Document Type : Research Paper
M.Sc. Student, Department of Animal Science, Yasouj University, Yasouj, Iran
Assistant Professor, Department of Animal Science, Yasouj University, Yasouj, Iran
Associate Professor, Department of Animal Science, Yasouj University, Yasouj, Iran
Assistant Professor , Department of Animal Science, Yasouj University, Yasouj, Iran
In order to investigate the changes of sexual steroids concentrations and expression of their receptors’ gene in the testes of Fars native roosters, 24 roosters in the age of 5, 6, 7 and 8 months were selected randomly. In each date of sampling, 6 roosters were slaughtered and blood samples for measuring the concentration of testosterone, estradiol and progesterone, and testis samples for evaluating the level of receptors gene expression of these sexual hormones, were collected. The results indicated that testosterone and progesterone concentrations in the blood of 7 and 8-month roosters were significantly higher compared to 5 and 6-month roosters. The maximum concentration of estradiol in blood was observed in 5 –month roosters and the minimum concentration was observed in 7 and 8-month roosters. The level of testosterone and estradiol receptors gene expression in the testes of 6, 7 and 8-month roosters were increased significantly compared to 5-month roosters, but the level of progesterone receptor gene expression decreased in 6-month roosters compared to 5-month ones. Progesterone receptor gene expression in 7 and 8-month roosters was not changed significantly compared to 5-month roosters. In conclusion the results indicated that both of the testosterone concentration in blood and the expression of its receptor gene in testis, were increased during the sexual maturity period of Fars native roosters but the estradiol concentration decreased while its receptor gene expression increased in the mentioned period.