Journal of animal science最新文献

{"title":"Short Communication: Genomic kinship, opposing homozygotes and genetic diversity in a selected population of Australian Angus cattle","authors":"Antonio Reverter, Malshani Samaraweera, Pâmela A Alexandre, Christian Duff, Laercio Porto-Neto","doi":"10.1093/jas/skaf207","DOIUrl":"https://doi.org/10.1093/jas/skaf207","url":null,"abstract":"Using molecular genotypes to check for Mendelian inconsistencies allows the identification of animals for which pedigree and genotype information disagree. A further use of molecular data is to understand and manage genetic diversity in a population. We sourced from the Angus Australia database a selected population of 11,224 animals, including 10,309 progeny born between 2013 and 2023 from 269 sires and 646 dams with at least 100 and 10 progeny, respectively. All animals had imputed genotypes for 61,105 autosomal markers. The additive and dominance genomic relationship (GR), as well as the number of opposing homozygotes (OH) were examined for pedigree-based relationship pairs including parent-offspring (PO; 21,307 pairs), full-sibs (FS; 35,486), half-sibs (HS; 677,421), grandparent-grandoffspring (16,308) and unrelated (62,232,954 pairs). Theoretical expectations for means and variances were compared against empirical observations. Consistent with expectations, the variance of additive GR among FS pairs was higher than the variance among HS, and the number of OH among FS was half the number of OH among HS. Expected to be 0.5, the observed additive GR among FS pairs and PO pairs was 0.483 (SD = 0.054) and 0.488 (SD = 0.037), respectively. The correlation (±SE) between additive and dominance GR was near unity for self-relationships (r = 0.935 ± 0.003) and zero for unrelated pairs (r = -0.001 ± 0.000). Expected to be zero, the number of OH among PO pairs averaged 11.6 and 77.5% of all PO pairs had an OH ≤ 12. Among FS pairs, the observed OH averaged 1,162.45 (expected = 1,150.17), and this average was surpassed by only 14 PO pairs, which was attributed to pedigree errors. Crucially, the anticipated negative correlation between additive GR and OH was affected by the degree of kindship being strongest negative among unrelated pairs (r = -0.762 ± 0.001). A principal components analysis and a network-based pipeline revealed the genetic diversity of the population with a focus on the role of the most influential parents. We conclude that, in our selected population of Australian Angus cattle, observed genomic relationships were close to expectations, while Mendelian inconsistencies were very rare and likely attributed to either errors in pedigree recording, mislabelling of samples, or error in genotypes and genotype imputation. Finally, our study reveals the genetic diversity and breeding management decisions occurring in modern Australian Angus breeding programs.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"249 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144503498","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":"45 The effects of N-carbamylglutamate and melatonin supplementation on testicular morphometrics of peripubertal Dorper lambs experiencing heat stress","authors":"Hannah Blasingame, Isabella Becerra, Mackenzie Hodge, Anna West, Rafael E Martinez, Zully Contreras-Correa","doi":"10.1093/jas/skaf170.165","DOIUrl":"https://doi.org/10.1093/jas/skaf170.165","url":null,"abstract":"Exposure to elevated environmental temperatures during the peripubertal period of male small ruminants fosters restricted growth of secondary sex characteristics, denoting poor reproductive performance in sexual maturity and therefore contributing to economic and productive loss. N-carbamylglutamate (NCG), a direct precursor to the amino acid arginine, has been shown to promote growth, feed efficiency, as well as reproductive performance in ruminants. Melatonin, a neuroendocrine hormone that works to control circadian rhythms, has also shown to elicit vasodilation and vasoconstriction responses in blood vessels to alleviate the effects of heat stress on ruminants. Although, the coupled supplementation of melatonin and NCG in peripubertal male lambs experiencing elevated levels of heat stress has not yet been comprehensively studied. Thus, the objectives of this study were to investigate the influence of heat stress and the supplementation of NCG and melatonin on macroscopic testicular morphometrics and testicular histological appearance in 24 commercial Dorper rams. After a 2-week acclimation period, the 4-month-old lamb rams were assigned into 1 of 4 groups based on body weight in a 2 x 2 factorial design. The groups consisted of a cooled environment (CL-CON; n = 5), a heat stressed environment (HS-CON; n = 6), and a cooled or heat stressed environment supplemented with 1.4g/h/d of NCG and 8mg melatonin/h/d (CL-NCGMEL, n = 5; HS-NCGMEL; n = 6). On day 42 posttreatment, rams were slaughtered and the testicles were collected to determine testicular weight and scrotal circumference. Data were analyzed utilizing the MIXED procedure of SAS v 9.4 including environment and dietary treatments as fixed effects and their corresponding interactions. An environment by dietary treatment interaction was observed for testicular weight (P = 0.0343), where HS-CON lambs had lower testicular weights (427.73 ± 36.76 g) compared with CL-CON and HS-NCGMEL (651.58 ± 51.09 vs. 557.22 ± 34.48 g, respectively). Nevertheless, no significant difference was observed between the testicular weight of CL-CON and HS-NCGMEL lamb rams (P > 0.05). Additionally, an environment by dietary treatment interaction was observed where testicular circumference (P = 0.043) in HS-NCGMEL animals was increased compared to control (30.422±0.85 vs. 27.375±0.94 cm). Similarly, The HS-CON had lower (P = 0.0383) testicular diameter (16.286±0.449 cm) compared with CL-CON and HS-NCGMEL (18.57±0.62 and 18.400±0.43 cm). Lastly, epididymal weights of the HS-CON group were decreased (P = 0.033) as compared to the HS-NCGMEL group (14.22±1.73 vs 19.69 ±1.57 g, respectively). The significant increase in testicle weight, circumference, diameter, and epididymal weight of HS-NCGMEL rams may indicate increased growth efficiency within secondary sex characteristics within the peripubertal growth period.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"103 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144503502","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":"194 SMART Foodscapes: Advancing sustainable beef production in Western U.S","authors":"Juan J Villalba","doi":"10.1093/jas/skaf170.023","DOIUrl":"https://doi.org/10.1093/jas/skaf170.023","url":null,"abstract":"Strategies that enhance plant community diversity promote heterogeneity in chemical, structural and functional landscape traits, offering foraging options that improve nutrition, reduce environmental impacts, and support livestock health. Bioactive compounds such as tannins can mitigate methane emissions, improve nitrogen balance, and enhance antioxidant status. To leverage these benefits, diverse legumes, forbs and shrubs rich in nutrients and functional phytochemicals are being integrated into resource patches or “islands” within a “sea” of grass-dominated rangelands. These islands serve as a cost-effective supplementation strategy to enhance biodiversity and improve the sustainability of beef production systems. We are evaluating native and introduced plant species for establishment and persistence across different ecosites in Utah. Using continuous culture fermenters, we evaluate how these forages and their interactions influence rumen fermentation, microbial growth, methane production, and nutrient digestibility. Additionally, modelling efforts explore the effects of strategic legume inclusion on cattle performance and environmental footprint. Our findings suggest that incorporating 15-20% legumes, allocated monthly, optimizes performance while reducing methane emissions and nitrogen excretion per unit of production. Based on in vitro and modelling results, strips of sainfoin, small burnet, forage kochia, birdsfoot trefoil, and alfalfa are being strategically deployed within grasslands to evaluate their impact on enteric methane emissions, nitrogen losses, and grazing behavior in beef cattle. These foodscapes are also being tested for their effects on pollinator, mammalian and avian wildlife habitat. This transdisciplinary project is progressing to create more sustainable beef production systems while engaging and educating current and future land stewards.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"68 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144503548","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":"179 Effect of feeding alternative coproducts in finishing calves","authors":"Colin T Tobin, Kendall C Swanson, Warren C Rusche, Madison Bierman, Zachary K Smith","doi":"10.1093/jas/skaf170.039","DOIUrl":"https://doi.org/10.1093/jas/skaf170.039","url":null,"abstract":"Recent expansion of oilseed crushing facilities and multiple designations of renewable diesel fuel have created competitive markets in protein supplements for beef cattle. More research on the direct comparison to identify differences in finishing of beef cattle fed alternative coproducts produced across the northern US is needed for these expanding opportunities. The objective of this study was to determine the effects of alternative coproducts on dry matter intake (DMI), growth performance, and carcass characteristics of calf-fed finishing steers. Two hundred fifty-one crossbred steer calves (n=251, initial shrunk body weight [BW], 344 ± 9 kg) were stratified by source, and assigned to one of twenty-four pens (n=10-11 steers/pen) and one of three dietary treatments. Diets were formulated to provide similar amounts of crude protein and NEg with dried distillers grains plus solubles (DDGS), canola meal (CM), or soybean meal (SBM). Steers were fed for a total of 155 and 170 days with individual weights taken on d -1, 0, 23, 50, 78, 110, 154, and 155 and d -1, 0, 31, 56, 85, 112, 169, and 170 for block 1-3 and block 4, respectively. A 4% pencil shrink was applied to the initial and final BW. Growth and carcass data were analyzed in a generalized randomized block design using the GLIMMIX procedure of SAS 9.4 with dietary treatment and block (source) as fixed effects and pen serving as experimental unit. Dietary treatment differences in growth performance were detected with final BW (P = 0.04), BW gain (P = 0.02), and average daily gain (ADG, P = 0.02). Steers fed CM had greater final BW (P = 0.03), BW gain (P = 0.01), and ADG (P = 0.01) by 2.3%, 5.8%, and 5.8% to steers fed SBM, respectively. No differences were detected in DMI and gain:feed (P > 0.1). Dietary treatment differences in carcass characteristics were detected with hot carcass weight (HCW, P = 0.02), 12th rib fat thickness (RF, P = 0.03), and dressing percentage (DP, P = 0.01). Additionally, dietary treatment tended to influence USDA yield grade (YG, P = 0.06). Steers assigned to CM had 3.6% greater HCW (P = 0.01) and tended to have 2.5% heavier HCW (P = 0.09) compared to steers receiving SBM and DDGS, respectively. The USDA YG tended to be greater for CM than SBM (3.87 and 3.66, respectively) which corresponds to 0.16 cm greater RF for the CM fed steers (P = 0.02). No differences were detected in ribeye area or marbling score (P ≥ 0.16). No performance adjusted net energy differences were detected between the coproducts (P ≥ 0.71).","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"22 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144503603","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":"48 Red clover leaf can partially attenuate fescue toxicosis-related heat stress in cattle","authors":"Alysa M Farrell, Tracy A Hamilton, Jennifer Weinert-Nelson, Ronald J Trotta, Daraja Maye, Allison Serda, Kiana Rivera, Brittany E Davis","doi":"10.1093/jas/skaf170.178","DOIUrl":"https://doi.org/10.1093/jas/skaf170.178","url":null,"abstract":"Ergot alkaloids in endophyte-infected tall fescue (E+TF) can negatively impact the welfare and growth of cattle by altering the physiology of the animal including systemic vasoconstriction resulting in decreased capacity for thermoregulation and increased heat stress susceptibility. The isoflavones in legumes, specifically red clover (RC), are known hypotensive agents and can be used to prevent vasoconstriction associated with E+TF. Based on the vasodilatory properties of RC, the objective of this study was to determine if low levels of RC could also prevent fescue toxicosis-related heat stress (HS). We hypothesized that cattle receiving E+TF seed with RC will have reduced rectal temperature (RT) and respiration rates (RR) in comparison to those that receive isoflavone-free orchardgrass (OG) when subjected to a HS challenge. Two blocks of 6 ruminally-fistulated beef-cross steers (Initial body weight (BW), block 1: 521.0±9.1kg and block 2: 360.8±11.6kg) were dosed intraruminally with E+TF seed (15 µg kg BW-1 ergovaline + ergovalanine) daily, and stratified by BW into 2 treatments of either 25 g head d-1 ground [5 mm] OG (E+OG) or RC leaf (E+RC). All steers were first adapted to their basal diet (ad libitum corn silage + dried distillers’ grains with solubles) for 14-d and then were subjected to treatments for 14-d including a 7-d thermoneutral period (TN: 21.0˚C, 64.0% humidity, Temperature-Humidity Index (THI)=67) followed by a 7-d HS challenge period (cyclical daily temperatures to mimic diurnal patterns; HS: 23.2˚C–33.6˚C, 39.5–70.0% humidity, THI=70.3–83.5). At 0630, 1230, and 1730-h each day, RR and RT were measured by counting flank movements for 15 s and using a rectal thermometer, respectively. Data were analyzed using the MIXED procedure with repeated measures of SAS (v.9.4) with significance observed at P ≤ 0.05. At the end of the adaptation period (no treatments), RR was 50±1.4 breaths·min-1 and RT was 38.6±0.05 ˚C on average. By days 5 and 7 of the thermoneutral period E+OG steers had greater RT (+0.5˚C) and RR (+11 breaths·min-1) in comparison with E+RC steers, regardless of sampling time, respectively (P < 0.05). During the HS challenge, RT and RR continued to increase in E+OG steers from day 8 to day 12 (day 13 for RR 0630-h) peaking at 40.1˚C and 121 breaths·min-1 at 0630, 40.3˚C and 143 breaths·min-1 at 1230, and 40.6˚C and 161 breaths·min-1 at 1730-h (P < 0.01). Rectal temperature and RR also increased in E+RC steers during HS period, peaking on days 12 and 13 (0630-h: 39.2˚C, 85 breaths·min-1; 1230-h: 39.5˚C, 106 breaths·min-1; 1730-h:39.4˚C, 109 breaths·min-1); however, on all days and sample times, RR and RT were lower in E+RC compared to E+OG steers (P < 0.05). Results of the current study indicate that a small amount of RC daily can partially attenuate fescue toxicosis-related heat stress.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"1 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144503634","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":"55 Beef steers acceptance of increasing doses of thymol to a basal forage diet","authors":"Jordan Suter, Greyson Fruge, Emma Fukuda, Russell Jessup, Merritt L Drewery","doi":"10.1093/jas/skaf170.171","DOIUrl":"https://doi.org/10.1093/jas/skaf170.171","url":null,"abstract":"The global population is estimated to reach 9.1 billion by 2050, requiring the livestock industry to increase output while also being mindful to animal health and sustainability of production. The use of antimicrobial plant-derived compounds, such as thymol, has been studied to improve feed efficiency, ensure herd health, and reduce methane production in cattle. However, much of the existing research has been conducted in-vitro, creating a gap in the literature regarding the acceptance of cattle for dietary thymol. The objective of this study was to evaluate the acceptance of beef steers to increasing doses of thymol provided as a supplement to a basal forage diet. Procedures involving animals were approved by the Institutional Animal Care Use Committee at Texas State University (#8693). The experiment was a 4×4 Latin Square design with four 3-d experimental periods, each followed with a 3-d washout period. Prior to initiation of the experiment, steers were adapted to individual housing for 10-d. Steers received ad libitum access to forage, a trace mineral block, and water. During the experimental periods, one of four treatments was provided: thymol at 0, 110, 220, and 330 mg/kg forage intake from the previous 3-d. Thymol was stabilized on nanocellulose and soaked on alfalfa cubes that were supplemented at 0.20% BW. Treatments were offered for 30 mins and subsequent refusals were collected. During washout periods, steers were provided 1 kg of cottonseed meal in addition to their basal hay diet. Forage and supplement intake were analyzed using the MIXED procedure in SAS v9.4. Terms in the model were treatment, period, day, and treatment × day, with steer and treatment × period × steer as the random terms. The repeated term was day with treatment × steer as the subject. Hay intake was not affected by treatment × day (P=0.71) or treatment (P=0.18) but was affected by day (P=0.01) with a significant difference between days 2 and 3 (P≤0.01) such that hay intake averaged 10.4 kg on day 2 and 9.2 kg on day 3 of the experimental periods. There was not an effect of treatment × day (P=0.51), treatment (P=0.17), or day (P=0.40) on supplement intake. Supplement intake was 1.14 kg/d for CON, 1.10 kg/d for 110 and 220 mg thymol/kg forage, and 1.06 kg/d for 330 mg thymol/kg forage. While the differences across treatments were not significant, there were numerical differences in the consumption of alfalfa and thymol such that intake was greater when concentrations were lower (110 mg/kg and 220 mg/kg), indicating that cattle may not tolerate thymol provided at 330 mg/kg forage intake. Future studies should determine the upper threshold beyond which cattle would not accept dietary thymol to inform the development of a commercial dietary thymol supplement.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"13 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144500482","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":"96 Correlating vaginal bacteria abundance and interferon-stimulated genes in lactating dairy cattle","authors":"Dallas R Soffa, Jennifer A Spencer, Rebecca K Poole","doi":"10.1093/jas/skaf170.067","DOIUrl":"https://doi.org/10.1093/jas/skaf170.067","url":null,"abstract":"Pregnancy relies on a variety of physiological factors and processes for successful establishment. The reproductive microbiome appears to influence pregnancy status, and previous research suggests that the expression of interferon-stimulated genes (ISGs) may play a role on pregnancy determination in cattle. However, the relationship between ISGs and reproductive microbiome has yet to be comprehensively evaluated in dairy cattle. Thus, the objective of this study was to analyze correlations between vaginal bacteria abundance and circulating ISGs in lactating dairy cattle in open and pregnant females. Lactating Holstein cows (n=27) were sampled on day of artificial insemination (AI) and day 18 post-AI. Sterile swabs were inserted into the vagina and rotated eight times along the vaginal wall prior to storage in sterile microcentrifuge tubes at -80°C. Swab samples were utilized for subsequent bacterial abundance analyses targeting the V4 hypervariable region of the 16S rRNA gene. Blood was collected via coccygeal venipuncture, placed on ice, and centrifuged at 2500 x g and 4°C for 20 minutes. Resulting buffy coats were collected, and samples stored at -80°C for real-time quantitative polymerase chain reaction (RT-qPCR) analysis. Cows underwent transrectal ultrasonography on day 32 post-AI for pregnancy determination. Selected target genes were interferon-stimulated gene 15 kDa (ISG15) and myxovirus resistance gene 2 (MX2). Mean relative mRNA expression of ISG15 was negatively correlated with phylum Tenericutes on day of AI (r = -0.43; P = 0.03). Concurrently, mean relative mRNA expression of MX2 was negatively correlated with phylum Bacteroidetes (r = -0.35; P = 0.08) and positively correlated with phyla Actinobacteria and Tenericutes (r = 0.41 and r = 0.41, respectively; P = 0.04). On day 18, MX2 mean relative mRNA expression was positively correlated with phylum Firmicutes (r = 0.39; P = 0.05). Regarding bacterial genera abundance, mean relative mRNA expression of ISG15 was negatively correlated with Ureaplasma on day of AI (r = -0.41; P = 0.04) and positively correlated with Sneathia on day 18 (r = 0.40; P < 0.05). MX2 mean relative mRNA expression was negatively correlated with Ruminococcus (r = -0.40; P = 0.05) and positively correlated with Ureaplasma (r = 0.42; P = 0.03) on day of AI. On day 18, mean relative mRNA expression of MX2 was positively correlated with Streptococcus (r = 0.42; P = 0.04). Interestingly, genera Ureaplasma and Sneathia have been previously associated with reproductive diseases in cattle, yet the current work suggests their bacterial load may not be indicative of inflammation. Further, the positive correlation of MX2 expression with phylum Actinobacteria may indicate potential pathogenicity as it has been previously associated with infertility in both women and cattle. Additional research is needed to further determine the relationship between reproductive microbiota and ISGs during pregnancy establishment.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"249 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144500810","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":"4 Supplementation of Bacillus-based direct-fed microbials for grazing Bos indicus-influenced beef heifers","authors":"Conner Crawford, Vinicius S Izquierdo, Joao M B Vendramini, Bruno Cappellozza, Philipe Moriel","doi":"10.1093/jas/skaf170.133","DOIUrl":"https://doi.org/10.1093/jas/skaf170.133","url":null,"abstract":"This study evaluated the effects of post-weaning supplementation with a Bacillus-based direct-fed microbials (DFM) on growth and reproduction of Bos indicus-influenced beef heifers. On day 0 (30 days after weaning), 64 Brangus crossbred beef heifers were stratified by their initial body weight (BW; 256 ± 31 kg) and age (283 ± 18 day of age), and randomly allocated into 1 of 16 bahiagrass (Paspalum notatum) pastures (1 ha and 4 heifers per pasture). Treatments were randomly assigned to pastures (8 pastures per treatment). Treatments consisted of daily concentrate dry matter (DM) supplementation at 1.50% of BW added (BAC) or not (CON) with a Bacillus-based DFM mixture (3 g per heifer; Bovacillus™; Novonesis, Lyngby, Denmark) from day 0 to 244. Heifers were assigned to an estrus synchronization protocol from day 98 to 112. Heifers detected in estrus from day 109 to 112 were inseminated (AI) 12 h after estrus detection. Heifers not detected in estrus were timed AI on day 112. All heifers were exposed to Angus bulls from day 119 to 210 (1 bull per pasture). Growth performance data and reproductive binary data were analyzed using MIXED and GLIMMIX procedures of SAS, respectively, and included pasture(treatment) as experimental unit and heifer(pasture) as random effect. Effects of treatment ´ day of the study were not detected (P ≥ 0.87) for herbage mass, herbage allowance, and heifer BW. Heifer average daily gain from day 0 to 244 (0.74 vs. 0.74 ± 0.02 kg/day, respectively) and mature BW at the start of the breeding season (70.0 vs. 70.3 ± 0.7%, respectively) did not differ (P ≥ 0.62) between BAC and CON heifers. Puberty attainment on day 60 (24.1 vs. 6.7 ± 6.6%, respectively) and reproductive tract score on day 90 (4.00 vs. 3.72 ± 0.12%, respectively) tended (P = 0.06) to be greater for BAC vs. CON heifers. Percentage of heifers detected in estrus (44.5 vs. 32.7 ± 9.0%, respectively), conception rate to AI (52.5 vs. 37.5 ± 9.1%, respectively), and final pregnancy rates (72.4 vs. 73.3 ± 8.4%, respectively) did not differ (P ≥ 0.24) between BAC and CON heifers. In summary, Bacillus-based DFM supplementation for developing replacement beef heifers tended to hasten puberty attainment but did not increase growth and pregnancy attainment compared to no DFM supplementation in year 1. The study will be repeated for a second year to confirm these results.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"13 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144500813","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":"180 Effects of finishing system on growth, efficiency, and carcass quality of Dairy × Beef crossbred steers compared to native beef steers","authors":"Ally J Grote, Zane N Grigsby, Paul A Beck, Tom Fanning, Dusty Turner","doi":"10.1093/jas/skaf170.038","DOIUrl":"https://doi.org/10.1093/jas/skaf170.038","url":null,"abstract":"Our objective was to determine the effect of calf-fed (CF) or yearling-fed (YF) finishing systems on performance and carcass characteristics of dairy-beef (DB) crossbred steers compared to native beef (NB) steers. The NB steers were acquired from Capitol Land and Livestock in Schwertner, Texas. The DB steers were acquired from 5-Star Dairy in Hart, Texas. The NBCF and DBCF steers were transported directly to commercial feedyard (Buffalo Feeders, Buffalo, OK) from the source. Yearling fed steers grazed mixed grass prairie for 144-d before finishing. At feedlot processing, steers were implanted with 100 mg of trenbolone acetate and 14 mg of estradiol benzoate (Synovex Choice, Zoetis Animal Health, Parsipanny, NJ). Steers were reimplanted with either 200 mg of trenbolone acetate and 28 mg of estradiol benzoate (Synovex One Feedlot, Zoetis Animal Health) or 200 mg of trenbolone acetate and 28 mg of estradiol benzoate (Synovex Plus, Zoetis Animal Health). The NBCF steers were fed a 26% roughage growing ration (15% CP and 1.2 Mcal NEg/kg) for 97 d then transitioned through a series of step-up diets (13% CP and 1.3 Mcal NEg/kg) for 13 d to a 7% roughage, finishing diet (13% CP and 1.6 Mcal NEg/kg). The CFDB were fed a series of step-up diets for 19 d each before transitioning to a finishing diet at d 64. The YF steers were fed a series of step-up diets for 29 d before transitioning to the finishing diet. For CF, initial BW did not differ for DB and NB (P=0.11). The initial BW of YFNB was 21 kg greater (P< 0.01) than YFDB. Yet at reimplant, YFDB and YFNB did not differ and both YF groups were greater than CF group which did not differ (P=0.73). The YFDB compensated for 114% of the previous difference in initial BW from YFNB. The DBYF steers had the greatest overall ADG (P< 0.01) with NBCF having the least ADG (P< 0.01) and NBYF and DBCF being intermediate. There was a finishing system by breed interaction for back-fat thickness (P=0.03) where NBCF had the greatest back-fat thickness, and DBYF having the least BFT, while DBCF and NBYF were intermediate. Yield grade was greater (P< 0.01) in YF than CF, but there was no breed effect (P=0.12). Overall liver abscesses had a breed (P< 0.01) and finishing system effect (P=0.01) with DB and YF steers having a higher incidence of liver abscesses. Dairy-beef yearling-fed steers exhibited compensatory gain from grazing within the first 83 d of being in the feedlot. Breed and finishing system had an impact of performance but exhibited minimal impact on carcass quality or liver abscesses.","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"48 1","pages":"31-32"},"PeriodicalIF":3.3,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144556571","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":"24 Effects of stocking density on growth, physiological responses, and puberty attainment of beef heifers reared in drylots","authors":"Izadora de Souza, Reinaldo F Cooke, Camila Prado, Shea Mackey, Kelsey M Harvey","doi":"10.1093/jas/skaf170.125","DOIUrl":"https://doi.org/10.1093/jas/skaf170.125","url":null,"abstract":"This experiment evaluated growth, physiological responses, and puberty attainment in beef heifers reared in drylots with different stocking density. A total of 120 heifers (75% Angus ´ 25% Brahman) were used in this experiment. Heifers were ranked by age (267 ± 2 d) and body weight (BW on d -5; 228 ± 2 kg) on d 0, and assigned to a) 1 of 3 drylot pens (10 × 14 m pens; 10 heifers/pen) with a stocking density of 14 m2/heifer (HDENS), b) 1 of 3 drylot pens (10 × 28 m pens; 10 heifers/pen) with a stocking density of 28 m2/heifer (MDENS), c) 1 of 3 drylot pens (10 × 42 m pens; 10 heifers/pen) with a stocking density of 42 m2/heifer (LDENS), or d) 1 of 3 pastures (1-ha pastures; 10 heifers/pasture) with a stocking density of 1,000 m2/heifer (CON). Negligible forage was available for CON, whereas heifers from all treatments received the same limit-fed diet (~7 kg/heifer daily, dry matter basis). Shrunk BW was recorded after 16 h of feed and water withdrawal on d -5 and 171 to calculate average daily gain (ADG). Blood samples were collected weekly for progesterone analysis (d 0 to 170). Hair samples from the tail switch were collected every 28 d (d 0 to 170). Data were analyzed with pen or pasture as experimental unit, via ANOVA using the MIXED or GLIMMIX procedures of SAS (SAS Inst. Inc., Cary, NC). No treatment effects were detected (P = 0.53) for heifer ADG during the experiment (0.582, 0.576, 0.548, and 0.567 kg/d for HDENS, MDENS, LDENS, and CON, respectively; SEM = 0.024). Hair cortisol concentrations were less (P < 0.05) for CON compared to all other treatments on d 170 (treatment × day interaction; P = 0.03). Heifers from CON experienced hastened puberty attainment as a greater (P < 0.05) proportion of CON heifers were pubertal beginning on d 120 compared with all other treatments (treatment × day interaction, P < 0.01). Puberty attainment was similar among HDENS, MDENS, and LDENS heifers (P ≥ 0.48). Collectively, results from this experiment demonstrate that heifers reared in drylots, even at lower stocking densities (i.e. 42 m2/heifer) still experience delayed puberty attainment compared with heifers reared on pasture. This work is supported by the USDA National Institute of Food and Agriculture (#2021-67015-34083).","PeriodicalId":14895,"journal":{"name":"Journal of animal science","volume":"27 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144503370","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}