing parameters on the properties and performance of mozzarella. He worked closely with the cheesemakers to adjust their make recipes and with end users of the cheese in pizza restaurants to better understand their requirements. He developed various new methods to measure important parameters like the hot viscosity of melted cheese, free oil release on pizza, and state of protein during the baking process. Kindstedt and his collaborators at Cornell University did pioneering work in this area. They investigated manufacturing parameters such as culture types, rennet types, stretching temperatures, milling pH, low-fat versions, preacidification, late-lactation milks, fortification options, and many more. Dr. Kindstedt has spoken at many conferences and industry symposia over the years going as far afield as New Zealand. Dr. Kindstedt also did a sabbatical in University College Cork, Ireland, working with Dr. Fox on late-lactation milk on properties of mozzarella. He has published several highly cited reviews and book chapters on the properties of mozzarella cheese. The US industry has relied on this foundational work to greatly improve mozzarella functionality over the last years. There continues to be an increasing demand for cheese with very precise and targeted properties for stretch, melt, shredding, chewiness, and color. Dr. Kindstedt’s foundational work has been critical in helping cheesemakers in tailoring cheese to meet these demanding performance requirements." |
| Paul Kindstedt Recognition Symposium | Symposium | Dairy Foods - Paul Kindstedt Recognition Symposium | 2025/06/22 14:00:00 | t93388 | Watch | 1004 | Recognition of the contributions of Dr. Paul Kindstedt: Exploration of cheese crystals. | 5 | G. F. Tansman | Kindstedt,cheese,crystal | G. F. Tansman1 | "Spanning over a decade of work, the Kindstedt laboratory at the University of Vermont produced innovative research into the formation of crystals in cheese during aging. The studies included elucidating mechanisms for crystal formation and the discovery of crystal phases not previously observed in cheese. Significant contributions included the development of image analysis techniques to characterize calcium lactate crystallization on Cheddar cheese, the characterization of 2 distinct chemical forms of calcium lactate crystallization in cheese, and the discovery of rare ikaite crystallization in washed rind cheese. The latter of these studies merited Kindstedt and his coauthors for the Hawley Medal by the Mineralogical Association of Canada for best publication of the year. This session highlights Dr. Paul Kindstedt’s contribution to the field of dairy science through his studies of and expanded understanding of crystallization phenomena in cheese." |
| Paul Kindstedt Recognition Symposium | Symposium | Dairy Foods - Paul Kindstedt Recognition Symposium | 2025/06/22 14:00:00 | t94947 | Watch | 1005 | Advances in the characterization of mozzarella cheese as influenced by Professor Paul Kindstedt’s legacy. | 6 | P. Sharma | mozzarella cheese,functionality | P. Sharma1,2 | "Mozzarella cheese is a pasta-filata style cheese widely consumed on pizza worldwide. The cheese has typical fibrous protein structures entrapping fat-serum channels forming a basis for pizza baking properties (i.e., meltability, oiling off, stretchability, and browning characteristics). To understand factors influencing these physicochemical characteristics of mozzarella cheese, it is important to have reliable, consistent, and repeatable testing methods. Professor Paul Kindstedt took an early initiative in developing and fine tuning some of the critical testing protocols on mozzarella, which later became a stepping stone in developing advanced characterization tools using texture analyzers, rheometer, image processing, and microscopy. This presentation will highlight Professor Kindstedt’s contributions to the cheese science that are especially important in the understanding and characterization of the physical and chemical properties of mozzarella cheese, as well as the processes that influence its texture, flavor, and quality. I will emphasize particularly how his research on evaluating oiling off and melting functionality, understanding the role of calcium on cheese functionality, and modifying cheese-making technology revolutionized mozzarella cheese research and manufacturing practices worldwide. I will also describe how my research conducted at Massey University, New Zealand, on establishing useful links between rheology and functionality of mozzarella cheese was influenced by Professor Kindstedt’s work." |
| Production, Management, and the Environment Symposium: The DairyUp Project—Attacking Major Challenges for Dairy in a Multidisciplinary Project | Symposium | Production, Management, and the Environment: The DairyUp Project: Attacking major challenges for dairy in a multidisciplinary project | 2025/06/24 13:30:00 | s11149 | Watch | | Intro | | | | | |
| Production, Management, and the Environment Symposium: The DairyUp Project—Attacking Major Challenges for Dairy in a Multidisciplinary Project | Symposium | Production, Management, and the Environment: The DairyUp Project: Attacking major challenges for dairy in a multidisciplinary project | 2025/06/24 13:30:00 | t93753 | Watch | 1444 | Case definition and metabolic disorders: More accurate phenotypes. | 1 | I. J. Lean | feed efficiency,genotypes,ruminal acidosis | I. J. Lean1,2, H. M. Golder1,2, D. Sheedy1,2, C. Old3, A. Lean4,2 | "Our objective is to more accurately define phenotypes of metabolic disorders. A lack of precision and clarity in defining metabolic disorders results in suboptimal progress in understanding, prevention, and treatment of these. Nondifferential errors in classification for dichotomous disorders result in weaker associations and drive hypotheses toward the null; differential errors result in unpredictable outcomes. For continuous variables, misclassification can result in differential errors; the degree and direction of this varies with the exposure distribution, category definitions, measurement error distribution, and the exposure-disorder relationship. Implications for definitions of feed efficiency (FE), ruminal acidosis, and lameness, and genetic progress are considered. Efficiency of beef and dairy cattle has been estimated by residual feed intake (RFI) based on residual estimates from a model predicting DMI as a function of ADG and BW0.75. Residuals derived from the model include true variation in FE, but variation from a latent variable, composition of tissue gain, that is protein, fat, and other reserves that are gained and maintained with different efficiencies. Differences in RFI ranking of beef cattle for this model and others that include estimated change in body composition exist. In dairy cattle, inconsistencies exist between the RFI rank of heifers and cows. Genetic selection based on flawed RFI models raises the risk of selection for less fit genotypes. Ruminal acidosis is a prevalent disorder of cattle, but its temporal nature and the heterogeneity of the rumen both within and between days limits the diagnostic value of pH alone. Definitions not solely based on ruminal pH offer a potential for better phenotypic characterization and selection of more fit genotypes possibly improving production and health. Lameness has a low heritability; however, this is not a single disorder and evaluating these conditions as such raises the potential for differential and nondifferential error. Data provided to assess lameness are characterized by under-reporting and also have temporal challenges. DairyUP structures will and have been designed to address challenges of disorder definition to more accurately define phenotypes." |
| Production, Management, and the Environment Symposium: The DairyUp Project—Attacking Major Challenges for Dairy in a Multidisciplinary Project | Symposium | Production, Management, and the Environment: The DairyUp Project: Attacking major challenges for dairy in a multidisciplinary project | 2025/06/24 13:30:00 | t93472 | Watch | 1445 | Do cows in total mixed ration systems have old lipid profiles compared with pasture-based cows? | 2 | D. B. Sheedy | n-3 fatty acid,lipidomics | D. B. Sheedy1,6, H. M. Golder2,6, S. C. Garcia1,6, Z. Liu3, P. Reddy3,4, P. Moate5, S. J. Rochfort3,4, J. E. Pryce3,4, I. J. Lean2,6 | "Disease and herd removal risks increase with parity, yet the underlying biochemistry of aging in cows is unknown. Feeding system may affect lipid profiles, but the consequences on aging and subsequent health is unknown. The objective of this cross-sectional study was to explore associations of plasma lipids with age, parity, and feeding system (TMR vs. pasture-based [PB]). Plasma was collected from dry (n = 696, ~27 d prepartum), and peak-milk cows (n = 796, ~58DIM) in a stratified (parity: 1,2,3, > 3) random sample from 15 PB and 15 TMR farms. A targeted liquid chromatography-MS approach quantified 185 lipid species, including phospholipids, sphingomyelins, and triacylglycerols. Dry and peak-milk cohorts were analyzed separately. Machine learning algorithms identified lipid classes stably associated with age and parity (multiple linear regression, partial least squares [PLS], random forest [RF], support vector machine), and feeding system (sparse logistic regressions, PLS, RF). Older and greater parity cows were associated with low concentrations of phospholipids with the long-chain polyunsaturated omega-3 (n-3) fatty acids (FA) of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Dry PB cows had greater phospholipids containing α-linolenic acid (ALA, 18:3 n-3) and ALA derivatives than TMR cows. Peak-milk TMR cows had increased phospholipids containing linoleic acid (LA, 18:2 n-6) and its derivatives than PB cows. The n-3 FA are linked to improved immune function, cattle health, reproduction, and milk quality, while n-6 FA are pro-inflammatory. Importantly, both ALA and LA are essential FA that cannot be synthesized by the body and must be provided in the diet. These findings suggest that TMR cows experience a comparatively low n-3, high n-6 lipid environment, resembling an older cow lipid profile. We speculate that the different FA profiles of pasture (high ALA, low LA) and maize silage (low ALA, high LA) contribute to this observation. The different contributions of pasture and maize silage in diets of PB and TMR farms could theoretically have unintended consequences on cattle health and longevity." |
| Production, Management, and the Environment Symposium: The DairyUp Project—Attacking Major Challenges for Dairy in a Multidisciplinary Project | Symposium | Production, Management, and the Environment: The DairyUp Project: Attacking major challenges for dairy in a multidisciplinary project | 2025/06/24 13:30:00 | t94022 | Watch | 1446 | The enteric and respiratory viral diversity of calves in health and disease—A state-wide metatranscriptomic study. | 3 | B. P. Brito | metagenomics,infectious diseases,calf | B. P. Brito1,4, Z. U. Abedien2,4, I. J. Lean3,4 | "Despite extensive diagnostic efforts, many cases of respiratory disease and diarrhea in cattle remain unresolved due to inconclusive etiological findings. Untargeted metagenomics is a powerful approach for pathogen detection, enabling the comprehensive identification of microorganisms. In this study, we estimated the occurrence of viral species and genotypes in dairy farms across New South Wales, Australia. A total of 72 farms were sampled, with a proportional distribution across all dairy regions. Samples were collected from calves younger than 49 d. RNA was extracted from nasal and rectal swabs of 918 calves, and total RNA sequencing was performed on 408 nasal and 593 rectal swabs from calves with varying disease statuses. Additionally, a survey on calf management practices was completed by 52 farms. In total, at least 22 viral species and multiple genotypes were identified. To assess the association between viral presence and disease, transcriptomes were mapped to the identified viral genomes using Kallisto v0.5.1.1, and the relative abundance of viral reads was analyzed using DESeq2 v1.44.0 to compare diseased and healthy calves. The viruses most strongly associated with enteric disease were rotavirus and bovine kobuvirus, while bovine rhinitis virus A showed the strongest association with respiratory disease. Additionally, viral infections were significantly associated with specific age categories (0–7, 8–14, 15–42, and >42 d), particularly for some species of caliciviruses and picornaviruses. Viral detection was widespread among the 72 farms sampled, with kobuvirus present in 69 farms and bovine rhinitis virus A in 30 farms. We reconstructed the evolutionary relationships of 15 viral species for phylogenetic analysis, revealing substantial diversity in bovine rhinitis viruses A and B, bovine picornaviruses, and caliciviruses. Viral characterization at the genotype level enables a better understanding of the variants associated with disease. This level of resolution is critical for developing more sensitive diagnostic tools capable of distinguishing pathogenic strains." |
| Production, Management, and the Environment Symposium: The DairyUp Project—Attacking Major Challenges for Dairy in a Multidisciplinary Project | Symposium | Production, Management, and the Environment: The DairyUp Project: Attacking major challenges for dairy in a multidisciplinary project | 2025/06/24 13:30:00 | t93751 | Watch | 1447 | Investigating genotype and environment effects on the rumen microbiome. | 4 | H. M. Golder | acidosis,dysbiosis,phenotype | H. M. Golder1,2, I. J. Lean1,2 | "Currently there is a lack of capacity to rapidly and accurately detect rumen dysbiosis. Our objective is to improve phenotypic definitions of the rumen microbiome and metabolome to better utilize host and environment interactions to rumen challenges to enhance productivity. Our investigations of ruminal acidosis suggest that there would be an incidence of 500 cases over the first 100 DIM per 100 cows. There is marked among animal variation in response to typical and challenge environments. The task is to quantify the distribution of risk over time among cows given the temporal dynamic nature of the rumen environment and its microbiome, especially when perturbed. In a 293-cow multisite and -country GWAS, there was only a tendency for an association with being in the low-risk acidosis category. There were associations between the host and relative abundance of individual bacterial phyla and families and markers or tendencies for markers for acetate, butyrate, iso-butyrate, iso-valerate, and caproate. Others demonstrate some rumen microbes have a heritability of ≥0.15. The rumen microbiome has substantial redundancy, which can produce inefficiency but offers protection against perturbation. Ruminants have a host-specific core microbiome, likely critical for basic function and a noncore probably for resilience. Investigation and understanding of the non-core may open greater potential for successful manipulation. Challenges in defining the rumen phenotype include what, where, who, and how often we should measure with high repeatability. We need to know whether some cows have nearly constant perturbation, while others exposed to the same diets are stable. Dairy UP is validating some potential markers and technologies from sensors, sniffers, artificial intelligence, camera surveillance, and bodily fluids at the individual and herd level to quantitate the lagged production responses and recoveries to dysbiosis. In summary if we don’t appropriately define phenotypes of the rumen microbiome and metabolome we will not progress the field and optimize health and production." |
| Production, Management, and the Environment Symposium: The DairyUp Project—Attacking Major Challenges for Dairy in a Multidisciplinary Project | Symposium | Production, Management, and the Environment: The DairyUp Project: Attacking major challenges for dairy in a multidisciplinary project | 2025/06/24 13:30:00 | t94621 | Watch | 1448 | The positive associations between calf and lactation performances in dairy cattle. | 5 | S. W. J. Legge | weaning weight (WWT),lactation performance,productivity | S. W. J. Legge1,4, P. C. Thomson1,3, C. E. F. Clark1,2, S. C. García1,4 | "Australian dairy farms are increasingly capturing a wealth of data throughout the lifecycle of animals through the deployment of technology. This includes, among other data, details such as the sex of the calf, calving difficulty, health interventions, movement events, calving dates and parity, and milk production quantities. The underutilization of these extensive data presents a significant opportunity to optimize management practices, and drive improvements in productivity. The relationships between birth weight (BWT), weaning weight (WWT), lactation performance, and key production parameters have been explored in efforts to improve dairy cattle management. Our initial study demonstrated that there were potential indicators of high and low performance (measured as WWT) at very early age. Whether WWT relates to future lactation performance, both in terms of milk yield and number of lactations, remains unclear. Here, data from a cohort of 1,440 female Holstein Friesians were used to assess the impact of WWT (proxy for calf-rearing performance) on the number of lactations, milk yield per lactation and total lifetime milk yield. This study assesses how calf-related measurements might affect first lactation, lifetime production and age when animals are removed from production. Our results from modeling reveal that although BWT showed a slight positive linear trend with lactation-specific milk yield and a significant effect, the influence of WWT was far more pronounced with an additional 53.1 ± 8.5 kg milk yield/kg WWT in each lactation. Moreover, WWT exhibited a strong positive effect on lifetime milk yield and the likelihood of completing multiple lactations. Notably, we observed that calf performance at weaning significantly impacted the probability of remaining within the herd, where a calf with a WWT of 50 kg has a probability of 0.17 of attaining 3 or more lactations compared with 0.41 for a calf with a WWT of 100 kg. This has implications for overall lifetime productivity. These findings underscore the importance of early calf management and management decisions in optimizing milk production and herd sustainability." |
| Production, Management, and the Environment Symposium: The Ruminant Farm Systems (RuFaS) Model—A Modular Approach to Research and Decision Support for Sustainable Dairy Farming | Symposium | Production, Management, and the Environment | 2025/06/24 09:00:00 | t94387 | Watch | 1363 | The RuFaS animal module: A comprehensive, flexible herd model. | 2 | K. F. Reed | dairy herd,modeling,animal module of the Ruminant Farm Systems (RuFaS) | K. F. Reed1, V. E. Cabrera2, J. C. Waddell4, S. P. HekmatiAthar2, A. Liu3, K. R. Briggs4, J. S. Adamchick3, H. Hu3, Y. Gong2 | "The animal module of the Ruminant Farm Systems (RuFaS) model simulates individual animals on a daily basis and offers a wide variety of animal, herd, and dietary options so users can flexibly represent management practices of interest. Each day, the animal module updates the basic physiological status of every animal on the farm including BW, pregnancy status and conceptus weight, and lactation status and milk production according to mechanistic models where available and empirical methods when needed. Milk production is predicted using Woods lactation curve models that are stochastically assigned to each animal based on published regional parameters that are then fit to annual herd milk production. The physiological updates inform management practice algorithms that direct movement of animals between pens, initiate breeding, culling decisions, and feeding. Diets are updated on a user-provided interval and can either be automatically formulated to meet requirements with a least-cost diet or defined by a user-provided recipe. If the provided diet does not meet the expected average nutrient requirements, milk production is reduced up to a user provided threshold. A single diet is fed to each pen before predicting individual animal enteric methane and manure excretion each day. Available farm grown and purchased feeds are provided by the feed storage module and aggregated manure is passed to the manure module, where it enters manure management chains that are assigned to each pen with many to many relationships. Other user options for herd and animal management include specifying reproduction programs for heifers and cows, setting culling rates by parity, breeding and animal sale timing, breed, and BW. Detailed outputs of milk production, animal sales, herd demographics, manure amount and composition, and enteric methane are produced on a daily basis and can be collected and summarized according to the application. The granularity and flexibility of the animal module offer a flexible platform for understanding the impact of animal management on farm-level production efficiency and nutrient cycling." |
| Production, Management, and the Environment Symposium: The Ruminant Farm Systems (RuFaS) Model—A Modular Approach to Research and Decision Support for Sustainable Dairy Farming | Symposium | ADSA Interdisciplinary Symposia | 2025/06/24 09:00:00 | t94153 | Watch | 1364 | The RuFaS manure module: Relevance, methods, and future directions. | 3 | D. A. Andreen | manure management,modeling,nutrient tracking | D. A. Andreen1, E. I. Hansen1, H. Hu1, S. P. HekmatiAthar2, V. S. Vempalli1, K. R. Briggs3, G. J. Thoma4, J. P. Oliver1 | "Manure is a critical component of nutrient cycling on dairy farms, but greenhouse gas emissions from manure also represent a considerable fraction of total emissions at the farm and industry level. Quantifying manure emissions is challenging as manure systems can be complicated and variable between farms, and biological and chemical processes underlying emissions are complex. The manure module is a crucial link in modeling circular nutrient flows on farms within the Ruminant Farm Systems Model (RuFaS). The objective of this symposium session is to review the methods, function, and future directions of the manure module. The main purpose of the manure module is to track the fate of nutrients (e.g., N, P, K, C) from excretion by animals until field application or off-farm export. The module quantifies manure nutrients available for agronomic or other use and illustrates how management choices impact manure composition and emissions. Manure is received daily from the animal module, which predicts manure mass and composition based on animal characteristics and nutrient intake, directly linking on-farm nutrient cycling to animal management. In the manure module, manure moves through a user-defined management chain including options for manure handling, mechanical solid-liquid separation, anaerobic digestion, and storage in liquid, slurry or solid form. Daily nutrient and mass transformations, losses (e.g., volatilization), and gains (e.g., bedding, wash water) are quantified and updated at each step along the chain. Development of the manure module is limited by insufficient data and understanding of the basic processes driving emissions, as well as multisite, applied research quantifying the impact of manure management on these processes. Process-based methods are prioritized for inclusion over empirical methods wherever possible but empirical models and emissions factors are incorporated as needed. In addition to supporting dairy farm systems analysis and relevant industry applications, the RuFaS manure module can serve as a tool to aid in identification of critical knowledge gaps and an avenue for rapid assimilation of new research." |
| Production, Management, and the Environment Symposium: The Ruminant Farm Systems (RuFaS) Model—A Modular Approach to Research and Decision Support for Sustainable Dairy Farming | Symposium | Production, Management, and the Environment | 2025/06/24 09:00:00 | t94168 | Watch | 1365 | The RuFaS soil and crop module: Integrating extant field-simulation models for flexible representation of dairy cropping systems. | 4 | P. Adhikari | nutrient cycling,modeling,cropping systems | P. Adhikari2, C. Marrow1, S. P. HekmatiAthar4, E. Hansen3, K. Panke-Buisse1, A. Rawal2, E. Young2, P. Vadas5, K. F. Reed1 | "Soil and crop is one of the 4 core biophysical modules in the Ruminant Farm Systems (RuFaS) model. This module simulates any number of fields, each with a configurable number of soil layers and options for growing and harvesting 22 common dairy crops from 7 plant species with explicit daily simulation of crop growth, C/N/P/Water Cycles, and erosion on a daily time step. The methodology of the soil and crop module integrates 3 widely used existing field and biogeochemical models (the Soil and Water Assessment Tool, SurPhos, and Daycent) in Python with a flexible field management algorithm that allows the user to specify dates and attributes of fertilizer and manure applications, irrigation, tillage, planting, and harvesting. Simulated outcomes include crop yield, nutrient content, and abiotic stresses such as temperature, moisture, and nutrient availability. In addition, the soil and crop module simulates soil nutrient transformations in response to environmental conditions including 6 soil organic and inorganic N pools, 3 soil phosphorus pools, 4 soil carbon pools, and soil water fluxes throughout the soil profile. Module-predicted crop yields, leaching, runoff, soil carbon sequestration, and emission of nitrous oxide, and ammonia under varying manure and synthetic fertilizer application rates and environmental conditions align with expected outcomes and model behavior. The soil and crop module receives manure inputs from the manure module in the form of liquid, slurry, or solid manure and reports harvested crops as an output for storage as dry hay, silage, or baleage. User-inputs include soil type and composition characteristics such as, bulk density, texture, moisture, and initial nutrient values, crop type, and field management practices. As a modular component of RuFaS, the soil and crop module represents an essential part of the dairy farm nutrient cycle and will help researchers and dairy producers identify management options for overcoming challenges related to efficiency, profitability, waste, and environmental impacts." |
| Production, Management, and the Environment Symposium: The Ruminant Farm Systems (RuFaS) Model—A Modular Approach to Research and Decision Support for Sustainable Dairy Farming | Symposium | Production, Management, and the Environment | 2025/06/24 09:00:00 | t94030 | Watch | 1366 | The RuFaS feed storage module: Connecting field and feed management to animal performance. | 6 | K. Panke-Buisse | feed storage,forage conservation,modeling | K. Panke-Buisse1, S. P. HekmatiAthar2, E. Hansen3, K. F. Reed1 | "The feed storage module’s role in the Ruminant Farm Systems (RuFaS) model is as a dynamic inventory of purchased and farm-grown feed and forage and their nutrient qualities. Feed may be added via purchase through the diet formulation function in the animal module and from the on-farm harvest function of the soil and crop module. Feed is removed from the inventory when it is fed out in the animal module and through loss predictions during storage and feeding. The feed storage module currently accepts corn (silage, dry/high-moisture grain), alfalfa, grass, cereal or small grain, and soybean to be stored dry (hay, grain, and concentrates), ensiled (in bag, bunker, or pile), or as baleage. Stored feed quantity and quality changes are simulated over the duration of storage depending on crop type, crop quality, user-specified storage conditions, and ambient climate conditions. Feed component values, proportions, digestibility, and availability subject to change during storage are mass, DM content, CP, NPN, NDF, ADF, starch, and water-soluble carbohydrates (WSC). Dry matter is lost during storage as gas, effluent, or particulates reduces the mass of feed components accordingly to accurately reflect the remaining feed and its qualities. Forage or feed quality can also be user-specified both before and after storage, offering flexibility and modularity of user needs. Stored feed can facilitate ration formulation in the animal module directly based on its simulated nutrient composition or by assigning a quality rating to align with published feed quality values." |
| Production, Management, and the Environment Symposium: The Ruminant Farm Systems (RuFaS) Model—A Modular Approach to Research and Decision Support for Sustainable Dairy Farming | Symposium | ADSA Interdisciplinary Symposia | 2025/06/24 09:00:00 | t93958 | Watch | 1367 | Optimizing dairy farm profitability and sustainability with the RuFaS economics module. | 7 | J. Greene | dairy economics,whole-farm modeling,integrated assessment model | J. Greene1, B. Limb1, J. C. Waddell2, P. Hekmati3 | "Economic considerations are a key driver of sustainability in dairy production, shaping the adoption and abandonment of diverse farm management practices and technologies. The Ruminant Farm Systems (RuFaS) model provides comprehensive environmental analysis for dairy operations; however, a robust economic module is essential for evaluating trade-offs between environmental and financial performance. This will be achieved by the RuFaS economics module, designed to integrate farm-scale financial modeling with scenario-based decision support. Although still under development, this presentation will provide an overview of its design structure, modeling approaches, key functionalities, and application for optimizing farm profitability and sustainability. The economics module connects farm management decisions to key financial metrics, integrating capital expenditures, operational costs, revenue streams, and financing structures. Designed for flexibility, it facilitates comprehensive assessments of return on investment, payback periods, and cost-benefit analyses across diverse dairy interventions. Key capabilities include evaluating the economic feasibility of anaerobic digesters by comparing revenue from biogas and carbon credits against capital investment, assessing trade-offs in feed production versus purchase decisions, and analyzing the financial impact of regenerative practices such as no-till farming and cover crops. The module is being developed through iterative testing with subject matter experts and will integrate with the existing RuFaS biophysical and energy use modules. Expected outputs include scenario-driven financial projections, sensitivity analyses, and integration with environmental performance metrics to provide holistic sustainability insights. By equipping farmers and advisors with transparent, data-driven economic assessments, the RuFaS economics module aims to accelerate the adoption of financially viable, sustainable dairy farming practices." |
| Production, Management, and the Environment Symposium: The Ruminant Farm Systems (RuFaS) Model—A Modular Approach to Research and Decision Support for Sustainable Dairy Farming | Symposium | Production, Management, and the Environment | 2025/06/24 09:00:00 | t94118 | Watch | 1368 | Farmers Assuring Responsible Management Environmental Stewardship program integrates the Ruminant Farm System model. | 8 | N. Ayache | participatory modeling,greenhouse gases,environmental impact | N. Ayache1, S. Saffran1, J. S. Adamchick2, J. C. Waddell3, S. P. HekmatiAthar4, K. R. Briggs3 | "The National Milk Producers Federation (NMPF), in partnership with Dairy Management Inc., created the National Dairy Farmers Assuring Responsible Management (FARM) Program in 2009 as a customer and consumer assurance program related to on-farm social responsibility, paid for and governed by US dairy farmers. In 2017, the program added the FARM Environmental Stewardship (ES) pillar to provide a comprehensive estimate of the GHG emissions and energy use on dairy farms. The FARM program undergoes a cycle of review and updates every 3 yr. In its Version 3.0 update in 2024, FARM ES integrated RuFaS to become the first process-based model for greenhouse gas accounting available to US dairy farmers. Processors and cooperatives representing 80% of the US milk supply currently participate in FARM ES and a working group of industry representatives including field staff and farmers contributed to the piloting and integration efforts. To evaluate the capacity of the RuFaS model to represent diverse dairy animal and manure management systems, we collected information on management practices to inform model inputs from 32 volunteer farms across the US and applied the RuFaS model to estimate the GHG emissions from animals (enteric CH4), manure (CH4, direct N2O, and indirect N2O), and feed production (CO2-eq). Volunteer farms varied in geographic location, herd size (30 to 10,000), herd management practices, and manure management strategies. Feedback from the volunteer pilot farms, co-op and processor field staff, and the FARM ES Working Group was used to improve the alignment between RuFaS inputs and on-farm management practices as well as enhance practice inclusion, reporting, and the user interface. FARM ES Version 3.0 with the integration of RuFaS has now been launched for use by US dairy producers, cooperatives, and processors. Due to the process-based nature of RuFaS, FARM ES now enables retrospective analysis of a farm’s footprint and comparative “what-if” scenario analysis to support on farm decision making and advance US dairy’s efforts toward GHG neutrality." |
| Production, Management, and the Environment Symposium: The Ruminant Farm Systems (RuFaS) Model—A Modular Approach to Research and Decision Support for Sustainable Dairy Farming | Symposium | Production, Management, and the Environment | 2025/06/24 09:00:00 | t94166 | Watch | 1369 | RuFaS as an open-source platform: What does it mean for your science program? | 9 | J. C. Waddell | modeling,environment,production | J. C. Waddell1, S. P. HekmatiAthar2, J. M. Tricarico1, K. F. Reed3 | "The Ruminant Farm Systems model (RuFaS) is an open source, process-based model, and this presentation explores how this platform improves access to information and advances opportunities for collaboration. Commitment to open-source means that users can explore every line of code in the simulation and fully trace the methods applied to produce any given output for every simulation. A strength of the open-source approach is that, by taking advantage of the virtual repository and version control platform GitHub, anyone that adheres to the requisite processes outlined in RuFaS’s charter can directly contribute to model development. Following the established protocols, anyone can report issues, request new features, and provide feedback on any part of RuFaS via the online repository. Git version control also allows users to easily make their own “branches,” or copies of the model, to make modifications for testing and evaluating new methods without affecting the current main version of RuFaS. Model modifications can be incorporated into the main branch after completing a review process. All potential contributions to the codebase, whether they are from current development team members or new contributors, can be submitted to be considered for integration into the main version of RuFaS through a thorough evaluation, testing, and documentation process. All interactions with the RuFaS codebase are documented and archived, allowing users to see details as to why specific changes were implemented or rejected. Several enhancements to the RuFaS model are in various states of development, including an animal health submodule, grazing systems, and water quality assessment. Given the rapidly changing landscape in the dairy sector, an adaptable system is necessary for long-term utility, and this is intrinsic to the architecture of the software. By using modern software engineering principles—which ensure that existing code facilitates improvement and expansion in the areas most relevant to the dairy industry—RuFaS provides a platform for scientific collaboration and not “just” a dairy farm model." |
| Reproduction Symposium: Carryover Effects of In Vitro Embryo Production in Dairy Cows—From Embryo Implantation to Next-Generation Performance | Symposium | Reproduction | 2025/06/25 09:00:00 | t95668 | Watch | 1527 | The ART of bovine reproduction: In vitro embryo production and its developmental impact. | 1 | P. Ross | | P. Ross1 | "In vitro embryo production (IVP) is transforming bovine breeding by accelerating genetic gain through shortened generational intervals and increased selection intensity. By enabling the large-scale generation of embryos from genetically superior animals at an early age, IVP enhances the efficiency and precision of selection strategies in both dairy and beef systems. However, the preimplantation period—a window of extensive epigenetic remodeling and dynamic gene expression—is highly sensitive to environmental conditions. When this development occurs in vitro, deviations from the in vivo environment can lead to reduced embryo quality, impaired development, lower cryotolerance, compromised pregnancy success, and increased pregnancy loss. Furthermore, IVP-derived embryos have been associated with altered fetal growth patterns, increased birth weight, higher rates of dystocia, and reduced neonatal survival. While the effects of ART on postnatal health and lifetime productivity remain less well documented, emerging evidence suggests potential long-term impacts that warrant further investigation. Importantly, when IVP is used primarily to generate elite sires for genetic dissemination—rather than production animals—the associated developmental risks are less likely to manifest at the farm level. In this context, the benefits of ART in accelerating genetic progress can be realized with minimal impact on commercial herd populations. This presentation explores the balance between genetic advancement and developmental risk in IVP, emphasizing the need for continued refinement of in vitro systems to ensure both reproductive efficiency and the long-term sustainability of genetic improvement programs." |
| Reproduction Symposium: Carryover Effects of In Vitro Embryo Production in Dairy Cows—From Embryo Implantation to Next-Generation Performance | Symposium | Reproduction | 2025/06/25 09:00:00 | t94374 | Watch | 1528 | Fertility in lactating dairy cows after timed artificial insemination or embryo transfer with fresh or frozen in vitro–produced embryos. | 2 | P. Lonergan | embryo loss,in vitro fertilization (IVF),assisted reproduction technology (ART) | P. Lonergan1, A. D. Crowe1,2, E. M. Murphy1,2, L. Thompson1, M. McDonald1, S. T. Butler2 | "Reproductive efficiency is crucial for profitable and sustainable dairy production systems. Pregnancy loss, rather than fertilization failure, is a key driver of reproductive failure in cattle. In vitro embryo production (IVP) is now an established technology in the toolbox of assisted reproductive technologies available to farmers and breeding companies for genetic improvement in dairy cow herds. The number of IVP bovine embryos transferred annually has increased year-on-year in the last decade and now surpasses the number derived by traditional superovulation, accounting for ~80% of all bovine embryos produced and transferred globally. In vitro embryo production offers significant advantages over traditional multiple ovulation embryo transfer (MOET) including increased flexibility in sire usage allowing multiple pregnancies from elite dam-sire combinations to be generated, the ability to produce more embryos per unit time per genetically elite female, the ability to use oocytes from prepubertal females (as young as 2 mo of age) to reduce the generation interval (so-called “juvenile in vitro fertilization embryo transfer,” JIVET) and the more efficient use of rare or high-cost semen straws. The increased use of sex-sorted semen to breed replacements and beef semen to improve calf quality in dairy herds will ultimately lead to a reduction in the pool of male dairy calves available as future potential AI sires. Targeted use of IVP with elite breeding stock will facilitate the production of future generations of elite bulls. Despite these benefits, significant challenges relating to pregnancy loss after embryo transfer, particularly after cryopreservation of IVP embryos, and issues relating to peri- and postnatal health and development of IVP offspring remain to be resolved and hamper the more widespread application of the technology. Improving our understanding of the underlying physiological and molecular mechanisms that regulate early embryo development, embryo-endometrial interactions and lead to successful pregnancy establishment is necessary to understand and elucidate the causes of pregnancy loss and provide a basis for new strategies to improve pregnancy outcomes and reproductive efficiency. Supported by the Irish Department of Agriculture, Food and the Marine Research Stimulus Fund (Grant 2021R665)." |
| Reproduction Symposium: Carryover Effects of In Vitro Embryo Production in Dairy Cows—From Embryo Implantation to Next-Generation Performance | Symposium | Reproduction | 2025/06/25 09:00:00 | t94413 | Watch | 1529 | Impact of in vitro embryo production on the performance of the next generation of dairy cows. | 3 | S. Lafontaine | in vitro fertilization (IVF),phenotypes,epigenetics | S. Lafontaine1, R. Labrecque2, P. Blondin3, R. Cue4, M. A. Sirard5 | "Assisted reproduction technologies (ART) are key tools in the genomic revolution of the dairy industry. Despite advancements in in vitro fertilization (IVF) and its growing use, concerns remain regarding its long-term effects on animal health and productivity. Research in epigenetics suggests that the artificial environment during early embryonic development may induce subtle metabolic, growth, and fertility alterations that persist throughout life. We explored the hypothesis that epigenetic differences arising from the ovarian and in vitro environment during late folliculogenesis and embryonic culture contribute to long-term phenotypic variations in dairy cows. First, we assessed the epigenetic programming quality of bovine embryos produced in vitro under different culture conditions and donor ages. The DNA methylation analysis of imprinted genes in d 7 and d 12 embryos revealed overall lower methylation levels and greater variability in all 3 in vitro conditions examined. To evaluate the real-world impact of these molecular differences, we conducted a retrospective cohort study (317,888 animals and 601,939 lactations) comparing IVF-derived cows to those conceived via artificial insemination (AI) and multiple ovulation embryo transfer (MOET). While milk production over the first 3 lactations was similar across conception methods when adjusted for genetic merit, IVF animals exhibited slightly reduced fertility, longer gestations, and distinct disease incidence patterns. Although IVF animals had a higher lifetime performance index (LPI), the rate of genetic improvement in their population from 2012 to 2019 was nearly half that of AI-derived cows. We postulate that an epigenetic penalty, consistent with and potentially caused by the molecular differences found in embryos following ART, decreases intergenerational genetic progress and explains the observed phenotypic alterations. Thanks to the quality and quantity of the data available, our work has made it possible to illustrate with unprecedented resolution the causes and long-term impacts of the gametes and early embryos environments. Our findings underscore both the challenges and progress in minimizing epigenetic dysregulation in elite dairy genetics. Although severe imprinting disorders have been largely mitigated, detectable molecular and physiological traces of ART remain." |
| Reproduction Symposium: Carryover Effects of In Vitro Embryo Production in Dairy Cows—From Embryo Implantation to Next-Generation Performance | Symposium | Reproduction | 2025/06/25 09:00:00 | n9301 | Watch | | Panel Discussion | 4 | | | | |
| Ruminant Nutrition Platform Session: Alternative Feed Ingredients for Dairy Rations | Symposium | Platform Session - Alternative Ingredients | 2025/06/24 13:30:00 | t95021 | Watch | 1436 | Of cows and bugs: Using insects as alternative feeds in dairy cattle nutrition. | 1 | E. Rico | dairy cow,insect feeding,sustainability | E. Rico1 | "The steady growth of the human population and the reduction in the number of people in extreme poverty have significantly increased the global demand for animal foods. Protein shortages are a current threat to global food security, prompting us to reduce food waste, and to lessen the competition for protein sources between humans and food-producing animals. Although dairy cows typically consume feedstuffs not in direct competition with human food (e.g., forage, co- and byproducts), some others, such as soybean products still constitute an important source of high-quality protein in their diets. The use of alternative protein sources in dairy cow nutrition may help enhance their integration into circular economies, leading to more sustainable food production. Although the nutritional composition of insects can vary depending on species, rearing methods, life stage, and diet, these animals constitute potentially important sources of key nutrients for farmed animals, such as high-quality protein, lipids, and micronutrients. Although the Western Hemisphere is largely reticent to the incorporation of insects in the human diet (i.e., neophobia), its acceptance for the sustainable feeding of food-producing animals appears to trend positively. In this context, the industrial production of insects for animal feeding has risen quickly in the past few years, and it is expected to continue growing in the next decades. This matches the anticipated increment in the use of insects to replace conventional proteins of animal and plant origin in industries such as aquaculture, livestock, and pet food. Although very limited data are currently available on the impact of incorporating insect meals in dairy cows, in vitro studies, and others in small ruminants, indicate the potential for methane mitigation and no negative effects on animal performance. Our current work is exploring the feasibility of using insect larvae from the black soldier fly, as a partial substitute for soybean meal in diets for high-producing dairy cows. This presentation will explore the potential opportunities and limitations of using insects in the diets of dairy cows, while highlighting current gaps in knowledge and future work." |
| Ruminant Nutrition Platform Session: Alternative Feed Ingredients for Dairy Rations | Symposium | Platform Session - Alternative Ingredients | 2025/06/24 13:30:00 | t94357 | Watch | 1437 | Alternative foodstuffs in dairy ruminant nutrition: Basic concepts, recent issues, and future challenges. | 2 | L. Pinotti | dairy cow,alternative feed,quality,safety | L. Pinotti1, M. Manoni1, M. Ottoboni1, M. Tretola2 | "The sustainability of animal production is a major challenge in modern food production systems. Farm animals compete for nutrients and for the use of scarce resources, such as land, water, and energy, which are also essential for human nutrition. Addressing this competition is part of the ongoing debate at the scientific and public level. The goal is to produce more food, feed and energy globally without further burdening the limited availability of natural resources, particularly water and land. It is thus essential to redesign the concept of nutrition. One promising approach is to explore synergies between human and animal nutrition. Former foodstuff products (FFPs) and insect represent 2 examples of promising strategy for reducing feed-food competition through partial replacement of grains and concentrate feed in ruminant diets without negatively affecting animal productivity and well-being. Although FFPs are rich in simple sugars and fats, excessive intake by ruminants may increase the risk of subacute rumen acidosis and modify bacterial microbial protein synthesis and methane emissions. Additionally, chemical substances present in FFPs (e.g., theobromine), and packaging remnants may alter ruminal function, milk production, and animal health. In the case of insects, the scenario is still ongoing, as in many countries, insect-based materials are not allowed as feed ingredients for ruminants. Furthermore, the stability of true proteins in the rumen is not so well defined, which complicates the definition of the possible rumen bypass of these matrices. As a result, farmers, nutritionists, industry, and governments are required to pay serious attention to the production processes of animal feed and to ensure the correct use of these materials in the target animals." |
| Ruminant Nutrition Platform Session: Alternative Feed Ingredients for Dairy Rations | Symposium | Platform Session - Alternative Ingredients | 2025/06/24 13:30:00 | t94946 | Watch | 1438 | Alternative feed for livestock: Opportunities and challenges to support a circular food system. | 3 | Z. Dou | alternative feed,dairy,sustainable livestock | Z. Dou1, S. Rassler1, C. Jiya2 | "The global livestock industry is at a crossroads to meet demand for animal-based food while simultaneously addressing sustainability challenges. Demand for meat, milk, and eggs is projected to increase by 60% to 70% by 2050. Much of the increase will come from developing countries due to increasing population, rising income, and urbanization. The heightened demand has increased requirements for livestock feed and other resources; however, feed production has been associated with deforestation, biodiversity loss, unsustainable resource extraction, and in particular climate change. Livestock-related emissions are estimated to contribute 11.1% to 19.6% of anthropogenic greenhouse gases, with a substantial portion originating from feed production and provision. Additionally, feed accounts for up to 60% of all farm expenses and has significant implications on livestock productivity. In this context, producing more meat, milk, and eggs for human consumption with fewer unintended consequences on the planet requires all workable solutions. Developing alternative feed is a viable option. Alternative feed is broadly defined as biomass materials that can be fed to livestock to support maintenance and production requirements, while improving agrifood system efficiency, contributing to the circular bioeconomy, and limiting competition of natural resources with human food production. This presentation will describe the nutritional attributes and feeding values of selected plant-based alternative feed ingredients. Two case studies will be presented focusing on the use of alternative feed in dairy production. The first will outline lessons learned from substituting culled fruit waste for conventional feedstuffs in modern dairy operations, and how collaboration with food supply chain stakeholders is integral throughout the process. The following case study will describe using human unfit biomass materials to support smallholder dairy operations in the Global South. These and other emerging opportunities, ingredient sourcing, and potential challenges to adopting alternative feed for enhanced sustainable livestock future will be reviewed." |
| Ruminant Nutrition Platform Session: Alternative Feed Ingredients for Dairy Rations | Symposium | Platform Session - Alternative Ingredients | 2025/06/24 13:30:00 | t94463 | Watch | 2524-SPOT | In vitro and in situ evaluations of black soldier fly larvae as a methane-mitigating protein substitute in dairy cattle diets. | 4 | H. Craig | black soldier fly larvae,methane,sustainability | H. Craig1, A. Tiwari2, R. Kohn2, J. E. Rico3,2, B. Lamp1 | "Black soldier fly larvae (Hermetia illucens; BSFL) meal is a high-quality protein product, compositionally on par with soybean meal (SBM). Previous in vitro work suggests BSFL may mitigate enteric CH4. Different BSFL products are available with fractions that vary in the concentration of nutrients (i.e., fat and protein) and antinutritional factors (e.g., chitin). Our objectives were to (1) determine the optimal inclusion rate of low- or high-fat BSFL meal to mitigate CH4in vitro (experiment 1; EXP1), and (2) compare the degradation rates of BSFL and SBM in vivo (EXP2). For EXP1, a batch culture system was used in a dose-response study testing low- (11.6% crude fat; LF) or high-fat (34.9% crude fat; HF) BSFL at 4 inclusion levels (0%, 10%, 25%, and 50% of DM). The experimental treatments were allocated in a randomized design with a 2 × 3 factorial structure. Each treatment was replicated 3 times across 3 independent experiments. Volatile fatty acids and CH4 were measured using GC. For EXP2, nylon bags with 5.0 g of either BSFL or SBM were incubated in the rumen of 2 fistulated Holstein cows and DM disappearance was evaluated at 0, 2, 4, 6, 8, 10, 12, 16, 20, 24, and 48 h of incubation. Data for EXP1 and EXP2 were analyzed using mixed models with fixed and random effects, and their interactions. In EXP1, CH4 increased over time (P < 0.05), and no treatment differences were detected for dose or fat type (P = 0.98 and P = 0.76, respectively); however, propionate and butyrate concentrations were higher in LF (P < 0.05). In EXP 2, DM cumulative degradation was higher in SBM relative to BSFL (P < 0.05), and DM disappearance rates were faster for BSFL from h 0 to 10, and slower between h 20 to 48, relative to SBM (P < 0.05). Although our findings do not support BSFL as an effective methane mitigating feed, our fermentation data indicates that it may still provide nutritional value. Further research is needed to determine the optimal use of BSFL in sustainable dairy diets." |
| Ruminant Nutrition Platform Session: Alternative Feed Ingredients for Dairy Rations | Symposium | Platform Session - Alternative Ingredients | 2025/06/24 13:30:00 | t94581 | Watch | 2520-SPOT | Incorporating Hermetia illucens larvae in Jersey cow diets: Effects on milk production and composition. | 5 | M. Moncada-Laínez | alternative feeding,black soldier fly,milk yield | E. O. Reyes1, M. D. Osorio1, J. Orozco1, K. L. David1, M. Moncada-Laínez1 | "The rising cost of traditional dairy cow feed ingredients, such as corn and soy, has driven the search for more sustainable and cost-effective alternatives. Hermetia illucens larvae, commonly known as black soldier fly larvae, have gained attention as a viable protein and energy source, with the added benefit of organic waste biodegradation. This study evaluated the effects of incorporating 10% and 15% Hermetia illucens larvae into the diets of Jersey cows on milk production and composition. The research was conducted at the Dairy Cattle Unit of Zamorano University, Honduras, over 2 mo, with an initial 2-wk adaptation period. Thirty Jersey cows in their second to fourth lactation were assigned to a completely randomized design (CRD) with 3 groups: a control group fed a conventional TMR and 2 experimental groups receiving TMR supplemented with different levels of Hermetia illucens larvae. The cows were managed in a semiconfined system, receiving TMR twice daily (0500 and 1500 h) for 3 h per feeding before being allowed to graze on Star-grass (Cynodon nlemfuensis) for the remainder of the day in an intensive rotational grazing system. Four key variables were analyzed: feed intake, milk production, body condition, and milk composition. Data were assessed using least squares means (LSMEANS) separation tests, with probability differences (PDIFF) calculated via the Statistical Analysis System (SAS) version 9.4, applying a significance threshold of P ≤ 0.05. Results show that a 15% inclusion of Hermetia illucens larvae increased milk yield by 1 kg compared with the control group (P < 0.0001), while the 10% group showed values similar to the control. However, the 15% inclusion reduced feed intake (P = 0.0004) and negatively affected body condition (P = 0.0078). In terms of milk composition, the group with the highest larvae inclusion exhibited a decrease in fat content (P = 0.018), while protein and nonfat solids remained comparable to the control group. These findings suggest that Hermetia illucens larvae could serve as a viable alternative feed ingredient for dairy cattle, offering potential cost savings without significantly compromising milk quality." |
| Ruminant Nutrition Platform Session: Alternative Feed Ingredients for Dairy Rations | Symposium | Platform Session - Alternative Ingredients | 2025/06/24 13:30:00 | t94571 | Watch | 2523-SPOT | Green economy: Incorporating spent mushroom substrate into dairy cattle diets for environmental sustainability. | 6 | J. O. Alabi | spent mushroom substrate,Pleurotus spp.,sustainability | J. O. Alabi1, O. O. Adelusi1, M. Wuaku1, C. C. Anotaenwere1, D. O. Okedoyin1, O. A. Oderinwale1, J. M. Enikuomehin1, A. E. Kholif1, U. Y. Anele1 | "Spent mushroom substrate (SMS) presents a cost-effective and nutrient-rich alternative feed resource for cattle production. This study examined 3 types of spent Pleurotus mushroom substrates (SMS1, P. ostreatus isolate 1; SMS2, P. pulmonarius; and SMS3, P. ostreatus isolate 3) using in vitro fermentation. The experiment used a 3×3+1 factorial design to assess 3 inclusion levels (10%, 20%, and 30%) as substitutes for corn silage. Four rumen-cannulated nonlactating dairy cows were used as inoculum donors. The results revealed a significant interaction (P < 0.001) between SMS type and inclusion level on nutrient digestibility. Specifically, SMS3 at 30% inclusion level increased neutral detergent fiber digestibility by 14% and 7%, while ADF digestibility increased by 20% and 18% at 24 and 48 h, respectively, compared with corn silage. At 48 h, ADL digestibility was 106% higher in the SMS3 group at 30% compared with the control. Additionally, fiber digestibility increased linearly (P < 0.001) with higher SMS inclusion levels. Main and interaction effects of SMS type and inclusion level had no significant effect on GHG and VFA production at 24 and 48 h. The pH was positively influenced (P < 0.01) by SMS inclusion at 48 h only, with higher pH observed in SMS 3 at 10% level. However, SMS inclusion reduced (P < 0.001) gas production from 24 to 48 h. In conclusion, incorporating SMS into dairy cattle diets enhances nutrient digestibility without negatively affecting VFA production, making SMS a viable feed resource for sustainable dairy production." |
| Ruminant Nutrition Symposium: Joint ADSA-NANP-ASAS-PSA Session—Anomalies in Analyzed Nutrient Composition of Feedstuffs | Symposium | NANP Session | 2025/06/24 09:00:00 | t93491 | Watch | 1370 | Unassigned organic matter in feeds. | 1 | F. N. Owens | feed analysis,nonstructural nonstarch carbohydrate,organic matter | F. N. Owens1, B. B. Grimes Francis2, Z. K. Smith2 | "Proximate analysis of feedstuffs is comprised of determination of 5 nutrients: moisture, crude ash, CP, extractable fat, and crude fiber. Nitrogen-free extract (NFE) is determined as the difference between the sum of these nutrients and DM. In tabular feed composition values, each of the 6 nutrients are routinely expressed as a fraction of feed DM. Yet, the sum of the individual nutrients often totals less than 100% of the DM portion This difference or “undefined fraction” is denoted as residual organic matter (ROM) from the equation: ROM = 100 − ash − CP − NDF − starch − (FA/FatFactor) − (CP − 0.64 × sNPNCPE) and is assumed to have an energy value of 4 Mcal/kg. This deficit fraction is substantial for some feedstuffs (11.2% for corn grain, 8.35% for corn silage, 51.4% for wet citrus pulp, −3.05% for feather meal). Therefore, the question is posed, why doesn’t the sum of its parts on a DM basis not equal the whole? Components of fermented feedstuffs may be lost during oven drying as volatile substances, minerals may be lost during oven-drying by converting anions to carbonate, thereby falsely increasing ash weight. Formation of Maillard products during drying, and under-recovery of ROM also occurs whenever feed components are not properly dried or assayed, particularly the nonstructural non-starch carbohydrates (NSNSC), pectins, and β-glucans. Certain nutrients may also be present in multiple fractions (e.g., ash and CP [N × 6.25]). Therefore, correction of NDF for protein and ash would seem preferable. It is recommended to include mean values for ROM and NSNSC within tabular feed tables as an index of the extent of unidentified substances and thereby the degree that energy values and digestibility may be altered to compensate for missing or excess DM or OM. Nutritional values of feedstuffs are imperative to diet formulation and discrepancies in actual versus estimated values may be underestimated and pose significant performance and economic detriments." |
| Ruminant Nutrition Symposium: Joint ADSA-NANP-ASAS-PSA Session—Anomalies in Analyzed Nutrient Composition of Feedstuffs | Symposium | NANP Session | 2025/06/24 09:00:00 | t94453 | Watch | 1371 | Inconsistencies in fiber analysis affecting feed analysis databases. | 2 | D. R. Mertens | NDF,ADF,lignin | D. R. Mertens1 | "Fiber is a nutritional entity that is defined by the method of measurement. Methods of drying or grinding samples, reagents or extraction methods, filtration methods or media, and basis for reporting results have changed over time. When created in the 1960s, NDF used sodium sulfite to reduce protein contamination. In the 1970s, starch contamination was discovered as a problem for analyzing corn silage and grains and the method was revised to include heat-stable α-amylase, but sulfite was removed because it might reduce lignin. Sometimes this NDF was adjusted for protein contamination. In the 1990s, the AOAC Official Method 2002.04 for aNDF was developed to include both sulfite and amylase, with an option for ash-free aNDF. This method included modifications that can alter results for specific feeds that are finely ground or contain excessive fats, pectins, or mucilages. Currently, ash-free NDF is the preferred method, but before this NDF was not measured as ash-free. The AOAC method for ADF included lignin analysis using sulfuric acid and asbestos as a filter aid. Banning of asbestos required modifications of the original lignin method and a permanganate method for lignin was developed, which makes reporting of ADL ambiguous. All of these methods were based on cutter-mill grinding through 1-mm screens and collection of fiber on cindered glass crucibles, with or without filter aids. Filter bag methods were developed for NDF, ADF, and lignin, that involved multiple updates in both methodology and filter bags, sometimes caused inconsistencies. Currently, most fiber results are generated by NIRS, which may introduce variability due to differences in calibration datasets and approaches. Finer grinds of NIRS samples will result in lower chemical analyses of fiber, when not using filter aids. Changes in methods may result in less than ±5 percentage-point changes in fiber values from published historical sources. Nevertheless, fiber analyses have proven useful in evaluating feeds and formulating rations. Simple averages of large numbers of unedited results from unknown methods, which are not internally consistent with themselves or other analyses, may be neither informative nor useful." |
| Ruminant Nutrition Symposium: Joint ADSA-NANP-ASAS-PSA Session—Anomalies in Analyzed Nutrient Composition of Feedstuffs | Symposium | NANP Session | 2025/06/24 09:00:00 | t93856 | Watch | 1372 | Protein analysis methodology. | 3 | G. A. Broderick | feed protein analysis,rumen undegraded protein (RUP),EAA composition | G. A. Broderick1 | "Crude protein has been estimated since the mid-19th century as N × 6.25. Dependance on Kjeldahl assays for feed N has been largely replaced by safer and more precise elemental N analyses; however, elemental analyzers also detect nitrate-N as part of total N. Total feed N itself says little about protein utilization. In dairy cattle nutrition, we must quantify feed contribution to RDP and RUP, plus we need to know the EAA composition of RUP digested in the small intestine. Feed RDP and RUP values are largely estimated indirectly using rates of CP disappearance from in situ bags; assumed rumen passage rates, and proportions of feed protein degraded and escaping the rumen are computed applying simple exponential models. In situ techniques have proven useful for more than 50 yr, but the assay has at least 3 inherent flaws: (1) solubility affects rate of CP disappearance and not all soluble proteins are equally degraded; (2) microbial CP contamination of in situ residues underestimates degradation, particularly for low CP feeds; and (3) nutritional value of feed RUP is largely based on digestibility and EAA analyses of feed before the in situ phase. Intestinal RUP digestibility can be estimated by a “3-step assay” where in situ residues from a single in situ incubation are subjected to proteases mimicking in vivo abomasal and intestinal digestion; however, both degradation and passage rates influence the correct incubation time. Published in situ RDP/RUP values for certain feeds proved unreliable when fit into the NASEM protein model, requiring alteration of rumen passage rates. Determination of feed EAA content requires acid hydrolysis plus basic hydrolysis for Trp; recently, mathematical adjustments were used to correct for loss or incomplete release of AA during hydrolysis. Modern analytical methods have reduced analysis time and improved accuracy of AA determination; NIRS calibrations for EAA quantitation are being developed. The NASEM model estimates milk protein yield from supply of several EAA not just that first-limiting, thus supply of all EAA should be known." |
| Ruminant Nutrition Symposium: Joint ADSA-NANP-ASAS-PSA Session—Anomalies in Analyzed Nutrient Composition of Feedstuffs | Symposium | NANP Session | 2025/06/24 09:00:00 | t93639 | Watch | 1373 | Success and continuing challenges in analyzing nonfiber carbohydrates. | 4 | M. B. Hall | starch,nonfiber carbohydrate,analysis | M. B. Hall1 | "Analysis of non-NDF carbohydrates (NFC) and their use in dairy cattle nutrition has progressed as we’ve partitioned a by-difference fraction into more nutritionally relevant fractions, but challenges remain. Currently, measured fractions include starch and water-soluble carbohydrates (WSC), and there is a calculated by-difference residual fraction (BDRF) that encompasses pectins, mixed-linkage β-glucans, and other unmeasured NFC. Starch analysis on gelatinized samples defines starch as glucose released by the hydrolytic action of thermostable ∝-amylase and amyloglucosidase times 0.9 to account for the weight of water added by hydrolysis. Analyses run at neutral pH give reduced values; failure to account for free glucose in samples inflates values. Without use of alkali or other chemical agent for gelatinization, only non-resistant starch is measured. The WSC encompass mono-, di-, and oligo-saccharides, and some polysaccharides such as fructans. In this empirical assay, samples are extracted with warm water, the sample centrifuged or filtered to remove particulate matter, and the extract analyzed using the phenol-sulfuric acid assay, typically using sucrose as the standard. Because different standards (e.g., glucose, lactose, sucrose) give different standard curves, use the likely predominant WSC in a sample as the standard for that sample. Because WSC will have some compositional diversity in most if not all samples and are measured against 1 standard, the WSC value will be an estimate. Water-soluble starch is detected as both starch and WSC. The WSC extract can be analyzed for free and enzymatically released glucose, allowing correction of the starch value for soluble starch. Long chain fructans and lactose are measured in WSC, but are not soluble or measured if 80% ethanol is the extractant. The BDRF is problematic. It is comprised of carbohydrates and unmeasured non-carbohydrates, and is affected by nitrogen factors and analytical error; the variance of BDRF values equals the sum of the variances of the analyses used to calculate them. Approach calculation and nutritional interpretation of BDRF with caution." |
| Ruminant Nutrition Symposium: Joint ADSA-NANP-ASAS-PSA Session—Anomalies in Analyzed Nutrient Composition of Feedstuffs | Symposium | NANP Session | 2025/06/24 09:00:00 | t93516 | Watch | 1374 | Assessing accuracy and validity of assays from commercial feed analysis laboratories. | 5 | N. Schlau | feed analysis,nutrient composition,analytical variability | N. Schlau1 | "Accurate and consistent analysis of feedstuffs is fundamental to supporting livestock nutrition, ration formulation, and research. However, multiple sources of error can obscure true compositional differences and introduce uncertainty into feed evaluation. Analytical error begins at collection, where factors such as inadequate sampling techniques and improper handling affect results before the sample even reaches the laboratory. Classification and sample preparation introduce further opportunities for error (e.g., misidentification or contamination). Near-infrared reflective spectroscopy (NIR) has become essential for ration formulation because it is a rapid and economical analysis. However, traditional NIR calibrations depend on pre-identification of sample types. Misidentification significantly reduces accuracy of predictions, and statistical tools for detecting such samples are imprecise. Contamination can occur during collection, sub-sampling, or processing, also impacting accuracy and interpretation of results. To mitigate these challenges, it is crucial that commercial feed laboratories implement quality assurance measures to ensure accuracy and validity of results. Many nutritional analyses are empirical measurements; the result is not a specific ion or molecule but is defined by the assay used to measure it. This makes quality control particularly challenging because we cannot rely on known chemical standards. Instead, systemic error is monitored through participation in certification programs and occasional round robin testing to assess whether there are consistent biases in a particular analysis. Internally, we use control charts to track trends and detect drifts requiring correction. Individual sample errors must also be identified, which are addressed through plausibility checks, including comparisons to historical data and expected ranges. The presentation concludes with a discussion on interpreting outlier results, providing examples of how a commercial laboratory differentiates analytical errors stemming from technical issues versus true outliers that challenge established nutritional assumptions." |
| Ruminant Nutrition Symposium: Joint ADSA-NANP-ASAS-PSA Session—Anomalies in Analyzed Nutrient Composition of Feedstuffs | Symposium | NANP Session | 2025/06/24 09:00:00 | t93419 | Watch | 1375 | Development of an evergreen, interactive, and consolidated dataset of feedstuff nutrient composition. | 6 | R. N. Dilger | National Animal Nutrition Program,feed composition database,nutrient variability | R. N. Dilger1 | "The objective of this presentation is to highlight how the National Animal Nutrition Program (NANP) Feed Composition Database addresses persistent challenges in feed analysis by providing a continuously updated, standardized, and publicly accessible dataset. Accurate characterization of feedstuffs is essential for formulating balanced diets, optimizing animal performance, and ensuring economic and environmental sustainability in livestock production. However, unexplained variation in nutrient composition, methodological inconsistencies, and gaps in available data complicate precise nutrient delivery. The NANP Feed Composition Database is designed to mitigate these challenges by consolidating compositional data from a wide variety of feedstuffs, enabling more accurate predictions of nutrient availability and utilization as part of the feed formulation workflow. This dynamic resource integrates historical and contemporary data, ensuring flexibility to incorporate emerging analytical methods while maintaining a consistent framework for diet formulation and modeling applications. By synthesizing diverse data sources, the database serves as a cornerstone for advancing nutritional science, enhancing the precision of nutrient requirement models, and improving decision making in feed formulation across production systems. As analytical techniques evolve and new feed ingredients emerge, a centralized, evergreen database is essential for supporting nutritionists across species. The NANP Feed Composition Database provides the foundation needed to bridge knowledge gaps in nutrient composition research, improve data harmonization, and enhance the practical application of feed analysis in animal nutrition." |
| Teaching Undergraduate and Graduate Education: Early Career Dossiers—Documenting Teaching Effectiveness | Symposium | Teaching/Undergraduate and Graduate Education | 2025/06/24 09:00:00 | t93903 | Watch | 1386 | The importance of teaching experience for academic careers. | 1 | M. M. Schutz | scholarship of teaching and learning,experience,academic career | M. M. Schutz1 | "Documentation of evidence of scholarship in teaching and learning is required for advancing through promotion and tenure in academia. The level of achievement and ways to document scholarship that meets or exceeds expectations differs widely across universities. A sample of guidance documents for evaluation of scholarship in teaching, learning, or instruction was collected from 9 departments of animal science. All documents agreed that delivery of resident credit courses, advising of undergraduate and graduate students, satisfactory student evaluation of instruction, advising, and contributions to curriculum development constituted scholarly activities in teaching. Some institutions included other activities, for example, novel instructional methods, advising undergraduate student clubs, advising undergraduate research, coaching competition teams, and securing external funding of educational programs as scholarly activities. Most documents also required evidence of peer review of teaching, measurement of learning outcomes, and dissemination of pedagogical contributions through publications in scientific or educational journals to measure scholarship of teaching and learning. Nearly all tenure-track positions in animal science programs include a majority or large minority appointment in research as well. Recruiting candidates with substantial evidence of scholarship in teaching and learning is rare, but candidates who have shown interest and gained some experience in scholarly activities related to teaching often predict their future success in teaching. Although experience in teaching is advantageous, interest, passion, innovation, organization, and clarity in presentation are attributes that can also predict achievement in scholarship of teaching and learning." |
| Teaching Undergraduate and Graduate Education: Early Career Dossiers—Documenting Teaching Effectiveness | Symposium | Teaching/Undergraduate and Graduate Education | 2025/06/24 09:00:00 | t94229 | Watch | 1387 | From barns to brains: How classroom research can be used to improve teaching as early career faculty. | 2 | Q. K. Kolar | education,undergraduate,youth programming | Q. K. Kolar1, A. A. Logan2 | "Animal science classes and departments around the United States are filled with students who are interested in animals and animal-related careers. Today, students entering animal science programs come to the classroom with a wide range of experiences with large animals. This is likely due to more limited opportunities to interact with large animal species such as horses and dairy cattle reflecting the shift in population to more urban and suburban settings. The introductory animal management courses pose a particular challenge to instructors as they teach students from a variety of backgrounds, majors, experiences, and interests. The objective of this analysis was to survey students enrolled in introductory species-specific animal science courses at Cornell University and Middle Tennessee State University (MTSU) to assess how background experiences in youth programming related to the course content correlate to performance. Students from MTSU Intro to Horse Care and Use (n = 19) and Cornell Dairy Cattle Principles (n = 56) were surveyed at the beginning and end of the Fall 2024 semester to evaluate how their perceptions and experiences changed through the semester. Of the students who completed the survey at the end of the courses, 38.6% (n = 29) participated in one or more youth programs. Of the youth programs students enrolled in the introductory courses primarily participated in 4-H (n = 23) and FFA (n = 13), and dairy breed or discipline associations (n = 9). Of students who responded they were extremely likely to work in the dairy or equine industry following graduation (n = 23), 78.3% of those students (n = 18) had previously participated in youth programs. Information collected as part of this research is intended to be used to help build collaboration with youth programming and continue to improve course delivery. This work is part of a 3-yr study, with plans for further data to correlate youth involvement with grade success across multiple semesters." |
| Teaching Undergraduate and Graduate Education: Early Career Dossiers—Documenting Teaching Effectiveness | Symposium | Teaching/Undergraduate and Graduate Education | 2025/06/24 09:00:00 | n9309 | Watch | | Panel Discussion | 3 | | | | |
| Teaching Undergraduate and Graduate Education: Early Career Dossiers—Documenting Teaching Effectiveness | Symposium | Teaching/Undergraduate and Graduate Education | 2025/06/24 09:00:00 | t94597 | Watch | 1388 | Undergraduate students’ demographics and extracurricular involvement are associated with course grades in an introductory food-animal science course. | 5 | M. Tipton | student support,student success,higher education | M. Tipton1, J. Ahola1, C. Cramer1 | "The impact of demographic factors and involvement in extracurricular activities (ECA) on student success are well documented in many science disciplines, yet little data exists for animal science programs. The objective of this study was to determine if demographic factors and ECA involvement were associated with students’ final grade in a 100-level Introduction to food animal science course. Students (n = 556) enrolled in the course at Colorado State University during the fall 2021, 2022, and 2023 semesters were anonymously surveyed at semester’s end regarding their final grade and ECA participation. Survey items included multiple choice, Likert-scale, and short answer questions. Multivariable logistic regressions assessed associations between final course grade (pass: A, B, or C; fail: D or F; outcome) and high school GPA (HSGPA; ≥4.00, 3.00–3.99, <3.00), ethnicity (0 = non-white; 1 = white), first-generation (FG) status (0 = no; 1 = yes), volunteering to care for university dairy calves (0 = no; 1 = yes), and involvement with undergraduate research (0 = no; 1 = yes). For each association, odds ratios (OR) and 95% CI were reported with the associated P-values. An interaction occurred between FG and HSGPA (P = 0.03), which showed that the difference in odds of passing between FG and non-FG students is larger at lower GPA levels. Non-white identifying students had lower odds of passing compared with white identifying students (OR: 0.24, CI: 0.14, 0.39; P < 0.0001), and students retaking the course had lower odds of passing the course than first-time enrollees (OR: 0.20, CI: 0.07, 0.59; P = 0.003). Students had greater odds of obtaining a passing course grade when they had volunteered to care for university dairy calves (OR: 2.3, CI: 1.4, 3.8; P = 0.002) or participated in department research (OR: 8.4, CI: 1.1, 62.0; P = 0.013), compared with students who did not. This study highlights the roles of involvement and demographics in academic performance and can be used to inform future student support programs in animal science disciplines." |
| Teaching Undergraduate and Graduate Education: Early Career Dossiers—Documenting Teaching Effectiveness | Symposium | Teaching/Undergraduate and Graduate Education | 2025/06/24 09:00:00 | t94145 | Watch | 1389 | The role of mentoring in graduate education and career development. | 6 | A. Faciola | career pathways,intercultural competence,transferable skills | T. Martins1, A. Faciola2 | "Graduate students play a pivotal role in advancing science, education, and extension, particularly in the field of animal and dairy sciences. As expectations on faculty productivity rise, effective mentoring becomes crucial for shaping future professionals and supporting institutional goals. This presentation will emphasize the distinction between academic advisors and mentors, arguing that while advisors guide short-term academic objectives, mentors foster long-term personal and career development. It highlights the importance of providing both roles within graduate programs and training faculty to be effective mentors. Structured mentorship programs, supported by tools like Individual Development Plans and mentor-mentee compacts, can improve student satisfaction and reduce attrition rates. The presentation will highlight how the growing transition of PhD holders from academia to industry underscores the need for graduate programs to integrate transferable skills into the curriculum. Additionally, intercultural competence and technological proficiency, particularly in artificial intelligence, are identified as essential for students’ success in a globalized job market. These efforts also contribute to the long-term success of academic institutions by modernizing graduate programs to prioritize flexible, student-centered mentoring, which prepares highly skilled and highly sought-after graduates who drive innovation and advance research and development in their fields, while also keeping these programs relevant and attractive to employers in a rapidly changing career landscape." |