{"title":"Random metaphylactic effects of tulathromycin on health outcomes, complete blood count, antimicrobial use, growth performance, and Salmonella enterica shedding in high-risk beef steers","authors":"C.W. Dornbach , P.R. Broadway , N.C. Burdick Sanchez , M.S. Grant , K.D. Childress , B.J. Sitka , T.A. Loeffler , L.G. Canterbury , M.L. Galyean , K.E. Hales","doi":"10.15232/aas.2025-02679","DOIUrl":"10.15232/aas.2025-02679","url":null,"abstract":"<div><h3>Objective</h3><div>We evaluated the effects of random metaphylaxis administered with tulathromycin at feedlot arrival to 0%, 33%, 66%, and 100% of high-risk beef steers on health outcomes, growth performance, complete blood cell count, <em>Salmonella</em> shedding, and antimicrobial use during a 35-d receiving period.</div></div><div><h3>Materials and Methods</h3><div>Crossbred beef steers (n = 232; arrival BW = 213 ± 6.3 kg) were used in a generalized complete block design consisting of 2 source blocks, each with 4 BW blocks and 4 treatments. Steers were randomly assigned to pen within source block, and experimental treatments were (1) negative control, s.c. injection with sterile saline (0M); (2) tulathromycin administered at random to 33% of steers within a pen (33M); (3) tulathromycin administered at random to 66% of steers within a pen (66M); or (4) conventional metaphylaxis with tulathromycin administered to 100% of steers within a pen (100M). Body weight, whole blood, and fecal samples were collected on d 0, 14, and 35. Metaphylactic treatment was included in the model as a fixed effect, and BW block within source block was included as a random effect.</div></div><div><h3>Results and Discussion</h3><div>Initial bovine respiratory disease treatments were 108% and 62.2% greater for 0M and 33M, respectively, compared with the average treatment prevalence for 66M and 100M steers. No differences were detected between treatments for BW, ADG, DMI, or G:F from d 0 to 35 with dead cattle excluded or included. Hematology metrics were mostly affected by day, though reticulocyte count and eosinophil percentage differed among treatments. Fecal <em>Salmonella</em> concentration and prevalence did not differ among treatments but increased from d 0 to 14 before equalizing through d 35.</div></div><div><h3>Conclusions and Applications</h3><div>These data suggest that metaphylaxis can be administered to 66% of cattle without increasing bovine respiratory disease morbidity or decreasing growth performance. Moreover, random metaphylaxis to 66% of steers at arrival decreased the amount of active drug compound administered compared with 0M and the number of antimicrobial injections administered in each pen compared with 100M. <em>Salmonella</em> shedding was not affected by random metaphylaxis with tulathromycin in high-risk beef steers.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 3","pages":"Pages 176-189"},"PeriodicalIF":1.4,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T.N. Andrews , K.M. Epperson , J.J.J. Rich , S. Menegatti Zoca , A.C. Kline , L.K. Quail , S.R. McCoski , C. Sanford , A.L. Zezeski , T.W. Geary , J.A. Walker , G.A. Perry
{"title":"Interactions of change in nutrition before and after artificial insemination on plasma and uterine histotroph mineral concentrations in beef heifers","authors":"T.N. Andrews , K.M. Epperson , J.J.J. Rich , S. Menegatti Zoca , A.C. Kline , L.K. Quail , S.R. McCoski , C. Sanford , A.L. Zezeski , T.W. Geary , J.A. Walker , G.A. Perry","doi":"10.15232/aas.2024-02634","DOIUrl":"10.15232/aas.2024-02634","url":null,"abstract":"<div><h3>Objective</h3><div>These studies evaluated embryo recovery and nutritional changes before and after artificial insemination (AI) on circulating and uterine histotroph mineral concentrations.</div></div><div><h3>Materials and Methods</h3><div>In study 1, heifers (n = 79) were assigned to 1 of 2 treatments before and after AI: (1) low, 90% and 81% of maintenance energy requirements, or (2) high, 162% and 148% of maintenance energy requirements. At AI (d 0) half of the heifers were reassigned to the other treatment. Uteri were flushed on d 7 or 8. In study 2, heifers (n = 50) were only treated after AI (77.5% or 161.5% of maintenance energy requirements) until uteri were flushed on d 14.</div></div><div><h3>Results and Discussion</h3><div>In study 1, the low diet after AI resulted in reduced uterine S and Ca, indicating nutrient restriction after AI altered the uterine histotroph. When an embryo was recovered, uterine S, Ca, K, and Al were reduced, and Mg tended to be reduced. Thus, the embryo is likely using these minerals for growth and development. Plasma Mn, Mo, Zn, and Se were affected by time, indicating mineral bioavailability may vary during the estrous cycle. In study 2, heifers on the low diet tended to have elevated plasma Co and reduced uterine Fe. When an embryo was recovered, uterine Mg and S were reduced, and uterine Ca tended to be reduced and Mn tended to be elevated. Thus, Mg and S may be used by the developing embryo.</div></div><div><h3>Implications and Applications</h3><div>In summary, energy restrictions after AI reduced mineral concentrations in the uterine histotroph, potentially hindering embryo development as embryos appeared to use S, Ca, and Mg for development.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 3","pages":"Pages 215-229"},"PeriodicalIF":1.4,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effects of low temperature and ensiling time on fermentation and nutritive value of sorghum- sudangrass silage","authors":"Elizabeth Coons , Matthew S. Akins","doi":"10.15232/aas.2024-02636","DOIUrl":"10.15232/aas.2024-02636","url":null,"abstract":"<div><h3>Objective</h3><div>The study evaluated the fermentation and nutritive value of freeze-affected sorghum-sudangrass si- lage stored at 2 temperatures.</div></div><div><h3>Materials and Methods</h3><div>Sorghum-sudangrass for- age affected by several frost/freeze events and lodging was harvested and chopped, then ensiled in vacuum-sealed plastic mini-silos. Silos were stored at either 4°C or 20°C for 5, 10, 15, 30, or 60 d with triplicate silos at each time. Resulting silage was evaluated for pH, silage acids and al- cohols, nitrates, and nutritive value. Aerobic stability was also measured on silages stored for 60 d.</div></div><div><h3>Results and Discussion</h3><div>Silage pH decreased more quickly at 20°C, with silage at 4°C having a 10-d lag be- fore pH decreased. Lactic, acetic, and propionic acid con- centrations were greater at all times for silage stored at 20°C. Ethanol and methanol were greater in silage stored at 20°C, which is speculated to be from increased yeast activity. The decreased fermentation for silage stored at 4°C resulted in 1% greater DM recovery; however, aerobic stability was better for silage stored at 20°C (149 h) than 4°C (47 h) likely due to greater acetic acid concentration. Silage storage at 4°C resulted in lower NDF concentration due to less silage acid production, with no other changes in nutritive value observed due to storage temperature. Nitrate concentrations were low in the initial forage (76 mg/kg DM) with concentrations lower after storage (43– 50 mg/kg DM), as expected.</div></div><div><h3>Implications and Applications</h3><div>Storage temperature of sorghum-sudangrass silage had a significant impact on silage acid production and aerobic stability with limited fermentation the first 10 to 15 d of storage. This research is applicable when harvesting forage during cold or freez- ing temperatures, which limits early fermentation. Allow- ing standing forage to thaw/warm before harvest may improve fermentation and aerobic stability. Additional research on changes in nitrates of frosted sorghum forage is needed to confirm results in forage with high initial nitrate levels.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 3","pages":"Pages 156-161"},"PeriodicalIF":1.4,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A.N. Hanratty , K.E. Hales , C.W. Dornbach , N.C. Burdick-Sanchez , A.B. Word , B.P. Holland , C.L. Maxwell , J.E. Hergenreder , L.G. Canterbury , J.T. Leonhard , J. Vasconcelos , D. LaFleur , S. Trojan , M.L. Galyean , P.R. Broadway
{"title":"Effects of supplementing Bacillus subtilis PB6 on health outcomes, Salmonella spp. prevalence, growth performance, and carcass characteristics in finishing beef cattle","authors":"A.N. Hanratty , K.E. Hales , C.W. Dornbach , N.C. Burdick-Sanchez , A.B. Word , B.P. Holland , C.L. Maxwell , J.E. Hergenreder , L.G. Canterbury , J.T. Leonhard , J. Vasconcelos , D. LaFleur , S. Trojan , M.L. Galyean , P.R. Broadway","doi":"10.15232/aas.2024-02671","DOIUrl":"10.15232/aas.2024-02671","url":null,"abstract":"<div><h3>Objective</h3><div>We evaluated the effects of supplementation with <em>Bacillus subtilis</em> PB6 on health outcomes, growth performance, fecal <em>Salmonella</em> prevalence, and carcass characteristics in finishing beef steers supplemented the first 60 d or the entire 224 d of the feeding period with <em>B. subtilis</em> PB6.</div></div><div><h3>Materials and Methods</h3><div>Crossbred beef steers (n = 3,150; arrival BW 274 ± 30.6 kg) were used in a randomized complete block design consisting of 3 dietary treatments (n = 15 blocks per treatment). Treatments included the following: (1) a control diet contained no <em>B. subtilis</em> PB6 (CON); (2) a diet that included CLOSTAT supplemented with 0.5 g/steer daily of <em>B. subtilis</em> PB6 (CLOSTAT 500, Kemin Industries Inc.) to provide 6.6 × 10<sup>9</sup> cfu/g active ingredient for the entire duration of the feeding period (CLO); or (3) a diet that included <em>B. subtilis</em> PB6 at a dose of 0.5 g/steer daily the initial 60 d of the feeding period (CLO60). Based on established criteria, metaphylaxis was administered after arrival to 7 blocks (21 pens) to prevent bovine respiratory disease. Fresh fecal matter was collected aseptically from multiple locations (n = 10 locations within each pen), and lymph nodes were obtained at slaughter from a subset of carcasses within each lot (n = 12) to determine <em>Salmonella</em> prevalence.</div></div><div><h3>Results and Discussion</h3><div>No interactions were observed between treatment and metaphylaxis throughout the study. The percentage of respiratory deaths was greater for steers in CLO60 than CLO and CON from d 0 to 60, but there were no growth performance differences noted among treatments. Likewise, there were no differences in lymph node prevalence of <em>Salmonella</em> among treatments; however, there was a decrease in fecal <em>Salmonella</em> prevalence for CON versus CLO and CLO60 steers from d 45 to 90.</div></div><div><h3>Implications and Applications</h3><div>Supplementation of <em>B. subtilis</em> PB6 for the first 60 d or the entire feeding period had no effect on health outcomes, growth performance, and carcass characteristics. Moreover, feeding <em>B. subtilis</em> PB6 for the first 60 d or entire feeding period did not affect <em>Salmonella</em> prevalence in the subiliac lymph nodes.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 3","pages":"Pages 205-214"},"PeriodicalIF":1.4,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Invited Review: The weaning transition in dairy calves—Why so traumatic?*","authors":"J.K. Drackley","doi":"10.15232/aas.2024-02657","DOIUrl":"10.15232/aas.2024-02657","url":null,"abstract":"<div><h3>Purpose</h3><div>The purpose of this review article was to identify physiological and management factors that affect the weaning transition in dairy calves, which can be a dif- ficult time for calves.</div></div><div><h3>Sources</h3><div>Peer-reviewed journal articles were used to compile the review.</div></div><div><h3>Synthesis</h3><div>Weaning is often a period of stress and lost performance for calves, in many cases resulting in respira- tory disease or diarrhea caused by coccidiosis or acidosis. Physiological factors contribute to the difficulty, including the expanding gut fill, allometric growth of the reticuloru- men and gastrointestinal tract, and development of the ruminal epithelium. Stabilizing ruminal pH above 6.0 so that fiber fermentation can proceed is a major challenge for calves. Management practices should aim to maximize starter intake while avoiding ruminal acidosis. Providing a high-quality calf starter is extremely important, including appropriate ingredient and chemical composition as well as physical form. Calves should not be weaned until they are consuming an adequate amount of starter to allow the discontinuation of milk intake and should be weaned gradually rather than abruptly. Although small amounts of forage before and after weaning may be useful in calves fed pelleted or ground starters and not bedded on straw, calves should not have free access to alfalfa hay. Water ac- cess is critical because the rumen needs water to support the developing microbial ecosystem. Stressful management tasks such as dehorning or vaccination should not be per- formed at the same time as weaning. Ruminal acidosis is likely more common than has been recognized and causes decreased intake, decreased growth, and diarrhea, espe- cially in calves soon after weaning.</div></div><div><h3>Conclusions and Applications</h3><div>The weaning tran- sition is a period of stress for calves. Managing starter quality, time and rate of weaning, forage and water avail- ability, concurrent stressors, and acidosis can help avoid difficult weaning and improve the welfare of young calves without losing performance.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 3","pages":"Pages 190-204"},"PeriodicalIF":1.4,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M.I. Marcondes , J.C.C. Chagas , A.F. Kertz , T. Allen , J.M. Bewley
{"title":"Invited Review: Connecting the dots—Calving difficulty, age at first calving, and enhanced cow production*","authors":"M.I. Marcondes , J.C.C. Chagas , A.F. Kertz , T. Allen , J.M. Bewley","doi":"10.15232/aas.2024-02620","DOIUrl":"10.15232/aas.2024-02620","url":null,"abstract":"<div><h3>Purpose</h3><div>We aimed to explore the relationships among calving difficulty (CD), production traits, age at first calving (AFC), and culling in dairy cattle.</div></div><div><h3>Sources</h3><div>Data from 687 US dairy farms, encompassing 1,048,574 CD observations scored from 1 to 5, were analyzed. Scores of CD 5 were adjusted to 4 due to limited interactions with other variables. The focus was on Holstein, Jersey, and dairy cross breeds, and parity was categorized as primiparous or multiparous.</div></div><div><h3>Synthesis</h3><div>The study comprised 4 steps. Step 1 assessed the effect of CD on milk yield, fat, protein, ECM, and peak milk production with fixed effects of CD, parity, calf sex (CS), and breed and random effects of calving year, calving season, and herd. Step 2 analyzed AFC, using linear and quadratic covariates, on the same parameters. Step 3 examined CD as the response variable in the step 2 database. Step 4 used logistic regression to assess risk factors associated with CD and culling reasons. Our results showed the following. Step 1: CD significantly affected milk yield, ECM, fat, protein, and peak milk production, with declines in production traits for CD >2, the least values at CD 4. Step 2: Significant linear and quadratic AFC covariates showed optimal milk performance at 27 to 28 mo. Step 3: CD was influenced by breed, CS, AFC, and interactions, with minimal CD observed at AFC of 23 to 26 mo. Step 4: Greater CD was linked to culling for nondairy purposes.</div></div><div><h3>Conclusions and Applications</h3><div>Calving difficulty affects production traits and is influenced by parity, breed, and CS, but its effect is less significant than expected. The AFC, particularly over 26 mo, has a more pronounced effect on CD. Greater CD levels are associated with increased involuntary culling.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 3","pages":"Pages 237-251"},"PeriodicalIF":1.4,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yarahy Leal , Samanthia Johnson , Modoluwamu Idowu , Taylor Sidney , Deborah Ologunagba , Ibukun M. Ogunade
{"title":"Whole blood immune gene expression in Angus bulls with divergent residual feed intake expected progeny differences","authors":"Yarahy Leal , Samanthia Johnson , Modoluwamu Idowu , Taylor Sidney , Deborah Ologunagba , Ibukun M. Ogunade","doi":"10.15232/aas.2024-02645","DOIUrl":"10.15232/aas.2024-02645","url":null,"abstract":"<div><h3>Objective</h3><div>Our objective was to examine the differ- ences in the whole blood mRNA expression profiles of im- mune-related genes in Angus bulls with either negative or positive residual feed intake expected progeny differences (RFI-EPD).</div></div><div><h3>Materials and Methods</h3><div>Twenty Angus bulls with the most negative (n = 10; RFI-EPD = −0.29) and most positive (n = 10; RFI-EPD = 0.26) RFI-EPD values were selected from a group of 106 Angus bulls (average BW = 376 ± 36 kg; 370 ± 1.3 d of age) after a 78-d feed ef- ficiency testing period. At the end of this testing period, blood samples were collected for RNA extraction followed by the mRNA expression analysis of 84 genes involved in innate and adaptive immunity using pathway-focused PCR-based arrays. Differentially expressed genes (DEG) were determined using false discovery rate (FDR) ≤0.10.</div></div><div><h3>Results and Discussion</h3><div>Results from the analysis revealed a total of 5 DEG (FDR ≤0.10) in bulls with divergent RFI-EPD values. We found <em>IL23A</em> to be up- regulated, whereas <em>IL18</em>, <em>TRAF6</em>, <em>TLR2</em>, and <em>MX1</em> were downregulated in negative RFI-EPD bulls, compared with the positive group. Gene ontology analysis of the DEG indicated the enrichment of different biological pathways linked to innate immune response, NF-κB signaling, cy- tokine and T cell regulation, lipopolysaccharide-mediated signaling pathway, and cellular response to bacteria.</div></div><div><h3>Implications and Applications</h3><div>These findings re- vealed that negative RFI-EPD bulls exhibit mRNA ex- pression of genes directly related to immune cell function and biological pathways involved in the activation of anti- microbial mechanisms, pathogen recognition mechanisms, and inflammatory response.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 3","pages":"Pages 230-236"},"PeriodicalIF":1.4,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P.S. Smith , J.B. Glaze Jr , H. Tejeda , J. Piaskowski , R.J. Collier , M. Chahine
{"title":"Evaluation of the use of beef semen on dairy operations: A survey of Idaho dairies","authors":"P.S. Smith , J.B. Glaze Jr , H. Tejeda , J. Piaskowski , R.J. Collier , M. Chahine","doi":"10.15232/aas.2025-02660","DOIUrl":"10.15232/aas.2025-02660","url":null,"abstract":"<div><h3>Objective</h3><div>The aim of this study was to survey current Idaho dairies on their use of beef semen and gain insights into the criteria and decisions made on farm.</div></div><div><h3>Materials and Methods</h3><div>A mail-in survey was sent to all registered Idaho dairies (n = 369). The survey consisted of 40 questions consisting of multiple choice, ranking, and open answer styles. The survey was mailed on August 8, 2022, with a reminder postcard sent on October 8, 2022, to dairies that had not returned the initial survey. The survey was mailed a second time on November 5, 2022, to all the dairies that had not responded to the initial survey. Responses were categorized by dairy herd size and region within Idaho.</div></div><div><h3>Results and Discussion</h3><div>We had a total response rate of 14.1%; of the dairies that responded, 78.8% breed a portion of their herd to beef semen. The use of beef semen was significantly affected by dairy herds size. “Failure to conceive” was ranked most important when deciding which cows were bred to beef, followed by “milk production.” Black Angus was the most chosen breed of a sire, followed by Charolais. Dairies ranked the “breeding service picks the bulls” as most important when selecting beef sires, followed by “calving ease” and “semen cost.” Only 26.8% of dairies raise their own beef × dairy calves, and 69.4% sell the beef × dairy calves as day-old calves. The economic benefit of breeding to beef was evident, with the average price for beef × Holstein, beef × Jersey, and beef × Holstein × Jersey being 3.14×, 1.36×, and 4× that for pure dairy, respectively.</div></div><div><h3>Implications and Applications</h3><div>These results add knowledge regarding the on-farm decision when breeding dairy cattle to beef sires. This will help guide future research in beef × dairy animals by keeping on-farm decisions in mind.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 3","pages":"Pages 265-271"},"PeriodicalIF":1.4,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}