Abstract: In this experiment, morula and blastocyst were bisected in three different partition liquid with micromanipulator.Demi-embryos were cultured and then the development rate was observed. Bisected embryos were co-transferred with trophoblastic vesicles (TRV).The results showed that morula were bisected in PBS +0.2 mol/L sucrose and PBS+5% PVP，splitting success rate significantly higher than in PBS (89.13%,86.73% VS 69.67%) (P<0.05),and the blastocysts rate and pregnancy rate were no significant difference (P>0.05); in PBS +0.2 mol/L sucrose and PBS+5% PVP in the bisection of blastocysts，splitting success rate significantly higher than in PBS (94.52%,92.52% VS 70.52%) (P<0.05), the blastocysts rate and pregnancy rate were no significant difference (P>0.05); the PBS were added in 0.2 mol/L sucrose and 5% PVP will help to improve splitting success rate of the dairy cow morula and blastocyst.

Key words: dairy cows; embryo bisection; the blastocysts rate; TRV; co-transferred; pregnancy rate