• 한국수정란이식학회지
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• 제15권1호
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• pp.47-56
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• 2000

This study was carried out to improve a technique of embryo transfer for twin calves production in Hanwoo cattle. Blastocysts for the donor of embryo transfer were classified into three criteria by accessment of morphology; early blastocyst, blastocyst and expanded blastocyst. Tow embryos were introduced transcervically into utrerine horn either of Hanwoo or Holstein by ipsilaterally or contralaterally to the corpus luteum. Thiry-six out of 57 recipients cows were inseminated by artificially on the next day of estrus, and followed by transfer of embryos into contralaterally. The pregnance rates of recipients following transfer of bovine embryos of day 7, 8 and 9 was 43.5, 18.2 and 8.3%, respectively. These results appeared that these was a significant (P<0.05) difference between on day-7 embryos and day-9 embryos, but not between on day-8 and day-9 embryos. Although there was not significant(P<0.05) difference in the pregnancy rates between the blastocysts(11/25, 44%) and expanded blastocysts(2/19, 10.5%) and between the blastocysts and early blastocysts(2/13, 15.4%), the embryos at blastocyst stage are more suitable than others for obtaining higher rate of pregnancy. There was no significant difference on pregnancy of the embryos transferred prior to presence(6/21, 29%) or absence (9/36, 25%) of artificial insemination. On pregnancy of Holstein, 2(15.4%) out of 13 recipients were pregnant in heifer. Similar Pregnancy rates were obtained between 1∼2 parities and 3∼4 parities by 30% (6/20) and 27.3%(3/11), respectively. Taken together, there was not significant difference in pregnancy rate due to small number of recipients used for this experiment. Both of Hanwoo and Holstein introduced the embryos by contralsterally to the corpus luteum were slightly higher pregnancy rate compare to by ipsilaterally (12/41, 29.3% vs, 3/16, 18.8%). The ratio of production of twin and single calves in Holstein was 20% (9/45) and 2.2% (1/45), respectively. However, in Hanwoo cows both of production of twin and single were similar as 8%. This result suggests that Holstein as recipients was superior to Hanwoo cows for production of twin calves. Out of all 15 pregnant, 12(80%) were produced a total of 22 normal calves in which the others composed of abnormal, as judging as 2(13.3%) for abortion and 1(6.6%) for stillbirth during the pregnant period.

• 한국동물위생학회지
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• 제35권4호
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• pp.263-268
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• 2012

From the end of July 2012, several cases of abortion have been happened at the Korean indigenous cattle farm with 124 heads in Chungbuk province, Korea. Serological tests such as Rose-bengal test (RBT) and standard tube agglutination test (STAT) have been performed according to the standard official protocols of bovine brucellosis and 41 cattle turned out to be brucellosis-positive simultaneously. To find out the main factors of brucellosis outbreaks and spreads, additional serological, etiological and molecular investigation were applied. Totally, 11 B. abortus were isolated from 10 cattle's specimens including lymph-nodes and/or testis, and drinking water in cowhouse. In genotyping by multi-locus VNTR assay (MLVA) using 17 loci markers, the present B. abortus isolates were shown all the same pattern, D1 genotype, which has been reported in Gyeonggi and Gangwon province, Korea. These results suggest that the input of brucellosis might come from neighboring farms directly or indirectly, even if by unknown factor and expansion within farm would accelerate by materials related with aborting cows.

• 한국수정란이식학회지
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• 제23권4호
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• pp.291-298
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• 2008

We separately cultured follicular oocytes collected from individual ovaries of slaughtered Korean native cows and examined both the embryonic development rate and pregnancy rate after embryo transplantation according to the meat yield and quality grades of the source beef carcass. Oocytes from meat yield grade B cows exhibited a higher fertilization rate and embryonic developmental rate to the eight-cell stage than oocytes from grade A or C animals (p<0.05), but there was no significant difference in rate of development to the blastocyst stage among meat yield grades A, Band C. The oocyte cleavage rate and development rate to the eight-cell stage from meat quality grade 3 cattle was higher than grades 1++, 1+, 1 and 2 (p<0.05). Embryos derived from grade animals displayed a development rate to the blastocyst stage of 19.4%, which was also higher than all other meat quality grades (p<0.05). Transplantation of in vitro-cultured oocytes from meat yield grade A ovaries led to a higher pregnancy rate (64.2%) than in vitro-cultured oocytes from meat yield grade B ovaries (56.5%), but there was no significant difference between the two groups in pregnancy or abortion rates. In conclusion, embryonic development rate and pregnancy rate has a close relation to meat quality grades of the source beef carcass, this results is to give information for the Korean native cows improvement of breed.

• Parasites, Hosts and Diseases
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• 제41권4호
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• pp.243-245
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• 2003

Neospora caninum is an important cause of abortion in cattle, and dogs are its only known definitive host. Its seroprevalence among domestic urban and rural dogs and feral raccoon dogs (Nyctereutes procyonoides koreensis) in Korea was studied by indirect fluorescent antibody test (IFAT) and by the neospora agglutination test (NAT), respectively. Antibodies to N. caninum were found in 8.3% of urban dogs and in 21.6% of dogs at dairy farms. Antibody titers ranged from 1:50 to 1:400. Antibodies to N. caninum were found in six (23%) of 26 raccoon dogs. However, the potential role of raccoon dogs as a source of horizontal transmission of bovine neosporosis needs further investigation. The results of this study suggest that there is a close relationship between N. caninum infection among dairy farm dogs and cattle in Korea. This study reports for the first time upon the seroprevalence of N. caninum infection in raccoon dogs in Korea.

• 한국동물생명공학회지
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• 제38권2호
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• pp.84-88
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• 2023

Because multiple ovulation embryo transfer (MOET) in cattle includes several benefits such as wide spreading of genetically superior offspring for long distance, this biotechnological method has been widely applied to Hanwoo. When the recipients are not stayed close after embryo recovery from donor, the embryos are moved to other farms via several vehicles (car, train, and airplane). However, air travel induces lesser oxygen level, increased vibration, lower air pressure, higher noise, and increased exposure of cosmic radiation to living things than ground level. It was still unknown that fresh embryos obtained from multiple ovulation of Hanwoo could maintain their fertility after being transported via air plane, the present case report introduced a clinical case of MOET in Hanwoo after shipping fresh embryos via air transportation. The donor was multi-ovulated via follicle-stimulating hormone series of injection, which was followed by a gonadotrophin-releasing hormone injection and artificial insemination twice. The embryos were recovered by the uterine flushing, packed in ministraws, transported to recipients for 6 h including 1 h air flight, and then transferred to the synchronized recipients. During pregnancy diagnosis of early gestation period, 5 of 7 recipients (71.4%) presented no heat signs and showed fetal sacs with fluid under transrectal ultrasonography. After normal gestation period, all recipients naturally delivered healthy calves (male n = 2 and female n = 3) without abortion, stillbirth, and premature birth. The present case report indicated that transportation of fresh embryos for MOET via domestic flight in Korea did not affect to their fertility.

• 한국수정란이식학회지
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• 제21권4호
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• pp.299-306
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• 2006

본 연구는 수정란이식의 현장 적용 측면을 중심으로, 한우 체외 수정란의 발생 단계, 일자 및 등급이 젖소 대리모에 이식 후 임신과 유산, 분만과 관련된 임신기간, 생시체중, 난산 및 쌍자율을 조사하였다. 또한 단자 및 쌍자 분만에 따른 임신기간, 생시체중, 성비 및 폐사율을 분석하였다. 발생 단계에 따른 임신율은 배반포 단계(64.4%), 유산율은 부화 배반포(HB) 단계(21.4%)가 유의하게 높았다(p<0.05). 발생 일령에 따른 임신율은 7일령 배가 49.0%로서 8일 및 9일령의 36.4 및 15.4%보다 유의하게 높았으나(p<0.05), 유산율은 0$\sim$10.7%로 비슷한 경향이었다. 등급에 따른 임신율은 41.4$\sim$42.5%, 유산율은 9.3$\sim$16.5%로서 차이가 없었다. 발생 단계에 따른 임신기간, 송아지의 체중 및 난산율은 비슷한 경향이었으나, 쌍자율은 HB 단계가 44%로서 배반포 단계의 15.8%보다 유의하게 높았다(p<0.05). 발생 일령에 따른 임신 기간, 난산율 및 쌍자율은 차이가 없었으나, 송아지의 체중은 9일령의 것이 평균 35.5 kg으로서 7일령 및 8일령의 평균 25.2 및 26.2kg보다 유의하게 무거웠다(p<0.05). 등급에 따른 임신 기간은 1등 및 2등급이 평균 278.5 및 276.1일로서 3등급의 평균 273.7일에 비하여 유의하게 길었으나(p<0.05), 체중, 난산율 및 쌍자율은 차이가 없었다. 분만한 송아지의 개체 수에 따른 임신기간은 단자가 평균 278.5일로서 쌍자의 평균 272.5일보다 유의하게 길었다(p<0.05). 생시 체중도 단자가 평균 29.6 kg으로서 쌍자의 평균 22.3kg에 비하여 유의하게 무거웠으나(p<0.05), 성비와 폐사율은 유사한 경향이었다.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2001년도 발생공학 국제심포지움 및 학술대회 발표자료집
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• pp.37-43
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• 2001

1. About fifty thousand of cattle embryos were transferred and 16000 ET-calves were born in 1999. Eighty percents of embryos were collected from Japanese Black beef donors and transferred to dairy Holstein heifers and cows. Since 1985, we have achieved in bovine in vitro fertilization using immature oocytes collected from ovaries of slaughterhouse. Now over 8000 embryos fertilized by Japanese Black bull, as Kitaguni 7~8 or Mitsufuku, famousbulls as high marbling score of progeny tests were sold to dairy farmers and transferred to their dairy cattle every year. 2. Embryo splitting for identical twins is demonstrated an useful tool to supply a bull for semen collection and a steer for beef performance test. According to the data of Dr. Hashiyada(2001), 296 pairs of split-half embryos were transferred to recipients and 98 gave births of 112 calves (23 pairs of identical twins and 66 singletons). 3. A blastomere-nuclear-transferred cloned calf was born in 1990 by a joint research with Drs. Tsunoda, National Institute of Animal Industry (NIAI) and Ushijima, Chiba Prefectural Farm Animal Center. The fruits of this technology were applied to the production of a calf from a cell of long-term-cultured inner cell mass (1988, Itoh et al, ZEN-NOH Central Research Institute for Feed and Livestock) and a cloned calf from three-successive-cloning (1997, Tsunoda et al.). According to the survey of MAFF of Japan, over 500 calves were born until this year and a glaf of them were already brought to the market for beef. 4. After the report of "Dolly", in February 1997, the first somatic cell clone female calves were born in July 1998 as the fruits of the joint research organized by Dr. Tsunoda in Kinki University (Kato et al, 2000). The male calves were born in August and September 1998 by the collaboration with NIAI and Kagoshima Prefecture. Then 244 calves, four pigs and a kid of goat were now born in 36 institutes of Japan. 5. Somatic cell cloning in farm animal production will bring us as effective reproductive method of elite-dairy- cows, super-cows and excellent bulls. The effect of making copy farm animal is also related to the reservation of genetic resources and re-creation of a male bull from a castrated steer of excellent marbling beef. Cloning of genetically modified animals is most promising to making pig organs transplant to people and providing protein drugs in milk of pig, goat and cattle. 6. Farm animal cloning is one of the most dreamful technologies of 21th century. It is necessary to develop this technology more efficient and stable as realistic technology of the farm animal production. We are making researches related to the best condition of donor cells for high productivity of cloning, genetic analysis of cloned animals, growth and performance abilities of clone cattle and pathological and genetical analysis of high rates of abortion and stillbirth of clone calves (about 30% of periparutum mortality). 7. It is requested in the report of Ministry of Health, labor and Welfare to make clear that carbon-copy cattle(somatic cell clone cattle) are safe and heathy for a commercial market since the somatic cell cloning is a completely new technology. Fattened beef steers (well-proved normal growth) and milking cows(shown a good fertility) are now provided for the assessment of food safety.

• 한국수정란이식학회지
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• 제21권4호
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• pp.307-313
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• 2006

본 연구에서는 수정란 이식을 위해 선발된 대리모에 이식 전 백신의 투여 시기가 임신과 유산에 미치는 효과와, 임신한 대리모의 분만 예정일 전에 백신의 투여가 송아지의 질병과 생존에 미치는 효과를 검토하였다. 실험 1에서는 한우 체외 수정란의 이식에 선발된 대리모의 백신 투여 시기가 임신과 유산에 미치는 영향을 검토하였다. 이식 전 $0{\sim}4$주째 백신 투여시 임신율이 31.5%로서 대조군 및 $4{\sim}8$주 투여군의 42.4 및 45.9%에 비하여 유의하게 낮았다(p<0.05). 유산율은 대조군과 처리군에서 4.9$\sim$13.5%로서 유사한 경향이었다. 실험 2에서는 체외 수정란을 이식하여 임신한 대리모에 백신 투여 시기가 송아지의 질병과 폐사에 미치는 효과를 검토하였다. 질병 발생율은 백신을 투여하지 않은 대조군이 22.4%로서 백신을 투여한 처리군의 2.2$\sim$3.1%보다 유의하게 높았다(p<0.05). 폐사율도 대조군이 27.6%로서 처리군의 11.1 및 7.8%와 유의차가 인정되었다(p<0.05). 폐사한 송아지의 원인은 사산이 15.4%, 난산 30.8%, 기형 3.8% 및 질병 50.0%였고, 질병으로 폐사한 송아지에서는 위장관 질병이 46.2%, 호흡기 질병이 7.6%였고 원인 불명이 46.2%였다.