Abstract: Fleckvieh beef cattle and Japanese Black beef were used as donor,local cattle as receptors in this study,then estrus synchronization and superovulation were conducted, and 234 embryos were obtained,of which were divided into four groups,including 113 fresh whole embryos,55 fresh double half embryos ,56 frozen whole embryos and 10 frozen double half embryos. The transplantation effect of whole embryo and double half embryo were detected. The results indicated that the pregnancy rate of fresh double half embryo was 65.45%,which was higher than fresh whole embryo group(63.72%),but no significant difference(P＞0.05).Frozen double half embryo group was 20.00%,which was not significantly lower than the corresponding whole embryo group(39.29%)(P＞0.05).However,both frozon groups were significantly lower than fresh groups. The calving rate of fresh double half embryo was 95.56%,of which 35.55% were twins and 72.09% were survived. The calving rate of fresh whole group was 63.16%,which was significantly lower than the fresh double half group(P＜0.05),but the surviving rate was significantly higher than the fresh double half group(90.00% and 72.09%)(P＜0.05). As for the birth weight,there was no significant difference among all of the four groups.

Key words: embryo bisection; double half embryo; pregnancy rates; calving rate; birth weight