Growth of the ovary follicles in the oestrus cycle in goats

Foliculogenesis in three Polish White Goats was studied daily during their breeding season, from September to November. Animals were kept in natural d aylight, oestrus behavior was detected twice a day with a vasectomized buck . Daily examinations were performed during four sequential oestrus cycles u sing transrectal ultrasonic imaging. The wave was defined as a group of fol licles which start to grow simultaneously and give origin to one or more fo llicles > 5 mm in diameter. The mean interovulatory interval was 20.4 days. The mean number of waves was five, but only follicles that grow > 4 mm hav e a wave pattern of growth, Emergence of smaller follicles was a continuum, The mean rate of growth of the largest follicles was 0.8 mm per day. The m aximum diameter of the largest follicles in nonovulatory waves was 6.2, and was bigger in the ovulatory wares: 7 mm (P < 0.05). There was a highly sig nificant difference between the two largest follicles in the ware. However, only in 53 % of waves there was a divergence, which is typical for dominat ion phenomenon in cattle. Therefore the mechanism and even occurrence of do minance is still unclear in goats.