Effect of Two Commercially Available Multivalent Modified-Live Viral Vaccines on Milk Production of Holstein Dairy Cows

Abstract

Vaccination of lactating dairy cows is a common practice among US dairy herds. The objective of vaccination during lactation is to bolster immunity against common agents that may cause failure to conceive, fetal loss, or respiratory disease. The viruses commonly included in these vaccines are bovine viral diarrhea virus (BVDV), bovine herpes virus 1 (BHV-1), bovine respiratory syncytial virus (BRSV) and parainfluenza-3 virus (PI-3). The vaccines may contain inactivated virus or modified-live virus (Compendium of Veterinary Products 2004). In addition to the cost of vaccine and labor to administer the vaccine, producers should consider the cost of lost production when evaluating the economic benefits of vaccinating a lactating cow. Vaccination with an inactivated viral vaccine in combination with leptospiral bacterin produced a significant decrease in production compared to controls (Scott 2001). The effect of modified-live viral vaccines on milk production has not been reported. The objective of this study was to determine the effect of two commercially available multivalent modified-live viral vaccines on milk productionof Holstein dairy cows.