Abstract

Ovaries were recovered either 0, 12, 24 or 36 hours or 10 days after CIDR withdrawal, from 25 hinds in which oestrus had been synchronised. All follicles > 2 mm diameter were dissected free of stromal tissue and their health assessed on the basis of oocyte and theca condition, follicular fluid oestradiol content, granulosa cell numbers and oestradiol synthesis. Hinds had an average of 26.6 + 3.45 follicles > 2 mm, of which about half were healthy and 1-3 were oestrogenic. Every animal had at least 1 healthy follicle > 7.5 mm diameter. Over the follicular phase, the percentage of healthy follicles ranged from 46-66%, but this did not change significantly with time. Neither did the mean diameter of the largest oestrogenic follicle change over the follicular phase. In summary, the total number of antral follicles varied widely, but every hind had at least one large healthy follicle present, irrespective of stage of the oestrous cycle.

BJ, McLeod, LM Meikle, DA Heath, KP McNatty, MW Fisher, and AJ Whaanga

Proceedings of the New Zealand Society of Animal Production, Volume 56, , 370-372, 1996