Plasmatic testosterone levels during the puberty of Moxotó male goats

Abstract

The objective of this study was to characterize the puberty process of Moxotó male goat, a regional breed. Six kids were used in this experiment in which the following variables were measured: birth weight, scrotal circumference, reaction to female in estrus, and penis detachment from the prepuce. It was determined the plasmatic levels of testosterone on 10th, 18th, 22nd, and 28th weeks. With 217 days old, the animals were slaughtered and their testis were hystologically analyzed. The covariance analyses showed a positive and significant (P<0.01) correlation between birth weight, weekly weight, scrotal circumference and age with testosterone levels. The penis detachment showed a positive and significant (P<0.01) correlation with the scrotal circumference and age. The reaction to female in estrus showed to be positive and significantly (P<0.01) correlated with birth weight, weekly weight, scrotal circumference, testosterone levels, penis detachment from the prepuce and age. The animals that released the penis showed all cells of the spermatogenesis process, while those that did not showed high prevalence of spermatides. It is concluded that plasmatic testosterone is involved in the beginning of the puberty process, and that the penis detachment from the prepuce can be used as criteria to determine the sexual precociousness of male Moxotó goats.