Comparison of two methods for one-step in-straw thawing and direct transfer of cattle blastocysts

The aim of this experiment was to evaluate the feasibility of dilution of the cryoprotectant by a sucrose solution in the straw followed by direct transfer without any selection of the embryos. A comparison was made between the method described by Renard et al. (7) and a method slightly modified from that published by Leibo (8). The feasibility is proved by a mean pregnancy rate of 41.4%. Although the difference was not statistically significant, the method described by Renard et al. (7) led to a higher pregnancy rate (44.7%) than that of Leibo (8) (38.5%).