Vaginal prolapse in sheep—Part IV: Cyclic changes in the vulva, vestibule, and vagina during the year

Astract

Extract

Many English breeds of sheep exhibit a well-defined breeding season which begins in the autumn about February–March in the southern hemisphere and ends about July–August. Over this period, the oestrous cycle, in unmated ewes, is repeated at intervals averaging 16 to 17 days. At other times of the year, these breeds are in anoestrum during which the 'ovaries and the tubular parts of the reproductive system are relatively quiescent.