Leptin and ghrelin in ruminant production

Abstract

These hormones are present in various mammals, including domestic animals. The known functions of leptin in the ruminant production are related to feed intake regulation, body status indication to the reproductive function and immune response stimulus. The polymorphisms of leptin gene can be used in the selection of animals with better productive traits, because they are associated to milk qualitative traits (fat and protein content) and carcass (backfat thickness and marble score). Ghrelin was widely studied in humans, and few functions of this hormone were reported for domestic animals. However, ghrelin is associated to leptin and both hormones have important function on feed intake regulation, and some evidences indicate that also affect reproduction. In this context, the objective of this review was to report leptin and ghrelin functions in ruminants and the influence of these hormones on productive traits of these animals.