Postnatal Development of Testis in Gaddi Goat (Capra hircus)

A study was conducted on the testicles of 30 male Gaddi goats, divided into 3 groups viz; prepubertal (0 day to 18 months), pubertal (<18 months to >5 yrs) and postpubertal (>5 yrs) ages. The study revealed that the testis was covered by fibroserous tunica albuginia having outer fibrous layer and inner vascular layer with smooth muscle fibers at birth. The tunica albuginia continuously grew in thickness from prepubertal to postpubertal animals. The septula testis arising from the tunica albuginia, divided the parenchyma in lobules and converged at mediastinum testis. Few differentiated and undifferentiated Leydig cells were present in the intertubular spaces of neonates, which enormously increased in pubertal animals and replaced by fibroblasts in the postpubertal animals. The parenchyma comprised of solid sex cords in new born kids. These were converted into luminated tubules after 6 months of age and had clear cut tubuli contorti and tubuli recti leading to the mediastinum testis. In “0” day old kids, sex cords were filled with undifferentiated small cells located peripherally along the basement membrane and large primordial germ cells located centrally. By six months of age, latter started showing sign of degeneration and thus luminization of tubules started. Spermatogenesis startedin the seminiferous tubules of 12-18 months goat. In pubertal animals all the stages of spermatogenic cells and Sertoli cells were identified in the seminiferous tubules. The population of gonia cells and primary + secondary spermatocytes were 35% and 30% respectively. In postpubertal animals gonia cells were reduced to <30% and Primary + secondary spermatocytes were <20%. Many degenerating seminiferous tubules showed hyalinization, fibrosis and giant cells. The stroma and parenchyma ratio which was 35:65 at birth became 30:60 at 6 months, 25:75 at 12 months and 15:85 in pubertal and 20:80 in postpubertal animals. Increased stroma in last phase was associated with replacement of seminiuferous tubules by fibrous elements.