Embryo Recovery by Direct Embryo Collection (DEC) in Korean Native Cattle (Hanwoo)

This study was performed in order to simplify the operation and minimize stress of donor and be readily available in the field with low cost and high quality embryos using the Direct Embryo Collection (DEC). Donors, at random stages of the estrous cycle, received a CIDR. 7 days later, 200 mg FSH was treated with 40, 30, 20, 10 mg FSH levels in declining doses twice daily by intramuscular injection for 4 days. On the 3rd day administration of FSH, 25 mg PGF₂α was administered and CIDR was withdrawn. After FSH injections were complete, donors were artificially inseminated twice at 12 hr intervals. The donor cattle received 250 ㎍ GnRH at time of 1 st insemination and embryos were recovered 8 days after the 1st insemination. Embryo collection from superovulated donors was performed to flushing by non-surgical methods of 3-way, 2-way and DEC (l-way). The average number of recovered embryos were 11.25±0.63, 12.5±0.65 and 11.75±0.48 from operations of 3-way, 2-way and DEC methods, respectively. There were no significant differences among the embryo collection methods. Also, The average number of transferable embryos were 6.25±0.48, 7.25±0.48 and 7.25±0.63 from each embryo collection procedures. The number of transferable embryos was no differences among the 3-way, 2-way and DEC methods, respectively. Meanwhile, the ratio of transferable embryos for all recovered embryos from DEC methods was higher as 61.7 % than 55.6 %, 58 % from methods of 3-way, 2-way. And the flushing solution required for recovering embryos by DEC method was significantly lower as 0.28±0.32 1 than 1.8±0.12 1, 1.75±0.10 1 from 3-way, 2-way methods (p less than 0.05). Also, the time required for recovering embryos by DEC methods was significantly lower as 27±2 min than 51±3, 45±2 min, respectively (p less than 0.05). In conclusion, these results suggest that DEC method for embryo collection may be effectively used for production of in vivo embryos using less flushing solution and, it might be effectively available in the field compared to conventional embryo recovery methods using 3-way or 2-way balloon catheter.