Postnatal Histological Development of the Ovary in Awassi Lambs Early and Late Immature Stage

The current study this study investigated the postnatal stages of female sheep were taken the ovary of healthy females, the age of the animals was determined depending on formula of milk teeth and eruption age of teeth. Across two age groups: 2–3 months age and 8–9 months age. In the first group (2–3 months), the ovarian structure lacked clear distinction between cortex and medulla, the germinal epithelium comprised a single layer of cuboidal to low columnar cells, overlying a moderately thick tunica albuginea made of dense connective tissue. The ovarian cortex displayed numerous primordial follicles beneath the tunica albuginea, each containing an oocyte surrounded by flattened granulosa cells. Early primary follicles with an enlarged oocyte and cuboidal granulosa cells were also observed. Occasional secondary follicles appeared with multiple granulosa layers and early thecal differentiation, but no antral cavities, indicating preantral development. The medulla contained loose connective tissue, fibroblasts, and numerous developing blood vessels. In contrast, in the second group (8-9month) which lambs exhibited clear compartmentalization into cortex and medulla. With surface lined by a simple squamous to low cuboidal germinal epithelium underlain by a thick collagen-rich tunica albuginea. The cortex contained follicles at all developmental stages, including primordial, primary, secondary, and Graafian. The medulla featured dense connective tissue, fibroblasts, and vascular networks.