Laparoscopy in the ewe: A photographic record of the ovarian activity of ewes experiencing normal or abnormal oestrous cycles

Daily observation of ovarian activity in cycling ewes by laparoscopy shows that visual estimation of the age of corpora lutea must be primarily related to changes in their colour rather than to changes in either their shape or size. The shape and size of corpora lutea varies widely depending upon their depth of origin within the cortex of the ovary.A 36-day oestrous cycle in one ewe was found to be associated with the maintenance of a mature corpus luteum rather than with a silent ovulation. By contrast, a 6-day oestrous cycle in another ewe was associated with the premature regression of the corpus luteum.