Journal of animal science最新文献

{"title":"PS10-15. Nitrogen Balance in Growing Pigs Fed Diets Containing Varying Levels of Standardized Ileal Digestible Threonine and Soybean Hulls.","authors":"Mariana G Lacerda, Kallita L S Cardoso, Gabriela R Silva, Elisa A Nogueira, Vanessa P Abreu, Amoracyr J C Nuñez, Allan P Schinckel, Luiz F Brito, Aline S M Cesar, Vivian V Almeida","doi":"10.1093/jas/skag272.518","DOIUrl":"https://doi.org/10.1093/jas/skag272.518","url":null,"abstract":"Fiber-rich feedstuffs, including soybean hulls (SBH), can reduce nutrient digestibility and increase endogenous losses of threonine (Thr), resulting in a greater Thr requirement for protein deposition. A nitrogen (N)-balance study was conducted to determine whether supplementing standardized ileal digestible (SID) Thr above the estimated NRC (2012) requirements would improve body protein deposition when pigs are fed diets with SBH. Four growing barrows (Large White x Landrace x Duroc; 37.73 ± 1.22 kg initial BW) were allotted to a 4 × 4 Latin square design with 4 diets and 4 periods. Corn-soybean meal-based diets were used as treatments, which were arranged in a 2 × 2 factorial with 2 levels of SID Thr (0.59 or 0.70%; 100 and 119% of NRC requirements, respectively) and 2 levels of SBH (0 or 15%). Each period lasted 12 d, which comprised 7 d of adaptation to the dietary treatment followed by 5 d of total fecal and urine collection. Daily feed allowance during the collection periods was calculated based on metabolic BW (BW0.75). Feed was offered daily in 2 meals, with 60% provided in the morning (0730 h) and 40% in the afternoon (1600 h), with ad libitum access to water. All data were analyzed using the MIXED procedure of SAS. No SBH × SID Thr interactions were observed for N intake, fecal N output, and apparent total tract digestibility (ATTD) of N. Regardless of SID Thr level, pigs fed SBH diets had greater N intake (P = 0.01) and fecal N output (P < 0.001), but lower ATTD of N (P = 0.001) compared with pigs fed diets without SBH. There was a SBH × SID Thr interaction (P = 0.03) for urinary N output, such that N output in the urine was decreased (P < 0.05) in diets with no added SBH combined with 0.70% SID Thr level. There were no SBH or SID Thr main effects or interactions for N absorbed, N retained, and protein deposition. In conclusion, combining the effects of dietary SBH inclusion and SID Thr level at 119% of NRC-estimated requirements did not increase protein deposition in growing pigs and further indicated that feeding SBH reduced N digestibility without compromising N retention and protein deposition efficiency.","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":"149077530","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":"PS10-13. Effects of Low-protein Amino Acid-balanced Diets on Growth Performance, Protein Metabolism-related Gene Expression, and Gut Microbiota Structure in Yellow-feathered Chickens.","authors":"Xinyue Liang, Sai Zhang, Jinling Ye, Yujie Huang, Dong Ruan","doi":"10.1093/jas/skag272.517","DOIUrl":"https://doi.org/10.1093/jas/skag272.517","url":null,"abstract":"This study aimed to investigate the effects of partial essential amino acid (methionine, tryptophan, arginine, isoleucine) removal from a low-protein diet on growth performance, physiological and biochemical indicators, amino acid transport, intestinal microbiota, and plasma free amino acid profiles in yellow-feathered chickens aged 1-30 days. A total of 1,080 1-day-old female medium-growing yellow-feathered chickens were randomly divided into 6 groups: normal protein group (SD, CP 20.5%), low-protein group (LP, CP 18%), and low-protein groups with removal of 20% methionine (LP-MET), tryptophan (LP-TRP), arginine (LP-ARG), and isoleucine (LP-ILE). Each group consisted of 6 replicates, with 30 chickens per replicate, the experiment lasted for 30-days. The results showed: (1) Growth performance: The final body weight (FBW) and average daily gain (ADG) of the LP group were significantly lower than those of the SD group (P < 0.05). The LP-ARG group exhibited the lowest FBW and ADG and the highest feed conversion ratio (FCR) (P < 0.05), while the LP-ILE and LP-MET groups showed significantly higher protein deposition rates compared to the SD and LP groups (P < 0.05). The LP group exhibited elevated plasma triglycerides (TG), blood urea nitrogen (BUN), and growth hormone (GH), as well as decreased insulin-like growth factor-1 (IGF-1) (P < 0.05). Removal of MET or TRP reduced TG to SD group levels, while removal of ARG or ILE decreased BUN (P < 0.05). The LP-ARG group showed the highest liver alanine aminotransferase (ALT) activity (P < 0.05). The jejunal expression of neutral amino acid transporter (B0AT) and excitatory amino acid transporter 3 (EAAT3) in LP group was significantly upregulated (P < 0.05), with partial recovery after specific amino acids were excluded. The LP group exhibited reduced α-diversity in the cecum microbiota and a decreased ratio of Firmicutes to Bacteroides (P < 0.05). The LP-MET group showed enrichment of beneficial bacteria such as Faecalibacterium, while the LP-TRP group demonstrated enrichment of Firmicutes phylum. The LP-ARG and LP-ILE groups exhibited a trend toward diversity recovery. Furthermore, the LP group exhibited reduced levels of taurine (Tau) and cysteine (Cys) (P < 0.05), with differential responses observed across amino acid restriction groups (e.g., elevated threonine in the LP-MET group and decreased arginine in the LP-ARG group). In summary, arginine restriction in LP diets had the most significant growth inhibitory effect, whereas ILE and MET restrictions could enhance protein deposition. These findings suggest the need for precise amino acid balance to optimize production performance and health in yellow-feathered broilers fed low-protein diets. For image description, please refer to the figure legend and surrounding text. For image description, please refer to the figure legend and surrounding text. For image description, please refer to th","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"10 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149077531","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":"150. Ruminal Microbial Efficiency and Fermentation Characteristics Modeled by the Addition of Methionine, Bound Zn-methionine, or Zinc Sulfate in a Continuous Culture System.","authors":"Beatriz Reis, Jhones O Sarturi, Bradley J Johnson, Allen McDonald, T J Biggs, Jennifer Schutz, Diego M Tosta","doi":"10.1093/jas/skag272.259","DOIUrl":"https://doi.org/10.1093/jas/skag272.259","url":null,"abstract":"The effects of zinc source and additional amino acid on ruminal microbial efficiency and ruminal fermentation characteristics were evaluated. A continuous culture system using ten 1-L dual-flow fermenter chambers (experimental units) were used during three 5-d batches. A generalized complete block design (block = batch) used 3 d for adaptation and 2 d for collections. Treatments were formulated as follows: 1) CONTROL, DI-water; 2) ZnSO4, zinc sulfate [514 mg of zinc/chamber-daily]; 3) ZnMet, zinc-methionine complex [514 mg of zinc +1,004 mg of DL-Methionine/chamber-daily]; 4) DL-Met, DL-Methionine [1,004 mg of DL-Methionine/chamber-daily], and 5) ZnSO4+DL, zinc sulfate plus DL-Methionine added separately (same doses). Two ruminally cannulated steers (BW = 400 ± 50 kg) receiving a steam-flaked corn-based finishing diet were used. Data was analyzed using treatment, time, and interaction as fixed effects and batch as the random effect. The DL-Met treatment tended to be greater than ZnMet (P = 0.11), while not different (P = 0.91) from ZnSO4+DL (treatment × time interaction, P = 0.03). Ammonia-N from ZnSO4-treated chambers (no added DL-Methionine) was not different (P = 0.32) from ZnMet. Chambers receiving the DL-Methionine had greater (P < 0.04) microbial organic matter flow, total N flow, microbial N flow, and microbial efficiency than ZnMet, ZnSO4+DL, ZnSO4, and Control treatments. The ZnSO4 tended (P = 0.13) to increase microbial efficiency compared to ZnMet, while ZnMet × ZnSO4+DL did not differ (P = 0.66). Treatments containing unbound zinc (ZnSO4+DL and ZnSO4) had lower (P < 0.01) total N flow through the chamber. Total volatile fatty acids increased (P ≤ 0.02) for ZnSO4+DL, while acetate:propionate ratio was not affected (P = 0.20). Chambers receiving ZnSO4+DL tended (P = 0.06) to have lower acetate compared to ZnMet and DL-Met, while greater (P ≤ 0.02) butyrate. Average pH decreased (P = 0.01) for ZnSO4 compared to DL-Met. The ZnSO4+DL had a greater (P = 0.03) max pH compared to ZnMet, while a tendency (P = 0.06) was also observed for ZnSO4 to induce the smallest minimum pH. The ZnSO4 showed greater time (P = 0.01) and tended (P = 0.07) for greater area below pH 5.0 compared to ZnMet, while ZnSO4+DL chambers did not differ (P ≥ 0.50) from ZnMet. The DL-Methionine treatment improved ruminal microbial efficiency, except with the combination of excessive ZnSO4 or when Zn was present but not available (ZnMet). The ruminal microbial efficiency during the in vitro model for either bound or ruminally available Zn was not improved in the presence of additional amino acids. For the complex Zn-methionine, such an effect was due to its ruminal-unavailable nature, while ZnSO4 was due to changes in ruminal fermentation characteristics.","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":"149077564","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":"PS10-14. The Effect of Varium® on Growth Performance, Gut Microbiome, and Health of Growing Pigs.","authors":"San Ching, Nguyen Quang Thieu, Phan Thi Thuy Quyen, Nguyen An Khang, Nguyen Kim Ngan, To Thi Hong Phuong, Pham Phuc Thinh, Nguyen Viet Hai","doi":"10.1093/jas/skag272.523","DOIUrl":"https://doi.org/10.1093/jas/skag272.523","url":null,"abstract":"Varium® was developed as an alternative to antibiotic-growth-promoters, containing minerals, organic acids, and yeast specifically designed to improve gut health in production animals. The objective of this study was to test the effect of Varium on growth performance, gut microbiome, and the overall health of growing pigs. A total of 200 growing pigs (Duroc X [Landrace X Yorkshire], at 70 days old (25.39 ± 4 kg) were used in this experiment and separated between two treatments. The first treatment was the designated control (CON), with the growing pigs fed a standard diet without Varium. The second treatment (VAR) included the control diet supplemented with Varium at a dosage of 1kg per ton of feed. There were 4 replicates (pens) in each treatment with 25 pigs per pen. Basal diets were formulated in mash form to meet the recommendation of the farm. The feeding program consisted of Phase I from days 1 to 28 of the trial and Phase II from days 29 to 50. Body weight measurements were taken on days 1, 28, and 50 of the trial, while feed consumption was measured daily to analyze growth performance. Mortality and diarrhea incidence were also recorded daily. The experiment was conducted as a completely randomized design with data analyzed by GLM procedures of Minitab 17. Treatment differences were measured via the Tukey test with differences of P < 0.05 as significant. The results showed average daily gains in VAR were numerically higher than that of CON on day 1, 28, and 50 with 498 vs. 492; 841 vs. 796; 649 vs. 626 g, respectively (P > 0.05). Average feed intake slightly decreased in VAR compared to CON during these 3 periods with 1115 vs. 1115; 1844 vs. 1927; 1438 vs. 1480, respectively (P > 0.05). This resulted in numerically improved feed conversions in VAR during these periods with 2.236 vs. 2.328; 2.181 vs. 2.518; 2.209 vs. 2.379, respectively (P > 0.05). During the trial period disease incidence was lower in VAR than in CON from day 1-28 (14.2 to 15.6, P = 0.185), significantly lower from day 29-50 (2.0 to 6.5, P < 0.05), and significantly lower from day 1-50 (9.1 to 12.1, P < 0.05). Reductions in E. coli population (log 6.27 vs. 6.59, P = 0.174) and an increase in Lactobacillus population (log 9.09 vs. 8.95, P = 0.487) were observed numerically in VAR when compared to CON. When analyzing improvements in these key metrics, an 8.71% better economic return was seen in VAR than CON. In conclusion, the addition of Varium at 1 kg/MT in the diet of growing pigs tends to improve growth performance, promotes microbiome balance, and significantly reduces disease incidence throughout the growth phase.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"32 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149077574","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":"PS7-21. Interaction Between Growth Stage of Pigs and Soluble Dietary Fiber-to-insoluble Dietary Fiber Ratio for Ileal Digestibility and Hindgut Disappearance of Energy and Nutrients.","authors":"Yujeong Hwang, Yoon Soo Song, Beob Gyun Kim","doi":"10.1093/jas/skag272.526","DOIUrl":"https://doi.org/10.1093/jas/skag272.526","url":null,"abstract":"Nursery pigs have relatively underdeveloped digestive and absorptive capacities. As pigs grow, the hindgut continues to develop and fiber fermentation occurs mostly in the hindgut. Fibers are partitioned into soluble and insoluble portions. Soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) differ in physicochemical properties and digestibility in the gastrointestinal tract of pigs. The objective of the present experiment was to test interactive effect of growth stage of pigs and SDF-to-IDF ratio on apparent ileal digestibility (AID), apparent total tract digestibility (ATTD), and hindgut disappearance of energy and nutrients. Two experimental diets with SDF:IDF of 0.08 and 0.32 were provided to nursery pigs and growing pigs in a 2 × 2 factorial arrangement. Six nursery barrows with an initial body weight of 14.8 kg (standard deviation = 1.4) and 6 growing barrows with an initial body weight of 59.7 kg (standard deviation = 2.5) were employed. Animals were surgically fitted with a T-cannula at the distal ileum and individually housed in pens. A low SDF:IDF diet contained 1.8% SDF and 23.1% IDF and consisted of 60.6% corn, 20.5% soybean meal, and 15.0% corn cobs (SDF 2.3% and IDF 84.1%) whereas a high SDF:IDF diet contained 5.9% SDF and 18.4% IDF and consisted of 58.0% corn, 18.0% soybean meal, and 20.5% sugar beet pulp (SDF 20.0% and IDF 47.6%). Both experimental diets were formulated to contain 25.0% total dietary fiber. In both growth stages, the pigs were assigned to 2 dietary treatments in a crossover design with 2 periods to obtain 6 observations for each simple effect. Each experimental period consisted of 5 days of adaptation, 1 day of fecal collection, and 2 to 3 days of ileal digesta collection. The high SDF:IDF diet caused less (P < 0.05) AID of energy, dry matter, and organic matter in growing pigs whereas the SDF:IDF did not affect the AID of energy and nutrients in nursery pigs (interaction P < 0.01). The high SDF:IDF diet caused greater hindgut disappearance of energy, dry matter, and organic matter with greater magnitude of increment in growing pigs compared with nursery pigs (interaction P < 0.05). The ATTD of energy, dry matter, and organic matter in pigs fed the high SDF:IDF diet was greater (P < 0.001) than those fed the low SDF:IDF diet regardless of growth stages of animals. Taken together, hindgut disappearance of energy and nutrients was affected by SDF-to-IDF ratio, more dramatically in growing pigs compared with nursery pigs.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"10 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149077578","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":"GWAS on imputed whole-genome sequence variants reveal novel candidate mutations affecting feed efficiency and body composition traits in a crossbred swine population","authors":"B N Keel, H L Bradford, W T Oliver, A K Lindholm-Perry, G A Rohrer","doi":"10.1093/jas/skag315","DOIUrl":"https://doi.org/10.1093/jas/skag315","url":null,"abstract":"A pig’s ability to convert consumed feed into saleable meat is an important component of production efficiency in the swine industry. Given the polygenic and environmentally influenced nature of feed efficiency and body composition traits, conventional selection approaches have limited ability to pinpoint causal genetic factors driving variation. In this study, we performed a single-step genome-wide association study, with whole-genome sequence data (imputed from 50 to 60K SNP arrays), for feed efficiency and body composition traits using a multi-generational crossbred swine population. Overall, the three-generation pedigree consisted of 14,242 pigs, of which 9,336 pigs were phenotyped and 7,339 were genotyped. Whole-genome sequence variants were clustered into 705,923 linkage disequilibrium (LD) blocks, ranging from 0.001 to 9981.80 kb in size. A total of 133 LD blocks were significantly associated with the studied traits, several with potentially large pleiotropic effects. A total of 453 candidate genes were identified in the genomic regions of significant LD blocks. Four functional candidate genes (SIRT2, RYR1, MC4R, and LEPR) were found to harbor moderate to high impact variants, expected to affect protein function.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"481 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149077689","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":"PS9-23. Pregnancy Losses Associated with Hormonal Factors in Beef Cows: A Systematic Review and Meta-analysis.","authors":"German Sanabria, Eduarda R Anhaia, Giovana S Giacomelli, Julio Otavio Barcellos","doi":"10.1093/jas/skag272.567","DOIUrl":"https://doi.org/10.1093/jas/skag272.567","url":null,"abstract":"Gestational losses represent a major challenge for cow–calf production systems because they compromise reproductive efficiency and cause economic losses to the livestock industry. Most of these losses occur during the embryonic or early fetal period and therefore represent reproductive failures that are often difficult to detect. In this context, due to the limited number of studies relating gestational losses to hormonal alterations in beef cows, the objective of this study was to compile and quantitatively analyze, through a systematic review and meta-analysis, the available data associating these factors at different stages of bovine gestation. Additionally, hormonal activity was evaluated among different categories and subspecies of beef females to identify groups with a greater predisposition to hormonal dysfunctions associated with pregnancy loss. More than 1,000 articles were identified in the Scopus, Web of Science, and PubMed databases and screened according to the PRISMA protocol. The inclusion criteria were: i) beef cows or heifers; ii) early pregnancy diagnosis by ultrasonography between d 28 and 32; iii) studies reporting the day or range of pregnancy diagnosis, subspecies, country, parity, and reproductive method; and iv) the presence of hormonal data, including progesterone, estradiol, GnRH, eCG, PGF2α, or pregnancy-associated glycoprotein (PAG) biomarkers. Of the identified articles, 30 studies met the inclusion criteria, totaling data from 48,643 beef females. The meta-analysis followed the methodology described by Borenstein, and statistical analyses were performed using Stata version 14.0 (StataCorp, Texas, USA). A nonparametric formula was used to estimate variance because most studies did not report standard errors or standard deviations. Among the 48,643 females evaluated, 20% experienced pregnancy loss (95% CI: 0.14–0.26), with high heterogeneity among studies (I² = 99%). Among the insemination protocols evaluated, those combining GnRH and progesterone showed lower pregnancy loss (approximately 17%; 95% CI: 0.03–0.31), whereas protocols based on progesterone and estradiol, with or without eCG, showed higher losses of approximately 23% (95% CI: 0.08–0.37) and 24% (95% CI: 0.16–0.33), respectively. The stage of pregnancy loss significantly affected the results (P = 0.004), with early embryonic losses being more frequent (30%; 95% CI: 0.18–0.42) than late embryonic and early fetal losses (11%; 95% CI: 0.01–0.20). Overall, the results of this meta-analysis indicate that gestational losses associated with hormonal factors in beef cattle vary widely among studies and production systems, and even when similar hormonal protocols are used, differences are still observed. In general, the average estimated loss was approximately 20%, and no clear statistical effect of the hormonal protocol type was identified, although numerical differences were observed among groups. Moreover, losses were greater during the early embryonic stage comp","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"9 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149077780","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":"76. Predicting Body Weight and Dry Matter Intake in Lactating Dairy Cows Using Depth Cameras.","authors":"Raphael R Mantovani, Guilherme L Menezes, Rafael Ferreira, Luca Cattaneo, Alessio Cecchinato, Erminio Trevisi, Joao R R Dorea","doi":"10.1093/jas/skag272.219","DOIUrl":"https://doi.org/10.1093/jas/skag272.219","url":null,"abstract":"Dry matter intake (DMI) is typically estimated at the group level or predicted using equations based on milk yield, body weight (BW), and days in milk (DIM). Computer vision systems (CVS) can generate large-scale phenotypes such as body volume, area, and length that may better predict intake than BW alone, because cows with similar BW can differ in body frame and intake capacity. Therefore, this study aimed to (1) predict BW using CVS to demonstrate the association between image-based features and BW and (2) predict DMI using image-based features rather than BW. Data were collected from September 2024 to June 2025 at CERZOO Ltd. farm (Piacenza, Italy) from 93 lactating Holstein cows (151 ± 82 DIM, 41 ± 8 kg milk yield, 27 ± 5 kg DMI, and 3 ± 1 lactations), totaling 8,587 BW measurements obtained using a walk-over scale and 8,168 DMI records. For individual identification, a depth camera was installed at the sorting gate where animals were identified. For feature extraction, a segmentation model using a U-Net architecture was trained on 4,328 top-down depth images and validated on 50 images. After segmentation, depth frames were processed to extract body biometric (BB) features from the dorsal body surface, including area, volume, circularity, extent, eccentricity, perimeter, and major axis length, after removing noise and correcting invalid depth pixels. In addition, a YOLOv8 pose estimation model trained on 2,098 annotated images and validated on 25 images detected seven anatomical keypoints (hips, pin bones, tail head, sacral vertebra, and cervical vertebra). Model performance was evaluated using a threshold equal to 5% of the square root of the image area, and Euclidean distances between keypoints were used as features. Extracted features were summarized by animal and week. For BW prediction, a random forest (RF) model using BB features was trained. For DMI prediction, RF models were trained using (1) milk yield, DIM, and BW or (2) milk yield, DIM, and BB features. Both models were validated using leave-one-animal-out cross validation. All keypoints were predicted with accuracy greater than 88%. The segmentation model achieved an average IoU of 0.86 (95% CI: 0.85, 0.87). The BW prediction model achieved an R2 of 0.53, CCC of 0.70, and RMSE of 39.2 kg, representing 5.9% of the observed BW. The DMI model using milk yield, DIM, and BW achieved an R2 of 0.29, CCC of 0.50, and RMSE of 2.9 kg (11.0% of the average observed DMI). When BB features replaced BW, model performance improved to an R2 of 0.33, CCC of 0.52, and RMSE of 2.8 kg (10.7% of the observed values). These results suggest that BB features extracted from depth cameras are associated with BW and better predict DMI than BW from walk-over scales.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"10 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149077781","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":"185. Influence of Ruminal or Postruminal 5-hydroxytryptophan Administration on Serotonin Metabolism and Arterial Hemodynamics in Growing Beef Steers.","authors":"Ellem Matos, David L Harmon, Brittany E Davis, Ronald J Trotta","doi":"10.1093/jas/skag272.271","DOIUrl":"https://doi.org/10.1093/jas/skag272.271","url":null,"abstract":"Serotonin is synthesized from tryptophan through hydroxylation and decarboxylation reactions, with 5-hydroxytryptophan (5-HTP) serving as the immediate precursor. Because 5-HTP bypasses the rate-limiting step of serotonin synthesis, it has been used to experimentally increase circulating serotonin in ruminants via enteral or intravenous administration; however, the capability of ruminally-supplied 5-HTP to escape microbial degradation and influence peripheral serotonin metabolism and vascular function has not been fully characterized. The objective of this study was to evaluate ruminal or postruminal 5-HTP administration on peripheral serotonin metabolism and caudal artery hemodynamics in growing beef steers. Five ruminally cannulated Angus × Holstein steers [body weight (BW) = 284 ± 10.6 kg] were randomly assigned to a 5 × 5 Latin square design and limit-fed an alfalfa cube diet. Treatments consisted of water (negative control), abomasal infusion of 0.5 mg 5-HTP/kg BW (positive control), or ruminal infusions of 1, 2, or 3 mg 5-HTP/kg BW administered as daily pulse doses for 5 d, with 5-d washout periods. Blood samples were collected serially over 24 h on days 1 and 5 of each period for analysis of tryptophan, kynurenine, 5-HTP, serotonin, and 5-hydroxyindolacetic acid. Caudal artery hemodynamics were assessed using color Doppler ultrasonography. Dry matter intake and plasma biomarkers of energy and protein metabolism were not affected (P ≥ 0.15) by enteral 5-HTP treatments. Abomasal 5-HTP infusion rapidly increased (P < 0.05) serum 5-HTP and increased serum serotonin concentration on day 5 (P < 0.05). Increasing ruminal 5-HTP infusion increased serum serotonin concentration in a dose-dependent manner, indicating partial escape from ruminal degradation and effective postruminal utilization. Relative to baseline, ruminal infusion of 3 mg 5-HTP/kg BW increased caudal artery cross-sectional area (P < 0.05), demonstrating peripheral vasodilation, whereas lower ruminal 5-HTP doses and abomasal 5-HTP infusion did not elicit measurable vascular responses. These results demonstrate that ruminal 5-HTP administration can increase circulating serotonin and, at sufficient doses, ruminal 5-HTP administration promotes peripheral vasodilation. This study provides the first in vivo evidence of arterial vasodilation associated with 5-HTP supplementation in cattle and establishes ruminal delivery as a viable route for modulating serotonergic and vascular function.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"63 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149077785","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":"181. The Effects of in vitro LPS Stimulation on the PBMC Transcriptome of Beef Steers with Negative or Positive Residual Average Daily Gain.","authors":"Yarahy Leal, Samanthia R Johnson, Modoluwamu Idowu, Godstime Taiwo, Taylor S Sidney, Ibukun M Ogunade","doi":"10.1093/jas/skag272.272","DOIUrl":"https://doi.org/10.1093/jas/skag272.272","url":null,"abstract":"This study characterized the peripheral blood mononuclear cell (PBMC) transcriptomic responses to in vitro lipopolysaccharide (LPS) stimulation in beef steers with divergent residual average daily gain (RADG), a residual-based index of feed efficiency. Positive-RADG (n = 6; RADG = +0.53 kg/d) and negative-RADG (n = 6; RADG = −0.46 kg/d) crossbred steers were selected from a cohort of 41 steers (average body weight = 384 ± 5.8 kg) following a 50-d performance testing period on a high-forage total mixed ration. PBMCs were isolated from positive-RADG and negative-RADG steers and assigned to LPS stimulation (20 μg/mL for 2 hours) or untreated control. RNA was extracted, sequenced and differentially expressed genes (DEGs; FDR ≤ 0.01, |log₂FC| ≥ 1) were identified by comparison with unstimulated controls. Gene ontology (GO) enrichment analysis was performed to characterize associated biological processes (P < 0.05). Prior to LPS stimulation, one DEG was identified between RADG groups, indicating near-equivalent baseline PBMC transcriptomes. Following stimulation, 2,739 DEGs were identified in positive-RADG steers (1,484 upregulated; 1,255 downregulated), and 3,299 DEGs in negative-RADG steers (1,555 upregulated; 1,744 downregulated). GO enrichment analysis revealed activation of canonical innate immune pathways in both groups, including cytokine production, positive regulation of IL-1 and IL-1β production, and immune response. However, positive-RADG steers exhibited a broader cytokine network enrichment profile, with the highest enrichment score for positive regulation of cytokine production, encompassing genes involved in effector activation, leukocyte trafficking, and inflammatory resolution, including NOS2, STAT3, PTX3, TGFB1, and SOD1. In contrast, negative-RADG steers exhibited disproportionate enrichment of IL-1β- and IL-6-centered inflammatory pathways, with SAA3 as the most highly upregulated DEG (log₂FC = 9.18 vs. 6.80 in positive-RADG steers), consistent with a more pronounced acute-phase transcriptional response. These findings demonstrate that while RADG-divergent steers share conserved LPS-responsive signaling pathways, they differ in the architecture of their immune transcriptional responses. The broader, more integrated cytokine network activation in positive-RADG steers, compared with the concentrated IL-1β/IL-6-driven inflammatory signature in negative-RADG steers, suggests that superior feed efficiency is associated with a more coordinated immunoregulatory capacity that may reduce the energetic cost of innate immune activation and facilitate return to metabolic homeostasis.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"23 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149077789","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}