Production of Korean Native Calf by In Vitro Maturation, Fertilization, Cultivation and Transfer of Embryos into Holstein Cows

체외성숙, 수정 및 배양된 한우 체외수정란의 유우이식에 의한 산자 생산

The objective of this study was to produce Korean native calves following transfer of in vitro matured, fertilized and cultured embryos into Holstein cows. The ovaries of Korean native cows or heifers were obtained from an abattoir and kept on 25 to 28$^{\circ}C$ and transported to laboratory within 2 hrs. The oocytes were matured in vitro (IVM) for 24 hrs in TCM-199 supplemented with 35$\mu\textrm{g}$/ml FSH, 10$\mu\textrm{g}$/ml LH, 1$\mu\textrm{g}$/ml estradiol-17$\beta$ and granulosa cells at 39$^{\circ}C$ under 5% CO2 in air. They were fertilized in vitro (IVF) by epididymal spermatozoa treated with heparin for 24 hrs., and then the zygotes were co-cultured in vitro (IVC) with bovine oviductal epithelial cells for 7 to 9 days. Late morulae and blastocysts produced in vitro were nonsurgically transferred to recipient cows by unilaterial. Recipients were monitored for estrus and for pegnancy by rectal plapation in 60 days after embryo transfer. One of them was pregnant to term and produced a female weighing 42.5kg at birth.