Gross anatomical changes at various developmental stages in the testis of Gurez sheep (Ovis aries)

The present study was designedwith the objective to give a detailed account of the gross anatomical changes in testis of Gurez sheep at different developmental stages. A total of 39 samples, which included 8 prenatal and 31 post-natal testes, were collected from slaughter houses of Gurez valley. The approximate age of embryos/foetuses and the post-natal animals was estimated using standard methods. The results revealed that at early gestation period the organogesis of testis had already initiated. The shape of testis changed from elongated oval to oval shape at complete maturity. Initially the testes were intra-abdominal upto 70 days of gestation period. The testicular descent, along with the development of spermatic cord, was observed around 120 days of gestation. The testes were closely related with the mesonephric kidney, which completely regressed at the late gestation stage, a period which coincided with the development of epididymis from the mesonephric duct. The blood vessels of the spermatic cord changed from cylindrical to cone shape with the advancement of age. The cremaster muscle enclosed the spermatic cord from all aspects except the caudal surface. The average testicular weight of a sexually mature Gurez ram was 120 grams, a value that is significantly much less than what has been reported in most of the other sheep breeds. While moving from pre-pubertal to pubertal stage, a 7.5 fold increase in the weight of testis was observed. The reports of the current study and the literature cited clearly indicate that the rate of growth in the testes of Gurez sheep was less when compared with the other sheep breeds of the same age group.