Location: Livestock Issues Research
2025 Annual Report
Objectives
Objective 1: Use high-throughput phenotyping, automated data capture, and data computational technologies to explore relationships among animal behavior, environment, and management practices on animal productivity and well-being.
Sub-objective 1.A: Utilize automated data capture technologies to study the influence of phenotype, environment and management strategies on production efficiency, well-being, and the prevalence of enteric and foodborne pathogens in beef cattle.
Sub-objective 1.B: Evaluate non-invasive infrared thermography for targeted metaphylactic antibiotic treatment to reduce the use of medically important antibiotics in feedlot production while maintaining animal productivity, health, and well-being.
Sub-objective 1.C: Evaluate the ability of non-antibiotic alternatives to reduce and mitigate Salmonella pathogenesis and its negative impacts on overall well-being in dairy calves and swine.
Objective 2: Reduce the incidence and severity of liver abscesses in cattle through management strategies.
Sub-objective 2.A: Continue development of an experimental model to study liver abscesses in cattle.
Sub-objective 2.B: Utilize nutritional supplements to reduce the incidence and severity of liver abscesses in cattle.
Objective 3: Evaluate natural variations, hormonal regulation, and nutritional modulation of immune cell activity and inflammation in livestock.
Sub-objective 3.A: Utilize in vitro immune cell phenotyping to determine the influence of temperament on immunity and disease resistance in beef cattle.
Sub-objective 3.B: Evaluate the role of ghrelin in vitro and in vivo as a means to reduce inflammation and improve well-being in cattle and swine.
Sub-objective 3.C: Evaluate changes in inflammatory and oxidative stress markers in cattle and swine fed various non-antibiotic feed additives including sorghum extracts and cotton seed oil products.
Approach
Animal health and well-being continues to be at the forefront of livestock production. Any progress to be made in responsibly producing livestock products must be made through providing tools to improve animal productivity and well-being. It is now understood that many factors influence animal well-being and productivity, including phenotype (i.e., temperament), nutrition, environment (i.e., climate changes), and health status. Further complicating the matter is the increased consumer pressure to decrease antimicrobial use in livestock, and the need to identify viable antibiotic alternatives in order to maintain animal productivity and health. Therefore, this research will increase understanding of the interactions among phenotype, nutrition, and environmental factors to improve/provide tools for producers to maximize productivity and well-being. Objective 1 will utilize high-throughput phenotyping and automated data capture and computation technologies to improve animal productivity and well-being. Additionally, non-invasive biomarker data capture techniques will be tested that can provide valuable information to producers. For Objective 2 we will continue development of an experimental model to study liver abscess development and strategies to reduce liver abscess incidence and severity in cattle. Lastly, Objective 3 will assess differences in immune cell function stemming from natural variations and non-antibiotic additives and will evaluate how these factors may be utilized to reduce inflammation and improve productivity. Together, these objectives will provide invaluable information to cattle and swine producers on the impact of phenotype, environment, and nutrition on livestock productivity, health and well-being, and provide tools to help producers continue to provide healthy animal products to consumers.
Progress Report
In the third year of this project plan, ARS researchers in Lubbock, Texas, conducted 7 studies aimed at gaining further insight and to provide resources to improve the well-being and productivity of cattle and swine. For Sub-objective 1A, a study was conducted to evaluate the use of ultrasound to detect liver abscesses in live cattle. Specifically, scientists in Lubbock, Texas, in collaboration with university partners, evaluated beef steers prior to harvest and weaned beef-dairy steers. Results found greater sensitivity in lighter weight cattle, but sensitivity across all cattle was low, suggesting a limited ability to detect liver abscesses in live cattle, even with recent technological advancements. Two studies were conducted under Sub-objective 1C. In the first study, ARS researchers, with university collaborators, evaluated changes in heat production from cattle exposed to an immune stimulant in order to calculate changes in energy use during activation of the immune system. No changes in energy use were identified in this preliminary study from 24 hours prior to 24 hours after immune stimulation. However, evaluation of the results continues. In the second study under Sub-objective 1C, ARS researchers and university collaborators studied whether administering an antibiotic to a subset of cattle rather than the entire group upon arrival at a feedlot would affect measurements of cattle health, growth performance and antibiotic usage. Results from this study mirrored previous study results using a different antibiotic, where the best health and growth performance was observed when 66 to 100% of the cattle in a pen were treated with an antibiotic upon feedlot arrival. Additionally, treating at least 66% of cattle in a pen with an antibiotic resulted in $2.25 per head cost savings in antibiotic costs during the first 35 days at a feedlot. Two studies were conducted under Sub-objective 2A. In the first study, ARS scientists and university collaborators evaluated the effect of diet and bacterial pathogens on the induction of liver abscesses in beef-dairy cross steers using an in-house developed model. Results indicated that acidosis is not required for liver abscess development, and that the presence of the bacteria was just as important or more important than dietary changes in the development of liver abscesses. In the second study, the role of different bacteria commonly found in liver abscesses were assessed using an in-house designed liver abscess model. Results from this study are currently in the initial stages of analysis. One study was conducted under Sub-objective 2B, where ARS scientists and university collaborators tested the effect of different non-antibiotic feed additives on the ability to reduce liver abscesses in cattle. Initial data suggest there was no effect of the tested feed additives on reducing liver abscesses in beef-dairy cross steers. One study was conducted under Sub-objective 3A. Specifically, ARS scientists, along with university collaborators, evaluated the effect of cattle temperament during the feedlot period on measurements of stress and immunity. Data from this study supports previous research indicating temperamental cattle have greater stress markers. Also, white blood cells did not differ between calm and temperamental cattle, but red blood cell markers were greater in temperamental cattle.
Accomplishments
1. Liver abscesses develop without dietary changes. Various complex factors affect the development of liver abscesses, a disease that costs the U.S. beef industry almost $1 billion each year. These include diet and management, as well as the presence of the bacteria commonly found in liver abscesses. ARS scientists in Lubbock, Texas conducted studies to assess the importance of diet in liver abscess formation using beef-dairy cross steers and an in-house developed liver abscess model. Results indicate that changes in diet are not necessary for liver abscess formation, challenging the long-held dogma that high-starch diets were required for disease development. In fact, bacteria presence may play a more prominent role in liver abscess development. This represents a key advancement in understanding the etiology of liver abscess disease and provides crucial insights into pathways that can be targeted to alleviate this costly disease in cattle.
2. Where is the liver abscess. Liver abscesses cost the cattle industry over $1 billion each year. However, limited diagnostic tools hinder our ability to not only detect but prevent or treat this costly disease. Aside from identification at harvest, ultrasound offers the best avenue to see liver abscesses in the live animal. However, not all of the liver can be seen on ultrasound, potentially limiting the usability of this technique. ARS scientists in Lubbock, Texas, along with university collaborators, utilized newer ultrasound technology in finished beef steers and weaned beef-dairy cross steers to evaluate its use in identifying liver abscesses. Results found greater sensitivity in lighter weight cattle, but sensitivity across all cattle was low, suggesting a limited ability to detect liver abscesses in live cattle. Liver abscesses continue to remain difficult to identify by ultrasound in live cattle.
3. Ghrelin in pigs: increases weight, decreases inflammation. Inflammation from disease or injury reduces growth performance. Ghrelin is a hormone commonly associated with increasing appetite. Yet, recent studies suggest that ghrelin may play a role in reducing inflammation. However, much of the research has been conducted in humans and rodents, and not in livestock species. ARS scientists in Lubbock, Texas and university collaborators assessed whether infusing pigs with ghrelin before and after inducing inflammation would alter the immune response. Results found that ghrelin increased pig weight gain, altered the innate immune response, and provided protection against inflammation within the small intestine.
Review Publications
Barker, S.N., Jackson, T.C., Sanchez, N.C., Carroll, J.A., Broadway, P.R., Hales, K.E., Ducharme, G., Sloan, B., Legako, J.F., Richeson, J.T. 2024. The effect of methionine1 supplementation on receiving beef steers following a lipopolysaccharide challenge. Translational Animal Science. 8. https://doi.org/10.1093/tas/txae147.
Mitchell, T.M., Sanchez, N.C., Carroll, J.A., Broadway, P.R., Legako, J.F., Bowen, B.M., Petry, A.L. 2025. Assessing the ability to immunomodulate the gastrointestinal immune system and oxidative status of weaned pigs through prenatal lipopolysaccharide stimulation. American Journal of Physiology - Gastrointestinal and Liver Physiology. 101(2). https://doi.org/10.1093/jas/skad341.293.
Childress, K.D., Hales, K.E., Nagaraja, T.G., Lawrence, T.E., Amachawaadi, R.G., Sanchez, N.C., Thompson, A.C., Hanratty, A.N., Dornbach, C.W., Abbasi, M., Shi, X., Galyean, M.N., Broadway, P.R. 2025. Evaluating the effects of acidosis and bacterial inoculum concentrations on the development of liver abscess in beef x dairy steers. Applied Animal Science. 41(2):93-103. https://doi.org/10.15232/aas.2024-02641.
Thompson, A.B., Perkin, T.L., Lawrence, T.E., Amachawadi, R.G., Nagaraja, T.G., Broadway, P.R., Sanchez, N.C., Machado, V., Galyean, M.L., Hales, K.E. 2025. Efficacy of ultrasonography to detect liver abscesses in cattle. Applied Animal Science. 41:21-27. https://doi.org/10.15232/aas.2024-02639.
Hoffman, A.A., Dornbach, C.W., Fernando, S.C., Broadway, P.R., Sanchez, N.C., Long, N.S., McDaniel, Z.S., Smock, T.M., Wells, J., Hales, K.E. 2025. Effects of a novel direct-fed microbial on occurrences of antimicrobial resistance in Salmonella enterica, Escherichia coli, and Enterococcus spp. measured longitudinally from feedlot arrival to harvest in finishing beef steers. Journal of Food Protection. 88(5). Article 100484. https://doi.org/10.1016/j.jfp.2025.100484.
McDaniel, Z.S., Hales, K.E., Nagaraja, T.G., Lawrence, T.E., Tennant, T.C., Amachawadi, R.G., Carroll, J.A., Sanchez, N.C., Galyean, M.L., Davis, E., Kohl, K.B., Line, D.J., Dornbach, C.W., Salih, H., Deters, A., Shi, X., Ballou, M.A., Machado, V.S., Smock, T.M., Broadway, P.R. 2024. Validation of an experimental model to induce liver abscesses in steers using an acidotic diet challenge and intraruminal bacterial inoculation. Applied Animal Science. 40(3):398-413. https://doi.org/10.15232/aas.2023-02485.
McDaniel, Z.S., Galyean, M.L., Broadway, P.R., Carroll, J.A., Sanchez, N.C., Hanratty, A.N., Dornbach, C.W., Line, D.J., Smock, T.M., Hoffman, A.A., Manahan, J.L., Hales, K.E. 2024. The effects of increasing roughage neutral detergent fiber concentration and bulk density of steam-flaked corn on performance, carcass characteristics, and liver abscesses in finishing beef steers fed diets without tylosin phosphate. Applied Animal Science. 40(3):269-278. https://doi.org/10.15232/aas.2023-02484.
Dobbins, T.W., Fuerniss, L.K., Hernandez, M.S., Johnson, B.J., Petry, A.L., Broadway, P.R., Sanchez, N.C., Legako, J.F. 2025. A pre- and postnatal immune challenge influences muscle growth and metabolism in weaned pigs. Journal of Animal Science. 102. https://doi.org/10.1093/jas/skae350.
Hoffman, A.A., Fernando, S.C., Wells, J., Woerner, D.R., Manahan, J.L., Long, N.S., McDaniel, Z.S., Smock, T.M., Line, D.J., Broadway, P.R., Carroll, J.A., Sanchez, N.C., Hales, K.E. 2024. Use of a novel direct-fed microbial as an alternative for tylosin phosphate to control liver abscesses and decrease antimicrobial use in finishing beef steers. Applied Animal Science. 40(3):307-316. https://doi.org/10.15232/aas.2023-02483.
Briggs, R.K., Legako, J.F., Broadway, P.R., Carroll, J.A., Sanchez, N.C., Ineck, N.E., Smith, Z.K., Ramanathan, R., Thornton, K.J. 2024. Effects of pre-mortem stress on protein expression, steak color, oxidation, and myofibrillar fragmentation index in the longissimus lumborum. Animals. 14(15). https://doi.org/10.3390/ani14152170.
Sanchez, N.C., Mitchell, T.M., Broadway, P.R., Boween, B.M., Davis, E.M., Dobbins, T.W., Barker, S.N., Legako, J.F., Petry, A.L., Carroll, J.A. 2025. Evaluation of the use of prenatal immune stimulation to alter postnatal immune function in weaned pigs. Frontiers in Animal Science. 101(3). https://doi.org/10.1093/jas/skad281.078.
Geeslin, M.D., Richeson, J.T., Hernandez-Gifford, J.A., Soto-Navarro, S.A., Sanchez, N.C., Samuelson, K.L. 2025. Corticotropin releasing hormone and vasopressin challenge affects metabolic, hematologic, and rumen fermentation parameters of growing beef steers. Journal of Animal Science. 8. https://doi.org/10.1093/tas/txae141.
DeHaan, E.R., Dornbach, C.W., Blair, A.D., Sanchez, N.C., Carroll, J.A., Broadway, P.R., Rusche, W.C., Hales, K.E., Smith, Z.K. 2025. Influence of source of origin and region of finishing on growth performance and carcass characteristics of finishing heifers fed in the United States. Journal of Animal Science. 103. https://doi.org/10.1093/jas/skaf013.
Dornbach, C.W., Broadway, P.R., Wells, J., Childress, K.D., Thompson-Smith, A.C., Sanchez, N.C., Mathieu, J., Schwarz, C., Laverde-Gomez, J., Tikhonova, M., Nagaraja, T.G., Galyean, M.L., Hales, K.E. 2025. Longitudinal assessment of the prevalence of Fusobacterium necrophorum, Fusobacterium varium, and Salmonella enterica throughout the gastrointestinal tract in finishing beef steers with and without liver abscesses. Frontiers in Microbiology. 16. https://doi.org/10.3389/fmicb.2025.1565303.
Sanchez, N.C., Dailey, J.W., Broadway, P.R., Davis, E.M., Bowen, B.M., Petry, A.L., Ballou, M.A., Hales, K.E., Carroll, J.R. 2025. Ghrelin modulates innate immune and ileal responses to lipopolysaccharide administration in weaned pigs. Frontiers in Animal Science. 6. https://doi.org/10.3389/fanim.2025.1572264.
Dornbach, C.W., Broadway, P.R., Sanchez, N.C., Grant, M.S., Canterbury, L.G., Childress, K.D., Sitka, B.J., Loeffler, T.A., Galyean, M.L., Hales, K.E. 2025. Random metaphylactic effects of tulathromycin on health outcomes, complete blood count, antimicrobial use, growth performance, and Salmonella enterica prevalence in high-risk beef steers. Applied Animal Science. 41(3):176-189. https://doi.org/10.15232/aas.2025-02679.
Dornbach, C.W., Sanchez, N.C., Hagenmaier, J., Brown, M.S., Carroll, J.A., Hales, K.E., Broadway, P.R. 2025. Characterization of metabolic and inflammatory responses following administration of three commercially available Mannheimia haemolytica vaccines to beef heifers. Frontiers in Animal Science. 6. https://doi.org/10.3389/fanim.2025.1560110.