A.B. Thompson , T.L. Perkins , T.E. Lawrence , R.G. Amachawadi , T.G. Nagaraja , P.R. Broadway , N.C. Burdick Sanchez , V. Machado , M.S. Grant , M.L. Galyean , K.E. Hales
{"title":"Efficacy of ultrasonography to detect liver abscesses in cattle*","authors":"A.B. Thompson , T.L. Perkins , T.E. Lawrence , R.G. Amachawadi , T.G. Nagaraja , P.R. Broadway , N.C. Burdick Sanchez , V. Machado , M.S. Grant , M.L. Galyean , K.E. Hales","doi":"10.15232/aas.2024-02639","DOIUrl":"10.15232/aas.2024-02639","url":null,"abstract":"<div><h3>Objective</h3><div>Our aim was to evaluate the use of ultrasonography to identify liver abscesses in cattle.</div></div><div><h3>Materials and Methods</h3><div>Finishing steers (n = 160, mean final BW = 649 kg) were used in Exp. 1 and Exp. 2 (n = 63, mean final BW = 593 kg). Liver abscess images were obtained 24 h before slaughter. Steers in Exp. 3 (n = 40; mean final BW = 168 kg) and 4 (n = 40; mean final BW = 159 kg) were beef × dairy steers used in a study to experimentally induce liver abscesses. Real-time ultrasound imaging of the liver was conducted on the day of slaughter.</div></div><div><h3>Results and Discussion</h3><div>In Exp. 1, the sensitivity of ultrasonography for detection of liver abscesses in finishing beef steers was 14.6%, and in Exp. 2 the sensitivity was 5.6%. In the lightweight beef × dairy steers, sensitivity was 50% in Exp. 2 and 41.1% in Exp 3. Ultrasound accuracy ranged from 70% to 75% within all 4 experiments. Specificity of ultrasonography ranged from 84.6% to 100% among all experiments.</div></div><div><h3>Implications and Applications</h3><div>Low sensitivity of detection in all experiments indicates ultrasonography has limited value for detecting liver abscesses in live cattle. Nonetheless, the greater specificity observed indicates that ultrasonography is effective at diagnosing a steer as negative, but the likelihood of detecting a negative is greater than detecting a positive because of the low prevalence of liver abscesses among the steers in each study. Even with modern ultrasound equipment with improved resolution, liver abscesses remain difficult to detect in live cattle, but sensitivity seems to be improved in lighter versus heavier weight cattle.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 1","pages":"Pages 21-27"},"PeriodicalIF":1.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143139431","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":"Case Study: Assessment of greenhouse gas intensities on exemplary small and mid-sized US dairy farms","authors":"L.A. Olthof , K.R. Briggs , J.R. Knapp , B.J. Bradford","doi":"10.15232/aas.2024-02624","DOIUrl":"10.15232/aas.2024-02624","url":null,"abstract":"<div><h3>Objective</h3><div>Our objective was to estimate greenhouse gas (GHG) intensities for 4 dairy farms representing the Northeast, Great Lakes, West, and Southeast US regions using the Farmers Assuring Responsible Management: Environmental Stewardship (FARM ES) life-cycle analysis model.</div></div><div><h3>Materials and Methods</h3><div>Four herds with <1,000 lactating cows, on farms selected as excellent environmental stewards, were assessed, with mean (±SD) production of 10,782 ± 2,037 kg/yr fat- and protein-corrected milk (FPCM). Data from 2021 were gathered from management software, interviews, and on-farm evaluations. Soil OM data for ≥7 yr were available on 3 farms. Emissions intensity was quantified as net CO<sub>2</sub> equivalents (CO<sub>2</sub>e) emitted per unit of FPCM sold.</div></div><div><h3>Results and Discussion</h3><div>Mean (±SD) GHG emissions intensity was 0.97 ± 0.16 kg of CO<sub>2</sub>e/kg of FPCM. In terms of point sources, FARM ES attributed 42 ± 6% of the farms’ emissions to enteric methane and 28 ± 9% to manure emissions. The remaining emissions were associated with feed production and energy use. Two farms that used manure separation had an average emissions intensity 0.20 kg of CO<sub>2</sub>e/kg of FPCM less than farms that did not. Average annual soil carbon sequestration rates ranged from −0.82 to 3.52 Mg of carbon/ha, decreasing mean net GHG emissions intensity by 18% on these farms (0.81 vs. 0.99 kg of CO<sub>2</sub>e/kg of FPCM).</div></div><div><h3>Implications and Applications</h3><div>Management practices have wide-ranging implications for dairy farm emissions intensities, and quantifying soil carbon sequestration is key for estimating net GHG emissions for a dairy farm.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 1","pages":"Pages 28-38"},"PeriodicalIF":1.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143139432","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}
Roger A. Arentson , Mark Knauer , Joe Gooding , Michael Shields , Scott N. Carr
{"title":"Effects of initiating dietary narasin, at different production stages, on growth performance and carcass characteristics of growing-finishing pigs","authors":"Roger A. Arentson , Mark Knauer , Joe Gooding , Michael Shields , Scott N. Carr","doi":"10.15232/aas.2023-02515","DOIUrl":"10.15232/aas.2023-02515","url":null,"abstract":"<div><h3>Objective</h3><div>Our objective was to determine the effects of initiating narasin, at different production stages, on growing-finishing pig performance.</div></div><div><h3>Materials and Methods</h3><div>In Exp. 1, 360 barrows (BW = 23.0 ± 0.13 kg) were used in a completely randomized design (45 pens; 15 replications) with 90-d treatments: (1) an unmedicated diet (CON), (2) 15 mg/kg narasin (NAR-90d), or (3) 11 mg/kg virginiamycin (VIR-90d). In Exp. 2, 480 barrows (BW = 26.3 ± 0.14 kg) were used in a completely randomized design (60 pens; 15 replications) with the following treatments: (1) unmedicated CON diet, (2) 15 mg/kg narasin (0 to 91 d; NAR-91d), (3) CON (0 to 56 d) followed by 15 mg/kg narasin fed from 56 to 91 d (NAR-35d), or (4) 27.6 mg/kg zinc bacitracin (0 to 91 d; ZB-91d). In Exp. 3, 416 barrows and gilts (BW = 84.3 ± 0.39 kg) were used in a randomized complete block design (52 pens; 26 replications) with 35-d treatments: (1) unmedicated CON diet or (2) NAR-35d.</div></div><div><h3>Results and Discussion</h3><div>In Exp. 1, pigs fed NAR-90d had greater BW (d 90) and ADG (d 0 to 90) compared with pigs fed the CON dietary treatment. The ADG of pigs fed NAR-90d were greater than those of pigs fed the CON treatment on d 0 to 28 and d 28 to 56 and VIR-90 on d 0 to 28. Pigs fed NAR-90d had greater hot carcass weights and yields than those fed CON or VIR-90d. In Exp. 2, pigs fed NAR-91d (d 0 to 56) and pigs fed NAR-35d (d 56 to 91) had greater ADG and ADFI than any of the other treatments. In Exp. 3, pigs fed NAR-35d had greater G:F than pigs fed the CON treatment.</div></div><div><h3>Implications and Applications</h3><div>Pigs fed narasin tended to have greater growth performance responses in the periods after first receiving narasin. However, when narasin is fed for the entire growing-finishing period, pigs may have carcass responses in some cases. Improvements in growth performance were realized whether narasin was initiated in the early grower or finishing phase.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"40 6","pages":"Pages 770-782"},"PeriodicalIF":1.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183207","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":"Perspectives and Commentary: Fat nutrition and metabolism of early-lactation dairy cows","authors":"A.F. Kertz","doi":"10.15232/aas.2024-02540","DOIUrl":"10.15232/aas.2024-02540","url":null,"abstract":"<div><h3>Purpose</h3><div>My objective was to review key factors involved in identifying and characterizing how dairy cows metabolize fat sources and their resultant effects on DMI, milk fat depression, and body condition, with emphasis on early lactation. Thus, short-term, mid-lactation studies were not included.</div></div><div><h3>Sources</h3><div>The main sources of information were peer-reviewed journal articles, some dairy nutrition conference proceedings, a monograph, several abstracts, a still pertinent periodical article (Lock and Bauman, 2007), and 50 yr of research and field experiences in this area.</div></div><div><h3>Synthesis</h3><div>Forms of fat, such as triglycerides or free fatty acids whether unsaturated or saturated, affect DMI, milk fat depression, and body condition. The more unsaturated that fatty acids (FA) are, especially the amount of linoleic acid, the more negatively these facets are affected.</div></div><div><h3>Conclusions and Applications</h3><div>Know what kinds of fat sources are being fed. What is the FA composition of feedstuffs fed and fat sources, especially the UFA and their levels? The more UFA sources there are, the more DMI and milk fat percentage may be negatively affected. Linoleic FA is a key marker for these negative effects, which may ensue if daily intake of linoleic acid is 300 to 400 g or more. This can be exacerbated by other factors such as low dietary forage levels, greater starch, wet forages, and finely chopped forages, which all contribute to lower rumen pH, which facilitates milk fat depression. Reduction in DMI is the major consideration when fat supplementation occurs, with digestibility of fat supplements being a secondary consideration. Either palmitic or stearic acid above 80%, but especially above 90%, in a fat supplement is of concern and may be less digestible because they can become more crystalline. This can also be a factor when physically blending these single sources together. However, if these 2 FA sources are melted and then prilled, this crystalline formation is not likely to occur. Palmitic and stearic acids melted together and then prilled incorporate the complementary benefits of both, potentially in ratios of 1:1 to 2:1, palmitic to stearic acid.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"40 6","pages":"Pages 729-737"},"PeriodicalIF":1.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183466","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 returns and market risk of extending days on feed for beef × dairy cross heifers","authors":"C.S. Schmaltz , T.C. Schroeder , L.J. Walter , J.P. Hutcheson","doi":"10.15232/aas.2024-02616","DOIUrl":"10.15232/aas.2024-02616","url":null,"abstract":"<div><h3>Objective</h3><div>Our objective was to estimate economic net returns and return risk for beef × dairy cross heifers as days on feed (DOF) are extended.</div></div><div><h3>Materials and Methods</h3><div>Cattle production information and carcass performance data were obtained from a recent publication detailing a beef × dairy heifer cross serial slaughter study. Before final implant date heifers were treated the same through the first 265 DOF. At terminal implant, heifers were randomized into 4 treatment groups. Treatment 1 was fed for 58 d after randomization; treatment 2 for 79 d; treatment 3 for 97 d; and treatment 4 for 120 d. Baseline budgets were constructed using 5-yr average prices. Scenarios varying prices and costs and risk analysis of price changes over extended DOF were analyzed.</div></div><div><h3>Results and Discussion</h3><div>Net returns varied in economically important ways as DOF were extended. In baseline scenario, treatment 1 had highest net return of $99.84/head (hd) and treatment 4 lowest return of $57.13/ hd. Changing feed cost, carcass base price, and QG adjustments generally did not alter ordering of net returns across DOF. With low feed prices or high carcass prices, extending DOF increased net returns in some scenarios. Sensitivity analysis changing prices revealed base carcass price was the dominant risk determinant representing >90% of return risk. Return standard deviations ranged $69.06/hd for 3 wk extended DOF to $114.52/hd for 9 wk.</div></div><div><h3>Implications and Applications</h3><div>Extending DOF reduced net returns in the baseline. With different market conditions from baseline, extending DOF could increase returns. Market risk, especially carcass base price changes, was prevalent when extending DOF.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"40 6","pages":"Pages 824-834"},"PeriodicalIF":1.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183210","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}
W. Cole Ellis, Zachary M. Duncan, Madeline S. Grant, William R. Hollenbeck, Evan C. Titgemeyer, Dale A. Blasi
{"title":"Restricting bunk space allotments to 15 or 25 centimeters per head has minimal effects on growth performance in limit-fed growing beef heifers","authors":"W. Cole Ellis, Zachary M. Duncan, Madeline S. Grant, William R. Hollenbeck, Evan C. Titgemeyer, Dale A. Blasi","doi":"10.15232/aas.2024-02625","DOIUrl":"10.15232/aas.2024-02625","url":null,"abstract":"<div><h3>Objective</h3><div>Our objective was to evaluate the effects of bunk allotment on growth performance of receiving beef heifers limit fed a diet based on high-energy corn and corn co-products, in pens that contained 18 to 28 heifers.</div></div><div><h3>Materials and Methods</h3><div>Beef heifers (291 ± 15.5 kg; n = 332) were used in a randomized complete block design. Heifers were blocked by origin, stratified by indi- vidual arrival weight, and assigned to pen within block. Pens were randomly assigned to 1 of 4 treatments, with 4 pens per treatment, that provided 15.2, 25.4, 35.6, or 45.7 cm of linear bunk per heifer. Heifers were limit fed a high- energy diet once daily at 2.0% of BW (DM basis) for 56 d. Individual BW were measured on d 0 and 56. Pen BW were measured weekly and used to adjust feed delivered for the following week.</div></div><div><h3>Results and Discussion</h3><div>Bunk allotments of 15.2, 25.4, 35.6, or 45.7 cm per heifer did not affect final BW, ADG, DMI, or G:F. At feeding, 43%, 62%, 79%, and 96% of heifers in the pen had access to the feed bunk when allotted 15.2, 25.4, 35.6, and 45.7 cm of linear bunk per heifer, respectively. The SD of ADG within the pen did not differ among feed bunk sizes.</div></div><div><h3>Implications and Applications</h3><div>Bunk allotments as low as 15.2 to 25.4 cm per heifer can be used without negatively influencing growth performance of growing beef heifers of about 290 to 360 kg of BW that are limit fed a high-energy diet at 2.0% of BW (DM basis) once daily in pens that contained 18 to 28 head.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"40 6","pages":"Pages 818-823"},"PeriodicalIF":1.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183455","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}
Zachary K. Smith, Becca B.G. Francis, Justin J. Delver, Forest L. Francis, Erin R. DeHaan, Thiago L.M. Ribeiro, Warren C. Rusche
{"title":"Evaluation of extruded and expelled soybean meal as a partial replacement for dried distillers grains plus solubles in diets for finishing beef steers","authors":"Zachary K. Smith, Becca B.G. Francis, Justin J. Delver, Forest L. Francis, Erin R. DeHaan, Thiago L.M. Ribeiro, Warren C. Rusche","doi":"10.15232/aas.2024-02581","DOIUrl":"10.15232/aas.2024-02581","url":null,"abstract":"<div><h3>Objective</h3><div>This study evaluated the use of extruded and expelled soybean meal (EESBM) as a partial replacement (30% or 60% replacement; DM basis) of dried distillers grains plus solubles (DDGS) in diets offered to finishing beef steers.</div></div><div><h3>Materials and Methods</h3><div>Steers (n = 144 steers; 399 ± 28.9 kg) were used in a 150-d finishing trial. Steers were group housed in 18 pens (n = 8 steers/pen) and allocated to one of 3 dietary treatments in a randomized complete block design (n = 6 pens/treatment). Treatments included (1) finishing diet that included 15% DDGS (DM basis; CON); (2) finishing diet that included 30% replacement (DM basis) of DDGS with EESBM (EESBM30), and (3) finishing diet that included 60% replacement (DM basis) of DDGS with EESBM (EESBM60). Steers were fed twice daily and managed for maximum intake using a slick bunk management approach.</div></div><div><h3>Results and Discussion</h3><div>Dry matter intake increased linearly when EESBM replaced DDGS. Average daily gain and gain efficiency (both live-basis shrunk 4% and from carcass-adjusted final BW), as well as hot carcass weight, increased linearly with greater inclusion of EESBM. No other carcass trait outcomes, nor the distribution of USDA YG and QG, lung scores, or liver health outcomes were influenced by dietary treatment.</div></div><div><h3>Implications and Applications</h3><div>Using EESBM in replacement of DDGS results in greater intake, efficiency, and final body and carcass weight with no detriment to carcass yield or quality.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"40 6","pages":"Pages 751-759"},"PeriodicalIF":1.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183467","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":"Evaluating the influence of heritable, metabolic, and production variables on the postpartum estrus expression of Holstein cows in a voluntary milking system","authors":"S.G. Johnson, T.M. Marins, S. Tao, J.F. Bohlen","doi":"10.15232/aas.2024-02603","DOIUrl":"10.15232/aas.2024-02603","url":null,"abstract":"<div><h3>Objective</h3><div>This observational study aimed to explore metabolic markers, nonesterified fatty acids (NEFA), glucose, insulin, and insulin resistance, alongside heritable fertility marker anti-Müllerian hormone (AMH), and their influence on postpartum estrus expression in a voluntary milking system (VMS).</div></div><div><h3>Materials and Methods</h3><div>Holstein cows (n = 95) were enrolled at 14 ± 3 DIM with blood samples taken weekly. All samples were analyzed for metabolic profiles of NEFA, glucose, and insulin until 49 ± 3 DIM. Insulin resistance was estimated at each time point using the Revised Quantitative Insulin Sensitivity Check Index (RQUICKI). Visits to the VMS and milk production data were collected on day of sampling and averaged with data from the preceding day and following day. Cows were fitted with DeLaval AM2 collars and monitored from calving until 100 DIM using DelPro Farm Manager. Both (++) (activity 5 SD above normal activity levels) and (+++) (activity 6 SD above normal activity levels) reproductive attentions in DelPro were used to identify an estrus event, with estrus intensity recorded. Cows were grouped by time to resumption of estrus expression, with the normal group (NG) having an estrus event on or before 45 DIM and the delayed group (DG) resuming beyond 45 DIM. Data were analyzed using the CORR and MIXED procedure of SAS.</div></div><div><h3>Results and Discussion</h3><div>Greater milk yield corresponded with increased VMS visits (r = 0.39). Blood glucose concentrations were greater for NG cows on d 35 and 42. Serum NEFA concentrations decreased in all animals over time. Insulin increased over time in all cows but did not differ between NG and DG cows. The RQUICKI did not change over time for either NG or DG cows. Estrus intensity was not different in NG (191% ± 6.6%) versus DG cows (179.1% ± 5.97%), and AMH was not different between NG (223.4 ± 28.62 pg/mL) and DG cows (217.6 ± 25.22 pg/mL).</div></div><div><h3>Implications and Applications</h3><div>Milk production and its association with glucose and VMS visits are key drivers for postpartum estrus expression of cows in a VMS.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"40 6","pages":"Pages 783-790"},"PeriodicalIF":1.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183208","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}