The objective of this study was investigate the superovulation treatment and to relate concentrations of blood urea nitrogen(BUN) in Hanwoo donors. Thirty six, at random stages of the estrous cycle, received a CIDR. Four days later, the animals were superovulated with a total of 28AU FSH (Antorin, 2AU=1 ml) administered twice daily in constant doses over 4 days. On the 3th administration of FSH, CIDR was withdrawn and 25 mg PGF2α was administered. Cows were artificially inseminated twice after estrous detection at 12 hr intervals. The cows received 100 μg GnRH at the time of 1st insemination. Embryos were recovered 7 or 8 days after the 1st insemination. Cows with BUN ＜10, 11～18 and ≥19 mg/dl had return of estrus of 34.6, 30.5 and 30.4 days respectively. Return of estrus after superovulation treatment was not significantly lower for cows with blood urea nitrogen (BUN) above 10 mg/dl than for cows with BUN below 10 mg/dl. Cows with BUN ＜10, 11～18 and ≥19 mg/dl had number of transferable embryos of 3.2±1.2, 5.4±1.9 and 4.1±2.1 respectively.

본 연구는 번식 효율 증진을 위해 BCS, BUN과 발정 발현과의 관계를 조사하였으며, 공시된 홀스타인 젖소 51두 중 37두에서 배란 및 28두에서 발정 발현을 확인하였다. 발정 유기율에서 BCS 와 인 우군에서는 각각 78.9% 및 73.9%인 반면 2.0 미만인 우군에서는 55.6%로 유의적인(p<0.05)차이를 보였으며, 발정 발현율과 승가 허용율에서도 BCS 인 우군에서 각각 73.3% 및 46.7%이고 BCS 인 우군은 각각 88.2% 및 6