Cryotop vitrification for in vitro produced bovine and buffalo (Bubalus bubalis) embryos at different stages of development

Abstract

The aim of this study was to evaluate the possibility to vitrify in vitro produced (IVP) buffalo and bovine embryos at different stages of development by an advanced version of the "minimal volume approaches": the Cryotop method. In both experiments, the embryos were vitrified at the tight morula (TM), early blastocyst (eBl), blastocyst (Bl), expanded blastocyst (xBl) and, only for buffalo, at the hatched blastocyst (hBl) stage. After warming, the embryos were cultured in vitro for 24 hours. Stage of development affected the freezability of IVP embryos of both species with the highest embryo survival rates at advanced stages (xBl=76% and hBl=75% for buffalos and xBl=75% for bovine). These results suggest that Cryotop vitrification is an efficient method for buffalo and bovine IVP embryo cryopreservation.