To establish the optimal culture systems for production of transferable embryos in Korean Cattle, pregnancy rates of IVF-derived blastocysts according to different culture media, culture method and culture duration were compared. Development of IVF-derived embryos to blastocysts was most effective in YS medium group co-cultre with cumulus cells. Blastocysts cultured for 6 to 8 d in vitro showed higher hatching rate and good quality. Pregnancy rates after transfer of IVF-derived blastocysts cultured for 7 or 8 d were high. Through our experiments, it is considered that improvement of culture media and culture method is necessary for mass production of blastocysts with excellent of good quality in Korean Cattle.

• 박흠대(대구대학교 공과대학 생물공학과)
• 김종환(한경대학교 동물생명자원학과)
• 정덕수(한경대학교 동물생명자원학과)
• 이동칠(한경대학교 동물생명자원학과)
• 김주환(한경대학교 동물생명자원학과)
• 윤산현(한경대학교 동물생명자원학과)