Effect of initial respiratory viral-bacterial combination vaccine on performance, health, and carcass traits of auction-market derived feedlot heifers

Abstract

A total of 2,528 lightweight heifers were used to compare 2 viral-bacterial respiratory vaccine products containing modified-live infectious bovine rhinotracheitis virus, parainfluenza-3 virus, bovine respiratory syncytial virus, bovine viral diarrhea virus types 1 and 2, and a Mannheimia haemolytica bacterial component, on performance, health, and carcass characteristics of cattle in a commercial feedlot setting. The vaccine products compared were Pyramid? 5+Presponse? SQ (PYR PSQ) and Bovi-Shield GOLD? One Shot (BOV ONE). No differences (P?0.68) in gain performance or feed conversion were observed between treatments. Hot-carcass weight tended to be less (P=0.06) in cattle administered PYR PSQ compared to cattle in the BOV ONE treatment group. Percentages of "no roll" and Yield Grade 4 carcasses were higher (P?0.04) for BOV ONE cattle, while the percentage of Yield Grade 1 carcasses was higher (P=0.05) in the PYR PSQ treatment. Neither BRD first treatment morbidity nor retreatment risks were significantly different among treatments (P?0.33), with 13.25% of all cattle receiving treatment for BRD. The incidence of chronics, case fatalities, and mortalities associated with BRD also did not differ (P?0.46) between treatments. Furthermore, the incidence of chronics and mortalities due to all causes did not differ (P?0.62) between treatments. There was little evidence to suggest that administration of these different combination vaccines to lightweight auction-market heifers upon arrival at the feedlot results in important health differences.