2014-10-312013-07-12ABUD, Lucas Jacomini. Peso, idade e perfil bioquímico, hematológico e hormonal de novilhas Nelore à puberdade. 2013. 81 f. Tese (Doutorado em Ciência Animal) - Universidade Federal de Goiás, Goiânia, 2013.http://repositorio.bc.ufg.br/tede/handle/tede/3504The age of puberty is a feature of great importance in beef cattle for it allows the anticipation of the reproductive activity of females and increases the productivity of the livestock sector. Anticipation of the puberty is possible due to the influence of environmental and genetic factors on this feature. The interaction of pubertal phisiology with these factors is not fully understood, hindering the application of managements for its reduction. To better understand the puberty physiology in heifers, we studied the involvement of the hormone leptin, leptin receptor gene and biochemical and hematological profiles in the occurrence of puberty. The study was conducted following 56 heifers raised on pasture during 17 months. Blood samples were collected at intervals of two months for biochemical characterization, hematological profiles, and to measure progesterone and leptin concentrations as well as the leptin receptor gene sequence. We observed a correlation between the occurrence of puberty and total protein, globulin, phosphorus, magnesium, alanine fosfatase (ALP), aspartate aminotranferase (AST), the number of red blood cells, hematocrit and platelets. In the present study it was not possible to define the role of biochemical and hematological components with the occurrence of puberty, thus more studies are necessary to better understand this relationship. A better understanding of the involvement of leptin in the pubertal phisiology more detailed study on leptin receptor gene, seeking a reliable molecular marker for sexual precocity, are also necessary.application/pdfAcesso AbertoBioquímica sanguíneaBos taurus indicusBovino de corteLeptinaPrecocidade sexualProgesteronaBiochemical profileBeef cattleSexual precocityLeptinProgesteroneZOOTECNIA::PRODUCAO ANIMALTese