Miles E. Theurer , Dale R. Woerner , Bradley J. Johnson , Reese Wilson , Jhones O. Sarturi , Raghavendra G. Amachawadi , T.G. Nagaraja , Jim Simpson , J. Trent Fox , Paige Adams , Kip K. Karges
{"title":"Effects of Saccharomyces cerevisiae CNCM I-1077 and calcium clinoptilolite zeolite compared with tylosin phosphate and negative control on health, performance, carcass outcomes, and liver abscesses of dairy-beef cross feedlot cattle*","authors":"Miles E. Theurer , Dale R. Woerner , Bradley J. Johnson , Reese Wilson , Jhones O. Sarturi , Raghavendra G. Amachawadi , T.G. Nagaraja , Jim Simpson , J. Trent Fox , Paige Adams , Kip K. Karges","doi":"10.15232/aas.2023-02475","DOIUrl":"10.15232/aas.2023-02475","url":null,"abstract":"<div><h3>Objective</h3><p>Our objective was to evaluate the effects of in-feed, non-antibiotic alternatives (<em>Saccharomyces cerevisiae</em> CNCM I-1077 and calcium clinoptilolite zeolite) on health, growth performance, carcass characteristics, and liver abscesses in dairy-beef cross composites in a commercial feedlot.</p></div><div><h3>Materials and Methods</h3><p>Dairy-beef, intact heifers (n = 2,088; average BW = 334.8 kg) were assigned to 1 of 3 treatment groups: (1) Negative control (no feed-grade antimicrobials for control of liver abscesses; NC); (2) <em>Saccharomyces cerevisiae</em> CNCM I-1077 (0.5 g/heifer per day to provide 1 × 10<sup>10</sup> cfu/heifer per day) and calcium clinoptilolite zeolite (replacing flaked corn at 1.2% on a DM basis; LB), or (3) tylosin phosphate (targeted at a rate of 68 mg/heifer per day; TY). Heifers averaged 228 d on feed at harvest. Individual carcass outcomes and liver scores were captured at harvest.</p></div><div><h3>Results and Discussion</h3><p>Heifers in the TY treatment had reduced DMI, increased G:F, and reduced cost of gain compared with the other treatments. Carcass characteristics were not affected by treatments. Heifers offered LB tended to have fewer total liver abscesses compared with the TY group, whereas NC was intermediate.</p></div><div><h3>Implications and Applications</h3><p>Feedlot performance improved for dairy-beef heifers offered tylosin; however, TY had the greatest percentage of liver abscesses compared with NC. Feeding the combination of <em>Saccharomyces cerevisiae</em> CNCM I-1077 and calcium clinoptilolite as a non-antimicrobial alternative for the mitigation of liver abscesses in dairy-beef females seems to be promising strategy; however, growth performance outcomes may be reduced compared with tylosin.</p></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590286524000557/pdf?md5=14393fa4a94269cddfae6171fcc6db2c&pid=1-s2.0-S2590286524000557-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141232090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Liver abscesses—New perspectives on a historic fed-cattle issue*†‡","authors":"P.R. Broadway , T.G. Nagaraja , T.E. Lawrence , M.L. Galyean , K.E. Hales","doi":"10.15232/aas.2023-02498","DOIUrl":"10.15232/aas.2023-02498","url":null,"abstract":"<div><h3>Purpose</h3><p>Our purpose was to provide commentary and new perspectives related to liver abscesses, a historic problem in beef cattle, by describing and discussing docu- mented research, anecdotal observations, and opinions re- garding the causation, detection, and prevention of liver abscesses.</p></div><div><h3>Sources</h3><p>Sources for this article include peer-reviewed, scientific literature; abstracts; proceedings; theses and dissertations; popular press articles; personal communica- tions; and unpublished research data.</p></div><div><h3>Synthesis</h3><p>Liver abscess (LA) disease in cattle is a multifactorial, polymicrobial disease that has wide-rang- ing effects on productivity and profitability throughout all stages of the beef production cycle. The interest in and the study of LA has drastically increased in the past several years, driven largely by efforts to identify alterna- tives to the use of antibiotics for LA control. Although a primary, prevailing theory on LA formation has existed for decades, recent research has led to alternative theo- ries as well as new questions about the role of breed-type specific management, behavior, feed intake patterns, and other factors on LA causation. The inability to detect LA before slaughter complicates research evaluating mitiga- tion strategies and disease etiology. Moreover, the inability to detect LA in live cattle has hindered researcher efforts to understand timing of abscess development or whether an abscess can resolve.</p></div><div><h3>Conclusions and Applications</h3><p>Although the prima- ry pathogens associated with LA have been identified, an effective mitigation strategy has eluded researchers. None- theless, new perspectives and research efforts are needed from both basic and applied perspectives using multidis- ciplinary, collaborative approaches to successfully combat the challenges faced by the beef industry related to LA.</p></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590286524000478/pdf?md5=397902bb972f142abb3ec6815dbdb679&pid=1-s2.0-S2590286524000478-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141233171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amanda K. Lindholm-Perry , Brittney N. Keel , Kristin E. Hales , James E. Wells , Larry A. Kuehn , John W. Keele , Matthew S. Crouse , Dan J. Nonneman , T.G. Nagaraja , Ty E. Lawrence , Raghavendra G. Amachawadi , Jeff A. Carroll , Nicole C. Burdick Sanchez , Paul R. Broadway
{"title":"Ileal epithelial tissue transcript profiles of steers with experimentally induced liver abscesses*†","authors":"Amanda K. Lindholm-Perry , Brittney N. Keel , Kristin E. Hales , James E. Wells , Larry A. Kuehn , John W. Keele , Matthew S. Crouse , Dan J. Nonneman , T.G. Nagaraja , Ty E. Lawrence , Raghavendra G. Amachawadi , Jeff A. Carroll , Nicole C. Burdick Sanchez , Paul R. Broadway","doi":"10.15232/aas.2023-02503","DOIUrl":"10.15232/aas.2023-02503","url":null,"abstract":"<div><h3>Objective</h3><p>Liver abscesses in cattle negatively affect production and cause economic losses across the beef cat- tle industry. Recently, a nutritional model has been devel- oped to induce liver abscesses that will provide a method to evaluate the underlying mechanisms driving their de- velopment. The objective of this study was to evaluate gene expression of ileal tissue from calves challenged using the new model.</p></div><div><h3>Materials and Methods</h3><p>In the model, calves were fed a diet to induce ruminal acidosis and were then in- traruminally inoculated with bacteria typically associated with liver abscesses. On d 21, following inoculation, calves were euthanized. Seven of the 13 calves had liver abscess- es. Ileal tissues were collected and total RNA was isolated for RNA-sequencing.</p></div><div><h3>Results and Discussion</h3><p>A total of 26 genes were dif- ferentially expressed in the calves with liver abscesses com- pared with those without. Two genes (<em>COX2</em>, <em>COX3</em>) are components of the cytochrome c oxidase enzyme in the electron chain transport pathway, and both were downreg- ulated among the animals with liver abscesses. Other genes involved in cellular restructuring, transport of compounds across cell membranes, protection of RNA, and protection of protein products were also identified. These functions il- lustrate that there are changes in the ileal epithelium that correspond to the development of liver abscesses.</p></div><div><h3>Implications and Applications</h3><p>We identified sev- eral genes that were differentially expressed in the ileal tissue of calves that developed liver abscesses using the combination of an acidosis-inducing diet and intraruminal inoculation of bacteria. Our results suggest that the ileum has a role in liver abscess development, and future studies to validate the involvement of the mucosal barrier of the ileum are warranted.</p></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590286524000624/pdf?md5=824739088a490b66c95125ad57378d2c&pid=1-s2.0-S2590286524000624-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141232603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Madeline E. Rivera , Luiz F. Dias Batista , Luis O. Tedeschi
{"title":"Investigation of virginiamycin to improve health of growing and finishing steers: I. Effects on ruminal acidosis and liver health*","authors":"Madeline E. Rivera , Luiz F. Dias Batista , Luis O. Tedeschi","doi":"10.15232/aas.2023-02511","DOIUrl":"10.15232/aas.2023-02511","url":null,"abstract":"<div><h3>Objective</h3><p>Our objective was to observe the effects of the interrelationship among virginiamycin (VM) inclusion (240 mg/d), ruminal pH dynamics, and hepatic plasma metabolites on rumen and animal health during a 150-d feeding trial.</p></div><div><h3>Materials and Methods</h3><p>Steers (304 ± 27 kg; n = 120) were assigned randomly to 1 of 6 dietary treatments: no VM (T<sub>000</sub>); VM for the last 50 d (T<sub>001</sub>); VM for the last 100 d (T<sub>011</sub>); VM for the first 50 d (T<sub>100</sub>); VM for the first 100 d (T<sub>110</sub>); and VM for 150 d (T<sub>111</sub>). All animals were orally administered 2 indwelling rumen pH and temperature recording boli on d 0 and 84. Blood samples were collected via jugular venipuncture on d −7, 28, 56, 84, 112, and 140, and plasma was analyzed for concentrations of albumin, alkaline phosphatase, direct bilirubin, total bilirubin, gamma-glutamyl transferase, and total protein using an automated blood analyzer. Concurrently, haptoglobin (HPT) was measured following a colorimetric method based on peroxidase activity. A random coefficients model with pen and animals within treatment as a random effect was used.</p></div><div><h3>Results and Discussion</h3><p>Animals that received VM for the first 100 d (T<sub>110</sub> and T<sub>111</sub>) had greater mean ruminal pH during d 50 to 100 when compared with animals that did not receive VM (T<sub>000</sub> and T<sub>001</sub>; 6.12 vs. 6.00, respectively). Moreover, T<sub>111</sub> tended to have less time under pH 5.8 (3.01 h/d) when compared with T<sub>100</sub> and T<sub>001</sub> (5.83 and 6.45 h/d, respectively). At slaughter, overall, 3.36% of cattle in the study were identified with liver abscesses (A and A−), and 24.3% had lung lesions. Plasma metabolite concentrations before slaughter did not predict the presence of liver abscesses (<em>P</em> ≥ 0.182). Based on acute phase responses, HPT was notably lower on d 84 after diet transition in VM-treated animals (46.1 vs. 68.9 mg/L). Additionally, VM inclusion boosted indicators of overall health with greater alkaline phosphatase levels and albumin-toglobulin ratios.</p></div><div><h3>Implications and Applications</h3><p>Virginiamycin has practical implications for rumen health and overall cattle health, where supplementation during the whole growing to finishing phases was more effective in capturing its full potential.</p></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590286524000569/pdf?md5=1e0798e2d38cc1ac69c7e5e44f6aca17&pid=1-s2.0-S2590286524000569-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141233350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reese A. Wilson , Bradley J. Johnson , Jhones O. Sarturi , Whitney L. Crossland , Kristin E. Hales , Ryan J. Rathmann , Christy L. Bratcher , Miles E. Theurer , Raghavendra G. Amachawadi , T.G. Nagaraja , Scott E. Speidel , R. Mark Enns , Milton G. Thomas , Blake A. Foraker , Matthew A. Cleveland , Dale R. Woerner
{"title":"Identification of blood-based biomarkers for detection of liver abscesses in beef × dairy heifers*","authors":"Reese A. Wilson , Bradley J. Johnson , Jhones O. Sarturi , Whitney L. Crossland , Kristin E. Hales , Ryan J. Rathmann , Christy L. Bratcher , Miles E. Theurer , Raghavendra G. Amachawadi , T.G. Nagaraja , Scott E. Speidel , R. Mark Enns , Milton G. Thomas , Blake A. Foraker , Matthew A. Cleveland , Dale R. Woerner","doi":"10.15232/aas.2023-02504","DOIUrl":"10.15232/aas.2023-02504","url":null,"abstract":"<div><h3>Objective</h3><p>The objective was to determine the effects of liver abscesses on complete blood counts (CBC) and liver function and to identify blood-based biomarkers for detection of liver abscesses in feedlot cattle.</p></div><div><h3>Materials and Methods</h3><p>Blood samples were collected on a subset of beef × dairy crossbred heifers with and without liver abscesses (n = 94; n = 113, respectively). From these blood samples, CBC and serum chemistry analytes related to liver health (alkaline phosphatase, gamma glutamyl transferase, bile acids, total bilirubin, and cholesterol) were analyzed to characterize animal health and model for liver abscesses. Abscess presence was predicted using logistic regression models and machine learning algorithms, with individual heifer serving as the experimental unit.</p></div><div><h3>Results and Discussion</h3><p>In a binary system (abscessed or not), heifers with liver abscesses had lower concentrations of lymphocyte (LYM) and total white blood cell (WBC) concentrations but elevated platelet-to-LYM ratio. Serum chemistry measures were not affected by abscess presence or liver score (severity). In univariate, predictive modeling of CBC measures, only total WBC concentration was accurate (65.85%) at predicting liver abscess presence; however, this was not deemed an acceptable biomarker due to its poor specificity (54.79%). Using total WBC, basophils, red blood cells, and procalcitonin as variables to predict liver abscess condition, the Logit- Boost model produced the greatest accuracy (80.65%) and specificity (85.71%). An accurate blood test that allows for the detection of liver abscesses during the finishing phase may allow for therapeutic management or alternative marketing of cattle; however, the marginal accuracy demonstrated in this study combined with the impracticality and cost of analyzing a blood sample may not be feasible. Regardless, the most explanatory CBC variables in cattle with abscessed livers were suggestive of an immune response.</p></div><div><h3>Implications and Applications</h3><p>Liver condition influenced the CBC of beef × dairy heifers but not serum chemistry. Multivariate predictive models showed potential for predicting liver abscess condition based on CBC. The results of this study warrant further investigation for biomarkers of the liver abscess condition. An antemortem indicator for liver abscesses could prove useful for making management decisions and in research applications, particularly in evaluating interventions.</p></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590286524000600/pdf?md5=2fc36d18a65db8e703f8e0f39ae8e6b1&pid=1-s2.0-S2590286524000600-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141229097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B.B. Grimes , T.J. McEvers , T.C. Tennant , J.W. Johnson , T.E. Lawrence
{"title":"Relationship of liver abnormalities with carcass performance and value*","authors":"B.B. Grimes , T.J. McEvers , T.C. Tennant , J.W. Johnson , T.E. Lawrence","doi":"10.15232/aas.2023-02482","DOIUrl":"10.15232/aas.2023-02482","url":null,"abstract":"<div><h3>Objective</h3><p>We evaluated the association of liver ab- normalities with carcass characteristics and value, using 2 independent databases generated from 2010 through 2021.</p></div><div><h3>Materials and Methods</h3><p>Liver abnormalities (ab- scesses, congestive heart failure [CHF], flukes, telangiec- tasis) and associated carcass outcomes were evaluated for 371,476 carcasses housed in database 1. Liver abnormali- ties of individual carcasses (n = 1,166,056) in database 2 were captured as lot-level (n = 7,196) audits and summa- rized as frequencies across demographic categories. Data were analyzed with mixed models.</p></div><div><h3>Results and Discussion</h3><p>Livers were scored as fol- lows: edible = no abscess or abnormality, A− = 1 to 2 small abscesses or inactive scars, A = 1 or 2 large ab- scesses or multiple small abscesses, A+ = multiple large abscesses, A+adhesion (A+AD) = liver adhered to part of the gastrointestinal tract or diaphragm or both, A+open (A+OP) = open abscess, A+adhesion/open (A+AD/OP) = combination of A+AD and A+OP score. Other non- abscess liver abnormalities recorded were CHF = dark mottled blue appearance and noticeably enlarged; flukes = presence of black lymph nodes, enlarged thickened bile ducts, visible dark tracts scattered throughout the dorsal side of the liver, or presence of flukes within the liver; and telangiectasis = peppering of blue/red dots on the surface of the liver tissue. Liver abnormality rates across both da- tabases were A− = 7.3% to 7.4%, A = 2.7% to 5.3%, A+ = 2.4% to 4.8%, A+AD = 3.9% to 6.2%, A+OP = 1.4% to 1.7%, A+AD/OP = 0.8% to 1.3%, CHF = 0.1% to 0.2%, flukes = 1.3% to 3.6%, telangiectasis = 0.6% to 0.7%, with 67.0% to 77.0% of livers being edible. Carcasses with se- vere abscesses (A+, A+AD, A+OP, A+AD/OP) or CHF had less hot carcass weight (HCW; 13.0 and 42.5 kg, re- spectively) compared with carcasses with edible livers. All abnormalities except telangiectasis reduced LM area. Less 12th-rib s.c. fat was observed for carcasses with A−, A, A+, A+AD, and CHF abnormalities compared with car- casses with edible livers. As liver abscess severity increased compared with edible livers, carcass value diminished and frequency of carcasses railed off line (removed from the production line) increased, particularly for A+AD (4.2%), A+OP (9.7%), and A+AD/OP (11.9%).</p></div><div><h3>Implications and Applications</h3><p>Based on analysis of this large database, liver abnormalities, especially severely abscessed and CHF outcomes, greatly affect HCW. These results indicate control of liver abscesses, and understand- ing the development of CHF, is important to prevent loss- es in carcass value.</p></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590286524000582/pdf?md5=43dcf3c03d1a18496646c60da5ef3fb9&pid=1-s2.0-S2590286524000582-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141234106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zach S. McDaniel , Kristin E. Hales , T.G. Nagaraja , Ty E. Lawrence , Travis C. Tennant , Raghavendra G. Amachawadi , Jeff A. Carroll , Nicole C. Burdick Sanchez , Michael L. Galyean , Emily Davis , Kesley Kohl , Dalton J. Line , Colten W. Dornbach , Mina Abbasi , Alyssa Deters , Xiaorong Shi , Michael A. Ballou , Vinicius S. Machado , Taylor M. Smock , Paul R. Broadway
{"title":"Validation of an experimental model to induce liver abscesses in Holstein steers using an acidotic diet challenge and intraruminal bacterial inoculation*†","authors":"Zach S. McDaniel , Kristin E. Hales , T.G. Nagaraja , Ty E. Lawrence , Travis C. Tennant , Raghavendra G. Amachawadi , Jeff A. Carroll , Nicole C. Burdick Sanchez , Michael L. Galyean , Emily Davis , Kesley Kohl , Dalton J. Line , Colten W. Dornbach , Mina Abbasi , Alyssa Deters , Xiaorong Shi , Michael A. Ballou , Vinicius S. Machado , Taylor M. Smock , Paul R. Broadway","doi":"10.15232/aas.2023-02485","DOIUrl":"10.15232/aas.2023-02485","url":null,"abstract":"<div><h3>Objective</h3><p>Our objectives were to develop and evaluate a model to induce liver abscesses (LA) in cattle and assess roles of <em>Fusobacterium</em> and <em>Salmonella</em> on LA formation and severity.</p></div><div><h3>Materials and Methods</h3><p>Holstein steers (n = 40; initial BW = 110 ± 12.0 kg) were assigned randomly to treatments (n = 10 per treatment): (1) control diet (CON); (2) acidotic diet (AD); (3) AD plus inoculation of <em>Fusobacterium necrophorum</em> ssp. <em>necrophorum</em> (8.81 × 10<sup>10</sup> cfu/steer; ADFn); or (4) AD and intraruminal inoculation of <em>F. necrophorum</em> (8.81 × 10<sup>10</sup> cfu/steer) and <em>Salmonella enterica</em> Lubbock (1.52 × 10<sup>11</sup> cfu/steer; ADFS). On d 0, steers were subjected to 4 acidotic cycles where they were fed the acidotic diet for 3 d and then the control diet for 2 d. Intraruminal bacterial inoculation was on d 20. From d 21, AD, ADFn, and ADFS steers remained on the acidotic diet until d 38. Euthanasia occurred on d 38, and gross pathology of the lung, rumen, liver, and colon were recorded.</p></div><div><h3>Results and Discussion</h3><p>Liver abscess prevalence was 40% in ADFn and 50% in ADFS versus 0% in CON and AD. No pathological differences were noted in lung nor colon among treatments; however, ruminal damage was more severe in ADFn and ADFS than in CON and AD steers.</p></div><div><h3>Implications and Applications</h3><p>Acidotic diet alone caused mild ruminal acidosis but no LA. Acidotic diet with intraruminal bacterial inoculation increased rumenitis severity and resulted in LA, thus validating the nutritional model to induce LA. Therefore, acidotic diet with intraruminal bacterial inoculation is a viable model to study the formation of LA.</p></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590286524000612/pdf?md5=b9e548639b076fbb06c5a5abb80db95b&pid=1-s2.0-S2590286524000612-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141229947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A.B. Word , K.J. Karr , B.P. Holland , C.L. Maxwell , S.K. Linneen , P.J. Defoor
{"title":"Removing tylosin phosphate from finishing diets with increasing roughage concentrations affects growth performance, carcass characteristics, and prevalence of liver abscesses of finishing steers*","authors":"A.B. Word , K.J. Karr , B.P. Holland , C.L. Maxwell , S.K. Linneen , P.J. Defoor","doi":"10.15232/aas.2023-02489","DOIUrl":"10.15232/aas.2023-02489","url":null,"abstract":"<div><h3>Objectives</h3><p>This study compared standard finishing diets with or without tylosin phosphate at an industry standard roughage concentration, as well as titrated roughage concentrations in finishing diets containing no tylosin.</p></div><div><h3>Materials and Methods</h3><p>Beef steers (initial BW = 387 ± 14.2 kg; n = 3,340) were used in a randomized complete block design with 12 pens/treatment and 65 or 70 steers per pen. Dietary treatments were (1) 7.0% corn stalks with tylosin (7TYL), (2) 7.0% corn stalks without tylosin (7NT), (3) 13.0% corn stalks without tylosin (13NT), or (4) 19.0% corn stalks without tylosin (19NT). Corn stalks replaced steam-flaked corn on a DM basis.</p></div><div><h3>Results and Discussion</h3><p>Increased corn stalks linearly increased DMI. Increased corn stalks linearly reduced final BW and ADG, and resulted in poorer G:F. Hot carcass weight was similar between 7TYL and 7NT; however, hot carcass weight (HCW) linearly decreased as corn stalk inclusion increased. Tylosin inclusion resulted in a 32% reduction in liver abscess prevalence (from 19% to 13%). Liver abscess prevalence decreased linearly with increased corn stalks; tylosin use reduced adhered livers, whereas increased corn stalks did not.</p></div><div><h3>Implications and Applications</h3><p>Replacing steamflaked corn with 13% or 19% inclusion of corn stalks in diets without tylosin phosphate could reduce liver abscess prevalence, but increased roughage may not decrease the severity of the liver abscesses. Importantly, decreased dietary energy density led to increased DMI and reduced HCW in cattle fed to the same days on feed.</p></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590286524000508/pdf?md5=5fcb510b4df3a47ab4abd20f11d8b52c&pid=1-s2.0-S2590286524000508-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141231583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}