Effect of Heat Stress on Different Reproductive Process in Animals and its Ameliorative Measures through Nutritional Management

In most mammalian species including cattle and buffalo heat stress has deleterious effects on nutritional, physiological and reproductive functions. Exposure of animals to a hot environment causes an increase in body temperature in mammals, including domestic animals. High ambient temperature also causes a decrease in the length and intensity of estrus by disturbing ovarian function as well as decreasing pregnancy rate after artificial insemination. Therefore, it is important to understand the effects of heat stress on reproductive function in order to improve the production of domestic animals. Heat stress decreases appetite, weight gain, and milk yield in dairy cattle. It also adversely affects the reproductive performance of both sexes. In female animas it adversely impacts oogenesis, oocyte maturation, fertilization development and implantation rate. There are several nutritional strategies to consider during heat stress. A common strategy is to increase the energy and nutrient densities (reduced fiber, increased concentrates, and supplemental fat) of the diet, as feed intake is markedly decreased during heat stress. The concentration of all nutrients will need to be increased in diets as dry matter intake decreases during heat stress.