Inter-relationships of periparturient diseases in dairy cows.

The associations between periparturient diseases in 3603 lactations over three calving seasons were assessed on 10 dairy farms in the south west of England by using logistic regression. Calf mortality and dystocia were strongly associated. Twinning and dystocia were important predictors of calf mortality. Twinning was also a significant predictor for retained fetal membranes. Retained fetal membranes, twins, calf mortality and dystocia, in that order of importance, were risk factors for vulval discharge. Twinning, dystocia, retained fetal membranes and lameness before service increased the risk of mastitis before service. Similarly, mastitis and dystocia before service increased the risk of lameness before service. Oestrus was less likely to be observed in cows that had twinned or suffered lameness before service, the latter having a significantly greater influence in first calvers than older cows.