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

Abstract

Ovarian samples were collected either through ovariectomy or slaughtering of Philippine water buffaloes at the Philippine Carabao Research and Development Centre (now Philippine Carabao Centre), Central Luzon State University, Philippines. From the young buffalo (6 –7 months, 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 paraffin wax and were serially sectioned at 10 microns. The sectioned ovaries were then stained with periodic acid/schiffs-Hematoxylin (PAS-H). Ovarian follices of the following categories (primary, growing, secondary, tertiary and atretic) were quantified in the young, pubertal, adult 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 numbers of primary follicle decreased as age of the animal increased, meaning the follicles are either ovulated or become atretic during the course of the estrous cycle. The growing follicles were highest in the pubertal animals with an average follicle number 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 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 atretic or become ovulated. The number of secondary follicles found in each age group decreased with age. The high number of secondary follicles counted in the pubertal revealed that there was a transition of the growing follicles to the secondary stage. Further decline in the number of tertiary follicle occurred, while the average number for 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.
Keywords: Quantification, Ovarian follicle and water buffaloes