Morphological and functional characterization of corpus luteum during different stages of estrous cycle in buffalo

Abstract

The objective of the present investigation was to study morphological changes in corpus luteum and luteal progesterone content during different stages of estrous cycle in buffalo (Bubalus bubalis). Uterus along with the ovaries were procured from the local slaughter house and classified into 4 stages; early (stage I, 1 to 5 days), mid (stage II, 6 to 11 days), late luteal phase (stage III, 12 to 16 days) and follicular phase (stage IV, 17 to 20 days) of estrous cycle based on morphological characteristics of corpus luteum and presence of surface follicles on the ovary. Dimensions of the corpus luteum gradually increased with its growth and significant peak values were observed at stage III followed by a decrease at stage IV of estrous cycle, suggesting regression of corpus luteum. The mean progesterone concentration per gram and content per corpus luteum significantly increased from stage I to III of estrous cycle with a peak at stage III and thereafter, it decreased at stage IV. The present study suggested gradual increase in dimension of CL and luteal progesterone contents with the growth of corpus luteum