The objective of this work was to determine the effect of corpus luteum (CL) grade on pregnancy rate after embryo transfer in Korean cattle and we found that CL development was linked to pregnancy rate. The in vivo derived blastocyst-stage embryos were transferred to 15 recipients synchronized in the estrus cycles. Based on size and palpable characteristics, CLs were categorized into three grade. The grade three CL is not to be identified by rectal palpation. The pregnancy rates tended to increase with the increase in CL size of recipients. In grade one, two, and three, the pregnancy rates were 62.5%, 50.0%, and 0%, respectively. This result suggests that pregnancy rates after embryo transfer might be affected by the CL status of recipients.

• 최창용(농촌진흥청 국립축산과학원)
• 손준규(농촌진흥청 국립축산과학원)
• 조상래(농촌진흥청 국립축산과학원)
• 강다원(경상대학교 의학전문대학원 생리학교실)
• 연성흠(농촌진흥청 국립축산과학원)
• 최선호(농촌진흥청 국립축산과학원)
• 김남태(농촌진흥청 국립축산과학원)
• 정연섭(농촌진흥청 국립축산과학원)
• 김성재(농촌진흥청 국립축산과학원)
• 정진우(농촌진흥청 국립축산과학원)
• 복난희(농촌진흥청 국립축산과학원)
• 최진석(농)