ENDOSCOPIC STUDIES OF OVARIAN FOLLICLE DEVELOPMENT DURING THE ESTRUS CYCLE IN HUNGARIAN LARGE WHITE GILTS

The processes of follicular growth, ovulation and luteolysis were foll owed between the second and third ovulations by repeated laparoscopy i n four Hungarian Large White gilts. Gilts were examined 6-7 times each between d -2 to d 6 and d 13 to d 20 of their second oestrus cycle an d representative stages of follicle development were photographed. Fol licle recruitment had begun by d 13 and follicles of 4 mm diameter on d 14 matured to the preovulatory stage while follicles of 2-3 mm becam e atretic. The growth of preovulatory follicles between d 14 and d 19 was about 1 mm/day. A rate of atresia of appromiximately 20 % was calc ulated, based on the difference between the number of follicles 2-3 mm and >4 mm. The mean ovulation rate was different (p<0.05) at the firs t, second and third oestrus (8.0+/-1.2, 9.5+/-0.5 and 11.0+/-1.4 corpo ra lutea/gilt), respectively. There was always a higher number of ovul ation on the left compared to the right ovary (5.8+/-1.1 v.s. 3.8+/-0. 9).