This study examined pregnancy and fetal loss rates according to different estrus synchronization protocols and injection of gonadotropin releasing hormone (GnRH) after transfer of Korean Native Cattle embryos to Holstein recipients. In Experiment 1, recipients received no treatment (Control, n = 119); two injections of prostaglandin ( ) 11 days apart (PGF group, n = 120); GnRH (day 0)- (day 7)-GnRH (day 9) (Ovsynch group, n = 120); and CIDR (day 0)- and CIDR removal (day 7)-GnRH (day 9) (CIDR group, n = 110). In Experiment 2, the control group was received no treatment of GnRH. The treatment groups were received GnRH at embryo transfer (ET) (day 0), 7 days later, 14 days later, ET and 7 days later, 7 and 14 days later, or ET, 7 and 14 days later. Recipients were assigned to treatment randomly and received two in vitro produced blastocysts. Pregnancy was diagnosed at day 60 by palpation per rectum. Fetal loss to term was determined by palpation every 90 days thereafter. In Experiment 1, the pregnancy rate in the CIDR group (59.1%) were higher than in the Control group (42.0%) (p<0.01); fetal loss rates were similar for all groups (12.0 to 18.5%). In Experiment 2, the pregnancy rate in Day 0+7+14 group was higher (60.2%) than the control (40.2%) (p<0.01) and resulted in a lower fetal loss (p<0.05) than the control (4.6 vs. 11.4%). There were no significant difference between other treatment and the control (p>0.05). These results show that pregnancy rates of bovine embryos can be enhanced by CIDR insertion or GnRH treatment. Additionally, fetal loss may be reduced with GnRH treatment after ET.
이 연구는 자연조건, 지형조건, 시설조건 및 다른 선박과의 상대적 위치 관계 등의 특정한 운항환경에서 조선자가 갖는 심리적 부담을 계량화하고, 이를 통해 해상교통의 안전성을 평가하는 환경스트레스 모델을 적용하여 부산항 접근수역의 현행 통항분리방식과 선행 연구에서 제안한 원형분리대방식에 의한 해상교통의 안전성을 상호 비교하여 그 타당성을 검증하고자 한다.