Effects of Multivalent BRD Vaccine Treatment and Temperament on Performance and Feeding Behavior Responses to a BVDV1b Challenge in Beef Steers

Abstract

Simple Summary Bovine respiratory disease (BRD) threatens cattle production and welfare globally. We sought to quantify the effects of vaccine treatments and animal temperament classification on feed intake, feeding behavior and weight responses following challenge with bovine viral diarrhea virus, one of the pathogens associated with bovine respiratory disease. Commercially available respiratory vaccines were utilized, and temperament classification was based on exit velocity. Although overt clinical signs of respiratory disease were not observed following challenge, feed intake, weight gain, feed efficiency, and feed bunk frequency and duration were negatively affected. Animals administered a modified-live vaccine had more desirable feed intake, feed bunk duration, longer meal events and slower eating rates compared with those administered a killed or no vaccine. Temperament affected feeding behavior patterns, where calm steers had a greater duration of feed bunk visits and meal events, and slower eating rates compared with excitable steers. There were greater differences due to vaccine treatments in most feeding behavior traits within calm vs. excitable steers. The modified live vaccine mitigated the negative effects of the viral challenge to a greater extent than the killed vaccine for feed intake and feeding behavior patterns, and corresponded with previously reported findings regarding the effects of these vaccine types on immune responses. Abstract This study examined the effects of multivalent respiratory vaccine treatment (VT) and animal temperament classification on feeding behavior traits, feed intake and animal performance in response to a bovine viral diarrhea virus (BVDV) challenge. Nellore–Angus crossbred steers (n = 360; initial body weight (BW) 330 ± 48 kg) were assigned to one of three vaccine treatments: non-vaccinated (NON), modified live (MLV) and killed (KV) regarding respiratory viral pathogens, and inoculated intranasally with the same BVDV1b strain. Cattle temperament categories were based on exit velocity. Overt clinical signs of respiratory disease were not observed, yet the frequency and duration of bunk visit events as well as traditional performance traits decreased (p < 0.01) following BVDV challenge and then rebounded in compensatory fashion. The reduction in dry matter intake (DMI) was less (p < 0.05) for MLV-vaccinated steers, and MLV-vaccinated steers had longer (p < 0.01) durations of bunk visit and meal events and slower (p < 0.01) eating rates compared with KV- and non-vaccinated steers following BVDV challenge. Greater differences in most feeding behavior traits due to VT existed within calm vs. excitable steers. Respiratory vaccination can reduce the sub-clinical feeding behavior and performance effects of BVDV in cattle, and the same impacts may not occur across all temperament categories.