Macroscopic study of testicular descent in caprine fetus

In this study, fetus samples were collected randomly from 200 pregnant goats which were slaughtered at Tabriz abattoir during autumn. The age of collected fetuses was calculated by the formula X=2.74 Y.15 proposed by Gull et al. After opening the abdominal cavity of the fetuses at different ages, the location of the testicles in the abdominal cavity and the time of their descent into the scrotum were investigated. Macroscopic studies indicated that the first testicular migration coincides with mesonephrous degeneration in 45 days old fetuses. At the age of 59 days, the mesonephrous is completely diminished and the remains of the mesonephric duct changed to epididymis. At this age, the gubernacular tissue is inflated and expanded. In days 89, testis is seen in the middle of the inguinal canal and until day 106 of pregnancy it descents from final of the inguinal canal into the opening of the scrotum. At the age of 153 days (birth time) complete descent of the testis into the scrotum takes place. On the basis of the results of the present study it can be concluded that the location of testis in the goat is similar to cattle, sheep, horse and humans at birth and its descent into scrotum follows retraction and degeneration of the gubernacular tissue.