Bovine respiratory disease during the mid-portion of the feeding period: Observations of frequency, timing, and population from the field
Miles E. Theurer, Myriah D. Johnson, Trent Fox, Travis M. McCarty, Ryan M. McCollum, Tom M. Jones, Deke O. Alkire
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.