RESUMO
Cryo-preservation is a suitable method for preservation and protection of genome, cells and embryo, especially in cases of endangered species. The aim of this study was to evaluate the effect two cryopreservation techniques on survival, maturation, fertilization and development of bovine cumulus oocyte complex [BCOC]. After aspiration of BCOC, they were cryo-preserved using slow freezing or vitrification. For slow freezing 1.5 M DMSO + 0.1M sucrose was used, while for vitrification 40% Ethelyenglycol + 18% V/W Ficol + 3 M sucrose + 105mg/ml BSA was used. After thaw percentage survival of BCOC were assessed using trypan blue vital staining, while percentage cleavage and development to 8-cell were taken as an index for BCOC maturation, fertilization rate and embryo development, respectively. The results showed no difference between the survival rate of BCOC in slow freezing [79%] and vitrification method [74.4]. However, the percentage of 2 and 8-cell embryos were significantly higher in the vitrification group as compared to slow freezing group. Although there is no difference between the survival rates of BCOC between the two procedures, however the maturation and development of BCOC is greater in the vitrification method, suggesting that this method preferred for cryo-preservation of BCOC