Relationship between ovarian weight and follicular population in heifers.

The size of the ovary varies substantially among cattle. This variation may influence the potential of the ovary to produce follicles. In the present study, we examined whether a relationship exists between the weight of the ovary and the number of antral follicles ≥1 mm. Paired ovaries were obtained from Holstein × Japanese Black F1 heifers. Follicles were classified into three size categories (small: 1.0 - 0.4, P 0.6, P 0.4, P<0.0001). These results suggest that 1) the weight of an ovary reflects the potential of the ovary to produce antral follicles, and 2) a rough estimation of follicular population might be possible by using the weight of the ovary contralateral to CL in heifers.