This study is to compare the effect of estrus synchronization and embryo transfer between Korean and Mongolian cattle. Embryos were collected from 9 donors housed in Asan city in South Chungcheong Province, South Korea. Embryos were collected 9 donors from Khushaat sum, Selenge province and Bayanchandmani sum, Tov province in Mongolia. Follicle Stimulating Hormone (FSH), Controlled Internal Drug Release (CIDR) and Prostaglandin (PG) were used for superovulation. Subsequently, Artificial Insemination (AI) was done for donor cow and embryo was collected after 7 and 8 days. Collected embryos were compared between Mongolian and Korean cattle. Finally, good quality and fresh embryos were transferred to 50 and 22 recipients of cows in Korea and Mongolia respectively. The findings show that Korean native cattle each donor cow produced on an average 16.9 embryos and, 10.9 embryos were found transferable. But in case of Mongolia the average production of embryos per donor cow was 8.6 embryos and, 6.2 embryos were found transferable. Embryo collection after 7 and 8 days was not difference in embryo production in Korea. But, in Mongolia embryo production after 8 days was found more efficient than the 7 days. Korean native recipient's cows (74.6%) and Mongolian recipient's cows (71.0%) respectively were found transferable ovarian stage. The result suggested that efficiency of embryo production from the superovulation method treated of Korean cow were higher than the Mongolian cow. The pregnancy rate of Korea native cattle was 72%, which was about 10% higher than that of Mongolia cattle.

INTRODUCTION
 MATERIALS and METHODS
  1. Experiment Animals
  2. Superovulation treatment and artificial insemination (AI) of Donor Cow
  3. Embryo collection and evaluation
  4. Embryo Transfer and Pregnancy Assessment
  5. Statistics
 RESULTS
  1. Embryo production of Korean and Mongolian Donor Cattle
  2. Embryo production according to flushing days after AI of Korean and Mongolian cattle
  3. Comparison of recipient cow effect of ovary status between Korean and Mongolian cattle
  4. Comparison of conception rates embryos transfer to Korean and Mongolian cattles
 DISCUSSION
 ACKNOWLEDGEMENTS
 REFERENCES

• Gantugs Chuluundorj(Animal Biotechnology, Graduate School of Bio and information Technology, Institute of Genetic Engineering Hankyong National University, Anseong, Kyeonggido, Korea.)
• Lee Ho-Jun1(Animal Biotechnology, Graduate School of Bio and information Technology, Institute of Genetic Engineering Hankyong National University, Anseong, Kyeonggido, Korea.)
• Son Dong-Soo(National Research Foundation of Korea(NRF), Seoul, Korea)
• Enkhmanlai Ganbaatar(Department of Biotechnology and Breeding, School of Animal Science and Biotechnology, Mongolian University of Life Sciences, Ulaanbaatar, Mongolia.)
• Baldan Tumur(Department of Biotechnology and Breeding, School of Animal Science and Biotechnology, Mongolian University of Life Sciences, Ulaanbaatar, Mongolia.)
• Yoon Jong-Taek(Animal Biotechnology, Graduate School of Bio and information Technology, Institute of Genetic Engineering Hankyong National University, Anseong, Kyeonggido, Korea.) Correspondence