Nutrition, Metabolic Status and Reproductive Efficiency in Dairy Herds

Nutrition of transition period in dairy cows dramatically increases requirements for energy, glucose, amino acids and other nutrients in dairy cows and, parallel to that, feed intake is depressed. An insufficient or imbalanced nutrient intake might lead to the malfunction of organs, causing reproductive failure. To minimize the metabolic/reproductive damage caused by negative energy balance (NEBAL), feeding of a glucogenic and lipogenic diet containing fat-enriched supplements is recommended. In heat-stressed dairy cows, the reduction of dry matter intake causes an energy deficit, thereby accentuating NEBAL. Heat stress may also have a direct impact on oocyte quality due to the high ovarian temperatures. The intrauterine environment is also compromised in heatstressed cows, with reduced blood flow to the uterus and increased uterine temperature; this may impair embryonic development, increase early embryonic loss and reduce the proportion of successful inseminations. Postpartum NEBAL suppresses immune function and promotes metabolic disorders, potentially explaining relationships between infectious and noninfectious transition disorders. In postpartum dairy cows, pathologic ovarian phenomena including ovulatory (cystic corpora lutea) and non-ovulatory (follicular and luteal cysts) forms frequently occur causing decreased fertility. The main objective of this review was summarizing the most relevant information regarding nutrition and reproduction in dairy cows.