Anatomical assessment of the development of testes and ovaries in red Sokoto goat (Capra hircus)

Abstract

The functional testis and ovary are essential for the continual existence of every species. The anatomical development of the testis and ovary in the fetuses of red Sokoto goats were evaluated in this study. A total of 40 apparently healthy pregnant red Sokoto goats were used for this study. After gross anatomical evaluations, samples of the testes and ovaries were obtained for histology and histomorphometry. The result showed that the testes were largely intra-abdominal in the 1st and early 2nd terms, with full descend into the scrotum occurring in the 3rd term. Histologically, the testes in the 1st term showed poorly formed seminiferous cords that became clearly delineated in the early 2nd term. The mean diameters of the left seminiferous cords increased significantly in the 2nd and 3rd terms, while the right seminiferous cords did not vary with age. On the other hand, the ovary in the 1st term contained oogonia which increased in population in the early 2nd term. The mean oogonia diameter of the right ovary increased linearly with age. Towards the 75th day of gestation, the ovary consisted of mostly primordial follicles, while, there were preponderance of primordial follicles with few unilaminar primary follicles towards full term.  In conclusion, the gross and histological changes in the developing testes of red Sokoto goats represent key structural repositioning essential for normal adult male life. The ovarian follicles which developed in this breed of goat in the late 2nd term could either become atretic during embryonic life or could persist till adult life.