Influence of Metabolic Hormones and Nutrition on Follicular Development in Cattle: Practical Implications

Abstract

Nutrition has a strong influence on the reproductive performance of female cattle, but not much is known about the mechanism through which such performance is affected. Moreover, recent studies have proved that, as a nutritional signal, metabolic hormones exert a direct effect on the ovary. Treatment with recombinant bovine somatotropin (rGH) in cattle significantly increases the colony of small ovarian follicles. Subsequent studies, both in vitro and in vivo, have demonstrated the importance of the joint action of IGF-I or insulin with FSH and LH. Recent work has aimed to solve some practical problems in dairy cattle reproduction. First of all, it was found that both the pretreatment with rGH and the increased food intake significantly improve embryo viability. Second of all, a slight increase in voluntary consumption during the formulation of diets to increase insulin concentration during early lactation shows that these animals reach the first postpartum ovulation more quickly, and it also shows an increased conception rate to first service. In short, nutrition influences ovarian ac-tivity, allowing follicle development in female bovines, possibly through changes in metabolic hormones. These interactions can be manipulated to improve reproductive performance in these animals.