Histomorphometry of ovarian follicular growth and atresia in summer and winter seasons in Iranian river buffalo

The ovaries of 24 adult and apparently healthy river buffaloes were collected in summer and winter of a year. The hitomorphometric study of ovaries revealed that, the mean dimension and weight of right ovary is significantly higher than the left ovary in both the seasons. The population of healthy follicles were significantly higher in winter than summer, but on the other hand the population of atretic follicles were significantly higher in the summer than winter. The populations of growing healthy follicles at follicular as well as luteal phases of the estrus cycle were significantly high in winter than that in summer. The populations of atretic primary and mature follicles were more than the populations of the secondary atretic follicles. It may be conclude that in the winter season the mean populations of the growing as well as healthy follicles are higher than the summer.