본 연구에서는 한우 체외수정란의 이식에 있어서 수정란 측 요인들이 수란우의 임신과 유산에 미치는 영향을 검토하였다. 이식에 제공하는 배반포의 수량에 따른 임신율은 1개, 2개 및 3개 이식 군에서 각각 32, 44 및 $32\%$였고, 유산율은 $6.3~13.6\%$로서 2개 이식군의 임신율과 유산율이 가장 높았으나 유의차는 인정되지 않았다. 배반포 등급에 따른 임신율은 $40.8~44.2\%$, 유산율은 $9.4~16.3\%$로서 유사한 경향이었다. 배반포의 발생 단계에 따른 임신율은 $39.1\%~45.3\%$로서 비슷하였으나, 유산율은 HB군$(20.8\%)$이 LB군의 $9.0\%$에 비해서는 유의하게 높았다(p<0.05). 배반포의 발생일령에 따른 임신율은 배반포 $7cdot7$일째와 $7cdot8$일째가 각각 $47.1\%$와 $53.9\%$로서 $9cdot9$일 및 $8cdot9$일째(29.8 및 $R27.7\%$)에 비해 유의하게 높았다(p<0.05). 유산율은$8cdot9$일령이 $30.8\%$로 가장 높았고 $7cdot7$일령의 $10.1\%$와는 유의차가 인정되었다.
In this study, we investigated the effects of number, grade, stage and day of embryos on pregnancy and abortion rates of Holstein heifer recipients after transfer of in-vitro produced Korean Native Cattle (Hanwoo) embryos. When one, two or three blastocysts were transferred to recipients, pregnancy (32.0, 44.0 and $32.0\%$) and abortion (12.5, 13.6 and $6.3\%$) rates did not differ among treatments. The pregnancy and abortion rates of different grades of blastocysts were $40.8~44.2\%;and;9.4~16.3\%$, respectively. However, they were not significantly different. According to the stage of blastocyst, the pregnancy rates were similar between $39.1\%;and;45.3\%$. However, the abortion rate in hatched blastocyst stage $(20.8\%)$ was significantly higher than that in late blastocyst stage $(9.0\%)$. The pregnancy rates in day $7cdot7$ and day $7cdot8$ blastocyst (47.1 and $53.9\%$, respectively) was significantly higher than that in the day $9cdot9;and;8cdot9$ blastocyst (29.8 and $27.7\%$, respectively). The abortion rate was the highest in the day $9cdot9$ blastocyst $(30.8\%)$ among treatments, and it was significantly different compared to that in the day $7cdot7$ blastocyst $(10.1\%)$. Therefore, this study suggested that the pregnancy rate was affected by only day of embryos, while the abortion rate was affected by stage and day of embryos.
