Effect of follicular wave synchronization using a progesterone-releasing intravaginal device-based protocol on in vitro embryo production in Bos taurus cows subjected to 14-day intervals ovum pick-up

Follicular wave synchronization (FWS) before ovum pick-up (OPU) is one of the strategies used to improve the efficiency of in vitro embryo production (IVP). This study aimed to evaluate the effect of FWS on the total follicular number, cumulus-oocyte complex (COC) recovery, and in vitro embryo development in Angus cows (n = 33) subjected to OPU with 14-day intersession intervals. Additionally, it was also evaluated the presence of carryover effects given the short intersession interval used. The experiment was run as a 2-treatment (FWS vs. Control) x 2-period (1 vs. 2) crossover design. Animals in the FWS group received an intravaginal progesterone implant (1gr), estradiol benzoate (2 mg), and D-cloprostenol (150 μg) on day 0 and the OPU was performed on day 5. Control group animals did not receive any hormone treatment. The FWS increased the number of 6–10 mm follicles (P = 0.05), but it decreased the COC recovery rate (P