May 23, 1991 (, Xinwei In April the tenth), the world's first test-tube embryos frozen test tube sheep was born to save the transplant.

1991 23, the world's first test-tube embryo cryopreservation transplant test tube sheep successfully born in Inner Mongolia University Laboratory Animal Research Center. The only full-term normal delivery of sheep for the male, weighing 3.2 kg. To verify this achievement as the world's first international online retrieval. This is the center since 1989, China's first child, the first "test-tube sheep" test-tube cow, achieved a major breakthrough in animal embryo engineering. The success of the in vitro embryo technology, the process of accelerating livestock production, sheep breed improvement and utilization of sheep embryos in vitro embryo engineering and gene engineering technology has important practical value. (L $ dj��.c��m)