Journal of animal science最新文献

{"title":"PSVII-25 Undergraduate students’ knowledge and perception of welfare and ethical issues in animal agriculture.","authors":"Victoria A Uyanga, Sakil Mahmud, Kimberly Cash, Jessica Epple-Farmer, Adrian Andrei","doi":"10.1093/jas/skaf300.756","DOIUrl":"https://doi.org/10.1093/jas/skaf300.756","url":null,"abstract":"Animal welfare and ethics are emerging issues influencing production practices, societal focus and legislation in animal agriculture. The objective of this work was to investigate the knowledge and perceptions of undergraduate students on animal welfare and ethical issues in production systems. An anonymous survey was developed with Qualtrics using a 5-point Likert scale: (1) strongly disagree, (2) disagree, (3) neutral, (4) agree, and (5) strongly agree. The survey was administered to 80 undergraduate students majoring in agriculture, and data were analyzed using descriptive statistics. A total of 53 participants completed the survey (response rate =66.25%), and they were mostly between the ages of 19 and 24 (81%), and females (52%). Students’ prior experiences with animals varied with those that had owned pets/companion animals (45%), grew up on livestock farms (24%), had ample experience with livestock (16%), to those that had little or no farm/animal experience (10%). About 52% strongly agreed that animal welfare was important in farm animal production, whereas 30% disagreed that human interests (e.g., profit, food production) should be prioritized over the welfare of farm animals. Majority of the students supported the use of animal welfare certifications (51%), but disagreed (55%) to the statement that animals should not be used for food production because the animal cannot consent to sharing of milk or eggs or to be slaughtered. About 44% of the students agreed that they were aware of animal welfare controversies related to factory farming, whereas 52% of the students were not familiar with the five freedoms of animal welfare. Some issues considered critical in farm animal welfare were animal confinement (60%); slaughterhouse practices (55%); use of antibiotics and hormones (53%); physical alterations (47%); transportation conditions of farm animals (43%); using animals for research (38%), continuous breeding for productivity (23%), among others. Half of the respondents (50%) agreed that the animal industry should implement effective practices and programs to assess animal welfare at farms and factories, and most students either agreed (43%) or strongly agreed (24%) that it was possible to balance the ethical treatment of animals with the need for food security in growing global populations. Students agreed (42%) that consumers had the right to know how farm animals were treated through labeling on animal products, and 43% strongly agreed that educational programs were essential in improving public knowledge and action on animal welfare. This study revealed important outcomes on the extent of students’ knowledge and perspectives on animal welfare and ethics, given their crucial role as consumers and future professionals in the animal industry. Therefore, the inclusion of animal welfare and ethics education into the agricultural curriculum is critical in expanding the formal education of undergraduate students and the training of future pro","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"1 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145226683","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":"PSIX-19 Effects of natural sources of brackish water on milk yield and composition of Alpine dairy goats.","authors":"Hirut Y Yirga, Woldemariam Dawit, Ryszard Puchala, Dereje T Gulich, Carlos Alvarado, Amlan K Patra","doi":"10.1093/jas/skaf300.739","DOIUrl":"https://doi.org/10.1093/jas/skaf300.739","url":null,"abstract":"This study aimed to evaluate the effects of various United States Geological Survey (USGS) water classifications on the milk yield and composition of lactating Alpine dairy goats. The experiment involved 32 Alpine dairy goats over a six-week period. Drinking water treatments were categorized as fresh water (FRW), West Pasture brackish water (BRW), USGS group 2 water (GR-2), USGS group 3 water (GR-3), and an unclassified water group (G-UC). The total dissolved solids (TDS) content for these treatments measured 383±119, 6385±356, 3099±227, 5410±125, and 2567±165 g/L of water, respectively. Goats were fed a total mixed ration comprising 50% forage and 50% concentrate, delivered at 4% body weight on an air-dry basis. Daily milk production was recorded, and milk samples were collected during both morning and evening milkings at weeks 0, 3, and 6. Milk yield was similar among water treatments (P=0.180, SEM=0.238), with averages values of 2.4, 2.4, 1.88, 2.16, and 1.74 kg/day for FRW, BRW, GR-2, GR-3, and G-UC, respectively. However, milk yield varied significantly over time (P< 0.001; SEM=0.122), declining in weeks 5 and 6 compared to earlier weeks. Weekly averages were 2.31, 2.23, 2.21, 2.21, 2.14, 1.88, and 1.81 kg/day for weeks 0, 1, 2, 3, 4, 5, and 6, respectively. Milk composition parameters, including butterfat, true protein and lactose levels, were unaffected by water treatments or time. Butterfat percentages were 3.33, 3.29, 3.87, 4.30, and 3.5% for FRW, BRW, GR-2, GR-3, and G-UC, respectively; and 3.67, 3.76, and 3.52% for week 0, 3, and 6, respectively. True protein percentages were 2.64, 2.67, 2.60, 2.69, and 2.76% for FRW, BRW, GR-2, GR-3, and G-UC, respectively (P=0.844); and 2.65, 2.59, and 2.78% for week 0, 3, and 6, respectively. Lactose levels of milk samples were also similar among water treatments (4.41, 4.35, 4.54, 4.43, and 4.53%, SEM = 0.062 for FRW, BRW, GR-2, GR-3, and G-UC, respectively); and 4.48, 4.48, and 4.40% for week 0, 3, and 6, respectively. Milk urea levels, however, exhibited a trend toward variation among water treatments (P=0.055), with levels of 18.9, 18.4, 20.8, 23.9, and 20.8 mg/dl for FRW, BRW, GR-2, GR-3, and G-UC, respectively. Additionally, milk urea levels increased over time, averaging 18.96, 20.39, and 22.38 mg/dL at weeks 0, 3, and 6, respectively (P=0.025; SEM=0.917). In conclusion, drinking water treatments had no significant impact on milk yield or most composition parameters. This suggests that Alpine dairy goats exhibit resilience when consuming brackish water from West Pasture, USGS group 2, group 3, and unclassified sources.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"55 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145226691","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":"375 Effect of natural additives as an alternative to monensin on the performance of Nellore males in a grazing system.","authors":"Fabiano Alvim Barbosa, Anderson Di Pietro, Jose Mauro Diogo, Sergio Lucio Salomon Cabral Filho, Gilberto Goncalves Leite, Jacob Goelema","doi":"10.1093/jas/skaf300.096","DOIUrl":"https://doi.org/10.1093/jas/skaf300.096","url":null,"abstract":"The study evaluated the potential of natural additives, essential oils (EO) and live yeast (LY), as alternatives to monensin (MON) to improve the performance of beef cattle in tropical grazing systems. 72 uncastrated Nellore males, 8 months old and 232 kg of initial body weight (BW), grazed on Urochloa grass, in a continuous grazing system in 12 paddocks (2 hectares each) for 416 days, 280 days for the growing and 136 days for the fattening phases. The animals had ad libitum access to feed and water. All animals were weighed after 16h fasting every 56 days. Animals were randomly distributed in four blocks designed with three treatments and 24 animals per treatment. Every 28 days, animals were moved to another paddock to eliminate possible paddock effects. The treatments during the growing phase were: protein supplement + MON, protein supplement + LY, and protein supplement + EO. The additives were added to the supplement and the average doses during the dry and rainy seasons, respectively were: MON (Rumensin) 172 and 150 mg/day, LY (ActiSaf SC47PWD) 4 and 2 g/day, EO (RumenPlus Pasture) 5 and 5 g/day. During the fattening phase, animals were semi-confined with high-concentrate (estimated daily intake of 1.8% of the body weight) with respective additives. The average doses were: MON (Rumensin) 279 mg/day, LY (50% ActiSaf SC47PWD and 50% Procreatin7) 5 g/day, EO (RumenPlus Feedlot) 5 g/day. Dry matter intake (DMI) was calculated using the indigestible neutral detergent fiber and Lipe® (external marker) to estimate total feces production. Carcass gain was calculated assuming a carcass dressing of 50% of initial BW and considering carcass gain post-slaughter. Average daily gain (ADG), carcass (weight and gain), BW, and DMI were analyzed using PROCMIXED in SAS, with treatment means compared via Tukey’s test. Significance was determined at P≤0.05, with trends noted at 0.05>P≤0.10. Results indicated that DMI was higher for LY compared to MON (P=0.0833), during the growing phase (dry season). In the fattening phase, MON had lower DMI compared to LY and EO (P=0.0022). However, there were no significant differences in Final BW, ADG, and carcass (weight and gain) among the treatments, during the growing and fattening phases. Essential oils or live yeasts are viable alternatives to Monensin for beef cattle performance in grazing systems.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"21 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145226605","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":"38 Increasing dietary amylose increases hindgut fermentation of starch and thereby alters microbial metabolites, gut immunity, and energy metabolism in weaned pigs.","authors":"F P Y Tan, L F Wang, L L Guan, M G G Gaenzle, R T T Zijlstra","doi":"10.1093/jas/skaf300.220","DOIUrl":"https://doi.org/10.1093/jas/skaf300.220","url":null,"abstract":"Starch with increasing ratio of amylose to amylopectin decreases ileal starch digestibility in pigs. Microbes in the large intestine ferment undigested starch producing short-chain fatty acids (SCFA). Benefits of SCFA for gut health stimulated interest in dietary strategies to increase carbohydrate fermentation and thus SCFA concentration in the gut. This study elucidated effects of increasing dietary amylose on nutrient digestibility, metabolite profiles, gut immunity, and lipid metabolism in weaned pigs. Weaned pigs (n = 32) were randomly fed 1 of 4 diets containing 67% purified starch varying in amylose content (0, 20, 35, or 70%) for 21 d. Pigs were euthanized to collect digesta, feces, blood, and tissue samples for measuring starch digestion, metabolite profiles, and genes associated to metabolite transport, butyrate production, gut immunity, and lipid metabolism. Increasing dietary amylose quadratically decreased ileal digestibility of starch (P < 0.001) and quadratically increased hindgut fermentation of starch (P < 0.001) and cecal (P < 0.001) and colonic (P < 0.05) digesta SCFA concentration. Increasing dietary amylose upregulated expression of SCFA transporters in the mid colon (P < 0.05) but downregulated GPR109A in the proximal colon (P < 0.05). The 35%-amylose diet upregulated mucosal expressions of tight junction proteins in ileum and proximal colon (P < 0.05). Increasing dietary amylose quadratically downregulated expression of fatty acid synthase in abdominal fat and liver (P < 0.05) and quadratically increased butyrate production pathway genes (P < 0.05). Total SCFA concentration was negatively correlated with pro-inflammatory cytokines (P < 0.05). Butyrate concentration was positively correlated with mucin-2 (P < 0.05). In conclusion, increasing dietary amylose enhanced hindgut starch fermentation and total SCFA levels in weaned pigs. The increased carbohydrate fermentation was associated with increased butyrate production enzymes and improved gut health mechanisms including maintenance of gut barrier function and reduced proinflammatory cytokine. High-amylose starch reduced lipogenesis by downregulating lipogenic enzyme gene expression.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"18 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145226607","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":"PSI-1 Effects of arginine, tryptophan, and threonine on cell viability, antioxidant capacity, and tight junction gene expression of chicken intestinal epithelial cells induced with oxidative stress.","authors":"Ju Yeong Park, Yeong Bin Kim, Gyu Lim Yeom, Ha Neul Lee, Geun Yong Park, Ji Won Shin, Jong Hyuk Kim","doi":"10.1093/jas/skaf300.424","DOIUrl":"https://doi.org/10.1093/jas/skaf300.424","url":null,"abstract":"The objective of this study was to investigate the effects of arginine (Arg), tryptophan (Trp), and threonine (Thr) on cell viability, antioxidant capacity, and tight junction-related gene expression in chicken intestinal epithelial cells (cIECs) induced with oxidative stress. The cIECs were isolated from 16-d-old specific pathogen-free (SPF) chicken embryos. The cells were grown in fibronectin-coated plastic culture dishes in growth medium (DMEM, 2.5% FBS, 10 μg/mL insulin, 100 μg/mL penicillin/streptomycin, 2.5 mg/mL gentamicin, and 20 ng/mL epidermal growth factor) and incubated at 37℃ with 5% CO2. The cells were exposed to 0 (control), 250, and 500 μM supplements of Arg, Trp, and Thr for 24 h with 6 replicates for each treatment. After 24 h, cells were incubated with fresh culture medium (PC) or 1 mM of H2O2 with different supplements (NC and each treatment) for 6 h. All data were analyzed by ANOVA using the PROC MIXED procedure of SAS (SAS Institute Inc., NC, USA). The replicate was considered an experimental unit. Significance for statistical tests was considered at P < 0.05. The cell viability was less (P < 0.05) in NC treatment than in PC treatment. All treatments of Arg, Trp, and Thr showed greater (P < 0.05) cell viability than NC treatment. Total antioxidant capacity (TAC) was significantly less (P < 0.05) in NC treatment than in PC treatment, whereas 250 μM Arg and 250 μM Trp treatments showed greater (P < 0.05) TAC than NC treatment. Superoxide dismutase activity was significantly greater (P < 0.05) in PC treatment than in other treatments, whereas no significant differences were observed between NC and other treatments. Expression levels of tight junction-related genes including zonula occludens-1 (ZO-1), claudin (CLDN), occludin (OCLN), and junctional adhesion molecule 2 (JAM2) were significantly greater (P < 0.05) in PC treatment than in NC treatment. Among supplemented treatments, 250 μM Arg treatment significantly upregulated ZO-1 expression than in NC treatment. In conclusion, oxidative stress impairs cell viability, antioxidant capacity, and tight junction integrity of cIECs. The 500 μM Thr enhances cell viability, 250 μM Trp increases antioxidant capacity, and 250 μM Arg upregulates ZO-1 gene expression in cIECs.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"33 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145226632","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":"101 Effects of vitamin B complex supplementation on blood metabolites and performance of weaned beef calves during a 42-day preconditioning program.","authors":"Erica Ferri de Oliveira, Aline Cristine Rezende dos Santos, Ana L P Ramalho, Carlos E M Dos Santos, Matheus Fellipe Lana Ferreira, Jeff S Heldt, Chance G Farmer, Juliana Ranches","doi":"10.1093/jas/skaf300.315","DOIUrl":"https://doi.org/10.1093/jas/skaf300.315","url":null,"abstract":"Preconditioning programs aim to improve calf health and performance by reducing stress and enhancing adaptability post-weaning and transportation. Stress during this period may negatively impact immune function, increase cortisol concentration, reduce feed intake and growth efficiency. It may also affect vitamin B synthesis by ruminal microbes. This study evaluates the effects of vitamin B complex supplementation on blood metabolites and feed intake in calves during a 42-day preconditioning program at the Eastern Oregon Agricultural Research Center (EOARC; Burns, Oregon). A total of sixty-three Angus × Hereford calves were stratified by body weight (BW) after weaning (d0) and allocated into 21 pens, with 3 calves per pen. Pens were randomly assigned to one of three treatments: (1) Control, (2) VitB1, or (3) VitB2. Calves assigned to vitamin B supplementation received vitamin B complex (1 vs. 2g/calf daily; Vivalto®, Selko® USA) mixed with 1.3 kg of dried distillers’ grains (DDG), while calves in the Control group received only DDG, serving as a negative control. Blood samples were collected on days 0, 1, 3, 7, 14, 21, and 42 to measure blood metabolites, and feed intake was recorded daily. All calves had free access to chopped alfalfa-grass hay and whole corn. Body weight was measured at weaning (d0) and d1, with the average used as the weaning weight. Blood samples were analyzed for cortisol, haptoglobin, and ceruloplasmin. Variables were analyzed as repeated measures using the MIXED procedure in SAS (SAS Inst. Inc., Cary, NC, USA). Statistical significance was set at P ≤ 0.05. Weaning weights were similar at the start of the study (252 ± 3.6 kg; P = 0.82). No treatment effects were found on final BW (283, 283, and 284 kg for Control, VitB1, and VitB2, respectively; P = 0.98) or average daily gain (0.735, 0.795, and 0.747 kg/d for Control, VitB1, and VitB2, respectively; P = 0.53). No treatment (P = 0.34) or treatment × day (P = 0.59) effects were observed for total feed intake. Similarly, no treatment effects (P = 0.71) were observed for blood cortisol concentrations. However, a day effect was found (P < 0.001), with a tendency for a treatment × day interaction (P = 0.08). On d3, cortisol concentrations were greater for VitB1 calves (2.18 µg/dL; P = 0.04) compared to Control (1.69 µg/dL), with VitB2 intermediate (1.77 µg/dL; P = 0.11). At the end of preconditioning, on the d42, cortisol concentrations were greater for calves assigned to Control treatment compared to calves assigned to vitamin supplementation regardless of level (2.46, 1.99, and 1.90 µg/dL, respectively for Control, VitB1, and VitB2). Vitamin B complex supplementation during preconditioning did not affect feed intake or calf performance but ameliorated cortisol concentrations by the end of the preconditioning.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"33 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145226647","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":"199 Breaking language barriers in animal welfare: Developing Spanish for specific purposes courses and internship programs for veterinary and animal science students in Spanish-speaking farm environments.","authors":"Allen Jimena Jimena Martinez Aguiriano, Silvana Pietrosemoli, Leonor Salazar, Arlene Garcia","doi":"10.1093/jas/skaf300.076","DOIUrl":"https://doi.org/10.1093/jas/skaf300.076","url":null,"abstract":"The increasing Spanish-speaking population in the United States (18.5%) highlights a critical challenge: language barriers between Spanish-speaking farmworkers and English-speaking veterinarians, impacting communication, animal welfare, and farm productivity. This study evaluates the effectiveness of Spanish for Specific Purposes in Agriculture (SSPA) courses and related internships in enhancing communication skills and animal welfare knowledge among veterinary and animal science students working in Spanish-speaking farm environments. A preliminary survey identifies communication gaps among non-Spanish-speaking and bilingual animal professionals, guiding the course development. With a collaborative effort of three institutions, three SSPA courses were developed and implemented, followed by six week on-farm internships where English-speaking students presented twelve topics (Euthanasia, Acts of Abuse, Animal Handling, Biosecurity, Animal Health, Records, Feeding and Water Intake, Lameness, Transport, Housing, Mortality, Behavior) to farmworkers in Spanish according to their specific specie: beef cattle, swine, poultry, or dairy. Student performance was assessed via course scores, while farmworkers’ knowledge was evaluated using pre- and post-intervention surveys and feedback. The data from these surveys were analyzed using the McNemar Test to examine changes in categorical responses and the Wilcoxon Signed-Rank Test to evaluate differences in ordinal data, providing a comprehensive analysis of knowledge improvements. Despite challenges such as the lack of course credits and academic workload, the course completion rate of SSPA was 53.62%, higher than in similar studies. Post-intervention results demonstrated significant improvements in farm workers’ knowledge and practices across topics such as Euthanasia, Animal Handling, Biosecurity, and Transport. Although not all questions reached statistical significance, 84% of the questions showed positive changes in the post-survey, further highlighting the overall effectiveness of the intervention. The study also revealed that farmworkers’ education level influenced training effectiveness, underscoring the need to tailor programs for those with higher education, particularly university degrees in Veterinary and Animal Sciences from their home countries. This study shows that SSPA courses, combined with hands-on internships, can effectively address language barriers in farm settings. Moving forward, this project plans to expand its reach through the development of an app and an online platform, making the SSPA courses accessible to the broader agricultural industry, and further enhancing communication and animal welfare practices across diverse farm settings.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"158 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145226661","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":"244 Gait changes in the aging canine.","authors":"Claire L Timlin, Sarah M Dickerson, Fiona B Mccracken, Craig N Coon","doi":"10.1093/jas/skaf300.117","DOIUrl":"https://doi.org/10.1093/jas/skaf300.117","url":null,"abstract":"With aging comes changes in gait and mobility in our companion animals. While aspects of these mobility changes have been quantified in humans, less have been identified in dogs. The aim of this retrospective data analysis was to identify age-related gait changes in Labrador Retrievers. Data collected in March of 2018 was available on 65 dogs, of which 34 had data collected again in August of 2024 and were at that time without known mobility issues based on kennel records. Of those 34 dogs, 16 (8 males, 8 females) had reached at least 10 years of age and were used in the final data analysis. Average age at the first data collection was 5.5 years old, and after the 6 year span average age increased to 11.9 years and body weights at this time averaged 31.8 ± 3.18 kg. Gait was analyzed using the Gait4Dogs system which measures spatial, temporal, and pressure variables for each limb. For each variable, the sum of the front limb or left limb values were divided by the sum of the hind limb or right limb values to generate the front:hind (H:R) or left:right (L:R) ratios, respectively. The average value for each gait variable was also calculated. Data were analyzed in SAS using a repeated measures mixed model with fixed effects of time. Age in 2018 was included as a covariate and type 1 sum of squares was performed. Sex was included as a random effect and dog as the repeated subject. We observed significant decreases in cadence, average step length, average stride length, and average swing percentage of cycle (P ≤ 0.05). Conversely, average step time, cycle time, swing time, stance percentage of cycle, and stance time all increased as dogs aged (P ≤ 0.05). Front:hind ratios for step time, cycle time, swing percentage of cycle, and swing time all decreased over time (P ≤ 0.01), while stance percentage of cycle and stance time F:H ratios increased (P ≤ 0.01). Overall, we observed that as Labrador Retrievers aged, they developed slower gaits with reduced step and stride lengths and a shift towards spending more time in the stance phase.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"17 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145226670","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":"191 Evaluating the Efficacy of Lactobacilli-Based Direct-Fed Microbials (DFM) in reducing Shiga-toxigenic Escherichia coli (STEC) O157:H7 colonization using cell and tissue culture models.","authors":"Yiran Ding, Eduardo Cobo, Tim A McAllister, Luo Le Guan, Dongyan Xu Niu","doi":"10.1093/jas/skaf300.157","DOIUrl":"https://doi.org/10.1093/jas/skaf300.157","url":null,"abstract":"Background: STEC O157:H7 is a major global food safety and public health concern, with cattle serving as the primary reservoir. Colonization of STEC O157 in the cattle gastrointestinal tract, particularly the terminal rectum, leads to beef contamination and causing frequent outbreaks. Effective on-farm interventions are essential to reduce STEC transmission. Direct-Fed Microbials (DFMs) are live microorganisms, including beneficial bacteria or yeast, that are directly administered to animals to enhance gut health, reduce pathogenic load, and improve overall performance. Among 14 DFM candidates screened in our previous study, Ligilactobacillus agilis strains L3 and L6 showed the highest in vitro antimicrobial activity, making them promising candidates for reducing STEC O157 colonization. However, there is limited research on their efficacy in reducing STEC O157 attachment to intestinal epithelial cells and tissues. Objective: This study evaluates the potential of L. agilis DFM strains L3 and L6 to reduce STEC O157 colonization using in vitro cell (cattle ileum epithelial cells) and cattle tissue (terminal rectum) culture models. Methodology: STEC O157 strains R508N and R318N were used. Cattle ileum epithelial cells were isolated via enzymatic digestion and mechanical scraping, followed by purification and culture. Terminal rectum tissue cultures were prepared from fresh cattle intestinal tissues. For the attachment assay, epithelial cells were seeded in 24-well plates and exposed to STEC O157 suspensions. Tissue pieces (2.5 cm²) were inoculated with STEC O157 (10⁶ CFU) and incubated for 4 hours. Bacterial adherence was quantified by lysing cells or tissues, followed by plating and colony counting. L. agilis strains L3 and L6 will be applied to these models to assess their ability to reduce STEC colonization. Results: Preliminary results showed STEC O157 effectively colonized both cell and tissue cultures, with attachment levels ranging from 10⁶ to 10⁷ CFU. The next phase involves applying DFM (L3 and L6) to cell and tissue culture models to evaluate their ability to inhibit STEC O157 colonization. The attachment assay will assess DFM impact on STEC attachment to epithelial cells, while tissue models will evaluate colonization reduction in the terminal rectum. The goal is to identify DFM formulations that effectively inhibit STEC colonization, providing a potential intervention strategy for reducing pathogen load in cattle. Conclusions and Expected Outcomes: The expected outcomes of this study include demonstrating the ability of L3 and L6 to reduce STEC O157 attachment to epithelial cells and terminal rectum tissues. By investigating the interactions between STEC O157, DFMs, and the host, this research will provide mechanistic insights that contribute to the development of effective strategies for controlling this pathogen in cattle and mitigating its transmission to humans. The application of L. agilis DFMs shows promising potential in reducing S","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"1 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145226688","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":"PSV-28 Effects of various adaptation protocols on performance and carcass traits of Nellore bulls in a pasture-based finishing system.","authors":"Fernanda F Alves, Maria Eduarda M Lopes, Leticia M Machado, Kalista E Loregian, Ana Laura J Lelis, Guilherme O Sgobbi, Gabriela F L Ferreira, Rodrigo J Oliveira, Pedro Henrique C Ribeiro, Daniel H M Watanabe, Ariany F Toledo, Danilo D Millen","doi":"10.1093/jas/skaf300.686","DOIUrl":"https://doi.org/10.1093/jas/skaf300.686","url":null,"abstract":"This study aimed to evaluate the effects of various adaptation protocols for a pasture-based finishing system on the performance and carcass traits of Nellore bulls. Twenty-eight Nellore bulls were blocked according to initial body weight (BW) of 337 ± 3.98 kg and randomly assigned to one of four paddocks of Urochloa brizantha cv. Marandu (n = 7 per paddock). The paddocks covered an area of 2.5 ha, and the bulls were fed in individual Calan Gates bunks for a duration of 111 days. Experimental treatments included T1: a 21-day adaptation period with an initial concentrate ration supply of 0.5% of BW, increasing to 2.0% of BW by the end of 21 days (n = 10); T2: a 14-day adaptation period with an initial concentrate ration supply of 0.5% of BW, increasing to 2.0% of BW by the end of 14 days (n = 9); and T3: a 14-day adaptation period with an initial concentrate ration supply of 1.0% of BW, increasing to 2.0% of BW by the end of 14 days (n = 9). The BW assessment and average daily gain (ADG) were recorded every 28 days, except for the 27 days of the final period. The carcass ultrasound measurements evaluated marbling, rib-eye area, subcutaneous fat thickness, and biceps femoris fat thickness on days 0 and 111. At the end of the trial, bulls were slaughtered, and the hot carcass weight (HCW) and dressing percentage were recorded. Data were analyzed using PROC MIXED from SAS (SAS Inst., Inc., Cary, NC), and differences were considered significant at P ≤ 0.05. Overall, cattle that received an initial concentrate supply of 1.0% of BW during a 14-day adaptation period (T3) exhibited greater BW (547.16 kg), ADG (1.890 kg), HCW (302.56 kg), and biceps femoris fat thickness (6.67 mm) (P ≤ 0.05; Table 1). Furthermore, no effect of adaptation length or initial concentrate supply was observed on dressing percentage, marbling, loin eye area, and subcutaneous fat thickness after 111 days of trial (P > 0.05). Cattle in T1 and T2 did not differ from each other in any of the evaluated variables (P > 0.05). Adapting Nellore bulls to consume large amounts of a concentrate ration in a pasture-based finishing system over 14 days, starting with an initial concentrate supply of 1.0% of BW, improved performance and carcass traits. These findings indicate that a shorter adaptation period alongside a higher initial concentrate level can enhance growth performance and carcass weight in a pasture-based finishing system for Nellore bulls.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"77 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145226690","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}