This research was investigated the relationship between the number of the transferable embryos and estrus expression rate, BCS (Body Condition Score), which affect the nutritional state of the cow, in Holstein donor cows. CIDRs were inserted into the vaginas of twenty two head of Holstein cows, regardless of estrous cycle. Superovulation was induced using folliclar stimulating hormone (FSH). For artificial insemination, donor cows were injected with and estrus was checked about 48 hours after the injection. Then they were treated with 4 straws of semen 3 times, with 12-hour intervals. Embryos were collected by a non-surgical method 7 days after the first artificial insemination. When BCS was 2.5, the total number of collected ova was 7.3 + 1.9, which is significantly lower (p<0.05) than the numbers 15.4 + 2.8 and 15.4 + 2.1 that were obtained when BCSs were 2.75 and 3.0, respectively. Whereas the numbers of transferable embryos were 5.2 + 1.4 when BCS was 2.5, which was smaller than the numbers 6.0 + 2.1 and 8.5 + 1.8 that were obtained when BCSs were 2.75 and 3.0, respectively; however, the differences were not significant. As for estrus induction rate, the cow groups whose BCSs were 2.75 and 3.0 showed 100.0% and 95.0%, respectively. Whereas the cow group whose BCS was 2.5 showed 57.1%, and the differences were significant (p< 0.05). As for estrous expression rate, the cow groups whose BCSs were 2.5, 2.75 and 3.0 showed 100.0%, 100.0% and 85.7%, respectively; however, the differences were not significant. According to the result of this research, it is considered that the total number of collected ova and the number of transferable embryos will be affected by the nutritional state before and after in vivo embryo production and superovulation treatment, and that although the mechanism is not clear, poor stockbreeding management and nutritional level would cause the decrease of ovum recovery rate and the number of transferable embryos in high-producing cows. On the other hand, diverse researches on the superovulation treatment method that is suitable for high-producing Holstein donor cows would contribute to preventing ovarian cyclicity disorder, as well as to the early multiplication of cows with superior genes by increasing the utilization value of donor cows.

This research was investigated the relationship, in high-producing Holstein donor cows, between the number of the transferable embryos and the blood serum concentrations of Blood Urea Nitrogen (BUN), glucose and cholesterol, which affect the nutritional state of cows. CIDRs were inserted into the vaginas of twenty two heads of Holstein cows, regardless of estrous cycle. Superovulation was induced using folliclar stimulating hormone (FSH). For artificial insemination, donor cows were injected with and estrus was checked about 48 hours after the injection. Then they were treated with 4 straws of semen 3 times, with 12-hour intervals. Embryos were collected by a non-surgical method 7 days after the first artificial insemination. The total numbers of ova collected from 3 experimental groups whose blood BUN concentrations were <10 mg/dl, 11~18 mg/dl and mg/dl were 8.9, 12.5 and 19.0, respectively; whereas the numbers of transferable embryos were 5.8 + 1.9, 7.9 + 2.8 and 5.2 + 1.4, respectively. When glucose concentration was <60 mg/dl, the total number of collected ova was 9.9, which was smaller than when the concentration was 60~70 mg/dl or mg/dl. When glucose concentration was 60~70 mg/dl, the number of transferable embryos was 7.1 + 2.4, which was slightly larger than the numbers 6.4 + 2.1 and 6.1 + 1.7 that were obtained when the concentrations were <60 mg/dl and mg/dl, respectively ; however, the differences were not significant (p>0.05). When cholesterol concentrations were <150 mg/dl, 150~200 mg/dl and mg/dl, the total numbers of collected ova were 11.2, 11.3 and 8.6, respectively. Whereas the numbers of transferable embryos were 7.1 + 2.1, 7.3 + 1.9 and 5.6 + 1.3, respectively ; however, the differences were again not significant (p>0.05). The result of this research showed no significant difference in ovum recovery rate and the number of transferable embryos according to major metabolite concentrations in high-producing Holstein donor cows. However, it is considered that the failure of maintaining proper nutritional status would cause the fall in in vivo embryo productivity.

The objective of this study was to investigate the relationship between body weight, body condition score (BCS), blood urea nitrogen (BUN), glucose, cholesterol and number of transferable embryos for the purpose of improving reproductive performance in Hanwoo donors. Seventy five cows, at random stages of the estrous cycle, received a CIDR together with injection of 1mg estradiol benzoate and 50 mg progesterone, and gonadotropin treatment begann. 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 3rd administration of FSH, CIDR was withdrawn and 25 mg was administered. Cows were artificially inseminated twice after estrous detection at 12 hr intervals. The cows received GnRH at the time of 1st insemination. Embryos were recovered 7 days after the 1st insemination. In conclusion, cows with body weight < 400, 400~450 and > 450kg had number of transferable embryos of , and , cows with BCS <2.25, 2.25~2.75 and had number of transferable embryos of , and respectively. These data indicate that a body weight and BCS for superovulation of CIDR-treated Korean native cows does not affect the embryo yield.

The objective of this study was to investigate the relationship between estrous expression, body condition score (BCS), blood urea nitrogen (BUN) and number of transferable embryos for the purpose of improving reproductive performance in blood of Hanwoo donors. Sixty, 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 1nd insemination. Embryos were recovered 7 or 8 days after the 1st insemination. The estrous inducement rate and estrous expression rate were significantly lower for cows with BCS below 2.25 than for cows with BCS above 2.25. There was 50.0% of rate of mounting in cows with BCS below 2.25 whereas the rate of mounting was markedly increased in cows with BCS above 2.25 (94.1% and 89.5% for BCS 2.25～2.75 and BCS above 2.75 cows, respectively). Cows with BCS ＜2.25, 2.25～2.75 and ≥2.75 had number of transferable embryos of 4.5±0.7, 5.9±1.8 and 5.6±2.3 respectively.

The objective of this study was to investigate the relationship between concentration of urea nitrogen, glucose, cholesterol and number of transferable embryos for the purpose of improving reproductive performance in blood of Hanwoo donors. Fifty five, 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 100μg GnRH at the time of 1nd insemination. Embryos were recovered 7 or 8 days after the 1st insemination. Cows with BUN ＜10, 11～18 and ≥19 mg/dl had number of transferable embryos of 4.3±1.3, 5.8±1.8 and 4.7±2.1 respectively. The mean numbers of total ova from < 10 and 10≤ of corpora lutea(CL) was 8.9 and 14.3, respectively. The number of transferable embryos differed between < 10 and 10≤ CL was 4.8 and 5.6, respectively.