The objective of this study was to apply the multiple ovulation and embryo transfer (MOET) program practically in dairy herds. Forty five superior Holstein cows ranked in 5% according to Type-Production Index(TPI) in Korea were selected as donors. The donors were superovulated with pFSH and the embryos collected from donors were frozen and preserved. The preserved embryos and frozen Holstein embryo imported from foreign country were thawed and transferred to recipients. The results obtained were as follows; 1. The total number of ova and freezable embryos collected per donor was 6.5 and 2.8, respectively. 2. The freezable embryos were obtained more(p<0.05) when the body condition score (BCS) of donors was in range of 2.50∼3.25(4.1) than in range of 3.50∼4.00(1.9), while the total number of ova was not changed. 3. The season affected on the collected number of freezable embryos(6.1 in winter, 4.5 in fall, 1.1∼1.5 in spring and summer, P<0.05), and the total number of obtained ova were more in winter than in other seasons(P<0.05). 4. Embryos were transferred to 343 recipients and 152 cows were confirmed pregnant(44.3%). 5. The higher pregnancy was obtained (P<0.05) when embryos were transferred in summer(53.3%) than in fall(36.0%), while the pregnancy rate was not affected by the origin and developmental stage of embryos, and the parity, BCS and estrus induction of recipients. From these results, the pregnancy rate was considered to be acceptable for the embryo transfer with domestic or imported Holstein embryos, however embryo production from superior Holstein donors was unsatisfactory for application of MOET scheme.

다배란 수정란이식(MOET)과 체외수정(IVF)기술을 이용한 육종체계에서 예상되는 유전적 개량량을 여러 집단의 크기에서 비교한 결과 체외수정기술이 MOET육종기술보다 특히 개량대상 유전력이 낮을때 훨씬 효율적으로 나타났다. 그러나 유전력이 높아지면 (h=0.3, 0.5), MOET와 IVF간의 상대적 차이는 미진하게 나타났다. 체외수정을 이용한 육종기술에서 암컷의 선발 강도는 대단히 높일 수 있는 반면 난자의 회수율이 많을수록 상대적으로 수컷에 대한 선