Abstract: In this experiment, it was designed to carry out superovalation on the two cloned cattle, vitrification and transfer of the embryos recovered from them. First of all, it was carried out vitrification on embryos obtained by IVF. Results showed that there was no significant difference between the blastocysts (obtained by IVF) vitrified in EPS10 and these in EPS20 in the resuscitative rate and the developmental rate. The hatched rate of the blastocysts vitrified in EPS10 (31.3%,35/112) was significantly higher than that in EPS20(12.2%,13/107)(P<0.01), so EPS20 was selected as the vitrification solution to freeze the embryos recovered from the cloned cattles. After superovulation, six (four usable embryos) and ten (nine usable embryos ) embryos were respectively recovered from "Kang kang"and "Shuang shuang". Two embryos were selected from the recovered embryos of each cloned cattle to freeze in EPS20, subsequently thawed and transferred into ipsilateral horns of 4 Holstein recipient cows after synchronization of estrus, respectively. At last, one recipient cow (No 9908) became pregnant and delivered one healthy calf (descendant of the cloned cattle-"Shuang Shuang").The results of this experiment shows that the cloned cattle as well as common cattle had better response to the exotic FSH and better ability to multiovulation, the embryos recovered from the cloned cattle can be vitrificated.

Key words: Cloned cattle, Superovulation, Embryo, Vitrification