Desenvolvimento gonadal de fetos suínos e sua relação com medidas fetais

Abstract

The objective of this work was to evaluate the histomorphometric traits of the testes and ovaries at different gestational ages, and correlate them with the length and head circumference, and thoracic perimeter. We divided by gender and gestational age 44 fetuses obtained from DB-90 pregnant gilts (DanBred). The gestational ages were of 50, 80 and 106 days. In the first and second groups, 5 males and 7 females were studied, and in the third, 5 males and 9 females. After slaughtering the gilts, the fetuses were removed, determining the head length and head and thoracic perimeters. Subsequently, the gonads were collected, weighed and subjected to histomorphometric analyses, such as cell counts and measuring the gonad structures. All gonad traits were subjected to ANOVA, statistically comparing the different gestational ages using the SNK test at 5% probability. Histomorphometric variables were correlated with fetal measurements by means of Pearson correlation. The weight of the testes increased (P<0.05) significantly during pregnancy, especially during the final third. The same occurred to the weight of the ovaries. After 106 days of gestation, the cordonal length and number of Sertoli cells increased (P<0.05) in the testes, however, the diameter of these cells from 80 days gestation was smaller. The weight, head length, head circumference and girth were positively correlated (P<0.01) with the weight of the testes, cordonal length and total number of Sertoli cells, however, were negatively correlated (P<0.02) with GSI and the average diameter of the Sertoli cells. Ovary analysis and total number of follicles was higher at 80 and 106 days of gestation, whereas the number of oogonia decreasing during pregnancy. The weight of the fetus and fetal measures were positively correlated (P<0.01) the weight of the ovaries, total number of follicles, an increase in number of follicles total volume of oogonia, however, were negatively correlated (P<0.05) with GSI, total number of oogonia and percentage of core of oogonia. We concluded that most cell proliferation in the testicle development of the ovaries and its organization are more pronounced in the final third of gestation. Fetal weight and size can be used to predict the development of histological gonads.