The aim of this study was to evaluate the effect of α-tocopherol on blastocysts development and subsequent cryosurvival of the vitrification. The α-tocopherol(0, 100, 200, 400 μM) was added in to culture medium for the bovine embryos. The blasocysts from the α-tocopherol and untreated control groups were then frozen-thawed, and their cryosurvival was assessed by in vitro culture for 48 h. There were no differences in the overall cleavage rate(56.14±4.66, 58.18±4.70, 62.97±6.86 and 51.17±7.28) among four treatment groups. However, in blastocyst development and total cell number were significantly higher in α-tocopherol 200 μM(38.60±7.12; 106.33±3.50) to culture medium than other treatment groups(29.30±5.24, 31.60±7.12 and 26.37±4.18; 101.36±5.12, 97.27±2.87, and 91.23±7.52 respectively). Before and after vitrification, the total cell number and blastocyst development of embryo were significantly higher in July to August than September to October. In conclusion, addition of α-tocopherol 200 μM to in vitro bovine embryo culture medium was beneficial for improving embryo quality by decreasing the embryo damage blsstocysts cell number and improving the tolerance of the embryos to cryopreservation.

본 연구는 기존의 수정란 이식기술을 다각적으로 분석하고 개선하여 한우 체내수정란의 생산 및 이식기술 체계를 확립하기 위하여 수행하였다 수정란의 생산 및 이식은 농협중앙회 가축개량사업소 한우개량부에서 사육하고 있는 공란우 232두와 수란우 434두를 이용하여 실시하였다. 본 연구에서 얻어진 결과를 요약하면 다음과 같다. 1. 수란우의 황체 위치와 등급에 따라 수정란이식을 실시한 결과는 오른쪽 난소의 A등급 황체, 왼쪽 난소의 B등급 황체가 존재할 경우가

본 연구는 기존의 수정란 이식기술을 다각적으로 분석하고 개선하여 한우 체내수정란의 생산 및 이식기술 체계를 확립하기 위하여 수행하였으며, 결과를 요약하면 다음과 같다. 1. 배란에 미치는 FSH analogue 간의 유의성은 인정되지 않았으나 수정률, 이식 가능 수정란 및 동결수정란 생산에는 처리간에 유의성(P<0.05)이 인정되었다. 특히, Super-OV는 Foll-tropin-V 및 Embryo-S에 비해서 이식 가능 수정란의 생산율이 유의적(P<

This study was carried out to establish an effective system for embryo transfer of techniques by analyzing several factors affecting the gestation length and the weight changes of calves produced from embryo transfer in Korean cattle. The results obtained in study on factors affecting the gestation length and the weight changes of calves produced from embryo transfer were as fallow; 1) The gestation length and the birth weight did not differ between male and female, but the weight changes after birth were remarkablely different between sex(P<0.05). 2) The gestation length between heifers and cows was not different, and body weights at birth and 6 months were remarkabley heavy in cows(P<0.05). Weight changes after 6 months were not different. 3) The gestation length and the birth weight were significantly different between the single and twin calving (P<0.05). Weight of twin at 6 and 12 months were remarkabely light. 4) Calving seasons did not affect the gestation length the and the birth weight. Weaning weight was significantly heavy(P<0.05), but weight changes after weaning were no different among the calving seasons. Conclusivley, this results suggest that cows will be better when considering growth of calves and twin produced from embryo trnsfer in Korean cattle.

This study was carried out to establish an effective system for embryo transfer techniques by analyzing several factors affecting in-vivo embryo transfer in Korean cattle Embryos were transferred into a toral of 301 recipients. The results obtained in studies on the factors affecting pregnancy rate after embryo transfer by condition of transfer time were as follows ; 1. The pregnancy rate by the seasons of transferred fresh and frozen embryos were not different, but the pregnancy rate was slightly higher in summer(80.8%). 2. The pregnancy rate by the days of embryo transfer after estrus were not different when fresh embryos were transferred, but the pregnancy rate was highest at 8 days when frozen embryos were transferred(P<0.01, 40.0%). 3. The pregnancy rate at estrus synchronization was remarkably higher with PGF treated than natural (P<0.05, 70.4%, 43.4%). 4. The pragnancy rate by the degree of estrus synchronization was best when the estrus was synchronized in both fresh and frozen embryos (83.3% and 29.7%, respectively), but the pregnancy rate was not different among 2 days. But the pregnancy rate of frozen embryos were slightly higher when the recipients exhibited estrus earlier than donors.

This study was carried out to establish an effective system for embryo transfer techniques by analyzing several factors affecting in-vivo embryo transfer in Korean cattle. Embryos produced in-vivo were transferred into a total of 301 recipients The results obtained in studies on the factors affacting pregnancy rate after embryo transfer by condition of recipients were as follows ; 1. The pregnancy rate by age and parity of recipients showed high in 5~8 and over 12 years old(72.7~73.9%), and 3rd~4th parity(82.1%) for fresh embryos(P<0.05). The pregnancy rate did not differ by age and parity of recipients in frozen embryos. The pregnancy rate of frozen embryos tended to be similar to that of fresh embryos(38.5% and 25.0~36.7%). 2. The number of observation for normal estrus cycles of recipients did not differ In pregnancy rate between one and 2 times in fresh embryos(64.9%, 69.8%). The pregnancy rate by transferred frozen embryos showed significantly higher after 2 times of observation(P<0.05, 16.3%, 37.5%). The pregnancy rate by days open did not differ between fresh and frozen embryos. But the pregnancy rate was slightly higher in 12 months and 6 months of days open for fresh and frozen embryos, respectively(70.1~71.1% and 24.5%, respectively). 3. The pregnancy rate of transferred fresh and frozen embryos into right and left side of uterine horn did not differ(62.1% : 65.9% 25.0% : 24.3%, respectively). The pregnancy rate by the grade of CL was not different in fresh embryos, but the pregnancy rate was significantly higher in the grade A than B for frozen embryos(P<0.01, 43.2%, 16.2%).

This study was carried out to establish an effective system for embryo transfer techniques by analyzing several factors affecting in-vivo embryo transfer in Korean cattle. Embryos produced in-vivo were transferred into a total of 301 recipients. The results obtained in studies on the factors affecting pregnancy rate after embryo transfer by condition of embryos were as follow ; 1. The pregnancy rate of 301 recipients was 45.2% and higher with fresh embryos than with frozen embryos(63.5% : 21.4%, P<0.01). Embryos superovurated by FSH-P had slightly greater than by SUPER-OV in pragnancy rate, athough these were no difference between two treatments. 2. The pregnancy rates of transferred morulae and blastocysts showed no difference between fresh and frozen embryos(63.5% : 63~6% ; 20.0% : 25.8%). However, the pregnancy rates by quality of flesh and frozen embryos were significantly different(P<0~05). The pregnancy rates were outstandingly high in the grade A, B of fresh embryos(59.0~66.4%), and in the grade A of frozen embryos(43.6%). 3. The number of transferred embryos showed no difference in pregnancy rate, but when frozen embryos transferred, the pregnancy rate was slightly higher with two embryos than that with one embryo.

This study was carried out to establish an effective and practical system for commercialization of embryo production techniques by analyzing several factors influencing in vivo embryo production on days and seasons of flushing in Korean native cattle. In vivo embryos were flushed 226 times from 128 donors. The results obtained for the factors influencing in vivo embryo production on days and seasons of flushing were as follows :1.The percentages of fertilized, transferable and freezable embryos by seasons were significantly different in both FSR-P and SUPER-OV(P<0.01). The percentages of them were highest in sunrrner with FS H-P and highest in autumn with SUPER -OV.2. The production of transferable and freezable embryos by flushing days was highest in 8 days with FSH-P, and there was no difference between 7 and 8 days for SUP ER-OV. 3. The failure rates of recovery were 17.0% in SUPER-OV and 21.2% in FSH-P, respectively. The donors superovulated but failed recovery were 8.5% in SUPER-OV and 12.9% in FSH-P, respectively. Nonsuperovulated donors was 8.4% and donors giving less than 2 eggs at recovery was 8.4% in both FSH -P and SUPER-OV 4. The donors returned to normal estrus after superovulation were 34.1% after 1 cycle,39.4% after 2 cycles, and 16.7% after 3 cycles by FSH-P, respectively. For SUPER-OV, they were 55.3, 33.0 and 9.6%, respectively. Generally, normal estrus after the treatment of superovulation was earlier and the occurrence of ovarian cyst was also lower in SUP ER-OV than in FSH-P.5.The percentages of blastocyst in embryos flushed at 7~8 days after estrus were 21. 9% and 54.3% in FSH -P and SUPER-OV, respectively. The development of embryos was faster in SUPER-OV than in FSH-P.(Key words : in vivo embryo, flushing days, superovulation, FSH-P, SUPER-OV)

This study was carried out to establish an effective and practical system for commercialization of embryo production techniques by analyzing several factors influencing in vivo embryo production on condition of donors treated FSH-P and SUPER-OV in Korean native cattle. In vivo embryos were flushed 226 times from 128 donors. The results obtained for the factors influencing in vivo embryo production by conditionof donors treated FSH-P and SUPER-OV were as follows :1. Age and parity of donors did not affect the transferable and freezable embryos among the treatments in FSH-P but the transferable and freezable embryos were decreased after 6 years old and 4th parity in SUPER-OV(P<0.01). 2. The production of embryos on the weight of donors was higher in over 400kg of body weight in FSH-P(P<0.01) and was higher in over 450kg than 400~450kg of body weight in SUPER-OV(P<0.05). For FSH-P embryo production was better responded in 350~450kg of body weight with 30~32mg doses, and showed a better result in over 450kg body weight with 32~34mg doses.(Key Words : in vivo embryo, donors, FSH-P SUPER-OV)

I. The Factors Influencing In Vivo Embryo Production by Condition of Superovulation Treatment These studies were carried out to establish an effective and practical system for comrnercialization of embryo production techniques by analyzing several factors influencing in vivo embryo production on superovulation treatment in Korean native cattle. In vivo embryos were flushed 226 times from 128 donors.The results obtained from the studies on the factors influencing in vivo embryo production by superovulation treatment were as follows : FSH-P had a significiant advantage(83.0%) over SUPER-OV in the percentage of fertilized embryos(P<0.01). No difference was found loetween FSH-P and SUPER-OV in the percentage of transferable and freezable embryos.2. The response of superovulation by SUPER-OV was greater than that of FSH-P The donors having 8~9 and more than 10 of corpora lutea(CL) derived by FSH-P were 40.0%(most frequent) and 33%, respectively. The donors having more than 12 and 10 CL derived by SUPER -OV were 33.3% (most frequent) and 56.6%, respectively.3. Embryo production after treatment of repeated superovulation was remarkablely decreased at 3rd time by FSH-P but did not differ among 1, 2 and 3rd times by SUPER-OV. Embryo production on intervals of repeated superovulation was significantly different for the number and percentage of fertilized, transferable and free-zable' embryos in FSH-P (P<0.01) and rernarkablely decreased in repeated superovulation of 81~120 interval days. The SUPER-OV showed no differences in interval days of repeated superovulation and was found better than FSH-P in the response of repeated superovulation. (Key words : in Vivo embryo, superovulation, FSH -P, SUPER-OV)