Location: Livestock Issues ResearchTitle: Adding complexity and confusion to understanding bovine respiratory disease Author
Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 5/21/2018
Publication Date: 6/19/2018
Citation: Carroll, J.A., Broadway, P.R., Sanchez, N.C. 2018. Adding complexity and confusion to understanding bovine respiratory disease. Meeting Abstract. Summit Conference Booklet/Page 10.
Technical Abstract: Bovine Respiratory Disease (BRD) continues to be the most common cause of mortality and morbidity in U.S. cattle feedlots, accounting for 70-80% of all illness and 40-50% of all cattle deaths. Annual cost associated with BRD is estimated to be $800-900 million, and individual animal treatment cost is estimated at $30 per head. The challenge associated with preventing and treating BRD is exacerbated by inherent variations in immune function that exist within the beef cattle population, as well as the lack of accurate biomarkers that are predictive of BRD incidence and severity. Our group has been investigating these inherent variations to a viral-bacterial BRD challenge, as well as the use of nutritional supplementation, in an effort to gain more insight into potential strategies to reduce the incidence and/or severity of BRD in feedlot cattle. To date, our research has revealed several relevant factors such as discrepancies between pre-challenge BHV-1 titers and subsequent severity of BRD symptoms, modulation of the immunological responses via supplementation with immunomodulators, and evaluation of predictive biomarkers for BRD severity. In a recent study, of the 17 variables measured, only IL-4 concentrations prior to BRD challenge was considered predictive (P = 0.08) of subsequent calf mortality. Additionally, IL-6 concentration (P = 0.08) at the time of peak febrile response was the only biomarker predictive of subsequent calf mortality. Our data from several studies indicate that there is no single predictive biomarker of the incidence/severity of BRD in feedlot cattle; however, supplementation with various immunomodulators may be beneficial.