Quantification of the Ovarian follicles of water buffaloes (Bubalus bubalis)

Abstract

Ovarian samples were collected either through ovariectomy or slaughtering of Phillipine water buffaloes at the Phillipine Carabao Research and development Centre (now Phillipine Carabao Centre), Central Luzon State University, Philippines. From the young buffalo (6-7months, 2 pairs of ovaries); pubertal (2 year; n=1 pair); adults (7-8 year; n=3 Pairs) and old (12-14 years; n=3 pairs) were used for the study. The ovaries were fixed, dehydrated and embedded in the paraffin wax and were serially sectioned at 10 microns. The sectioned ovaries were then stained with periodic acid/schiff's-Hematoxylin (PAS-H). Ovarian follicles of the following categories (primary, growing, secondary, tertiary, and atretic) were quantified in the  young, puberial, adults and old water buffaloes. In the young and pubertal buffaloes, the average follicular population of 75,604 and 85, 358 primary follicles were counted, respectively. The number of primary follicles decreased as age of the animal increased, meaning the follicles are either ovulated or became atretic during the course of the estrous cycle. The growing follicles were highest in the pubertal animals with an average follicle of 7, 317 which is 8. 75 percent of the primordial follicles. The young and adult buffaloes had an average count of 71 and 18 growing follicles respectively. The tremendous increase in the number of the growing follicles during the pubertal stage may indicate that follicle are continually being recruited and they grow from stage to stage and end life by becoming atritic or ovulated. The number of secondary follicles found in the pubertal revealed that there was a transition of the growing follicles to the secondary stage. Further decline in the number of tertiary follicles occurred, while the average number for the tertiary follicles in the young, adult and old were 3, 9, 7, respectively which is quite low. Data showed that there was a high incidence of atresia occurring in the ovarian follicles of buffaloes ranging from 127 in the young to 142 in the pubertal.