Role of metabolic hormones in the regulation of ovarian function in cattle (review)

The role of metabolic hormones in the mediation of the regulatory influence of nutrition on the ovarian function in cows is considered in the present review. The characterization of the hormone effects on the follicle maturation in vivo and functional activity of ovarian cells in vitro is given. The separate attention is devoted to the data suggesting a participation of endogenous somatotropin, insulin-like growth factor I, insulin and leptin in the regulation of ovarian activity in cattle. The influence of the metabolic state of high yielding dairy cows on reproductive parameters and the association of these latter with the level of metabolic hormones in the blood are discussed. It was shown, that metabolic hormones can act directly on ovarian level resulting in the modulation of proliferous activity, steroidogenesis and viability of ovarian cells and also on hypothalamo-hypophysis axis with regulation of gonadotropic hormones secretion. It was proposed, that these effects are the part of complex mechanism by means of which the nutrition influences on reproductive function of animals. The authors made the conclusion about a necessity of widening of investigation aimed at revelation of complicated interrelation between the nutrition, metabolic hormones and reproductive function for optimization of control and regulation of reproductive potential in cattle.