A Survey on Morpho-Histological Features of Foetal and Adult Ovaries in Kurd sheep

This survey investigates the morpho-histological features of Kurd sheep. So, 40 foetal and 10 adult ovaries were obtained from slaughtered Kurd sheep in Kurdistan abattoir. Crown rump length method used to determine the ages of the adult ewes while the age of foetuses were determined by dentition method. The foetal and adult ovaries were divided into five different groups using specific age intervals as gestation day as follows: (GD) 50–65, 66–95, 96–125 and 126–145, as well as adult sheep. The ovaries were fixed, processed and routinely stained with H&E for histological studies. The ovarian follicles were classified into 5 types according to granulosa cell layers surrounding the oocytes. The number of ovarian follicles per microscopic field was determined for each group at 400× magnification. Grossly, the foetal ovaries were like pin head, oval in shape, uniformly smooth and creamy in color. The adult ovaries had follicles with different sizes. The adult mean ovarian weights were significantly higher (P < 0.01) than those of the foetuses. Microscopically, the GD 50–65 ovaries had no distinct cortex and medulla. Oogonia were numerous among other stromal cells toward the periphery of the ovary. By GD 66–95 the ovaries contained types 1, 1a, 2 and 3 follicles. GD 96–125 ovaries contained type 4 and type 5 follicles with early antrum formation and those of GD126–145 comprised type 5 among other follicles. The adult ovaries comprised all the ovarian follicle types. The number of type 1 follicles increased significantly (P < 0.01) with foetal age while It was the least in the adults.