Hormonal and Metabolic Interactions on Reproductive Activity of Goats

Economical productivity is connected closely with increasing or controlling reproduction. In the recent studies, the relationships among reproductivity and live weight changes, some blood metabolites, blood hormone concentrations in fasted or marginally fed goats are being discussed. It has been emphasized in the investigations on ruminants that Insulin Growth Factor (IGF) I and II and their binding proteins affect quality of oocyte and embriyo growth. It has also been emphasized that energy substrats transported via blood may play metabolic signalling role that carries information on nutrition for GnRH secretion. It has been signified that in goats subjected to fasting or restricted feeding, catabolic substrate levels in the blood increased in parallel with body weight losses and GnRH activity is suppressed. Conflicting results regarding to changes in hormonal concentrations and ovarian activity in studies applying shock feeding with high level nutritions in the short-time have been reported. In this article, current some researches related to hormonal and metabolic control of reproduction in goats are summarized.