Abstract

Follicular population and repartition in the ovarian cortex was investigated in the ovaries of the Oulmès-Zaers cattle breed and its crosses. A total of 30 ovaries were collected at slaughterhouse in Casablanca and Rabat from Oulmes-Zaers breed and its crosses (2 genotypes) of 3 age groups (<3; 3 to 5; >5 years). The histological study of the ovary revealed that the ovarian cortex is composed of different areas (from the periphery to the medulla), the non stratified epithelium of the ovary, the tunica albuginea composed of two areas rich of collagen fibers directed into different ways white variable thickness. The primordial and antral follicles appear in underlying areas. Therefore, the follicles cannot appear on the ovarian surface when situated under thicker Layers. At the quantitative level, the ovary of the Oulmes-Zaears breed seems to contain less follicles in animals less than 3 years of age as compared to the crossbreed (P< 0.05). Between 3 and 5 years of age, the follicles occupied similar areas of the ovaries (17% and 18% for oulmes-Zaers and its crosses, respectively). This study shows that the ovary of the Moroccan local cattle breed (Oulmes-Zaers) is equipped with a whole plain follicular population that is more important than the one visible on the surface of the ovary and which is exploited by aspiration and picking techniques.

Key words: Ovary, Oulmès-Zaers, follicular population, bovine, age.