Bovine respiratory disease (BRD) is one of the primary causes of death in young calves. Vaccination against infection by the common bacteria causing BRD is possible; however, the physical condition of the young calves that enables antibody production when stimulated by early immunisation remains to be elucidated.
Healthy young female Holstein calves on a commercial dairy farm were fed a colostrum replacer and administered primary and booster immunisations with an inactivated vaccine against the bacterial pneumonia agents
Antibody titre at the primary and BMI at both immunisations were significantly higher in the positive than in the negative group (P < 0.05). Additionally, serum gamma globulin was significantly higher in the positive group (P < 0.05), indicating a strong correlation between maternal antibody and serum gamma globulin levels.
Elevated maternal antibody titre and higher BMI are positive factors for successful early immunisation, for which suitable colostrum may also be fundamental in young calves administered inactivated vaccines.