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.

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 (n = 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; P = 0.048) and calves born in the 2nd cycle were more likely than 3rd-cycle calves to be treated for BRD (OR: 2.90; P = 0.01). The odds of mortality for CON calves born in the 2nd cycle were higher (OR: 4.8; P = 0.001) than for VAC calves. Weaning weights were higher for VAC calves (P = 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.