Although high reproductive efficiency is critical to sustainable dairy farming, reproductive failure is the primary reason for culling dairy cows in many countries. Yet, high milk production and high first-service conception rates often co-exist in well-managed dairy herds. The use of artificial insemination (AI) to improve the genetic merit of dairy cows started as early as the 1930s, and because of the widespread use of AI in the dairy industry, accurate oestrus detection and timely and skilful performance of AI are of paramount importance to optimize reproductive efficiency if cattle are bred following detection of oestrus. This chapter presents various strategies to improve fertility in cows from simple methods of increasing oestrus detection efficiency to cross-breeding. It suggests ways to improve reproductive efficiency and manage both cow nutrition and the production environment to ensure the best reproductive results.