Real time ultrasound evaluation of changes in follicular populations during oestrous cycle in buffalo

Changes in ovarian follicular populations during oestrous cycle were examined by real time ultrasonography in buffaloes. The endpoints used were number of follicles 3-4 mm, 5-6 mm, 7-10 mm, greater than or equal to 11 min and the diameters of the largest and the second largest follicles, between day 0 and day 15 of oestrous cycle. The profile of the diameter of the second largest, but not the largest follicle was bimodal. There was a significant difference among different days in the diameters of both the largest and the second largest follicle. There was a Significant difference in the numbers of follicles 5-6 mm and 7-10 mm in diameter but not in the numbers of follicles 3-4 mm and 11 mm, and the total number of follicles 3 mm in diameter among different days. Our results suggest that the follicular populations exhibit dynamic changes during oestrous cycle in buffaloes.