The present study was carried out to investigate effects of gonadotropin, age of donor, day of estrus cycle gonadotropin injection started and season on embryo production after superovulation in dairy cattles. Embryo collection records were obtained from 177 embryo donor collections from 98 Holstein cows aged from 3 to 9 years during 4 years(1993~1996) at National Livestock Re-search Institute. Superovulation was induced by injections of 3 gonadotropins(FSH-P, FOLLTROPHIN-v* or SUPER-OV*) beginning on days 9 to 14 of the estrus cycle. Em-bryos were collected from donors using a nonsurgical technique on days 6 to 8 after insemi-nation. The results were as follows ;Number of total and freezable embryos per donor cow was affected by gonadotropin(P<0.01). The more number of total and freezable embryos wereobtained by use of FOLLTROPHIN-V (13.2, 7.4) or FSH-P (11.0, 5.7) than SUPER-OV* (5.0, 2.4). Age of donor, the day that gonadotropin was started or season didn't affect total or freezable embryos(P >0.05).

This study was carried out to establish the techniques for producing the calves of genetically superior Korean Native cattle by transfer of frozen-thawed embryos. The effects of some factors related to embryo recovery following superovulation and pregnancy rate following transfer of frozen-thawed embryos were evaluated. Also calving state was investigated. The results obtained were as follows ; The mean number of total and transferrable embryos recovered per superovulated cow was 8.72 and 4.90, respectively, from a total of 72 superovulations using 34 donor cows. There were no significant differences in the number of total or transferrable embryos recovered per superovulated cow between products of follicle stimulating hormone (FSH), years, seasons, and collection numbers. The pregnancy rate was found 44.44% following transfer of frozen-thawed embryos of Korean Native cattle to a total of 180 recipient cows including 82 Angus, 27 Charolais, 62 Hereford and 9 Korean Native cows. The pregnancy rate was significantly (P<0.05) higher in the transfer of excellent (42.99) and good embryos (40.17%), compared with fair (5.90%) grade embryos. And the pregnancy rate was significantly (P<0.05) higher in the transfer of embryos of morula stage (43.86%) than blastocyst stage (15.51%). But there were no significant differences in pregnancy rates between natural and induced estrus estrus asynchrony of 1 days, breeds, and parities of recipient cows. The normal calving rate of 80 pregnant cows following transfer of frozen4hawed em-bryos was 87.5% and the other 10 pregnant cows showed abortion during the period from pregnancy diagnosis at 50~60 days to calving. The average gestation length of normally delivered recipients was 288.50 days and the average birth weight of 70 calves born was 24.22 kg. The gestation length was significantly (P<0.05) shorter in the recipients delivering female calves (286.70 days) than males (289.39 days). But there were no significant differences in gestation tength and birth weight of calves born between the recipient breeds.

This study was carried out to produce monozygotic twin calves by transfer of bisected embryos. Four Korean native cattle donors were superovulated with FSH and flushed to collect embryos on day 6 or 7 of the estrus cycle. Morula and early blastocyst embryos showed 1 or 2 grade were bisected with microblade and each set of demi-embryos without zona pellucida were transferred nonsurgically to 10 recipients respectively. The results obtained were as follows; 1. Twenty four demi-embryos (92.3%) were separated from 13 original embryos and among them 20 demi-embryos (83.3%) had normal appearance without severe damage. 2. Four sets of fresh demi-embryos were transferred to 4 recipients and one recipient was twin pregnant 3. Six sets of frozen-thawed demi-embryos were transferred to 6 recipients. Two recipients were pregnant, one of them twin.

This study was carried out to propagate Korean native cattle using beef recipients by embryo transfer. Seven Korean native cattle donors were superovulated with FSH 32mg and Embryos collected from donors were frozen and preserved in National Animal Breeding Institute. Frozen-thawed embryos were transferred to synchronized 40 beef recipients nonsurgically in Daekwanryeong Branch of National Animal Breeding Institute. The results obtained were as follows : 1. Total ova and transferable embryos per donor were 11.4 and 11.1 from 7 donors, respectively. 2. Among 40 recipients transferred with frozen-thawed embryos, 20 were pregnant(50.0%). 3. The pregnancy rate according to time from embryo thawing to transfer was higher when transferred within 3 hours than after 3 hours(57.6% vs. 14.3%). 4. The cow recipients showed slightly higher pregnancy rate than the heifer(53.3% vs. 48.0%). 5. Two grade embryos showed higher pregnancy rate than 1 grade(66.7% vs. 45.2%).

1. In vitro system, LR and FSR accelerated and facilitated meiotic progression, and LH selectively improved cytoplasmic maturation which is required to promote the formation of a male pronucleus. 2. Caffeine (2mM) in the fetilization medium was required not only for inducing zona penetrating ability of boar also for developing to the male pronucleus of the penetrat- ing spermatozoa in vitro. 3. The germinal vesicle (GV)stage was observed for the first 17.6 hr;germinal vesicle break-down (GVBD)stage between 17.6~26.4 hr ;metaphase I (M-I)from 26.4 - 30. 9hr;anaphase I(A-I)ranged from 30. 9~33.4hr;telophase I(T-I) at 33.4~34.4hr; and metaphase II(M-II) at 34.4-48hr. 4. The addition of 10%(v /v) pig follicular fluid (pFF) to maturation media significantly increased the rate of nuclear maturation of pig oocytes (p<0.01), whereas the rate of nuclear maturation of pig oocytes among three different media did not differ. 5. The presence of a primary culture of POEC promotes in vitro development of early cleavage stage pig embryos.

This study was carried out to produce superior dairy cattle by embryo transfer. Seven dairy cows were superovulated with divided injection of FSH 4Omg for 5 days started on day 9 to 14 of the estrus cycle and injection of PGF 45mg on day 4 of FSH injection. Donor cows were flushed to collect embryos on day 7 or 8 of the estrus cycle. Fresh embryos collected were transferred to synchronized dairy recipients or frozen using glycerol 3 step method to he equilibrated. And 35 embryos which were frozen using glycerol 6 step method were imported from U.S.A. After glycerol dilution of frozen embryos was done by reverse density during freezing. frozen-thawed embryos were transferred to synchronized dairy or beef recipients. The results obtained were as follows; 1. Total of 24 embryos were collected from 7 donor cows flushed and transferable embryos were 18 (75.0%). 2. Among 24 embryos. morula, early blastocyst, blastocyst, expanded blastocyst and unfertilized ova were 3 (12.5%), 1 (4.2%), 10 (41.6%), 4 (16.7%) and 6 (25.0%), respectively. 3. Heat inducing rate after 1st and 2nd injections of PGF in Holstein and beef cattle was 83.3% and 71.4% and 62.5% and 69.2%, respectively. 4. Among 56 recipients, 23 head were pregnant (41.1%). The pregnancy rate of fresh embryos was 50.0% (1/2 heads) and the pregnancy rate of frozen embryos which were frozen using glycerol 3 step and using glycerol 6 step imported from U.S.A. was 52.6%(l0/19 heads) and 34.3%(12/35 heads), respectively. 5. The pregnancy rate of blastocyst (60.0%) was higher than that of morula (39.0%), early blastocyst (25.0%) and expanded blastocyst (0%). 6. The pregnancy rate of grade I embryos (52.2%) was higher than that of grade 2 (34.6%) and grade 3 (28.6%). 7. The pregnancy rate according to synchrony of recipient with donor was higher in simultaneous recipient (55.0%) and +l2hrs' (53.8%) than -24hrs' (23.5%), -l2hrs' (20.0%) and +24hrs' (0%).

도축된 돼지의 난소에서 난포란을 채취하여 체외 성숙시킨 후 인위적으로 활성화시켜 이배체 배발달을 유기하기 위해 cytochalasin B를 2.5, 5.0, 농도로 3, 5, 7 시간 처리한 후 NCSU23 배양액으로 7일간 배양하여 배발달율에 미치는 영향을 검사하였다. 체외 성숙된 돼지 난모세포를 활성화 처리하여 2일째 분할율을 관찰한 결과 각 처리의 분할율은 로 나타났으며, 처리별로 유의차가 없었다. 7일간 배양하여 상실배기 이상으로 발달한 난자들의

소 체외성숙시 난포란에 영향을 주는 과립막세포와 난자의 핵성숙을 촉진하는 물질이 확인되지 않은 혈청내의 물질 뿐만 아니라 호르몬이나 생리활성인자 등에 의해 촉진됨이 밝혀졌다. 이에 따라 체외성숙 및 체외발달에 사용되는 배양액의 조성도 복합배양액에서 단순배양액으로 전환을 시도하고 있으며, 체내의 조건에 보다 더 접근하고자 하는 시도들이 수행되고있다. 본 연구는 한우 난포란의 체외성숙율 및 체외수정 후 배발달율을 향상시키기 위하여 TGF-의 첨가가 미치는

TGF- super family는 난소를 포함하여 여러 기관 및 조직의 성장에 광범위하게 영향을 미치는 것으로 알려져 있으며, TGF- super family는 난자의 매우 초기에 영향을 미치며, 난포의 성장을 촉진하여 초기의 난자의 형태를 이루는데 중요한 역할을 하는 것으로 알려져 있다. 한편 TIMP-1은 난관상피세포로부터 분비되는 난자의 생리활성 촉진인자로 보고되고 있다. 따라서 본 연구는 한우난포란의 체외성숙에 난자의 생리활성 촉진인자를 이용하여

소에 있어서 수정란이식이 활성화되고, 수정란이식 기술이 첨단기술도입의 근간이 되면서, 수태율의 향상은 첨단기술의 활성화에 필수적인 요소가 되었다. 또한 수태율 향상을 위해 임신유지를 도와주는 progesterone의 정기적인 투여나 수정란이식 시기에 hCG 등을 투여하여 수태율을 향상시키고자 여러가지 방법이 시도되고 있으나, 수태율 향상에 대한 명확한 기술이 정립되지 않은 상태이다. 따라서 본 연구는 착상시 황체의 Progesterone의 분비를 촉진시

멸종위험성이 높은 재래돼지를 유전자원으로서 안전하게 보존하고 유전적 다양성을 유지하기 위해 체내수정란의 동결보존 방법을 수행하였다. 재래돼지의 과배란유기는 altrenogest를 1일 20mg씩 18일 경구투여하고 PMSG 500~l,000IU 근육주사후 80시간에 hCG 500~750IU를 근육주사하였다. 발정이 관찰된 개체는 발정개시후 12시간과 24시간에 자연교배 또는 액상정액을 이용하여 2회씩 수정시켰다. 최종 수정후 5일째에 외과적으로 개복수술

2002년도 국내에서 실시된 가축의 수정란이식 현황을 파악하기 위하여 전국의 수의ㆍ축산분야의 대학, 국ㆍ공립 축산관련 연구소, 농업기술센터, 가축인공수정소 및 동물병원 등의 168개 관련기관에 2002년 1월 1일부터 12월 31일까지 소, 돼지 및 기타 동물의 수정란 생산, 이식 및 임신진단 결과에 대하여 설문서를 통하여 조사하였으며, 설문서를 작성하여 제출한 32개기관의 자료를 분석한 결과는 다음과 같다. 가축의 수정란이식을 실시하고 있는 기관은 국

번식효율이 높은 우수한 후보종빈돈의 조기선발기술을 개발하기 위해 후보종빈돈의 첫발정일령과 첫수정일령 및 첫수정시 등지방두께가 산자수에 미치는 요인을 분석한 결과는 다음과 같다. 본 시험에 공시된 후보종빈돈은 충남 천안시에 위치하고 있는 양돈장에서 자돈을 생산ㆍ육성하여 체중 80∼90kg에서 선발하였고, 체중이 약 110kg 도달하였을 때 최종 선발하여 이용하였으며, 사양관리는 양돈장의 관행에 따라 실시하였다. 첫발정조사는 생후 22주령때부터 매일 아침,

번식효율이 높은 우수한 후보종빈돈의 조기선발기술을 개발하기 위해 후보종빈돈의 첫발정일령과 첫수정일령에 미치는 요인을 분석한 결과는 다음과 같다. 본 시험에 공시된 후보종빈돈은 충남 천안시에 위치하고 있는 양돈장에서 자돈을 생산ㆍ육성하여 체중 80~90kg에서 선발하였고, 체중이 약 110kg 도달하였을 때 최종 선발하여 이용하였으며, 사양관리는 양돈장의 관행에 따라 실시하였다. 첫발정조사는 생후 22주령때 부터 매일 아침, 저녁으로 2회씩 외음부의 충혈

본 연구의 목적은 젖소에서 다배란유기법의 확립을 위해서 호르몬을 처리법을 달리한 결과이다. 난포의 발생을 자극하는 FSH 호르몬을 하루에 2번의 호르몬 주사를 하는 데, 이는 혈액내에 난포자극호르몬의 농도를 연속적으로 유지하여 난소에서 다난포 발생의 목적을 달성하고자 하는 방법이다. 하지만 빈번하게 호르몬을 주사하는 방법은 처리하는 노력이 필요하고 공란우도 스트레스로 작용한다. 이러한 단점을 극복하기 위해 한번에 많은 난포의 성숙을 유도하는 다배란처리법

유전적으로 우수한 미경산우를 선발하여 조기에 우수한 수정란을 생산하여 이식 후 개량을 촉진한다는 것은 소의 육종개량에서 매우 중요한 일이다. 일반적으로 경산우에 비해 미경산우는 수정란의 생산효율이 떨어진다는 보고가 있다. 최근에는 다배란 처리시 FSH와 Estradiol Benzoate(EB)를 사용하여 다배란처리 효율을 개선하였다는 보고(Matoba 등, 2002)가 있어 EB의 첨가가 미경산우에 있어 수정란 생산 효율을 개선하는 지를 조사하기 위해