Comparison of milk production changes in adult Holstein cows vaccinated with a 5-way modified-live virus vaccine containing a Mannheimia haemolytica toxoid versus a 5-way modified-live virus vaccine containing a 5-way Leptospira bacterin

Abstract

A total of 105 Holstein cows 21 to 31 days-in-milk were vaccinated with a 5-way modified-live virus (MLV) vaccine containing bovine herpesvirus-1, bovine viral diarrhea virus (types 1 and 2), parainfluenza-3 virus, and bovine respiratory syncytial virus combined with either a Mannheimia haemolytica toxoid or a 5-way Leptospira bacterin. Milk production was monitored for 3 days pre- and 3 days post-vaccination. There was a 0.52 lb (0.24 kg) increase in mean milk production for the group vaccinated with the 5-way MLV vaccine plus 5-way Leptospira bacterin. There was a 0.32 lb (0.15 kg) decrease in mean milk production in the group vaccinated with the 5-way MLV vaccine plus M. haemolytica toxoid. The difference in mean milk production between the 2 groups was 0.85 lb (0.38 kg) (P=0.4076). There was no statistical difference in mean daily milk production changes between treatment groups when parity was taken into account. Vaccination during lactation using a M. haemolytica toxoid in combination with a 5-way MLV vaccine resulted in a small, but insignificant, decrease in milk production.