Uterine histomorphological and immunohistochemical investigation during follicular phase of estrous cycle in Saidi sheep

Background Saidi sheep are one of the most important farm animals in Upper Egypt, particularly in the Assiut governorate. Since they can provide meat, milk, fiber, and skins from low-quality roughages, sheep are among the most economically valuable animals bred for food in Egypt. Regarding breeding, relatively little is known about the Saidi breed. The uterus is an important organ for reproduction in mammals. Therefore, the purpose of this work was to provide further details on the histological, histochemical, and immunohistochemical analyses of the uterus during the follicular phase of the estrous cycle. In order to examine the histological changes in the uterus, 11 healthy Saidi ewes (38.5 ± 2.03 kg weight) ranging in age from 2 to 5 years were used. Results In Saidi sheep, the uterine histological and immunological picture during follicular phase of estrous cycle was characterized by epithelial and stromal proliferation and apoptosis. Leucocytic recruitment (lymphocytes, plasma cells and mast cells) was also observed. The most prominent features of the follicular phase were uterine gland adenogenesis, vascular angiogenesis, and oxidative marker expression, epithelial, stromal and muscular expression of PRA. Conclusion This study provides new evidences of the uterine morphological and immunohistochemical picture of the Saidi sheep during the follicular phase of the estrus cycle. These findings have growing significance to understand the key mechanisms that is characteristic of successful reproduction in Saidi sheep in order to enhance fertility and reproductive health of this livestock species.