Applied Animal Science最新文献

{"title":"Evaluation of antimicrobial activities of probiotic bacterial culture supernatants against liver abscess-causing bacterial pathogens","authors":"H.M. Salih ,&nbsp;R.G. Amachawadi ,&nbsp;Q. Kang ,&nbsp;M.E. Theurer ,&nbsp;A. Skidmore ,&nbsp;P.R. Broadway ,&nbsp;K.E. Hales ,&nbsp;T.G. Nagaraja","doi":"10.15232/aas.2025-02683","DOIUrl":"10.15232/aas.2025-02683","url":null,"abstract":"<div><h3>Objective</h3><div>The objectives of our study were to evaluate the abilities of probiotic bacterial culture supernatants to inhibit the liver abscess-causing pathogens <em>Fusobacterium necrophorum</em>, <em>Trueperella pyogenes</em>, and <em>Salmonella enterica</em> in pure cultures or in an in vitro rumen simulating batch culture of rumen microbial model.</div></div><div><h3>Materials and Methods</h3><div>Probiotic bacterial species were cultured, centrifuged, filter sterilized, and stored at −20°C. Liver abscess-causing pathogens were cultured in anaerobic brain-heart infusion broth (for <em>Fusobacterium</em>) and in Muller-Hinton broth (for <em>S. enterica</em> and <em>T. pyogenes</em>), each with and without probiotic culture supernatants. Bacterial growth was measured in a spectrophotometer or by spread-plating on blood agar, or both.</div></div><div><h3>Results and Discussion</h3><div>Only the supernatant of <em>L. helveticus</em> reduced the growth of both <em>Fusobacterium</em> subspecies, <em>T. pyogenes</em>, and <em>S. enterica</em>. Addition of <em>L. helveticus</em> supernatant to in vitro batch culture of rumen microbes containing ruminal fluid, buffer, and substrates (glucose, lactic acid, or ground cattle feed) exhibited reduction in the spiked culture of <em>F. necrophorum</em>.</div></div><div><h3>Implications and Applications</h3><div>Probiotic cultures, such as <em>L. helveticus</em>, may have potential for use as a feed supplement to control liver abscesses.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 5","pages":"Pages 418-432"},"PeriodicalIF":1.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145236295","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 reducing dietary nutrient density after the second dose of a gonadotropin-releasing-factor immunization on growth performance and carcass characteristics of intact male pigs and market gilts","authors":"B.M. Bohrer ,&nbsp;J.L. Landero ,&nbsp;M. Young ,&nbsp;B. Hansen ,&nbsp;D.S. Pollmann ,&nbsp;L. Van De Weyer ,&nbsp;A. Aldaz","doi":"10.15232/aas.2024-02670","DOIUrl":"10.15232/aas.2024-02670","url":null,"abstract":"<div><h3>Objective</h3><div>The effects of reducing dietary nutrient density after the second dose of gonadotropin-releasing- factor (GnRF) immunization on growth performance and carcass characteristics of intact male pigs and market gilts were investigated.</div></div><div><h3>Materials and Methods</h3><div>During this 102-d grow- finish study, one dietary program was formulated to meet the recommended ratio of standardized ileal digestible (SID) lysine to NE for nonimmunized physically castrated males and nonimmunized market gilts, and another dietary program was formulated with greater SID lysine for GnRF-immunized pigs than for physically castrated males (15.0% to 20.0% greater SID lysine). During the final 2 dietary phases (final 46 d), additional treatment diets were formulated for diets fed to GnRF-immunized pigs to evaluate nutrient dilution programs (consisting of diluted AA, vitamins, and trace minerals).</div></div><div><h3>Results and Discussion</h3><div>There were no significant linear effects of diet dilution for G:F or hot carcass weight (HCW) for either male or female GnRF-immunized pigs. For the overall period, G:F was improved and HCW was greater for male GnRF-immunized pigs when compared with nonimmunized pigs. Additionally, G:F tended to be improved, whereas HCW was not different, for female Gn- RF-immunized pigs when compared with nonimmunized pigs.</div></div><div><h3>Implications and Applications</h3><div>Diluting nutrient density during the post-second-dose period of GnRF im- munization did not affect growth or carcass attributes, and both male and female GnRF-immunized pigs grew faster and were more feed efficient compared with nonim- munized pigs.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 5","pages":"Pages 482-501"},"PeriodicalIF":1.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145236385","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":"Bovine appeasing substance: A meta-analysis of the effects on production, health, and stress indicators in growing cattle","authors":"Ian J. Lean ,&nbsp;Anabel A. Garcia ,&nbsp;Helen M. Golder","doi":"10.15232/aas.2025-02712","DOIUrl":"10.15232/aas.2025-02712","url":null,"abstract":"<div><h3>Objective</h3><div>Our objective was to use meta-analytical methods to evaluate the effectiveness of treating growing cattle with bovine appeasing substance (BAS) to improve production, health, and stress indicators.</div></div><div><h3>Materials and Methods</h3><div>A search of 3 search engines identified experiments that examined the effectiveness of treating growing cattle with BAS to improve production, health, and stress indicators. Results of experiments were evaluated to ensure that these were from peer-reviewed journals or theses published in English, were in vivo and evaluated use of BAS, were randomized, had appropriate analysis of data, and contained data to determine the effect size for outcomes. The standardized mean difference was estimated for continuous data and risk difference between groups for dichotomized disease data. Multilevel models were used when experiments were nested within studies. Publication bias was assessed through funnel plots. The potential influence of pseudo-replication and duration of experiment were assessed through meta-regression.</div></div><div><h3>Results and Discussion</h3><div>A total of 13 studies with up to 18 experiments were included. There was no significant difference in initial BW or evidence of publication bias for any outcome. For stress outcomes, only blood cortisol was reduced by treatment by 3.85 ng/mL (95% CI: −7.60 to−0.09), supporting the proposed mode of action of BAS, but did not result in overall production or health benefits, including hair cortisol. However, there were positive point directions and results in some individual experiments, particularly for final BW, mortality, and virus antibodies. The limited number of experiments and large variation in study design prevented extensive exploration of potential sources of heterogeneity.</div></div><div><h3>Implications and Applications</h3><div>The reduction in blood cortisol concentrations by BAS indicates its potential to mitigate the effects of routine animal husbandry stress on cattle. Positive, but nonsignificant, point directions for final BW, mortality, and virus antibodies suggest the need for more experiments to determine whether the intervention can be justified on a cost-efficacy or ethical basis.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 5","pages":"Pages 521-552"},"PeriodicalIF":1.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145236441","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":"Different sources of lipids for finishing feedlot lambs","authors":"Nauara Moura Lage Filho ,&nbsp;Lázaro José da Silva ,&nbsp;Cristian Faturi ,&nbsp;Edwana Mara Moreira Monteiro ,&nbsp;Felipe Nogueira Domingues ,&nbsp;Thiago Carvalho da Silva ,&nbsp;Bianca Rafaela Costa e Silva ,&nbsp;Alessandra de Souza Mourão ,&nbsp;Davide Rondina ,&nbsp;Aníbal Coutinho do Rêgo","doi":"10.15232/aas.2024-02571","DOIUrl":"10.15232/aas.2024-02571","url":null,"abstract":"<div><h3>Objective</h3><div>The aim of this study was to evaluate the effects of different dietary lipid sources on feed performance in feedlot lambs.</div></div><div><h3>Materials and Methods</h3><div>A total of 30 noncastrated male lambs, Santa Inês (initial average weight of 29 ± 2 kg), were distributed in a randomized block design into 3 treatment groups (10 lambs per group): a diet with soybean oil, residual frying oil, or palm oil. The 3 experimental diets included lipids at 60 g∙kg⁻¹ of DM. The formulated diets, at a roughage-to-concentrate ratio of 40:60, consisted of elephant grass silage, milled corn, soybean bran, wheat bran, oil (soybean, residual frying oil, or palm), calcitic limestone, and urea. Fatty acid composition was determined. Sheep intake, digestibility, and performance were analyzed.</div></div><div><h3>Results and Discussion</h3><div>Dry matter and nutrient intakes, as well as average daily weight gain and G:F, were similar among the treatment groups. The difference was in the coefficient of digestibility of ether extract; in that regard, palm oil (852.2 g∙kg⁻¹) was superior to soybean oil and residual frying oil (77.96 and 81.40 g∙kg⁻¹, respectively). Among the oil tested, soybean oil had the highest levels of unsaturation (824.2 g∙kg⁻¹), followed by residual frying oil (779.6 g∙kg⁻¹), and palm oil (576.5 g∙kg⁻¹), which indicated that unsaturation levels do not alter nutrient intake when sheep diets contain adequate amounts of ether extract.</div></div><div><h3>Implications and Applications</h3><div>We conclude that lipid sources that differ in levels of unsaturation may be used without restriction in diets that contain normal amounts of ether extract (approximately 60 g∙kg⁻¹). Moreover, residual frying oil is an alternative lipid source that may be used in the diets of feedlot lambs.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 5","pages":"Pages 458-464"},"PeriodicalIF":1.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145236382","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":"Exploring Alabama beef producers’ perceptions and implementation of sustainable practices within the beef industry","authors":"Gabriella F. Johnson ,&nbsp;David S. Martin ,&nbsp;Jason T. Sawyer ,&nbsp;Donald R. Mulvaney","doi":"10.15232/aas.2025-02698","DOIUrl":"10.15232/aas.2025-02698","url":null,"abstract":"<div><h3>Objective</h3><div>With sustainability in the agriculture industry becoming a greater focus, it is important to understand how beef producers view sustainability and sustainable initiatives. The objective of this research study was to assess Alabama beef producers’ opinions of sustainability, sustainable practices within the industry, and their implementation rate of those practices.</div></div><div><h3>Materials and Methods</h3><div>An online survey with 36 questions was developed and distributed to Alabama beef producers from July to November 2024. Questions asked producers their opinions on the importance of resources and stakeholders when it comes to environmental impact and sustainability, their knowledge of Climate-Smart Commodities programs, their implementation of certain sustainable practices, and what tools or resources are necessary for their operation to adopt or further improve sustainability practices.</div></div><div><h3>Results and Discussion</h3><div>Results show that 105 primarily cow-calf producers from 42 of the 67 counties in Alabama have varying implementation rates (~9%–90%) of practices that can improve sustainability and resource management, specifically utilizing grazing management plans, growth-promoting technologies, and animal handling and welfare training. There appears to be a stated interest in learning more about sustainable practices, but further research and financial information are important for continuing interest in sustainability and implementation.</div></div><div><h3>Implications and Applications</h3><div>Providing producers with information or counseling about the financial implications of sustainability practices and carbon programs could increase interest or implementation on their operations. Extension professionals can use the results from this survey to inform financial programming development and sustainability resources to provide information to producers in the region.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 5","pages":"Pages 563-572"},"PeriodicalIF":1.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145236443","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":"Longitudinal assessment of Fusobacterium necrophorum and Fusobacterium varium in the nasal cavity of finishing beef steers with and without liver abscesses","authors":"Colten W. Dornbach ,&nbsp;Mina Abbasi ,&nbsp;Paul R. Broadway ,&nbsp;James E. Wells ,&nbsp;Kallie D. Childress ,&nbsp;Aubrey C. Thompson-Smith ,&nbsp;Landon G. Canterbury ,&nbsp;Nicole C. Burdick Sanchez ,&nbsp;Xiaorong Shi ,&nbsp;Leigh A. George ,&nbsp;Raghavendra G. Amachawadi ,&nbsp;T.G. Nagaraja ,&nbsp;Michael L. Galyean ,&nbsp;Kristin E. Hales","doi":"10.15232/aas.2025-02707","DOIUrl":"10.15232/aas.2025-02707","url":null,"abstract":"<div><h3>Objective</h3><div>We longitudinally assessed the prevalence of <em>Fusobacterium necrophorum</em> ssp. <em>necrophorum</em>, <em>Fusobacterium necrophorum</em> ssp. <em>funduliforme</em>, and <em>Fusobacterium varium</em> in the nasal cavity of finishing beef steers with and without liver abscesses (LA).</div></div><div><h3>Materials and Methods</h3><div>Crossbred beef steers (n = 225; arrival BW = 353 ± 39.6 kg) were transported to a feedlot and used in a case-control study. From d 0 to harvest, steers were fed a feedlot diet representative of the High Plains region (NE_g = 1.50 Mcal/kg). Nasal swabs were aseptically collected after feedlot arrival (d 5), after adaptation to the finishing diet (d 35), and the day before harvest (harvest). Livers were collected at harvest and examined for LA, and cattle were subsequently assigned into either case (LA present) or control (LA not present) groups. Nasal swabs from cattle with LA (n = 42) and without LA (n = 42) were analyzed for <em>Fusobacterium</em>. Individual animal was the experimental unit, with fixed effects of abscess, sampling time, and abscess × sampling time interaction.</div></div><div><h3>Results and Discussion</h3><div>Overall LA prevalence was 18.7%. Nasal prevalence of <em>F. necrophorum</em> ssp. <em>necrophorum</em> and <em>F. varium</em> did not differ by LA status or sampling period. Conversely, an abscess × sampling interaction occurred, where steers with LA had lesser <em>F. necrophorum</em> ssp. <em>funduliforme</em> prevalence on d 35 than those without a LA. Nevertheless, the number of enumerable <em>F. necrophorum</em> ssp. <em>funduliforme</em> samples did not differ between steers with or without LA or across sampling time.</div></div><div><h3>Implications and Applications</h3><div>This is the first report of <em>Fusobacterium</em> detection and enumeration from the nasal cavity of feedlot beef steers. Although these data suggest that <em>Fusobacterium</em> species are present in the nasal cavity of finishing beef steers throughout the feedlot period, a direct link between nasal <em>Fusobacterium</em> populations and LA development was not detected. High variability and small sample sizes limited our ability to detect subtle associations. Future research is needed to evaluate relationships between <em>Fusobacterium</em> populations in the respiratory tract, respiratory disease prevalence, and LA formation.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 5","pages":"Pages 441-447"},"PeriodicalIF":1.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145236380","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 byproduct-based diets or grain-based diets on performance and carcass quality of beef steers finished on pasture","authors":"M.L. Johnson ,&nbsp;C.E. Gruber ,&nbsp;K.R. Vierck ,&nbsp;S. Gadberry ,&nbsp;K. Coffey ,&nbsp;C.T. Shelton ,&nbsp;R.C. Jones ,&nbsp;G. Gourley ,&nbsp;J.D. Rivera","doi":"10.15232/aas.2025-02684","DOIUrl":"10.15232/aas.2025-02684","url":null,"abstract":"<div><h3>Objective</h3><div>A study was conducted to evaluate effects of 2 pasture-based finishing systems, compared with a conventional finishing method, on live performance and carcass quality of steers.</div></div><div><h3>Materials and Methods</h3><div>Sixty-three crossbred beef steers (363.9 ± 28.7 kg) were blocked by BW and randomly assigned to one of either 7 pens or 14 pasture paddocks. Treatments consisted of conventional finishing diet (FDLT), or 2 pasture-based diets fed at 2% to 2.25% of BW of either grain-based (STCH) or byproduct-based diets (BYPD). In addition to their diet, steers on the pasture-based treatments were able to graze warm-season perennial forages. Steers were fed their respective diets once daily for 161 d and were harvested at a commercial slaughter facility in Arkansas City, Kansas. Performance and carcass data were analyzed using PROC GLIMMIX and PROC MIXED (SAS 9.4); pen and pasture were the experimental units, treatment was a fixed effect, and block was considered a random effect.</div></div><div><h3>Results and Discussion</h3><div>Cattle fed FDLT and BYPD had greater BW on d 112 and 140 (<em>P</em> ≤ 0.02), and greater overall carcass-adjusted BW (<em>P</em> = 0.03) compared with STCH. Due to the limit-fed nature of the treatments, both STCH and BYPD had more efficient nonpasture-only feed conversion through d 56, between d 85 and 140, and between d 0 and 161 (<em>P</em> ≤ 0.05). Hot carcass weight tended (<em>P</em> = 0.13) to be greater for BYPD and FDLT compared with STCH. Marbling score tended (<em>P</em> = 0.14) to be greater for BYPD compared with FDLT and STCH. No differences (<em>P</em> ≥ 0.34) were noted in other carcass characteristics.</div></div><div><h3>Implications and Applications</h3><div>Data from this study suggest that feeding byproduct feed mixtures to beef cattle grazing pasture could successfully be used as an alternative finishing method without affecting carcass quality.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 5","pages":"Pages 465-472"},"PeriodicalIF":1.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145236383","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":"Review: Production and prediction of enteric methane in dairies in the Texas Panhandle and surrounding areas","authors":"M.S. Grant ,&nbsp;K.E. Hales ,&nbsp;M.A. Ballou ,&nbsp;M.L. Galyean","doi":"10.15232/aas.2025-02676","DOIUrl":"10.15232/aas.2025-02676","url":null,"abstract":"<div><h3>Purpose</h3><div>We reviewed the current understanding of methane production, prediction, and mitigation strategies in dairy cattle located in the Texas Panhandle and surrounding High Plains region.</div></div><div><h3>Sources</h3><div>Peer-reviewed literature was the primary source of information.</div></div><div><h3>Synthesis</h3><div>The dairy industry in the Texas Panhandle and surrounding High Plains region has expanded greatly in recent decades, reflecting a geographic shift from historically significant dairy production areas in Central and Northeast Texas and states in the Western United States. Along with this geographic shift, the US dairy cattle population has decreased 4.5% since 1990. Nonetheless, enteric CH₄ emissions increased 13% from 1990 to 2022. Enteric CH₄ emissions can be affected by numerous diet- related factors including feed intake, diet composition, and feed additives (hydrogen sinks and direct inhibitors) that alter CH₄ production in the gastrointestinal tract. Accurate, direct estimates of enteric CH₄ emissions are challenging and costly to measure from individual animals, which has resulted in the use of mathematical models as a means to predict CH₄ emissions in dairy cattle. We evaluated commonly used equations to predict CH₄ emissions in lactating cows, nonlactating cows, and growing heifers when applied to diets and performance typical of dairies in the Texas Panhandle. The CH₄ emissions (g/d) among the 3 equations used with 3 lactating cow diets ranged from 431 to 507 g/d. Additionally, the CH₄ emissions among the 2 equations used with 3 dry cow diets ranged from 251 to 278 g/d. For dairy heifers, CH₄ emissions among the 2 equations used with 3 growing heifer diets ranged from 157 to 175 g/d. Predicted CH₄ yield for equations and diets used ranged from 17.8 to 20.9 g/kg of DMI for lactating cows, 17.9 to 19.8 g/kg of DMI for dry cows, and 14.6 to 20.2 g/kg of DMI for growing heifers.</div></div><div><h3>Conclusions and Applications</h3><div>Dietary factors affecting enteric CH₄ production are generally well defined. Moreover, potential mitigation strategies exist to decrease CH₄ emissions, but our ability to accurately and precisely predict feed intake and digestibility, which are major factors affecting CH₄ production, needs improvement. Future research measuring enteric CH₄ emissions from cows fed diets typical of those used in the Texas Panhandle and High Plains region across a range of DMI would be useful to validate and potentially improve existing prediction equations for their utility in these regions. Improvement in predicting enteric CH₄ emissions will allow dairies to address potential regulatory challenges and understand practical effects of mitigation approaches.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 5","pages":"Pages 553-562"},"PeriodicalIF":1.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145236444","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":"Liver abscess bacterial pathogens in healthy liver tissues, normal tissues of abscessed livers, and corresponding ruminal epithelial tissues of beef-on-dairy cattle*","authors":"Mina Abbasi ,&nbsp;Reese A. Wilson ,&nbsp;Xiaorong Shi ,&nbsp;Leigh Ann George ,&nbsp;Dale R. Woerner ,&nbsp;Raghavendra G. Amachawadi ,&nbsp;T.G. Nagaraja","doi":"10.15232/aas.2025-02704","DOIUrl":"10.15232/aas.2025-02704","url":null,"abstract":"<div><h3>Objective</h3><div>Our objective was to determine the prevalence of <em>Fusobacterium necrophorum</em> ssp. <em>necrophorum</em> and ssp. <em>funduliforme</em>, <em>Trueperella pyogenes</em>, <em>Salmonella enterica</em>, and <em>Escherichia coli</em> and quantify <em>F. necrophorum</em> in parenchymal tissues of healthy livers and abscessed livers and ruminal epithelial tissues of beef-on-dairy cattle.</div></div><div><h3>Materials and Methods</h3><div>Samples, collected at slaughter, included 107 healthy livers and 110 abscessed livers, and 101 matched ruminal tissues each from cattle with healthy or abscessed livers. Culture methods to isolate the bacterial species and quantitative PCR to determine prevalence and concentrations of <em>F. necrophorum</em> were used. Statistical analyses included Fisher’s exact test for prevalence and ANOVA for bacterial concentration comparisons.</div></div><div><h3>Results and Discussion</h3><div>Culture and quantitative PCR data indicated prevalence of the 4 species of pathogens and <em>E. coli</em> in tissues of healthy livers and abscessed livers. The prevalences of the 2 subspecies were greater in ruminal than liver tissues. <em>Fusobacterium necrophorum</em> ssp. <em>funduliforme</em> was the dominant subspecies in both tissues, likely because it is the most prevalent subspecies in ruminal contents of cattle. Only one healthy liver yielded <em>T. pyogenes.</em> Both tissue types yielded <em>S. enterica</em>, and the dominant serotype was Montevideo. The prevalence of <em>E. coli</em>, an indicator of bacterial flow from the gut, ranged from 55% to 100%. Approximately, 8% of the liver tissues had quantifiable concentrations of <em>F. necrophorum</em>. More ruminal tissues from cattle with abscessed livers (76%) had quantifiable concentrations of the 2 subspecies than those from cattle with healthy livers (57.4%). Our data suggest that healthy livers harbor pathogens and ruminal tissues serve as a reservoir of pathogens that enter the portal blood.</div></div><div><h3>Implications and Applications</h3><div>Tissue-embedded pathogens exist in healthy livers, normal regions of abscessed livers, and ruminal epithelium of cattle. There is likely a threshold of concentration required to initiate abscess development, and delineating factors that trigger this process may aid in novel intervention strategies.</div></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 5","pages":"Pages 405-417"},"PeriodicalIF":1.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145236294","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":"Call for Submissions","authors":"","doi":"10.1016/S2590-2865(25)00086-2","DOIUrl":"10.1016/S2590-2865(25)00086-2","url":null,"abstract":"","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":"41 5","pages":"Pages iv-vi"},"PeriodicalIF":1.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145236293","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}