Efeito da Gonadotrofina Coriônica Humana na maturidade sexual em touros da raça Nelore

Abstract

Androgens play a crucial role in sexual development, reproductive health, and metabolic homeostasis in males. Human chorionic gonadotropin (hCG) has a similar action to luteinizing hormone, stimulating testosterone production in the testicles and contributing to the process of spermatogenesis. This study aimed to investigate the effect of hCG on the sexual maturity of Nelore bulls, with the purpose of advancing their entry into reproduction. Twenty Nelore bulls aged 14 to 16 months were divided into two groups: Group 1 (control) and Group 2 (treated with 2500 IU of intramuscular hCG every 7 days for 28 days). All animals underwent clinical evaluations at each experimental stage, as well as 30 days after the end of the applications. Measurements of weight and reproductive parameters were performed. Semen was collected through electroejaculation, and analyses of physical and morphological characteristics were conducted. The results showed no significant differences between the treated animals and the control group regarding scrotal circumference, sperm morphology (total defects, major and minor), and sperm concentration. However, the treated animals exhibited lower values of sperm motility and vigor compared to the animals in the control group. Therefore, the use of hCG in 14 to 16-month-old Nelore males did not demonstrate efficacy in advancing sexual maturity.