This study was carried out to investigate the effect of co-culture system(bovine oviduct epithelial cells; BOEC) and defined culture system (modified TALP ; mTALP) on the conception of embryos transferred, and pregnancy and twin birth rates after transfer of fresh or frozen-thawed bovine blastocysts produced in vitro were also evaluated. Oocytes from the slaughterhouse ovaries were matured and fertilized using general protocol. The results obtained were as the following. The pregnancy rate after transfer was higher in co-culture group than in mTALP group, but was not signficantly different, and there is no difference between fresh embryo group and frozen-thawed embryo group in conception rate. The conception rate was not different whether 3∼4 blastocysts or 2 blatocysts transferred into a recipient, but the production rate of twin calves was significantly higher (p<0.05) when 3∼4 embryos transferred. The average birth weight of twin calves(24.38kg) was numerically, but not significantly lighter than that of single calves(26.68kg).

This study was carried out to investigate the effect of co-culture system(bovine oviduct epithelial cells; BOEC) and defined culture system(modified TALP ; mTALP) on the development of IVM-IVF embryos, and survival of in vitro produced blastocysts after freezing and thawing. Occytes from the slaugheterhous ovaries were matured and fertilized using general protocol. The results obtained were as the following: 1. Survival rates of frozen-thawed blastocysts using 10% glycerol as cryoprotectant was higher in day 7 blastocysts than in Day 8 and 9 blastocysts from co-cultrue system, but survival rate of frozen-thawed blastocysts was higher in Day 10 blastocysts than in day 8 and 9 blastocysts from defined culture system. Regardless of their age, survival rate of frozen-thawed blastocysts was significantly higher (p<0.05) in co-culture system than in defined culture system. 2. The cell number of blastocysts was significanlty higher (p<0.05) in Day 7 blasotcysts than in Day 8 and 9 blastocysts from co-cultures, but the cell number of blsstocysts was significantly higher (p<0.05) in Day 10 blastocysts than in Day 8 and 9 blastocysts from defined culture system. Regardless of the culture system, blastocysts with higher cell number showed higher survival rates after freezing and thawing.

The objectives of the study were to establish sperm separation method and duration of insemination for bovine IVF. Oocytes from slaughterhouse ovaries were matured and fertilized using general protocol. After 18 or 42 h of insemination, six to ten embryos were placed into a 30 drop of each medium, and the embryos were examined 7~10d post in semination without medium renewal. First, we compared Percoll gradient will swim-up technique for sperm separation. There was no difference in cleavage rates between them, but the development rates over morula stage of oocytes fertilized with sperm separated by Percoll gradient was significantly higher than that sperm selected by swim-up technique (p<0.05). Second, we evaluated development of bovine embryos derived from the IVF procedure with different durations(18 vs 42 h) of fertilization. There was also no difference in cleavage rates, but the development to blastocyst stage of oocytes exposed in cleavage rates, but the development to blastocyst stage of oocytes exposed to sperm for 42 h was significantly higher than that exposed for 18 h (p<0.05). In conclusion, Percoll gradient can be used for sperm selecton, improving of embryonic development. Also, 42h of IVF may improve the development of bovine embryos.

최근, 한우의 수정란 체외이식두수가 급격히 늘어나고 있으나, 모축의 등록번호를 대부분 확인 할 수 없으며, 확인이 가능할지라도 개체별 수정란의 생산이 거의 이루어지지 않고 있다. 본 실험에서는 모축의 등록번호가 확인된 개체의 난소로부터 채취한 난포란만을 체외성숙, 수정, 배양하여 배 발생율을 조사하고, 동결성적을 조사하였다. 도축된 한우의 난소를 개체별로 채취하여 2생리식염수에 넣어 3시간 이내에 실험실로 운반하고, 난포란을 채취하였다 개체별로 채취한

근래, 혈청배지로 생산한 체외배양 수정란은 이식후, 낮은 수태율, 과체중의 산자 생산, 높은 유산율과 사망율 등 문제가 지적되고 있다. 그러나 무혈청 배지로 생산한 체외배양 수정란은 이러한 현상을 개선할 수 있다는 보고가 있어, 본 연구는 세포성장인자가 첨가된 완전 무혈청 배양액에서 생산된 수정란으로 2001년5월 부터 2002년 12월까지의 신선란 및 동결란으로 이식한 결과이다. 이식은 신선란 및 동결란에서 A급 수정란은 1개, B급 수정란은 2개를

난자의 체외성숙 및 체외배양에는 일반적으로 동물의 혈청을 기본배양액에 5-10% 정도 첨가한 배양액을 사용하고 있다. 그러나, 혈청으로부터 바이러스, 세균, 마이코 플라즈마 등에 오염될 가능성이 있기 때문에, 본 실험에서는 완전 무혈청 배양액에서 난자의 성숙, 배발생, 세포수, 동결성을 검토하였다. 도축된 한우의 난소로부터 채취한 난자는 선별하여 TCM199+10% FBS와 IVMD 101 배양액에서 22~24시간 동안 체외성숙시킨 후, IVF 100(