Adipokines and Reproduction in Ruminant Livestock

Abstract

An adipose tissue is the principal storage site for fat and secretes adipokines, including leptin, adiponectin, resistin, chemerin, visfatin, and apelin. Adipokines and their receptors have been demonstrated to be present and to play a role in the reproductive systems of various livestock species. Livestock reproductive function is thought to be influenced by adipokines, or hormones derived from adipokines. These adipokines have been implicated at all levels of the reproductive axis, including the hypothalamic-pituitary axis and gonads. Adipokines can amplify reproductive activity by increasing energy levels and triggering the production of essential reproductive hormones. The development of reproductive hormones, semen, estrus behavior, ovulation, and subsequent development of the corpus luteum and seminal concentrations are all regulated by adipokines. In this way, adipokines could impact key elements like ovarian follicles, corpus luteum, Leydig cells, and spermatogenesis. Moreover, polymorphisms of adipokines genes have been identified in domestic animals with economic traits. Domestic animal production and reproduction traits are also affected by genetic variability in the adipokine genes. Therefore, this review aims to summarize adipokines and how they are known to regulate reproductive physiology, such as the production of steroid hormones, cell proliferation, oocyte maturation, and sperm development in domestic animals.