초록
This study was carried out with 46 cows to investigate the ovarian response to the administration of PMSG, PGF2$\alpha$ and hCG, and the developmental stage of embryos recovered. Superovulation was induced by the injection of 2,000IU to 3,000IU PMSG on the days of 7-13 of the estrus cycle followed 48 hours later by the injection of 22.5mg PGF2$\alpha$. Of 29 cows treated with 3,000IU PMSG and 22.5mg PGF2$\alpha$ 18 cows were given 2,000IU hCG at the onset and 7 after artificial insemination. The results obtained were summarized as follows; 1. The number of developed follicles per cow after an injection of 2,000, 2,500, 3,000IU of PMSG and 3,000 PMSG-2,000IU hCG in combination with 22.5mg PGF2$\alpha$ were 12.6, 19.6, 21.5 and 29.3, respectively. This result indicated that the no. of developed follicles per cow was increased according to the increase of PMSG dosage and the combination with hCG injection. 2. The highest number of ovulation was 17.1 in cows treated with PMSG-hCG and the number of matured corpus luteum was increase as the dosage of PMSG was higher. 3. Ovulation rate from cows treated with 2,500IU PMSG was 71.0% and this reulst was higher than the average of ovulation rate (59.3%). 4. Average recovery rate was 36.8%(232/631), and the number of ova per cow was 5.0. 5. Of 232 recovered embryos, the number of morulae and blastocysts were 76 (32.8%) and 83 (35.8%), respectively. 6. 28.4% of total recovered embryos was abonormal morphologically.