Interpretive Summary: Factors associated with bovine respiratory disease case fatality in feedlot cattle

By: Dr. Emily Taylor

Bovine respiratory disease (BRD) is the cause of 60- to 90% of morbidity and mortality cases in feedlot cattle. Suppose factors associated with an animal first identified with BRD that is also associated with increased mortality risk could be identified. In that case, this may allow for improved management and more targeted treatment programs for these higher-risk animals. Therefore, the objective of the current study was to identify factors associated with BRD case fatality risk that could be used to make more timely decisions regarding at-risk animals and develop more informed disease management strategies that may help reduce the number of BRD mortalities in feedlots. 

Feedlot steers were monitored daily for visual signs of BRD and were removed from the herd once identified. Average daily gain (ADG) and weight were reduced for animals that died due to BRD. These animals received higher visual BRD scores and more BRD treatments than animals that survived. They were also 5.66 times more likely to be seronegative for bovine viral diarrhea virus 1 (BVDV-1) and 13.73 times more likely to have a positive bovine coronavirus nasal swab. Blood concentrations of a glucose chain, b-hydroxybutyrate, leucine, phenylalanine, and pyruvate com were higher, while lower concentrations of acetate, citrate, and glycine were seen. 

Researchers of the current study identified that there were significant differences in animal health and production measures for animals that died compared to those that survived BRD. While these measures could be used as indicators to predict mortality risk after the first BRD diagnosis, more research is needed.

This article is now available in the Journal of Animal Science.