Dietary energy influences ovarian morphology and in vitro maturation of oocytes in goats

Abstract

The present study aimed to determine the effects of dietary energy levels on follicular development and in vitro maturation of oocytes in pre-pubertal goats. Thirty-six female six-month-old stall-fed Black Bengal goats were divided into three equal groups that were randomly assigned to receive three iso-nitrogenous diets containing different levels of metabolizable energy (8.67, 10.20, and 11.73 MJ/kg DM). After 150 days of rearing, the weight, length and width of the ovaries increased significantly in medium and high levels of dietary energy groups than in the low-energy group. Medium and high-energy levels in the diet significantly increased the number of visible antral follicles and large antral follicles than the low level of dietary energy. The number of antral follicles per ovary was higher in high-energy fed goats than medium- and low-energy groups. The low-energy group showed more non-growing primordial follicles and degenerated follicles than the other groups. The medium- and high-dietary energy levels significantly increased the maturation rate of oocytes to metaphase II than the low-energy group. These results reveal that the level of dietary energy positively influences follicular development and meiotic competence of goat oocytes.

Keywords

• dietary energy
• follicle
• goat
• in vitro maturation
• oocyte