Modulation of Ovarian Follicular Dynamics and Conception Rate in Buffalo Cows Exposed to Ovsynch Protocol Combined with a Recombinant Bovine Somatotropin

Abstract

The objectives of this study were to elucidate the impact of the administration of recombinant bovine somatotropin (rbST), in combination with Ovsynch protocol on the preovulatory follicle (POF) diameter, a daily growth rate of the dominant follicle (DF), ovulation rate, and the subsequent conception rate in buffaloes. Fifty buffaloes (Bubalus bubalus) were utilized in this study and divided into two groups {rbST group (rbSTG), n = 25; and control group (CG), n = 25}. Ultrasonography of ovaries revealed that the mean diameter of POF was larger (P < 0.05) in rbSTG compared to CG buffaloes (14.23 ± 0.34 mm vs. 10.67 ± 0.95 mm). Also, the daily growth rate of the DF from Day 7 till the day of ovulation was higher (P < 0.05) in rbSTG compared with CG buffaloes (1.24 ± 0.15 vs. 0.64 ± 0.10 mm/day). Besides, the ovulation rate in rbSTG was higher [(88%), P < 0.05] compared with the CG cows (64%). Thus, the conception rate in rbSTG buffalo was higher (56%; P < 0.05) compared with CG counterparts (40%). In conclusion, rbST combination with Ovsynch protocol for the synchronization of estrus and ovulation significantly improved the follicular dynamics and subsequent conception rate of buffaloes