Effects of main reproductive and health problems on the performance of dairy cows: a review

This review focuses on the potential effects of twinning, dystocia, stillbirth, abortion, retained placenta and metritis on the productive and reproductive performances in dairy cattle. These are diverse disorders that are similar in that they all can result in impaired performance of dairy cows. Reproductive problems occur frequently in lactating dairy cows and can dramatically affect reproductive efficiency in a dairy herd. Poor reproductive performance is a major cause of involuntary culling and therefore reduces the opportunity for voluntary culling and has a negative influence on the subsequent productivity of a dairy herd. Reproductive performance is influenced by the interactive effect of environment, management, health, and genetic factors. In addition, diseases mainly affect dairy cow productivity by decreasing reproductive efficiency, shortening the expected length of productive life and by lowering milk production. Deciding whether to breed, treat, or cull dairy cows showing one or more of these problems is a challenge for both veterinarians and dairy producers. In addition, there is considerable debate among dairy scientists and bovine practitioners regarding the economic impact of these problems in a dairy operation and the most effective management or therapeutic intervention for treating them. Because of this controversy, dairy managers should focus on prevention and control of risk factors associated with each problem rather than on prescriptive therapeutic interventions.