Polymorphism of exon 20 of the leptin receptor gene and serum leptin concentrations of Nellore heifers raised on pasture

Abstract

The physiological changes that occur at puberty in heifers are objectives of study in order to better understand this phenomenon and to identify alternatives to achieve greater sexual precocity. Among the most important factors that influence puberty the leptin hormone and its receptor can be highlighted, as they are factors that perform communication between the nutritional status and the reproductive axis, and its participation in reproductive physiology is not fully understood. Therefore, the aim of this study was to determine the serum profile of the leptin hormone, to identify polymorphisms at exon 20 of the leptin receptor and associate them with the occurrence of puberty in heifers raised on pasture. We followed 56 heifers for 17 months and carried out the progesterone assay for determining the puberty occurrence, leptin dosage and sequencing of the leptin receptor gene for identifying the occurrence of SNP polymorphisms. After identifying the manifestation of puberty in 37 heifers and the association of serum leptin and the occurrence of SNPs with the occurrence of this physiological phenomenon, no correlation was found between variables with the onset of puberty.