Bovine respiratory disease during the mid-portion of the feeding period: Observations of frequency, timing, and population from the field

Abstract

The objective of this study is to provide observations related to bovine respiratory disease (BRD) in high-performing cattle during the mid-portion of the feeding period describing the occurrence, timing, and population. Data from a feedlot in Kansas were evaluated for temporal occurrence of BRD in high-performing and high-risk calves on a lot level. High-performing calves were categorized based on performance potential and carcass characteristics. High-risk calves were categorized based on administration of a macrolide at arrival processing. Cumulative incidence of BRD was evaluated within high-performing and high-risk categories. Models included the fixed effects of categorization (high performing and high risk), days on feed (DOF), and 2-way interaction between categorization and DOF and the random effect for repeated measures on individual lot. Additional data came from high-performing calves from Noble Research Institute cooperators’ cattle from 2 separate feedlots. The cumulative percentages of BRD for the high-performing and high-risk categories at 45 DOF were 33.7 and 67.2%, respectively. High-performing calves had BRD occurring later in the feeding period compared with high-risk calves. Cumulative BRD from the Noble Research Institute cooperators’ calves had an earlier onset of BRD morbidity compared with other high-performing cattle. Morbidity caused by BRD in high-performing cattle is greater than expected. Timing of BRD morbidity occurs at later DOF in high-performing calves compared with high-risk calves. Incidence for BRD occurred at ≥45 DOF in all 3 feedlots evaluated. Additional research is needed to identify potential causes for BRD morbidity during the mid-portion of the feeding period.