The effect of the pre-maturation with bovine follicular fluid (bFF) on developmental competence of immature bovine oocytes was studied. Cumulus-oocytes complexes (COC) and bFF were obtained from ovaries collected at slaughterhouse. bFF was inactivated prior to use and COCs were distributed in four treatments: (T1) 70% of bFF in Talp hepes, (T2) 100% of bFF, (T3) 100% of Talp Hepes medium, and (T4) control group. In T1, T2, and T3, COCs were incubated during 5h at 37ºC before proceeding with in vitro maturation. In T4, maturation was performed soon after follicular aspiration. After in vitro fertilization, the presumptive zygotes were co-cultured with cumulus cells during 10 days. It was evaluated cleavage, blastocyst on seventh and eighth days post-fertilization (PF), overall blastocyst and hatched blastocyst on eighth and ninth days PF. It was also calculated the ratio of blastocyst on seventh and eighth days, and hatched blastocyst in function of overall blastocyst production. Cleavage, overall blastocyst and hatched blastocyst rates were similar (P>0.05) among treatments. However, blastocyst production on seventh day was lower (P<0.05) for bFF and Talp Hepes. These results indicate that bFF and Talp Hepes in pre-maturation for five hours caused a delay on embryonic development, although the overall blastocyst production and viability were not affected.
bovine; oocyte; follicular fluid; embryo production
