Comparative histological and histochemical study of the ovary in laying hens(ISA Brown) and broiler chickens(Broilers Rose 308) at different ages

The study aimed to compare the histology and histochemistry of the female reproductive system between two chicken species laying hens ( ISA Brown) and broiler chickens (Broilers Rose 308). Histologically, using routine stains (hematoxylin and eosin (H&E), the ovary at the age of 2 months in both chicken species was covered by the germinal layer, which consists of simple cuboidal epithelium. Towards the inside of the cortex, there were primary and secondary ovarian follicles, but the number of follicles was greater in laying hens than in broiler chickens. The ovary of laying hens was more clearly visible than in broiler chickens. The ovarian cortex in both chicken species contained primary, secondary, and tertiary ovarian follicles, but in broiler chickens, it showed atrophy, depressions, and an irregular shape. The ovary of a 6-month-old laying hen contains mature ovarian follicles in the center of the ovary, indicating sexual maturity and readiness for ovulation. This is in contrast to the ovary of a broiler, where the follicles were few, appeared atrophied, and were close to the ovarian cortex. The results of histochemistry using Masson's trichrome stain revealed that the ovaries of both laying hens and broiler hens exhibited a positive reaction at different ages, with the cytoplasm of the ovarian follicles and connective tissue fibers showing a red color. Collagen fibers, however, took on a green color from the stain and were abundant in the ovaries of broiler hens of different ages, compared to the ovaries of laying hens, which showed a lower reaction to the stain.