Applied Animal Science最新文献

{"title":"Invited Review: Factors influencing colostrum production of multiparous Holstein and Jersey cows*","authors":"P.S. Erickson ,&nbsp;T.C. Stahl ,&nbsp;S.C. Allen","doi":"10.15232/aas.2024-02621","DOIUrl":"10.15232/aas.2024-02621","url":null,"abstract":"<div><h3>Purpose</h3><div>Our purpose is to provide insight and new perspectives on factors influencing colostrum yield in dairy cows by describing nutritional, environmental, and management techniques to mitigate the failure of colostrum production and to provide new theories as to why this challenge sometimes occurs in dairy farms.</div></div><div><h3>Sources</h3><div>Sources come from peer-reviewed primary research articles and previously published review articles on certain topics pertaining to colostrum production.</div></div><div><h3>Synthesis</h3><div>Diminished or absent colostrum production in dairy cows has been a challenge for producers and researchers. The lack of colostrum production may be attributed to many factors including adequate energy in the prefresh cow diet and increasing dry period length, along with the environmental temperature and possibly hormonal disruptions. These components appear to play a major role in the production of colostrum.</div></div><div><h3>Conclusions and Applications</h3><div>The results of this review indicate the factors (dry period length, nutrition, environment, and genetics) that have been identified that producers can use to alleviate the challenge of reduced or no colostrum production.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"40 6","pages":"Pages 791-801"},"PeriodicalIF":1.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183209","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":"Substitution of modified distillers grains with soybean meal with or without soyhulls had negligible effects on growth performance, efficiency, and carcass traits in yearling beef steers","authors":"Cassidy R. Ross,&nbsp;Ana Clara B. Menezes,&nbsp;Forest L. Francis,&nbsp;Zachary K. Smith,&nbsp;Warren C. Rusche","doi":"10.15232/aas.2024-02575","DOIUrl":"10.15232/aas.2024-02575","url":null,"abstract":"<div><h3>Objective</h3><div>The objective of this study was to evaluate animal performance, carcass traits, and dietary net energy utilization in finishing beef steers when soybean meal (SBM) with or without soybean hulls (SBH) replaced modified distillers plus solubles (MDGS).</div></div><div><h3>Materials and Methods</h3><div>Predominately Angus steers (n = 240; initial shrunk BW = 435 ± 23.2 kg) were allotted to 1 of 24 pens. Steers were blocked by location within the feedlot and randomly assigned to 3 treatments: MDGS fed at 15% diet DM (MDGS) replaced by either soybean meal and corn (9 and 6% of DM, respectively; SBM), or soybean meal and soyhull pellets (9% and 6% of DM, respectively; SBM-SBH). Growth performance was calculated on a carcass-adjusted basis (hot carcass weight/0.625). Data were analyzed as a randomized complete block design with random effect of block and fixed effect of treatment; pen was the experimental unit. Orthogonal contrasts were used to determine the effects of protein source (MDGS vs. SBM and SBM-SBH) or starch compared with NDF (SBM vs. MDGS and SBM-SBH). Steers were fed for 118 d until shipped for slaughter at a commercial abattoir where carcass data and liver abscess scores were collected.</div></div><div><h3>Results and Discussion</h3><div>No differences among treatments (<em>P</em> ≥ 0.11) were observed for carcass-adjusted final BW, DMI, ADG, or G:F. Dietary treatment did not affect (<em>P</em> ≥ 0.11) carcass measurements and distributions of USDA Quality or Yield grades were unaffected by treatment (<em>P</em> ≥ 0.39). Dietary treatment did not affect liver abscess prevalence or severity (<em>P</em> = 0.11). Net energy values calculated from animal performance agreed closely with tabular estimates.</div></div><div><h3>Implications and Applications</h3><div>Steers fed MDGS as the supplemental protein source did not demonstrate a performance advantage compared with those fed SBM- based protein supplements, despite the enhanced diet conditioning attributes and greater RUP concentrations provided by MDGS.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"40 6","pages":"Pages 760-769"},"PeriodicalIF":1.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182790","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":"A 12-year summary of the effects of estrous synchronization and body weight at breeding on reproductive success of Bos indicus-influenced beef heifers grazing warm-season grasses","authors":"C.C. Brauner,&nbsp;V.S. Izquierdo,&nbsp;J.M.B. Vendramini,&nbsp;P. Moriel","doi":"10.15232/aas.2024-02630","DOIUrl":"10.15232/aas.2024-02630","url":null,"abstract":"<div><h3>Objective</h3><div>The objective was to evaluate the effects of estrus synchronization and body weight before the start of breeding season on reproduction of <em>Bos indicus</em>-influenced beef heifers.</div></div><div><h3>Materials and Methods</h3><div>Data were collected from grazing, Brangus crossbred beef heifers (n = 594) weaned at 280 ± 26 d of age and fed concentrate from 2 wk after weaning until the end of the breeding season (189 ± 24 d of supplementation). Heifers were initially sorted into those that were (SYNC) and were not (NOSYNC) as- signed to an estrous synchronization protocol before the start of the breeding season. Then, within each synchro- nization group, heifers were sorted into those that were below (BE) or above (AB) 295 kg (65% of mature BW) at the start of the breeding season.</div></div><div><h3>Results and Discussion</h3><div>Effects of synchronization × BW at breeding and synchronization were not detected for growth performance, but tended to be detected for pu- berty attainment, which was the least for NOSYNC+BE, did not differ between SYNC+BE versus NOSYNC+AB, and was greatest for SYNC+AB heifers. Pregnancy and calving percentages were greater for AB versus BE heifers.</div></div><div><h3>Implications and Applications</h3><div>Results of this study indicate that <em>Bos indicus</em>-influenced beef heifers need to achieve ≥65% of mature BW at the start of the breeding season to optimize reproduction, whereas estrous synchro- nization protocols enhanced puberty attainment (regard- less of BW) and early calving distribution when heifers were &lt;65% of mature BW at the start of the breeding season.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"40 6","pages":"Pages 847-854"},"PeriodicalIF":1.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183212","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":"Economic evaluation of grazing steers on summer annuals sod-seeded into warm-season perennial pasture","authors":"IvaNelle Meyer ,&nbsp;Michael P. Popp ,&nbsp;Christine C. Nieman ,&nbsp;James L. Mitchell ,&nbsp;Kenneth P. Coffey","doi":"10.15232/aas.2024-02569","DOIUrl":"10.15232/aas.2024-02569","url":null,"abstract":"<div><h3>Objectives</h3><div>Sorhgum-sudangrass (SS) and cowpea (CW) can increase cattle gains when sod-seeded to mixed bermudagrass (MB); however, establishment time and cost may not be recouped by improved animal production. Additionally, valuing weight gain at varying production stages, without a market transaction, prompted an evaluation of different pricing methods.</div></div><div><h3>Materials and Methods</h3><div>Cattle gains on MB, SS, and a 50:50 mix of SS+CW (SSCW) pastures were evaluated. One pricing method linearly interpolated 10-yr-average prices across weight categories. A second, regression-based approach added corn and feeder cattle futures to weight to explain prices. The third used experimental years only.</div></div><div><h3>Results and Discussion</h3><div>Greater forage quality in annuals pastures where cattle had greater ADG (1.01 kg/ head per day for SS and SSCW vs. 0.79 kg/head per day for MB) led to different cattle gains by forage and year. In 2021 grazing days were 91, 68, and 60 d for MB, SS, and SSCW, respectively, whereas they were 95 d for MB and 92 d for SS and SSCW in 2022. Despite greater ADG with annuals, delayed planting of annuals led to numerically lesser cattle gains and lesser partial returns than MB in 2021. In 2022 drought forced a rest period in MB pastures; however, greater weight gains with annuals did not recoup costs regardless of pricing method.</div></div><div><h3>Conclusions and Applications</h3><div>Timely planting is important for increasing grazing days with annuals. With seasonal and cyclical dynamics affecting the value of weight gain, heavier ending weights were not rewarded with prices that would cover annuals establishment.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"40 6","pages":"Pages 697-707"},"PeriodicalIF":1.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183462","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":"Effects of displacing modified distillers grains with dry-rolled corn in a totally mixed ration on performance of growing beef steers consuming cornstalk residue from different harvest methods","authors":"V.B. Ferrari ,&nbsp;R.G. Bondurant ,&nbsp;G.E. Erickson ,&nbsp;K.H. Wilke ,&nbsp;J.C. MacDonald","doi":"10.15232/aas.2024-02551","DOIUrl":"10.15232/aas.2024-02551","url":null,"abstract":"<div><h3>Objective</h3><div>The objective was to determine the effects of displacing modified distillers grains with dry-rolled corn in a TMR for steers consuming corn residue from 2 baling methods on growth of beef steers.</div></div><div><h3>Materials and Methods</h3><div>Crossbred beef steers (n = 120; initial BW = 281; SD = 15 kg) were assigned in a randomized complete block design with a 4 × 3 factorial treatment arrangement (10 steer/treatment). Factors included proportion of modified distillers grains with solubles (MDGS) and dry-rolled corn (DRC; 100:0, 80:20, 60:40, and 40:60 respectively) in the concentrate, and 3 forages; either high quality (70% brome hay and 30% sorghum silage; HQ) or corn residue from 2 baling methods. Corn residue was baled as a conventional rake and bale system (RB), or by disengaging the spreader on the combine and baling the tailings (DS). Steers were fed diets as a TMR (60:40 roughage:concentrate) individually for 84 d making steer the experimental unit.</div></div><div><h3>Results and Discussion</h3><div>A significant interaction was observed for DMI. At each proportion of MDGS in the concentrate, DMI for HQ (8.7, 9.2, 9.4, 8.5 kg/d) was greater than for RB (6.0, 5.5, 5.2, 5.6 kg/d) and DS (5.5, 5.0, 5.5, and 4.8 kg/d), which were not different. The interaction was due to the magnitude of the difference between intakes at the 40% MDGS level. Steers fed HQ had greater ending BW (393 kg) and ADG (1.31 kg/d) than those in RB (350 kg; 0.81 kg/d) and DS (346 kg; 0.76 kg/d). The G:F was not different for HQ, RB, and DS (0.148, 0.146, 0.149, respectively). As MDGS:DRC ratio decreased, ending BW (369, 365, 362, 356 kg), ADG (1.03,0.98, 0.96, 0.87 kg/d), and G:F (0.153, 0.153, 0.145, 0.139) decreased linearly.</div></div><div><h3>Implications and Applications</h3><div>Disengaging the spreader on the combine could result in similar animal performance as raking and baling for producers feeding crop residues. Decreasing the ratio of MDGS to DRC fed to growing steers fed a forage-based TMR reduced ending BW and ADG suggesting the energy supplied by MDGS cannot be replaced with DRC.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"40 6","pages":"Pages 717-724"},"PeriodicalIF":1.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183464","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":"Fabrication yields and allometric growth coefficients of carcass components of serially slaughtered implanted or non-implanted beef steers","authors":"Kaitlyn R. Wesley ,&nbsp;Sierra L. Pillmore ,&nbsp;Tylo J. Kirkpatrick ,&nbsp;Kimberly B. Cooper ,&nbsp;Forest L. Francis ,&nbsp;Travis C. Tennant ,&nbsp;Wade T. Nichols ,&nbsp;Lee-Anne J. Walter ,&nbsp;John P. Hutcheson ,&nbsp;Ty E. Lawrence","doi":"10.15232/aas.2024-02580","DOIUrl":"10.15232/aas.2024-02580","url":null,"abstract":"<div><h3>Objective</h3><p>Our objective was to quantify differences in carcass fabrication yield and allometric coefficients of carcass components from implanted and non-implanted steers.</p></div><div><h3>Materials and Methods</h3><p>Steers (n = 80; initial BW 271 ± 45 kg) were paired and randomized to slaughter date (d 0, 42, 84, 126, 168, 210, 252, 294, 336, 378). Individuals were randomized to treatment of negative control (CON) or Revalor-XS on d 0 and 190 (REV). One side of each animal was fabricated after a 48-h chill into primals, denuded subprimals, lean trim, trimmed fat, and bone. Weights (g) of non-carcass and carcass components were log-transformed and consolidated to arithmetic means by treatment and slaughter date. Growth coefficients were calculated using the allometric equation.</p></div><div><h3>Results and Discussion</h3><p>Cattle administered REV had increased cold side weights (CSW) 7.7%, bone yield 4.9%, and red meat yield 8.5%, with no differences in fat yield. Forequarter primal weights (chuck, brisket, foreshank, rib) increased 8.4%, 6.9%, 7.2%, and 5.2%, respectively, for REV cattle. Hindquarter primals (loin, flank, round) increased by 7.0%, 8.6%, and 6.3%, respectively, for REV steers. Length of feeding period notably did not affect chuck or loin yields proportionate to CSW. Fat as percentage of CSW increased at 0.04% per day, whereas bone and red meat yield decreased at −0.013% and −0.024% per day, respectively. Allometric growth coefficients were greater for REV in 2 carcass components (chuck eye roll, eye of round), whereas CON was greater in 1 component (flank steak). All primals except the round (0.81) and foreshank (0.87) exhibited growth coefficients greater than the empty body.</p></div><div><h3>Implication and Applications</h3><p>These data indicate that REV steers are more likely to have heavier side weights, greater bone yield, and increased red meat yields than CON steers. Additionally, minimal differences were observed in allometric growth coefficients between CON and REV steers. Steers administered REV greatly improved carcass yield over CON during a 378-d finishing period.</p></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"40 5","pages":"Pages 647-660"},"PeriodicalIF":1.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590286524000971/pdf?md5=57c150e525b5f0dec631ed6fc340b939&pid=1-s2.0-S2590286524000971-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142243570","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":"Effects of lubabegron dose and duration on calculated cumulative ammonia gas emissions and growth performance by feedlot steers during the last 28, 56, or 84 days of the feeding period","authors":"Matt Edmonds ,&nbsp;John C. Kube ,&nbsp;Janet B. Allen ,&nbsp;Michelle Calvo-Lorenzo ,&nbsp;David McKenna ,&nbsp;Dale Woerner ,&nbsp;Mahesh Nair ,&nbsp;Ashley Corona ,&nbsp;John Scanga ,&nbsp;Phil Rincker ,&nbsp;K. Camara ,&nbsp;M.S. Brown","doi":"10.15232/aas.2023-02518","DOIUrl":"10.15232/aas.2023-02518","url":null,"abstract":"<div><h3>Objective</h3><p>Our objective was to characterize the effects of lubabegron (Experior 10; Elanco Animal Health, Greenfield, IN) on ammonia gas emissions, growth and carcass merit, and animal mobility of feedlot steers.</p></div><div><h3>Materials and Methods</h3><p>Crossbred beef steers were used in a randomized complete block with a 4 × 3 factorial arrangement of dietary lubabegron concentrations. (LUB; 0, 1.5, 3.5, or 5.5 mg/kg of DM) and duration of feeding (28, 56, or 84 d before slaughter). Blocks were slaughtered after an equal time on feed.</p></div><div><h3>Results and Discussion</h3><p>Calculated cumulative ammonia gas emissions per kilogram of hot carcass weight decreased after 28 d (linear) as LUB increased and responded quadratically after 56 and 84 d (LUB × duration). Steer DMI (LUB × duration) decreased linearly as LUB increased after 28 and 56 d. Final shrunk BW and ADG (LUB × duration) increased (linear) as duration increased and increased (quadratic) as LUB increased. The increase in G:F (LUB × duration) as LUB increased was linear within each duration, with an increasingly smaller magnitude as duration increased. Steer G:F increased linearly as duration increased when 0, 1.5, and 3.5 mg/kg of DM was fed. Steer DP (LUB × duration) increased quadratically as duration increased and linearly as LUB increased. Marbling score (LUB × duration) decreased quadratically as LUB increased when fed for 84 d and decreased linearly when 1.5 or 3.5 mg/kg of DM was fed. Average YG decreased (LUB × duration) linearly as LUB increased. Neither LUB nor duration altered the distribution of mobility scores at lairage before slaughter.</p></div><div><h3>Implications and Applications</h3><p>Feeding lubabegron resulted in lesser calculated ammonia emissions per kilogram of output, ≤0.3 kg/d lesser DMI, up to 19 kg more hot carcass weight, and leaner carcasses with a lesser marbling score after 56 d and did not alter health status or animal mobility after transport to slaughter.</p></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"40 5","pages":"Pages 669-680"},"PeriodicalIF":1.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590286524000995/pdf?md5=faabfaf8d5100e91eb8ca696bb5b1ce2&pid=1-s2.0-S2590286524000995-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142243572","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":"Effects of lubabegron supplementation on live performance, carcass characteristics, and mobility of Holstein steers","authors":"William C. Kayser ,&nbsp;Randall C. Raymond ,&nbsp;Phillip J. Rincker ,&nbsp;Sara Linneen ,&nbsp;Cory T. Herr","doi":"10.15232/aas.2023-02528","DOIUrl":"10.15232/aas.2023-02528","url":null,"abstract":"<div><h3>Objective</h3><p>The objectives of this study were to assess the effects of feeding Lubabegron (LB; Experior, Elanco, Greenfield, IN) for 0, 28, 56, or 84 d on live growth, car- cass, and mobility in Holstein steers.</p></div><div><h3>Materials and Methods</h3><p>Holstein steers (n = 438; 521 kg ± 35.5 kg) were used in a completely randomized study with 4 duration treatments: control, LB for 28 d, LB for 56 d, and LB for 84 d. Feed intake, BW, and car- cass data were all measured and analyzed on an individual basis.</p></div><div><h3>Results and Discussion</h3><p>In the pooled analysis, steers fed LB had greater total gain, ADG and G:F on a live and yield-adjusted basis relative to the controls. Lubabegron treated cattle had greater hot carcass weight, dressing per- cent and ribeye area, and decreased marbling score and average yield grade compared with the control treatment. There were no differences detected between LB or control steers in mobility at either shipment to abattoir or in lai- rage.</p></div><div><h3>Implications and Application</h3><p>Supplementation with LB favorably altered growth and carcass responses. Steers fed LB had no differences in mobility or other health maladies during the feeding period. These results indicate that feedyard producers can utilize LB without negatively affecting feeding performance or carcass quality.</p></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"40 5","pages":"Pages 681-687"},"PeriodicalIF":1.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590286524001009/pdf?md5=46450c1511a970321716c4dc779ed23c&pid=1-s2.0-S2590286524001009-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142243586","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":"Comparison of a single extended-release implant and a re-implant strategy on performance and carcass characteristics of beef finishing heifers","authors":"J.L. Sperber ,&nbsp;E.A. Schumacher ,&nbsp;D.J. Jordon ,&nbsp;R.J. Cooper ,&nbsp;T.L. Scott ,&nbsp;S. Bundy ,&nbsp;D.B. Burken ,&nbsp;G. Sides ,&nbsp;R.M. Cleale ,&nbsp;G.E. Erickson","doi":"10.15232/aas.2023-02533","DOIUrl":"10.15232/aas.2023-02533","url":null,"abstract":"<div><h3>Objective</h3><p>A commercial feedlot experiment evalu- ated the effects of implanting heifers with an extended- release implant (Synovex One Feedlot) compared with a re-implant strategy (Synovex Choice followed by Synovex Plus) on finishing heifer performance, animal health, and carcass characteristics.</p></div><div><h3>Materials and Methods</h3><p>Using a randomized com- plete block design, crossbred heifers (n = 1,737; initial BW = 313 kg ± 15.3 kg) were randomly assigned to 24 pens across 2 treatments for an average of 181 d experi- ment. Treatments included a single extended-release im- plant administered on d 0 (Synovex One Feedlot; ONE) or a re-implant strategy of Synovex Choice (d 0) followed by Synovex Plus (CH/PLUS) on d 93 to 95.</p></div><div><h3>Results and Discussion</h3><p>There were no differences in live final BW or ADG between the 2 implant strate- gies; however, heifers implanted with CH/PLUS had 2.5% greater carcass-adjusted feed efficiency than ONE heif- ers. The CH/PLUS strategy produced heavier hot carcass weight (387 vs. 384 kg), larger LM area (87.9 vs. 85.3 cm²), and greater DP (62.30% vs. 61.96%) compared with ONE. Heifers implanted with ONE had greater marbling score, calculated YG, and 12th-rib fat (1.97 vs. 1.89 cm) compared with CH/PLUS heifers, resulting in a difference in QG and YG distribution between the 2 implant strate- gies. No differences were observed between treatments in morbidity, mortality, or pen removals.</p></div><div><h3>Implications and Applications</h3><p>These results indi- cate that heifers receiving a more aggressive re-implant strategy have heavier hot carcass weight, greater yield, and larger LM area, but reduced marbling compared with heifers that received an extended-release implant.</p></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"40 5","pages":"Pages 661-668"},"PeriodicalIF":1.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590286524000983/pdf?md5=b6620ca113d87dba00b2ad7fd5fb3d29&pid=1-s2.0-S2590286524000983-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142243571","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":"\"October\" Cover","authors":"","doi":"10.1016/S2590-2865(24)00102-2","DOIUrl":"10.1016/S2590-2865(24)00102-2","url":null,"abstract":"","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"40 5","pages":"Page OFC"},"PeriodicalIF":1.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590286524001022/pdfft?md5=40f45ee6e6186e91df88d5861cfe9b8a&pid=1-s2.0-S2590286524001022-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142244109","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}