Season and Photoperiod Effects on Follicles and Atresia in the Sheep Ovary

Since follicles that ovulate during the breeding season in sheep begin their growth and development during the anoestrous season, the ovarian follicular population was investigated in late oestrus, midanoestrus and early oestrus. The effects of photoperiod (8 h light per day) and 2-bromo-a-ergocryptine (2 mg per day per sheep) throughout the anoestrous season on the follicular population were also studied.