Journal of animal science最新文献

{"title":"PS11-7. Effects of Weaning Age on Fall-calving Cow Performance and Economics.","authors":"Jackson B Matthews, Joshua C McCann, Greg R Osman, Daniel W Shike","doi":"10.1093/jas/skag272.437","DOIUrl":"https://doi.org/10.1093/jas/skag272.437","url":null,"abstract":"The objective was to evaluate the effects of weaning age on cow performance and economics. A two-year study was conducted utilizing commercial Angus-influenced, fall-calving cows (n = 138/year). Cow/calf pairs were stratified by dam age and BW and were allotted to 6 groups/year with 23 cows/group. Each group was randomly assigned to 1 of 2 treatments: early wean (EW) or normal wean (NW). Calves were weaned from EW cows at 82 ± 11 days of age (day 0) and NW calves were weaned from cows at 208 ± 9 days of age (day 125). At early weaning, all groups were randomly assigned to pastures that were approximately 4.05 hectares until weaning of NW calves on day 125. All cows received free-choice grass hay and were supplemented with a 50/50 blend of corn and dried distillers grains (1.13 kg/cow·day-1 for EW cows, 2.27 kg/cow·day-1 for NW cows). Reproductive performance was analyzed for both AI pregnancy and overall pregnancy results from the first year as well as the subsequent breeding season. Cow BW was collected at breeding, pregnancy check, weaning, pre-calving, subsequent breeding, and subsequent weaning. Cow BCS was collected at weaning and subsequent breeding season. Economics were based on 3-year averages of annual cow costs and feeder calf values. Reproductive data were analyzed using the GLIMMIX procedure of SAS 9.4 and all other data were analyzed using the MIXED procedure of SAS 9.4. There was no difference (P = 0.99) in cow BW at the beginning of the trial; however, EW cows had greater BW (P ≤ 0.05) than NW cows at pregnancy check, weaning, pre-calving, and subsequent breeding. There was a tendency for EW cows to have a greater (P = 0.06) BW at pregnancy check of the subsequent breeding season. The EW cows had a greater (P < 0.01) BCS at weaning of the NW calves (day 125). The EW cows tended to have greater (P = 0.09) BCS in the subsequent breeding season. There were no differences (P ≥ 0.32) in calf birth BW in subsequent calving season. Calf weaning BW in subsequent season was greater (P = 0.03) for EW cows. The value of NW calves at weaning was greater (P < 0.01) than the value of EW calves at weaning ($1,586.66 vs. $1,247.72, respectively). The NW cows were more (P < 0.01) profitable than the EW cows ($582.81 vs. $185.72, respectively). There were no differences (P ≥ 0.17) in AI pregnancy or overall pregnancy for both the initial and subsequent breeding season. In conclusion, normal weaning calves in a fall-calving system was more profitable and had no effect on reproductive performance or calf birth BW, but did result in lower cow BW, BCS, and subsequent calf weaning BW.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"41 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149077620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PS8-12. Effects of Essential Oil Supplementation on Health and Performance of Newly Received Beef Cattle Grazing Bermudagrass.","authors":"Miriam A Snider, Cody Shelton, Cyle C Jones, Grayson Gourley, Henry Hilscher, Daniel Rivera","doi":"10.1093/jas/skag272.562","DOIUrl":"https://doi.org/10.1093/jas/skag272.562","url":null,"abstract":"Essential oils have been evaluated as natural feed additives due to their potential rumen-modulating and antioxidant properties, which may improve feed efficiency and animal performance. However, health and performance responses to essential oil supplementation in receiving cattle in forage-based systems have been inconsistent. The objective of this study was to assess the health and performance of newly received heifers grazing bermudagrass (Cynodon dactylon) that were limit-fed dried distillers grains (DDGS) with or without a proprietary blend of essential oils. A total of 72 crossbred beef heifers (235.4 ± 0.64 kg) were shipped from a contract facility in Montgomery, AL to the Southwest Research and Extension Center Stocker Unit (Hope, AR). After a holding period of 6 h, animals were ear tagged, administered lutalyse, weighed, and allowed to rest for 48 h prior to the initiation of the study. On d0, cattle were vaccinated against respiratory and clostridial pathogens, de-wormed, and administered metaphylactic tilmicosin. Animals were stratified by weight and assigned to one of two treatment groups: 1) DDGS supplement only (CON; n = 6 paddocks) or 2) DDGS supplement top-dressed with an essential oil blend (EO; 0.50 g/heifer daily; n = 6 paddocks). Treatments were administered over a 42-d period with supplements offered to heifers at a rate of 2.0% body weight (BW). Heifer BW was recorded on d0, d21, and d42 with animal health monitored daily. Average daily gain (ADG), BW, and gain:feed (G:F) were analyzed using the MIXED procedure of SAS with treatment as a fixed effect and block as a random effect. Pasture served as the experimental unit. Morbidity and mortality were analyzed using the GLIMMIX procedure as nonparametric data with binomial distribution. Heifer BW did not differ between groups through the 42-d supplementation period (P > 0.05). However, on a deads-in basis, ADG (P = 0.05) and G:F (P = 0.04) were greater for EO heifers between d22 and d42. Neither ADG or G:F differed between d0 and d21 nor for the duration of the study between treatment groups (P > 0.05). On a deads-out basis, both ADG and G:F were greater for EO heifers between d0 and d21 (P ≤ 0.02) and between d0 and d42 (P ≤ 0.04). Although morbidity and mortality did not differ between treatment groups (P > 0.05), incidences of morbidity in EO heifers occurred earlier in the supplementation period compared to CON heifers (P = 0.001). These results suggest that supplementation with essential oils may improve gain efficiency but did not influence overall health outcomes during the receiving period.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"5 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149077589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PS5-20. Experiential Learning Influences Impressions and Reflections of the Beef Industry in College Students.","authors":"Victoria Garcia, Alice P Brandao, Tryon A Wickersham, Merritt L Drewery","doi":"10.1093/jas/skag272.388","DOIUrl":"https://doi.org/10.1093/jas/skag272.388","url":null,"abstract":"Experiential learning (EL) opportunities are high-impact experiences where students are immersed in environments to view and perceive practical applications of course concepts. Students pursuing animal science degrees may benefit from EL due to the applied nature of the discipline and because a greater proportion are now coming from urban or suburban areas and do not have prior agricultural experiences. The objective of this study was to assess the impact of EL on college students' impressions and reflections of beef industry concepts during a beef industry tour using qualitative instruments. Two cohorts of students from Texas A&M University (n = 53) or Texas State University (n = 21) attended a 5-day beef industry tour in the Texas Panhandle in May 2022 or 2024 which included cow-calf operations, feedlots, a packing plant, and allied industries. Students experienced beef production and interacted with industry representatives. At the beginning of the tour, students were given journals with prompts to be reflected on throughout the tour. Eight prompts from each journal across both cohorts were coded, categorized, and merged into themes of Reflection, Location, Information, Impressions, Sustainability, Public Perceptions, and Concepts emphasizing the beef industry. Pearson correlation analysis was conducted between codes within the same journal and significant correlations (P ≤ 0.001) were included in the matrices for network analysis. Of the nine clusters that emerged (Q = 0.682), one was especially interconnected and contained several nodes that belonged to the parent codes of Impressions, Public Perceptions, Reflection, Concepts, and Information. Within this cluster, there was strong co-occurrence among codes related to industry characteristics, operational performance, and empathy for producers. Greater betweenness nodes (i.e., those connected to several others) included Sustainable, Fast-paced/Efficient, High-quality product, and Diversification, suggesting these concepts were frequently mentioned together in student journals. This indicates cohesion in students' understanding of how the beef industry is organized and of the value of resulting products. Nodes present in structurally central positions within the cluster exhibited high betweenness - i.e., Empathy for producers/respect for the industry and Sustainable. These nodes linked students' perceptions of the beef industry (e.g., Logistics, Diversification) with value-based judgements (i.e., Poor animal welfare [nested within the parent code of Public Perceptions], Animals cared for [nested within Impressions]). This indicates students understand mechanisms and efforts that underlie beef production while also acknowledging that audiences naïve to livestock production may not understand standard animal husbandry practices and procedures. These data suggest that exposure to beef production via EL promoted formation of an interconnected understanding of the industry in which efficiency, ","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"33 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149077634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"52. Transferability of Methane Emission SNP Effects from Dairy to Beef Cattle Populations.","authors":"Timothy T Houghton, Samla M F Cunha, Madeline J McLennan, Katie M Wood, Angela Canovas, Filippo Miglior, Christine F Baes, Flavio S Schenkel","doi":"10.1093/jas/skag272.090","DOIUrl":"https://doi.org/10.1093/jas/skag272.090","url":null,"abstract":"Transferring single-nucleotide polymorphism (SNP) effects across cattle breeds has often proven to be unreliable for a range of traits, even when using higher-density SNP panels. However, methane production (MeP) may exhibit greater portability across breeds because it has not been subjected to the prolonged, intense selection applied to many economically important traits. The objective of this study was to predict direct genomic values (DGVs) for MeP in a crossbred beef population using SNP effects estimated in a dairy population and to assess correspondence between DGVbased groupings and observed emission levels. The dairy training set comprised 648 Canadian firstparity Holstein cows between 110 and 210 days in milk, measured with a GreenFeed system from 2017 to 2025 for 5 consecutive days, 3-4 times per day. Outlier records 3 standard deviations from the mean were removed, and records were averaged by day and then by week to yield a single record per cow. The pedigree contained 6,687 animals across 12 generations, out of which 2,787 animals were genotyped using the Illumina 50k SNP panel, including the 648 cows recorded for MeP. Genomic breeding values were estimated by fitting a linear animal model using single-step GBLUP, and SNP effects were back-solved using the software POSTGSF90. The target beef population consisted of 77 Angus x Simmental cows in their final trimester of gestation (average parity = 3). Beef cow MeP was measured using two voluntary GreenFeed systems over two 7-day collection periods. After excluding cows with insufficient MeP records (< 30) and those>3 standard deviations from the mean, 73 animals remained. Records were averaged by day and then across all days to create 1 record per cow. Cows were genotyped using the Illumina 100k SNP panel; 29,434 SNPs common to both panels were used for DGV prediction. DGVs were computed as the sum over loci of genotype dosages multiplied by their corresponding SNPeffect estimates from the Holstein population and partitioned into three tertiles (lowest, middle, highest values). When comparing DGV tertiles to MeP tertiles, out of the low-emitting MeP cows, 12/24 (50%) cows were correctly classified as low-emitters by their DGVs, while 6/24 (25%) were misclassified as high-emitters. Out of the high-emitting MeP cows, 9/24 cows (37.5%) were correctly classified as high-emitters, while 4/24 (16.7%) were misclassified as low-emitters. The study shows that there is moderate ability to phenotypically classify the 1/3 lowest or 1/3 highest MeP Angus x Simmental cows using about 30k SNPs from a Holstein population. However, the beef dataset size used in this investigation is small and limits broader inferences. Ongoing work will compare DGVs to adjusted MePs for known sources of environmental variation and will use larger datasets to validate and refine these preliminary findings.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"16 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149077522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PS4-1. Changes in Steer Gait and Joint Physitis During the Finishing Phase.","authors":"Gracie Kristufek, Annette M McCoy, Joshua C McCann","doi":"10.1093/jas/skag272.418","DOIUrl":"https://doi.org/10.1093/jas/skag272.418","url":null,"abstract":"The objective of this study was to evaluate changes in gait and rear leg physitis development during the finishing phase of feedlot cattle in a slatted floor facility. Inherent individual differences in structural conformation and changes over time may be related to cattle mobility and growth performance in a slatted floor facility. Accelerated growth of feedlot cattle may also present challenges for proper joint development. Simmental × Angus steers (n = 22; body weight = 284 kg) were evaluated during the early (d 61) and mid-finishing (d 144) phases in an indoor slatted facility. Individual steers videos were recorded using a Panasonic Lumix DMC-FZ1000 recording at 120 frames per second camera and four frames were selected to estimate gait traits in ImageJ. Additionally, body morphometric measurements were determined for hip height and cannon bone length to generate a pixel-to-centimeter conversion for each animal. Hock and cannon bone circumference were also measured. Radiographic imaging was used to assess structural conformation of the rear leg, including dorsoplantar (DP) and lateral views of both hock and fetlock joints. Images were evaluated for physitis and classified as none, very mild, mild, moderate, or severe. Data were analyzed using the MIXED procedure of SAS 9.4. Hip-to-hock length increased (P < 0.01) from 63.5 cm on d 61 to 80 cm on d 144 and corresponded with cattle growth. However, there was no change (P > 0.32) over time for front and rear step length. There was also no change (P > 0.17) in front and rear stride length from d 61 to 144. Hock circumference increased (P < 0.01) over time from 43.9 cm on day 61 to 48 cm on day 144. Cannon bone circumference increased (P < 0.01) over time from 22.6 cm on day 0 to 24.1 cm on d 144. On d 61, radiographs indicated 80% of steers had very mild or mild physitis in rear fetlock joints, but this did not increase by d 144. On d 61, 50% of steers had mild physitis and 30% had moderate physitis in rear hock joints. However, physitis severity increased by d 144 such that moderate or severe physitis was observed in more than 80% of rear hock radiographs. In conclusion, step and stride length did not increase with time during the finishing phase and may be related to greater severity of physitis observed in the rear hock joints of feedlot cattle in slatted floor facilities.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"36 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149077529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PS12-11. Prepartum Rumen-Protected B Vitamin Complex Supplementation Improves Maternal Reserves, Colostrum Yield, and Reproductive Responses in Beef Cows.","authors":"Luiza Kladt, Ana Clara Araújo, Salvador Venuto, Jenifer Varizi, Sarah Dean, Victoria Asselstine, Dalton Henriques, Nicola Serão, Claudia B Sampaio, Mateus P Gionbelli, Marcio S Duarte","doi":"10.1093/jas/skag272.441","DOIUrl":"https://doi.org/10.1093/jas/skag272.441","url":null,"abstract":"Late gestation is characterized by increased metabolic demands that may compromise maternal reserves and influence fetal development and postpartum performance in beef cows, and B-complex vitamins act as essential cofactors in oxidative metabolism, gluconeogenesis, and one-carbon metabolism, with their availability potentially becoming limiting during periods of high physiological demand despite ruminal synthesis. This study evaluated the effects of prepartum rumen-protected B-complex vitamin supplementation on maternal metabolism, body composition, colostrum production, placental traits, calving outcomes, and postpartum performance and reproductive responses in beef cows. Fifty-six pregnant Nellore cows carrying male fetuses (initial BW = 444.1 ± 12.7 kg) were maintained under grazing conditions until day 179 of gestation and then adapted to individual pens while receiving 70% of gestational requirements; from day 193 of gestation until calving, cows were assigned to either a control group (n = 28) or a B-vitamin-supplemented group (n = 28), with supplemented cows receiving the same basal diet as controls plus 3 g/cow/day of a rumen-protected B-vitamin blend (Lactation VB®, Jefo, St. Hyacinthe, QC, Canada). Data were analyzed using mixed models (PROC GLIMMIX, SAS), including treatment as a fixed effect, day and the treatment × day interaction for repeated measures, parity as a covariate, and sire as a random effect. B-vitamin supplementation did not affect circulating glucose, NEFA, or BHB concentrations (P > 0.05), nor body weight or average daily gain during late gestation (P > 0.05); however, at 43 and 15 days prepartum, supplemented cows had greater body condition score (P ≤ 0.01), ribeye area (P < 0.01), and subcutaneous fat thickness (P = 0.01) compared with controls. At calving, supplemented cows exhibited greater body weight (458.09 ± 15.23 vs. 426.29 ± 15.33 kg; P = 0.04) and body condition score (4.65 ± 0.29 vs. 3.78 ± 0.30; P = 0.01), as well as increased colostrum yield (1.86 ± 0.20 vs. 1.41 ± 0.20 kg; P = 0.03), whereas colostrum quality was not affected (P > 0.05). Placental weight was greater in supplemented cows (P = 0.04), while calf birth weight and neonatal vigor were not affected (P > 0.05). Additionally, supplemented cows had reduced odds of endometritis (P = 0.04), greater likelihood of complete uterine involution at 30 days postpartum (P = 0.02), and a tendency for increased pregnancy probability (62.9 vs. 34.8%; P = 0.06), without effects on ovarian follicular dynamics (P > 0.05); no differences were observed in average daily gain from 20 to 100 days postpartum (P = 0.36). In summary, prepartum rumen-protected B-complex vitamin supplementation improved maternal body reserves, increased colostrum yield, and enhanced uterine health and reproductive outcomes, without major effects on postpartum productive performance.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"36 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149077646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PS6-15. Modulation of Intestinal Salmonella Enteritidis Colonization by Dietary Onion Peels in Broiler Chickens.","authors":"Odinaka Iwuozo, Oluwabunmi Apalowo, Oluteru E Orimaye, Safiu Suberu, Samuel Quarmyne, Lekan Elegbede, Olanrewaju Binuyo, Deji Abiodun Ekunseitan, Yewande Fasina","doi":"10.1093/jas/skag272.391","DOIUrl":"https://doi.org/10.1093/jas/skag272.391","url":null,"abstract":"Salmonella Enteritidis (SE) remains a major foodborne pathogen of global concern, posing significant risks to poultry production and public health. Onion peel powder (OPP) is rich in polyphenolic compounds that have potential to reduce intestinal Salmonella colonization and support improved growth performance in broiler chickens. The objective of study is to evaluate the efficacy of OPP on SE colonization and growth performance in broiler chickens. Ross 708 (day-old) broiler chicks (n = 500, male) were randomly allocated to five treatments (5 replicates of 20 chicks each) in completely randomized design. Treatments include CON, CONSE (0 g/kg OPP), BMDSE (0.055 g/kg bacitracin methylene disalicylate), OPPXSE (3 g/kg OPP), and OPPYSE (6 g/kg OPP), all fed corn-soybean meal basal diets. All treatments, except CON, were challenged with 1 mL SE (4.80 × 10⁸ CFU/mL) at 2 days of age. On days 2, 5, 12 and 19 post-challenge (PC), cecal lobes were collected for SE enumeration on xylose lysine deoxycholate agar. The birds were weighed on days 5 and 19 PC to evaluate body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR). Data were analyzed by one-way ANOVA using SAS software (P < 0.05). On day 2 PC, chicks in CON were negative for SE, while chicks in SE-challenged treatments had ceca SE concentrations of 4.835 (CONSE), 4.568 (BMDSE), 4.540 (OPPXSE), and 4.402 (OPPYSE) Log10 CFU/g (P > 0.05), thus confirming SE infection in the latter birds. On day 5 PC, chicks in OPPYSE had lower SE (3.185 Log10 CFU/g; P < 0.05) compared to those in CONSE (4.659 Log10 CFU/g). By days 12 and 19 PC, chicks in OPPXSE (1.184 and 0.283 Log10 CFU/g) and OPPYSE (0.586 and 0.108 Log10 CFU/g) had lower (P < 0.05) ceca SE concentrations compared to CONSE chicks (3.879 and 1.983 Log10 CFU/g) respectively. BWG was unaffected (P > 0.05) on days 5 and 19 PC across all treatments, whereas FI was transiently reduced (P < 0.05) in OPP-fed chicks on day 5 PC but remained unchanged by day 19 PC, indicating stable feed consumption during the reduced SE colonization. Moreover, on days 5 and 19 PC, OPP-supplemented treatments showed improved (P < 0.05) FCR relative to other groups, reflecting more efficient nutrient utilization as birds redirected energy toward lowering SE colonization and supporting intestinal health. Overall, OPP supplementation effectively reduced intestinal SE colonization and improved feed efficiency without compromising growth, demonstrating its potential as a functional dietary strategy to enhance intestinal health and performance in broiler chickens.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"12 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149077677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PS12-8. Prevalence and Distribution of Major Bacterial Pathogens in Liver Abscesses of Beef-on-dairy Cattle.","authors":"Haitham Alneaemy, Raghavendra G Amachawadi, Haiyan Wang, Harith M Salih, Taghreed S Mahmood, T G G Nagaraja","doi":"10.1093/jas/skag272.347","DOIUrl":"https://doi.org/10.1093/jas/skag272.347","url":null,"abstract":"Liver abscesses represent a significant economic issue for the beef cattle industry, accounting for about 67% of liver abnormalities in slaughtered cattle in the U. S. The primary causative agents, believed to originate from the rumen, include Fusobacterium necrophorum (subspecies necrophorum and funduliforme), Trueperella pyogenes, and Salmonella enterica. Prevalence ranges 10–20%, reducing carcass value by up to $38 per animal for severe cases. This study aimed to determine the prevalence and distribution of major bacterial pathogens associated with liver abscesses in beef-on-dairy cattle and to assess associations with liver abscess score, sex, and feedyard-level clustering. A total of 219 liver abscesses were collected at slaughter from two feedyards, consisting of 15 and 21 lots, respectively. Abscesses with intact capsules were sampled and processed for bacterial isolations and identifications under anaerobic, aerobic, and with 5% CO2 using enrichment and selective media. Pathogen prevalence was evaluated by culture and quantitative PCR (qPCR) methods. Data analyses were performed using R (version ≥ 4.5.2), with liver abscess samples as the unit of analysis. Descriptive statistics summarized pathogen prevalence as proportions and stratified by liver abscess severity (A+, A, A−), sex (heifer vs. steer), feedyard, and lot. Associations between pathogen prevalence and categorical predictors were assessed using Pearson’s chi-square or Fisher’s exact tests. Logistic regression models with a binomial distribution and logit link were fitted for each pathogen to evaluate main effects of liver abscess score and sex, their interaction, and potential clustering by lot nested within feedyard. Patterns of pathogen co-occurrence were summarized descriptively, and heatmaps visualized within-score prevalence of individual pathogens and multi-pathogen combinations. Statistical significance was evaluated at α = 0.05. Fusobacterium necrophorum subsp. necrophorum was the most frequently detected pathogen (culture: 90.4%; qPCR: 92.7%), followed by T. pyogenes (28.3%; 53.0%), subsp. funduliforme (19.2%; 57.1%), and S. enterica (3.7%; < 1 %). Culture-based T. pyogenes prevalence was higher in steers than heifers (39.3% vs. 20.8%; p = 0.004), while S. enterica was detected only in heifers (6.2% vs. 0%; p = 0.022). Liver abscess score was not significantly associated with culture or qPCR prevalence of any pathogen. Co-occurrence analyses indicated that single-pathogen infections dominated, while multi-pathogen abscesses were rare. The qPCR-based detection revealed higher prevalence of subsp. funduliforme and T. pyogenes compared with culture. Logistic regression confirmed sex-specific differences for T. pyogenes and S. enterica, whereas liver abscess score was not a significant predictor. Together, these results provide a characterization of pathogen prevalence in beef-on-dairy liver abscesses, highlighting sex-related differences for select pathogens, and e","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"48 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149077908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PS8-7. Swathgrazing Polycrops to Build Cow-Calf Resilience and Profitability in Alberta.","authors":"Mary-Juliet N Uwakwe, Janet Nowosad, Carien Vandenberg, Erick Santos, Obioha N Durunna","doi":"10.1093/jas/skag272.565","DOIUrl":"https://doi.org/10.1093/jas/skag272.565","url":null,"abstract":"The cow-calf industry in Alberta accounts for over 40% of Canada’s beef breeding stock; therefore, evaluating factors that improve the sustainability and profitability of the cow-calf sector will positively impact Canada’s economy. Swathgrazing is a management practice in which annual forage crops are cut and left in windrows for livestock to graze during the fall or winter. This study assessed animal performance, mineral supplement intake, and carbon dioxide (CO2) and methane (CH4) emissions from cow-calf pairs. The study was laid out in a randomized complete block design with two treatments and three replicates (6 paddocks in total measuring 12-ha (213.4 x 625 m)). Treatments were either a monocrop system of CDC-SO1 oats (Avena sativa L.) or a polycrop forage system (oats, forage peas (Pisum sativum L.), turnips (Brassica rapa L.), and rape (Brassica napus L.)). Eighteen cow-calf pairs were stratified by body weight, and three pairs were allocated to each paddock of 2-ha and dimensions of 35.6 x 625 m. Animals grazed for 72 days and had ad libitum access to an automatic feeding unit to collect individual mineral intake. Greenhouse gas (GHG) emissions were tracked using a Greenfeed Emissions Monitoring System. Animals were weighed at the start (SOT) and end (EOT) of the trial, and every 21 days during the trial. Backfat ultrasound scans were collected at SOT (day 0) and EOT (day 72) of the trial. Statistical analyses of animal performance, mineral intake, and CO2 and CH4 emissions data were performed using PROC MIXED in SAS. Fixed effects included treatments (oats and polycrops), animal class (calves and cows), and their interaction, with paddock as a random effect in the analyses of mineral intake and GHG emissions. There was a Treatment × Class interaction (P = 0.02) for average daily gain (ADG). The calves gained 0.89 kg/day under the oats monocrop system and 0.92 kg/day under the polycrop system. In contrast, the cows gained 0.33 kg/day under the oats monocrop system and lost 0.09 kg/day under the polycrop system. Pairwise comparisons showed that oats significantly improved ADG in cows compared with polycrop (P = 0.003), whereas no significant difference between treatments was observed in calves (P = 0.83). Mineral intake was influenced by animal class (P = 0.01), with cows consuming more than calves. The GHG emissions were also affected by animal class (P < 0.01). Cows produced more CO2 and CH4 than calves in both treatments. The results showed that calves’ ADG increased regardless of the treatment, and the cows benefited more from oats. There was no difference in GHG emissions between the treatments.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"33 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149078019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PS10-16. Effects of Short Chain Fatty Acids Derivatives on Local Recruitment of Intestinal Immune Cells and Gene Expression of Weanling Pigs Challenged with F4 and F18 Enterotoxigenic Escherichia coli.","authors":"Shuhan Sun, Sangwoo Park, Yating Zhao, Youngmin Park, Linh Truong, Jinuk Nam, Supatirada Wongchanla, Peng Ji, Xunde Li, Yanhong Liu","doi":"10.1093/jas/skag272.519","DOIUrl":"https://doi.org/10.1093/jas/skag272.519","url":null,"abstract":"The objective of this study was to investigate the effects of monobutyrin, monovalerin, or their combinations on intestinal gene expression and local recruitment of intestinal immune cells of weanling pigs infected with F4 and F18 enterotoxigenic Escherichia coli (ETEC). A total of 176 pigs (7.14 ± 1.12 kg, 88 gilts and 88 barrows, 21 to 24 days old) were housed individually and randomly allotted into 11 treatments (n = 16) in a randomized complete block design with group and sex as blocks. The treatments included a negative control (NC) without ETEC infection, a positive control (PC) with ETEC, and 9 additional groups supplemented with 50 mg/kg carbadox, 2,500 mg/kg zinc oxide (ZnO), 0.10% sodium butyrate, 0.10% or 0.15% monobutyrin, 0.10% or 0.15% monovalerin, a low dose combination (0.05% monobutyrin and 0.05% monovalerin), and a high dose combination (0.075% monobutyrin and 0.075% monovalerin), respectively. The experiment lasted for 28 days, including 7 days’ adaptation and 21 days’ post inoculation (PI). After the adaptation, all piglets except those in the NC group were orally inoculated with 3 mL dose containing equal amount of 5 × 109 CFU F4 and 5 × 109 CFU F18 ETEC for three consecutive days. Sixty-six pigs (n = 6) were euthanized to collect ileum segment on d 5 PI for immunohistochemistry assay. Ileal mucosa were collected to extract RNA for analyzing the expression of genes related to immunity and gut integrity by qPCR. Cell count of macrophage and neutrophil per villi area were measured. Data were analyzed by ANOVA using SAS with a randomized complete block design using pig as experimental unit. On day 5 PI, pigs supplemented with low dose combination had greatest (P < 0.01) macrophage cells/mm2 compared with other treatments. Supplementing 0.10% monobutyrin, 0.10% monovalerin, 0.10% combination and 0.15% combination yielded greater (P < 0.01) recruitment of macrophage cell/mm2 compared with NC. Pigs in antibiotics, ZnO, sodium butyrate, 0.10% and 0.15% monobutyrin had average macrophage cell count per villus comparable (P < 0.01) to that of NC. Pigs supplemented with 0.15% monovalerin and high dose combination had greater (P < 0.05) neutrophil recruitment compared with pigs in NC, PC, antibiotics, and ZnO. Supplementing high dose ZnO, sodium butyrate, 0.10% and 0.15% monobutyrin, and 0.15% combination significantly lowered (P < 0.05) the expression of CFTR compared with PC. Pigs in all supplemented groups had lower (P < 0.05) expression of IL8 than PC, except 0.10% combination group. In conclusion, dietary supplementation of monobutyrin, monovalerin, or their combination may modulate local intestinal immune cell recruitment and ileal mucosal gene expression of weaning pigs infected with ETEC F4 and F18.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"1 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149077535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}