Comparison of pre-weaning bovine respiratory disease treatment rates between non-vaccinated control and variably primed and boosted beef calves receiving commercially available bovine coronavirus vaccines.

Abstract

OBJECTIVE: The primary objective was to determine effectiveness of bovine coronavirus (BCoV) vaccination of neonatal calves in the face of natural respiratory infection in a commercial herd. ANIMALS: At a privately owned ranch in north-central Alberta with a history of bovine respiratory disease (BRD), beef calves of mixed sex and breed were randomized into a clinical vaccine trial. PROCEDURE: At birth, 447 calves were enrolled into the vaccine (VAC) group and administered an intranasal dose of BCoV vaccine, and 439 calves were enrolled as controls (CON). Most VAC calves (= 389) also received an intramuscular dose of BCoV vaccine at an average of 49 d (SD: 7 d). Treatment for BRD and total mortality were recorded until pasture turnout. Weaning weights were collected at the end of the grazing season. A partial budget comparison included costs of vaccination and treatment, as well as potential revenues using weaning weights and regional sale summaries. RESULTS: Calves in the CON group were more likely than VAC calves to be treated before turnout vaccination (OR: 1.50;= 0.048) and calves born in the 2nd cycle were more likely than 3rd-cycle calves to be treated for BRD (OR: 2.90;= 0.01). The odds of mortality for CON calves born in the 2nd cycle were higher (OR: 4.8;= 0.001) than for VAC calves. Weaning weights were higher for VAC calves (= 0.04) and, despite increased costs due to vaccination, revenue for VAC calves was an average of $10.50/head higher. CONCLUSION: Vaccination of neonatal calves with BCoV vaccine reduced the frequency of BRD treatment and total mortality and improved weaning weights and revenue potential in this herd. CLINICAL RELEVANCE: Vaccination with commercial BCoV vaccines could be an important tool to control neonatal BRD, particularly in herds with a history of disease not responsive to other BRD vaccines.