Histological Feature of Ovarian Structures Throughout the Reproductive Cycle in Alpine Goats (Capra Hircus)

Abstract

Abstract The knowledge about ovarian physiology in small ruminants is still limited, especially when compared to other domestic species. Ovarian function in goats is mainly assessed by ultrasonographic techniques, whereas a quali-quantitative feature of the follicular and luteal structures throughout the reproductive cycle in naturally cycling goats is scarce. This study provides a detailed description of the functional morphology and size of 742 ovarian structures (follicles, corpora hemorrhagica and corpora lutea) in relation to the oestrus phase, the body weight and the age of 25 Alpine goats (Capra hircus). The current study demonstrated that, the number and size of the follicles were related to the stage of the reproductive cycle (P < 0.0001). Also, the mean number of follicles was high during both prepubertal anestrus and diestrus, whereas it was low in the oestrus. Large (3-4 mm in diameter) and very large follicles (> 4 mm) (P < 0.001), and small follicles (< 2 mm; P < 0.05) varied throughout the reproductive cycle, while medium follicles (2-3 mm) were invariably observed. Large and very large follicles were predominant during the diestrus phase and small follicles in the prepubertal anestrus. It is evident from the current study that the number of follicles (P < 0.05) was significantly affected with both body weight and age. On the other hand, the size of follicles was significantly affected with body weight only (P < 0.0001). These results could contribute to a deeper understanding of ovarian transformations with important implications in assisted reproductive technologies, thereby concurring in advancing the efficiency of ultrasound in breeding programs for this species.