EN
In this study the dynamics of follicular growth during estrous cycle after cloprostenol, FGA and PMSG stimulation in goats was compared. On the day 11 of the estrous cycle Group I of the goats (n = 4) was injected with 0.25 mg of cloprostenol for luteolysis stimulation. The follicles which started to grow after treatment formed the ovulatory wave. Group II of the goats (n = 4) was stimulated for 17 days by intravaginal sponges with FGA. After withdrawal of the sponges goats were injected with a single dose of 500 I.U. of PMSG (day 17). Observation of growing follicles on the ovaries were carried out every day through the two consecutive estrous cycles, and was finished on the day of ovulation at the end of second estrous cycle. No differences were observed in total number (4.25 ± 0.5) and the number of the large follicles ≥ 5 mm (2.75 ± 0.5) of the ovulatory wave after cloprostenol injection in comparison to waves of follicles growing during the luteal phase. In Group II of the goats stimulated with sponges impregnated with FGA the number of growing follicles did not differ from the number of follicles in Group I of goats and goats with a natural estrous cycle. After PMSG injection the number of follicles growing in the ovulatory wave increased rapidly. After synchronised ovulation in Group II of the goats follicular cysts were observed and disturbed folliculogenesis of the subsequent estrous cycle. No second wave of follicles was observed and the number of follicles growing was significantly lower (p ≤ 0.05), even in the ovulatory wave, but the ovulation rate did not change in comparison to the natural estrous cycle.