Journal of animal science最新文献

{"title":"Diurnal and day-to-day movement patterns of finishing pigs on deep straw bedding during the last 20 d before slaughter.","authors":"Marko Ocepek","doi":"10.1093/jas/skag122","DOIUrl":"https://doi.org/10.1093/jas/skag122","url":null,"abstract":"<p><p>Monitoring movement patterns of pigs provides valuable insight into welfare, health, and adaptation to housing environments, yet individual- and time-resolved evidence from deep-straw systems is limited. We monitored 16 finishing pigs housed on deep straw bedding during the last 20 d before slaughter using an RFID (radio-frequency identification)-LoRaWAN (Long Range Wide Area Network) system. One-Hz detections were converted to estimated distance from the receiver and aggregated to hourly movement (cm·h-1). In total, 7,680 pig×day×hour records were possible (16 pigs × 20 d × 24 h); hours without valid positioning data were excluded, resulting in 6,026 records for inferential analyses. Hourly movement was analyzed using a linear mixed model with fixed effects of hour, day, and their interaction, a random intercept for pig, and an AR(1) residual structure. Pigs exhibited a clear diurnal rhythm with movement lowest during the night and peaking between midday and afternoon. Movement differed among days, and the day × hour interaction showed day-specific modulation of the diurnal profile. Between-pig differences were substantial (ICC ≈ 0.29), supporting the use of individual baselines for precision monitoring. Environmental covariates (temperature, relative humidity, PM2.5) were not associated with movement in the day-by-timeline model. These results highlight the value of hour-aware and individualized approaches when using movement data for precision livestock farming applications in enriched housing.</p>","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147856234","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":"Estimates of genetic parameters and genetic trends for body weight, body composition, and reproductive traits in U.S. Suffolk sheep.","authors":"Artur O Rocha, Ali Haider Saleem, Hilal Yazar Gunes, Felipe E De Carvalho, Carrie S Wilson, Bradley A Freking, Thomas W Murphy, Joan M Burke, Ronald M Lewis, Luiz F Brito","doi":"10.1093/jas/skag124","DOIUrl":"https://doi.org/10.1093/jas/skag124","url":null,"abstract":"<p><p>The Suffolk is a meat-type sheep that is the predominant terminal-sire breed in the U.S. Known for its rapid growth, high carcass yield, and efficient feed conversion, Suffolk rams are crucial in commercial crossbreeding systems. Despite its importance, the parameters used by the National Sheep Improvement Program (NSIP) in its genetic evaluation have not been updated in over two decades. Therefore, we re-estimated genetic and phenotypic parameters and calculated theoretical accuracies and genetic trends for various growth, body composition, and reproductive traits in U.S. Suffolk sheep. The traits evaluated were birth weight (BWT), weaning weight (WWT), post-weaning weight (PWWT), post-weaning eye muscle depth (EMD), post-weaning fat depth (CFAT), and number of lambs born (NLB) and weaned (NLW) per ewe lambing. The dataset consisted of a pedigree comprising 70,271 individuals and up to 48,000 phenotypic records per trait across more than 100 flocks. Variance components were estimated using the Restricted Maximum Likelihood method and animal models with maternal and permanent environmental effects fitted when appropriate. Records were pre-adjusted for age at recording, birth type, rearing type, and dam age as relevant. For lamb traits, contemporary group (CG; concatenation of flock, birth year, management group, sex, lambing interval, and recording date, except for BWT) was the only fixed effect included in the models. For reproductive traits, CG combined flock and lambing year; ewe age was added as a categorical fixed effect. Heritability estimates (±SE) ranged from 0.04 ± 0.008 for NLW to 0.24 ± 0.025 for CFAT. Maternal heritabilities ranged from 0.02 ± 0.01 for PWWT to 0.16 ± 0.011 for BWT. Genetic correlations among growth traits ranged from 0.47 ± 0.07 to 0.67 ± 0.04, and genetic correlations between PWWT and body composition traits were positive (0.30 ± 0.09 with EMD and 0.55 ± 0.08 with CFAT). A strong genetic correlation (0.81 ± 0.03) was observed between NLB and NLW. Theoretical accuracy was highest for proven animals with progeny records. Genetic trends showed progress in growth and muscling traits but declining maternal breeding values for growth traits. Several updated genetic parameters diverged from legacy NSIP estimates, likely due to shifts in management, and trait definitions. These results emphasize the need for regular re-estimation of genetic parameters to ensure accurate genetic evaluations and promote balanced genetic progress across traits.</p>","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147856264","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":"Optimal replacement value of betaine for dietary methionine in broilers from 22 to 42 days of age.","authors":"Heng Wang, Lin Liu, Xi He, Bin Peng, Guozhi Bian","doi":"10.1093/jas/skag084","DOIUrl":"https://doi.org/10.1093/jas/skag084","url":null,"abstract":"<p><p>Betaine acts as a methyl donor and has been proposed as a potential substitute for methionine (Met) to reduce feed costs. This study aimed to investigate the optimal replacement value of betaine for dietary Met in broilers aged 22 to 42 days. A total of 1,440 male broilers were randomly divided into 6 treatments (6 replicates/pen). The positive control (PC) received a standard diet (0.53% Met), while the negative control (NC) received a low-Met diet (0.33% Met) with 2000 mg/kg betaine. Four additional groups received the NC diet supplemented with 0.05%, 0.10%, 0.15%, or 0.20% Met. Data were analyzed using one-way ANOVA and three regression models. Results indicated that Met deficiency significantly impaired growth performance: final body weight (BW) decreased from 1696 g (PC) to 1604 g (NC) (P < 0.001), while the feed-to-gain ratio (F/G) increased from 1.87 to 2.01. No significant differences were observed in slaughter performance (P > 0.05). Regarding metabolism, the NC group exhibited significantly elevated serum homocysteine (19.42 vs. 7.94 μmol/L) and hepatic ALT activity (11.77 vs. 4.35 U/g prot), alongside reduced hepatic BHMT activity (17.47 vs. 103.14 ng/mg prot, P < 0.001). Furthermore, Met deficiency downregulated the mRNA expression of genes related to one-carbon metabolism and intestinal tight junctions (relative expression ∼0.20 vs. 1.00 in PC, P < 0.05). Supplementation with 0.10% Met restored these parameters to levels statistically equivalent to the PC group. One-slope straight broken line and two-slope straight broken line regression analysis of the F/G ratio (R2 = 0.8598) determined the optimal replacement dose to be 0.1474% Met, corresponding to a 27.81% substitution efficiency.</p>","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147856308","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":"The impact of barefoot racing in young Swedish trotters on career length.","authors":"P Berglund, S Andonov, E Strandberg, S Eriksson","doi":"10.1093/jas/skag127","DOIUrl":"https://doi.org/10.1093/jas/skag127","url":null,"abstract":"<p><p>In several European countries, racing without shoes, i.e., barefoot, is a common strategy in trotting races to improve the speed of the horse. Why some trotters can race barefoot without damage to the hoof from excessive wear and others cannot, has been shown to partly be explained by differences in hoof composition. In particular, durable hind hooves are believed to be important to sustain racing without shoes. Also, variation in the proportion of the races the horse races with barefoot hind hooves, has been shown to be affected by genetic differences in Swedish Standardbred trotters (SB) and Swedish-Norwegian Coldblooded trotters (CB). When racing barefoot, the protective properties of the shoe, which prevent the hoof from excessive wear and tear, are absent. If the hoof cannot withstand wear and tear, the damage of the hoof may pose a risk to animal welfare. The question of how barefoot racing should be regulated, especially for young horses, is under discussion in Sweden and elsewhere in Europe. Regulations regarding barefoot racing in young horses differ between countries, and there is a lack of published studies to base regulations on. Therefore, this study aimed to analyze the effect of racing with barefoot hind hooves in young SB and CB on career length. Datasets including shoeing information from 3-year-old SB, and 3- and 4-year-old CB were analyzed, including up to 12,161 horses. Cox proportional hazard models were fitted to analyze the effect of proportion of barefoot races at a young age on the hazard of ending the career at a given time point. Other effects such as sex, year of birth, started as a 2-year-old or not (SB only), early earnings, best racing time, and number of early starts were also included in the models. For SB, horses that raced more than 30% barefoot had an14% higher hazard of ending their career at a given time point compared to the reference group that raced 5% or less barefoot. In CB, the hazard of ending the career at a given time point was 67% higher in the group with the highest proportion of barefoot races compared with the reference group. Although for SB, the reduction of the career length in days was minor. For CB, the effect was larger and verified the negative effect in SB but estimated based on fewer observations. Further studies of voluntary as well as involuntary reasons why Swedish trotters end their careers, are needed to better understand the possible impact of racing barefoot as a young horse.</p>","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147856318","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":"Does quantity equal quality? Source of protein influences American dog owner purchasing decisions more than the quantity of protein in the absence of marketing claims.","authors":"Pawanpreet Singh, Sydney Banton, Michael von Massow, Zhe Peng, Guido Bosch, Christopher Pf Marinangeli, Anna K Shoveller","doi":"10.1093/jas/skag136","DOIUrl":"https://doi.org/10.1093/jas/skag136","url":null,"abstract":"<p><p>Protein is the most expensive macronutrient worldwide, yet protein-related claims like \"high protein\" or \"protein #1 ingredient\" strongly influence dog food purchases. Little is known about how dog owners define protein quality (PQ) and how this knowledge shapes purchasing decisions. This study investigated how perceptions of dietary protein translate from personal to dog feeding habits, the level of PQ knowledge among dog owners, and whether protein source or amount has a greater influence on dog food choice. A 60-question survey was distributed to dog owners across the United States using Qualtrics (Utah, USA) (n = 691). Each respondent answered 12 choice experiment questions in which dog food options varied by protein amount (20%, 35%), protein source (peas, chicken, chicken meal), and price ($80, $95, $110). Descriptive statistics were analyzed in SPSS Statistics (Version 29, IBM Corp.), and a multinomial logit model in STATA (Version BE) was used for choice experiment analysis, with significance set at p < 0.05. Chicken had the greatest influence on purchasing choice, followed by chicken meal, and 35% protein, compared to a baseline diet of 20% protein and peas (p < 0.001). The majority (30%) of respondents believed PQ was parallel to quantity, while only 18% could correctly define PQ as the ability of an ingredient to meet the indispensable amino acid requirements of an individual. For respondents who correctly defined PQ, all protein sources positively influenced choice, while greater protein quantity negatively influenced choice (p < 0.001). Ultimately, protein source, not amount, drives purchasing behaviour in the absence of protein-related claims on dog food.</p>","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147856252","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":"Effects of dietary 25-hydroxyvitamin D3 (25(OH)D3) supplementation on production performance, egg quality, tibia quality and mineral metabolism of ducks during peak laying period in the cage rearing system.","authors":"Liang Huang, Zhongwei Miao, Chengfu Pan, Li Li, Xiaopan Liu, Linli Zhang, Zhiming Zhu, Lu Lin, Xiudong Liao, Nenzhu Zheng, Qingwu Xin","doi":"10.1093/jas/skag081","DOIUrl":"https://doi.org/10.1093/jas/skag081","url":null,"abstract":"<p><p>25-Hydroxyvitamin D3 (25(OH)D3) has been reported to improve production performance and egg quality in ducks during late laying period, but its effects during the peak laying period remain rarely studied. The aim of this study was to investigate the effects of dietary 25(OH)D3 supplementation on the production performance, egg quality, tibia quality and mineral metabolism of ducks during peak laying period in a cage rearing system. A total of 360 Liancheng white laying ducks at 30 weeks (wks) of age were randomly assigned to 5 groups, each consisting of 6 replicates with 12 ducks per replicate. Ducks were fed a basal diet with 25(OH)D3 supplementation at 0, 1000, 2000, 3000, and 4000 IU/kg throughout the trial for 8 wks. One-way ANOVA was employed to assess the influence of supplementation level, and linear and quadratic regression analyses were performed for statistical evaluation of dose-dependent effects. 25(OH)D3 supplementation linearly and quadratically increased the laying rate, average egg weight and egg mass and quadratically decreased the feed conversion ratio (FCR). The mean of eggshell strength and thickness at 4 and 8 wks increased linearly and quadratically with increasing 25(OH)D3 levels, and the 4000 IU/kg 25(OH)D3 increasing the eggshell thickness by 5.7% (at 4 wks) and 2.9% (mean of those at 4 and 8 wks) relative to those of the non-supplemented group. At the end of wks 4 and 8 of the trial, serum 25(OH)D3, bone glutamyl protein (BGP) and carbonic anhydrase (CA) increased linearly (P < 0.05), and serum parathyroid hormone (PTH) decreased linearly (P < 0.05); the 4000 IU/kg group had the highest serum 25(OH)D3 (4.24 ng/mL) and BGP (3.11 ng/mL) concentrations at 8 wks. Additionally, the tibial breaking strength, trabecular bone number, BGP content, and alkaline phosphatase (ALP) activity and mRNA levels increased linearly with 25(OH)D3 supplementation (P < 0.05). The optimal dietary 25(OH)D3 supplementation levels were approximately 2355, 2347 and 3269 IU/kg on the basis of the quadratic model of the laying rate, FCR and eggshell strength, respectively. In summary, 25(OH)D3 supplementation improved the production performance and eggshell quality of ducks during peak laying period by maintaining calcium and phosphorus homeostasis and enhancing tibia quality. A diet that contains 2347-3269 IU/kg of 25(OH)D3 displayed beneficial effects on maintaining calcium and phosphorus homeostasis, and improving the tibial quality, which was recommended for ducks during peak laying period in the cage rearing system (30-38 wks of age).</p>","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147856294","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":"Effects of replacing dietary glucose with fructose on intestinal morphology, oxidative status, and epithelial responses in weaned pigs.","authors":"Min Wang, Xin Wang, Yutong Zeng, Mingming Guo, Zhaobin Wang, Lanmei Yin, Qiye Wang, Jianzhong Li, Huansheng Yang","doi":"10.1093/jas/skag153","DOIUrl":"https://doi.org/10.1093/jas/skag153","url":null,"abstract":"<p><p>This study evaluated the effects of replacing dietary glucose with fructose on intestinal development in weaned pigs and assessed epithelial growth using a small intestinal organoid model. A total of 26 weaned pigs ([Yorkshire × Landrace] × Duroc, 21 days old) were randomly assigned to three groups: a control group (10 pigs, 3% glucose), a low-fructose (LF) group (8 pigs, 1.5% glucose + 1.5% fructose), and a high-fructose (HF) group (8 pigs, 3% fructose), with one pig per pen. The experimental period lasted 28 days, including a dietary transition on day 15. Results showed that dietary fructose did not affect growth performance (P > 0.10). Fecal scores were not significantly different among treatments (0.05 < P < 0.1), although numerically lower values were observed in the LF group. The HF group had a greater relative length of the large intestine than the LF group (P < 0.05), whereas the LF group showed reduced kidney weight (P < 0.001). Regarding intestinal morphology, dietary fructose tended to reduce duodenal crypt depth and ileal villus height (0.05 < P < 0.1). Ileal malondialdehyde (MDA) levels were affected by dietary treatment (P < 0.05), whereas digestive enzyme activities were not altered (P > 0.10). At the molecular level, fructose significantly downregulated genes involved in carbohydrate metabolism (FBP1, FBP2, LDHA, PKM) and glucose transport (GLUT2) (P < 0.05). Stem cell-associated genes (LGR5 and BMI1) and tight junction-related genes (OCLN and CLDN1) were significantly downregulated (P < 0.05), whereas Ki67 expression was not significantly affected (P > 0.10). In organoid cultures, fructose concentrations did not affect budding efficiency (P > 0.10), but significantly affected the number of buds per organoid (P < 0.05), with higher values observed at 1 mM and 5 mM. Overall, replacing dietary glucose with fructose did not impair growth performance, but altered oxidative status, epithelial-related gene expression, and intestinal epithelial responses in weaned pigs. These findings indicate that intestinal responses are sensitive to dietary monosaccharide composition under practical feeding conditions.</p>","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147838064","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":"A preliminary assessment of the effects of summer transport on behavioral and physiological stress biomarkers in cull sows selected for heat stress tolerance or sensitivity in the F1 generation1.","authors":"Rick O Hernandez, Luiz F Brito, MaryKate Harrod Byrd, Hui Wen, Jay S Johnson","doi":"10.1093/jas/skag142","DOIUrl":"https://doi.org/10.1093/jas/skag142","url":null,"abstract":"<p><p>Cull sows transport in hot summer months can cause morbidity and mortality due to heat stress (HS), and there is a need to reduce these risks. Therefore, the study objective was to evaluate whether genomic selection for HS tolerance (TOL) or sensitivity (SEN) in the F1 generation would alter behavioral and physiological indicators of HS in cull sows transported during the summer. We hypothesized that TOL sows would have a reduction in behavioral and physiological stress responses relative to SEN sows during summer transport. One day post-weaning, 14 TOL and 14 SEN primiparous sows (Large White x Landrace) were loaded onto a trailer (0.65 m2/sow) and transported for 4 h 53 min on 50% two-lane and 50% four-lane roads in central Indiana, USA on July 26, 2023. Data loggers were placed within the trailer to record dry bulb temperature and relative humidity in 5 min intervals. Prior to transport, 9 TOL and 7 SEN sows were fitted with data loggers to record vaginal temperatures (TV) in 5 min intervals. In addition, a thermal imaging camera was used to record temperatures of the periocular area and lacrimal caruncle and salivary cortisol was assessed in all sows pre- and post-transport. Finally, sows were imaged throughout the transport process using mounted cameras to evaluate standing, lying, sitting, and mounting behaviors. All data were analyzed using R software V4.1.1. and the \"lmea4\", \"lmertest\", and \"nlme\" R packages with the sow considered as the experimental unit. Dry bulb temperature, relative humidity, and Enthalpy Comfort Index (ECI) during the trip were 29.7 ± 0.2 °C, 70.33 ± 1.74%, and 76.45 ± 2.76 kJ/kg dry air, respectively. Lacrimal caruncle temperature was greater (P < 0.05) for SEN (34.1 ± 0.40 °C) versus TOL (32.7 ± 0.40 °C) sows. Sitting behavior was positively associated with transport time (β  =  0.10; P < 0.01). Likewise, lying behavior was positively associated with transport time (β  =  0.03; P < 0.05) and with ECI (β  =  1.05; P < 0.01). Salivary cortisol levels were increased overall (P < 0.01) during loading (27.1 ± 2.64 ng/mL) versus post-transport (6.9 ± 3.07 ng/mL), regardless of the genetic line. No other differences were detected with any comparison (P > 0.10). In summary, cull sow transportation during the summer increased behavioral and physiological signs of stress in sows. However, only lachrymal caruncle temperature was influenced by genomic selection in the F1 generation.</p>","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147838133","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":"Associative effects of external buffers and plant secondary metabolites on ruminal fermentation during an induced subacute ruminal acidosis challenge in beef steers.","authors":"Andrés Fernandez-Lehmann, Camila Gomez-Lopez, Federico Tarnonsky, Ignacio Fernandez-Marenchino, Araceli Maderal, Federico Podversich, Tessa M Schulmeister, Juan De J Vargas, Georgia Dubeux, Cristian Erazo-Mendes, Wilmer Cuervo, Mauro Venturini, Liza Garcia, Alejandro R Castillo, Nicolas Dilorenzo","doi":"10.1093/jas/skag123","DOIUrl":"https://doi.org/10.1093/jas/skag123","url":null,"abstract":"<p><p>Subacute ruminal acidosis (SARA) is a prevalent problem in cattle consuming highly fermentable diets. It was hypothesized that a novel feed additive (BRIC) containing alkaline salts and traces of plant secondary metabolites may modulate ruminal fermentation. The experiment evaluated four treatments during an induced SARA protocol. Treatments were (DM basis): 1) sodium bicarbonate at 1.2% (BICARB), 2) a commercial buffer at 1.2% (BRIC), 3) a blend of tannins and saponins at 0.15% (BXS), and 4) a combination of 1.2% BRIC plus 0.15% BXS (BRIC-BXS). Eight ruminally cannulated steers were used in a replicated 4 × 4 Latin square with four 16 d periods and ad libitum access to a basal diet (DM basis: 35.5% corn silage, 22.0% bermudagrass hay, 21.5% corn grain, 18.7% cottonseed meal, 1.0% mineral-vitamin premix and treatment supplements). For the BXS and BRIC-BXS, dietary ingredients were proportionally increased to achieve 100% of the diet DM minimizing changes in basal diet TMR composition. The study included baseline measurements (3 d), treatment adaptation (7 d), feed restriction (1 d at 50%), SARA challenge (1 d), recovery (4 d), and washout (20 d). An ex vivo batch culture incubation was conducted on the last day of baseline and the last day of recovery. Ruminal fluid was collected daily pre-feeding (0 h) and postfeeding (4 h), and every 2 h for 14 h during the SARA challenge to evaluate pH, volatile fatty acids (VFA), and ammonia nitrogen concentration (NH3-N). Data were analyzed as a replicated 4 × 4 Latin square, with data collected during the SARA challenge analyzed as repeated measures. Feeding BRIC and BRIC-BXS led to greater NH3-N (P < 0.01) in the ex vivo incubations. Postfeeding ruminal pH was lower during adaptation (P = 0.02) and feed restriction (P = 0.01) for BXS compared with the buffers. During pre-feeding feed restriction, NH3-N and butyrate were greater (P < 0.05) for BRIC compared with BXS. Additionally, BXS exhibited greater propionate and lower branched-chain VFA (P < 0.05) compared with the buffers. During SARA, butyrate proportions were greater (P < 0.01) for BRIC compared with BICARB. The responses indicate that BRIC favored butyrate production, potentially enhancing ruminal epithelial function, whereas BXS favored propionate, potentially supporting glucogenic pathways.</p>","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147838073","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":"Social network analysis of tail-biting interactions among growing-finishing pigs with intact tails housed in two group sizes.","authors":"Yuzhi Li, Courtney Archer, Ty Schmidt, Benny Mote, Jon Anderson, Lee Johnston","doi":"10.1093/jas/skag149","DOIUrl":"https://doi.org/10.1093/jas/skag149","url":null,"abstract":"<p><p>Tail biting compromises the welfare and performance of pigs. Understanding the dynamics of this behavior is essential for developing management strategies to minimize outbreaks. We used social network analysis (SNA) to evaluate the effect of group size on tail-biting interactions among pigs and to examine differences in tail-biting network position between barrows and gilts, and biters and non-biters. Pigs (n = 315, initial weight = 22.1 ± 3.76 kg) with intact tails of mixed sexes were housed in small (9 pigs/pen) or large (18 pigs/pen) pens on slatted floors for 14 weeks until market weight (120.2 ± 11.47 kg). Floor and feeder space allowances were identical for pigs in both group sizes. Growth performance, tail injury, and behavior were recorded. Videos recorded the day before the first TBO were manually reviewed to document tail-biting events and identify pig roles. The top 25% of pigs responsible for the most tail-biting incidents were classified as tail-biters, and the remaining pigs as non-biters. Tail-biting network metrics were calculated using RStudio. Data were analyzed using SAS. Pigs in small pens exhibited higher density, reciprocity, out- and in-degree centrality, betweenness centrality, and closeness centrality (all P < 0.05), suggesting greater direct and indirect involvement in tail-biting interactions than pigs in large pens. Gilts had higher out-degree centrality (P < 0.01), indicating they initiated more tail biting than barrows. Both sexes had similar in-degree centrality, suggesting they were bitten equally. In gilts, biters tended to have lighter final weight (P = 0.08) and lower ADG (P = 0.10) and were injured less frequently (P = 0.02) by tail biting than non-biters. In both sexes, biters and non-biters had similar in-degree centrality, suggesting that they were bitten equally. These results indicate that pigs housed in different group sizes exhibit different social structures and positions in tail-biting networks, which potentially affects tail damage. Further research should evaluate network metrics across a wider range of group sizes and during multiple TBO.</p>","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147838087","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}