BRD Viruses

BEEF CATTLE RESEARCH UPDATE Britt Hicks, Ph.D., PASArea Extension Livestock SpecialistOklahoma Panhandle Research & Extension CenterMarch 2019 Effects of Vaccination Timing on Performance, Antibody Response, and Health in Feedlot Cattle The bovine respiratory disease (BRD) complex is the most is the most devastating health problem of the beef industry. 1, 2 It is the primary cause of morbidity (70%–80%) and mortality (40%–50%) in feedlots in the United States and continues to contribute to substantial losses in feedlot performance, health, and carcass quality. 3 A 2011 USDA survey of U.S. feedlots with a capacity of 1,000 or more head indicated that most feedlots vaccinated cattle and that the most common vaccinations administered were for the prevention of BRD.4 As a percentage of all feedlots, 96.6% vaccinated for bovine viral diarrhea and 93.7% vaccinated for infectious bovine rhino-tracheitis (IBR), while 89.1% vaccinated for bovine respiratory syncytial virus and 85.1% vaccinated for parainfluenza-3 virus. It is widely accepted that vaccination of healthy calves for respiratory pathogens is important for preventing BRD and maintaining optimal calf health. Hence, most feedlot receiving protocols include vaccination against BRD viruses for high-risk cattle within 48 hours of arrival. However, research suggest that vaccine efficacy is reduced when administered to highly stressed animals since immune function can temporarily be compromised. Weaning, marketing, and shipment of feeder cattle to feedlots are major stressors to cattle.5 For these reasons, altering the time of vaccination against BRD has been investigated as an approach to enhance vaccine efficacy, immunity to BRD, and […]