Correlation of blood flow of the preovulatory follicle to its diameter and endocrine profile in dairy buffalo.

Blood flow of the preovulatory follicle (POF) wall can be used as a predictor of the quality of POF. Our aim was to determine the correlation of blood flow of POF with the POF diameter, and intra-follicular and plasma concentrations of Insulin-like Growth Factor-I (IGF-1) and oestradiol in dairy buffalo. Nine Murrah buffalo subjected to an ovulation synchronization protocol (Ovsynch) were assessed on day 10 of the protocol for diameter and blood flow of POF, followed by the aspiration of follicle fluid. Prior to follicular aspiration, blood samples were obtained from jugular vein for estimation of IGF-1 and oestradiol. The vascularity of POF was determined (Range: 250-967 pixel(2) ) along with intra-follicular and plasma concentration of IGF-1 (Range: 9.3-31.8 ng/ml and 14.7-29.7 ng/ml respectively) and oestradiol (Range: 124.2-447.9 ng/ml and 0.25-1.05 ng/ml respectively). Diameter of the POF was weakly correlated (r = 0.21, p < 0.01) with blood flow to it. As compared to POF diameter, the blood flow of POF had greater positive correlation with intra-follicular and plasma concentrations of hormones (IGF-1 and oestradiol). A strong positive correlation was recorded between intra-follicular IGF-1 and oestradiol. Also, plasma concentrations of oestradiol and progesterone were negatively correlated In brief, assessment of the blood flow of the POF is a non-invasive and reliable indicator of its functional competence as compared to the POF diameter.