The effect of vaccination with a Mannheimia haemolytica subunit vaccine on milk yield in lactating dairy cows
Many herds in the US use a mannheimia vaccine in lactating dairy cows as an aid in reducing the impact of bovine respiratory disease (BRD). Producers often report significant post-vaccination milk drop following the use of some mannheimia vaccines. A review of the literature found no reports documenting milk loss following administration of mannheimia vaccines, but there were reports documenting milk loss from other vaccines of up to 4 lb (1.8 kg)/d for 3 d. This adds to the cost of vaccinating the lactating herd and should be considered when developing vaccination programs. If milk income over feed cost is $0.13/lb ($0.28/kg) then the 3-d milk loss can add up to decreased revenue from milk sales of $1.56 per cow. The objective of this study was to quantify the milk loss associated with the use of Mannheimia haemolytica subunit vaccine* (MHSV) in lactating dairy cows.