The current study aimed to evaluate the follicular dynamics, superovulatory response, and embryo recovery in Egyptian buffaloes following superstimulatory treatment PMSG+rbst and its comparison with PMSG alone. Twelve buffalo cows, 60-120 days postpartum,  3-5 parities used and divided into two groups (6 animals each), the 1st group was superovulated with PMSG only, while the 2nd with PMSG+rBST. The ovarian response was followed using ultrasonography before treatments, at estrous day and before flushing process. All follicles with diameter < or ≥ 8mm, numbers of corpora lutea (CL) and unovulated follicles (UOF)/buffalo were recorded.
Obtained results showed that PMSG+rbst resulted a positive ovarian response and increased numbers of small and large follicles in the ovaries (3.0±0.52and 8.67±0.49) compared with those treated with PMSG alone (2.83±0.17and 5.83±0.4, respectively). Furthermore, it increased the number of luteal particles, unovulated follicles and ovulation rate% (5.83±0.31, 2.33±0.33 and 70.68±3.98) in G2 compared to that observed in G1 (3.67±0.33, 1.83±0.31 and 66.74±4.67, respectively). The average number of total embryos, transferable embryos and the %transferable embryos/head in G2 were (3.0±0.37., 2.0±0.37., 66.7±4.65, respectively) greater than that harvested from G1 (1.83±0.48, 1.17±0.31., 63.9±5.96., respectively). Also, embryos recovery rate harvested from the PMSG+rbst treated buffaloes was (51.5%) slightly higher than that obtained from the PMSG treated buffaloes (49.9%). In conclusion, the current study indicates that superovulation buffaloes with combination of PMSG + rbst can improve ovarian response, recovery rate and percentage of transferable embryos more than those treated with PMSG alone.