Synchronization with estradiol benzoate in the presence of the corpus luteum in Wagyu cows increases the number of medium follicles but does not interfere with in vitro production of embryos

Abstract

Reproductive biotechnologies emerge as an important element for livestock, however, some strategies must be modified to adapt the different breeding systems, such as the use of follicular synchronization protocols. This study aimed to evaluate follicular synchronization using estradiol benzoate, with the presence of the corpus luteum, on the in vitro embryo production (IVEP) from Wagyu oocytes donors. Routines of IVEP were performed in heifers and cows (n=19), classified into three groups: G1/CL- animals with corpus luteum; G2/SCL- animals without corpus luteum, these groups being the control, and had the natural process of follicular dynamics and G3/CL + EB - animals with the presence of corpus luteum, submitted to follicular synchronization at D0, with estradiol benzoate. The results obtained showed that the synchronization of the follicular wave with the application of EB, in the presence of the corpus luteum (CL), reduced the number of small (6.05 ± 0.55) and large follicles (0.45 ± 0.15), but increased (P0.05). It was concluded that follicular synchronization using estradiol benzoate in Wagyu oocyte donors, presenting a corpus luteum, increased the number of medium follicles, however, there was no improvement in the efficiency of ovum pick-up, in vitro embryo production and pregnancy rate.

Keywords

• Reproduction biotechnology
• Wagyu donors
• Follicular aspiration
• Follicular synchronization.