Ovarian antral follicular activity and serum estradiol-17β concentrations in buffaloes during different periods of the year*

Abstract

Ovarian antral follicular activity in buffaloes was studied from November to April 1998-99 (cooler and warmer periods of the year), using the ovaries collected from Civil Slaughterhouse, Bangalore. Antral follicular population on the surface of the ovary was studied and simultaneous serum estradiol-17β was assayed by radioimmunoassay to determine the ovarian activity in the animals. Total number offolliclcs on the surface of the ovary, number of medium and large sized follicles, and number of functional corpora lutea reduced significantly (P<0.05) as the ambient temperature increased. The serum concentration of estradiol-17β was significantly lesser (P<0.05) in animals without large follicle than those with large follicle, and it reduced significantly with increase in ambient temperature. The study revealed that the buffaloes show variability in the ovarian activity during different periods of the year. The activity was higher during the colder months. The results indicate sensiti'vity of buffaloes to higher ambient temperature.