Effect of Nutrition on Reproductive Performance of Postparturient Dairy Cows in the Tropics: A Review

In tropical countries such as Thailand, dairy cows particularly raised in small-holder farms are confronted by a problem of improper nutritional management and its consequences, which may lead to impair their production, health and fertility. This review attempted to summarize some nutritional factors influencing reproductive performance especially during postparturient period. The small-scale farmers have a limited skill on feed and feeding management for their cows during periparturient period or more specifically transition period. Negative energy balance during the transition period is more evident; in addition, fatty liver, as a consequence of negative energy balance, is also frequently observed in Thai dairy cows kept by small-holder farms. Cows with severe negative energy balance accumulate greater amount of triacylglycerol in the liver and have poor postpartum reproductive performance. Dairy cows fed with a high rumen degradable protein have an increase in blood urea nitrogen, which has been proven to reduce fertility. Hypocalcemia also impairs postpartum reproductive performance. Selenium and vitamin E also play important roles in maintaining reproductive efficiency in dairy cows. In order to optimize productivity of dairy cows, farmers should pay attention to optimize body condition score at calving, to properly prepare the rumen function and to offer a good quality and balanced diet to the cows. However, preventive measures to prevent adverse effects of nutritional mismanagement on reproduction in periparturient dairy cows should be concerned.