Estudo de embriões ovinos em laboratório a partir de doadoras juvenis da raça Santa Inês submetidas a estimulação ovariana

Abstract

This study aimed to verify the superovulatory response of juvenile Santa Inês sheep and to evaluate the viability of oocytes obtained for in vitro production (IVP) of embryos. Eight females aged between 6 and 8 weeks were selected, distributed in 2 homogeneous groups of 04 animals. The females in Group 1 (G1) were submitted to exogenous ovarian stimulation and in Group 2 (G2) the females were aspirated free of hormonal treatment. From a total of 309 retrieved oocytes (G1 = 187 and G2 = 122), cleavage rates of 49.2% and 40.2% were obtained for G1 (n = 92) and G2 (n = 45) respectively, and 18.72% and 17.96% of viable embryo development in D7 (G1 = 35 and G2 = 19). Although the results suggest a better efficiency in the recovery of oocytes and cleavage rate in G1, the rates of obtaining viable embryos in D7 did not differ numerically between the two groups. Our results suggest that, although there was great variation in the amount of oocytes obtained and the production of embryos among animals, regardless of treatment, the production of embryos by in vitro fertilization (IVF) from juvenile females treated or not with exogenous hormones proved to be viable, even with good efficiency of the hormonal protocol used for females of the Santa Inês breed.