Influence of Nutrition and Weight Loss on Reproduction and Early Embryonic Death in Cattle

Abstract

Maintaining acceptable levels of reproductive performance in cattle is a challenging problem, particularly when cows are producing high yields of milk or when nutrient intake is below the demand for extended periods of time. In such situations, the associated negative energy balance may result in prolonged postpartum anestrus, lower levels of progesterone secretion by corpora lutea (CL) and lower rates of conception. Fertility in high-producing cattle also may be affected by excessive intake of protein, inadequate intake of fibrous feeds or other nutritional imbalances. There is some evidence that such factors affect embryonic survival. This paper will review some of the current thinking in these areas and provide insights into potential biological mechanisms through which fertility is influenced by these factors. The paper will focus primarily on the postpartum dairy cow.