• Reproductive and Developmental Biology
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• v.36 no.1
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• pp.87-93
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• 2012

The purpose of this experiment is to compare the pregnancy rate (PR) according to the state of the ovaries and uterus, according to the number of embryos transferred from cows and heifers and to investigate the method of artificial twin induction with Hanwoo $in$ $vitro$ fertilized (IVF) embryos by embryo transfer (ET). Looking at the PR according to the condition of the ovaries and uterus, the result was not influenced by the condition of the ovaries, but was significantly influenced by the state of the uterus. The PR according to the number of embryos transferred from cows was 36.8%, 53.0%, 50.5% for 1, 2, and 3 embryos respectively, and although there was a higher frequency of twin calves with 3 embryos than with 2, the calving rate was the highest with 2 embryos. In case of heifers, the transfer of 1 embryo showed the best pregnancy and calving rate, and although the PR was similar with 2 embryos (67.7 versus 66.4), in case of 2 embryos transferred there was high frequency of embryonic loss( 6.1%) occurred when a cow was diagnosed at 28 and 53 d after ET, total loss (21.3%; sum of fetal death, abortion and stillbirth after pregnant diagnosis at 60 day).

• Reproductive and Developmental Biology
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• v.36 no.2
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• pp.95-101
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• 2012

The purpose of this experiment was to compare the pregnancy rate (PR) according to the state of the ovaries and uterus, according to the number of embryos transferred from cows and heifers and to investigate the method of artificial twin induction with Hanwoo in vitro fertilized (IVF) embryos by embryo transfer (ET). Looking at the PR according to the condition of the ovaries and uterus, the result was not influenced by the condition of the ovaries, but was significantly influenced by the state of the uterus. The PR according to the number of embryos transferred from cows was 36.8%, 53.0%, 50.5% for 1, 2, and 3 embryos, respectively and although there was a higher frequency of twin calves with 3 embryos than 2, the calving rate was the highest with 2 embryos. In case of heifers, the transfer of 1 embryo showed the best pregnancy and calving rate, and although the PR was similar with 2 embryos (67.7 versus 66.4), in case of 2 embryos transferred there was high frequency of embryonic loss (6.1%) occurred when a cow was diagnosed at 28 and 53 d after ET, total loss (21.3%); sum of fetal death, abortion and stillbirth after pregnant diagnosis at 60 day.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.1
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• pp.45-49
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• 1992

Bovine drumstick of neutrophil leucocytes was studied on the quantitative and morphological characteristics and was evaluated as a diagnostic measure for bovine freemartin in newborn calves. Nuclear area of neutrophil (A, ${\mu}m^2$) and drumstick area (B, ${\mu}m^2$) were significantly correlated with average diameter of drumstick (ADD, ${\mu}m$) and following regression equations were obtained : $A=45({\pm}3)$ ADD-8, r = 0.74, $s.e.{\pm}0.6$, p < 0.01, $B=1.72({\pm}0.05)$ ADD-0.98, r = 0.93, $s.e.{\pm}0.1$, p < 0.01 Eight female siblings of heterosexual multiplets were diagnosed as freemartin from the results of chromosome analysis. Heterosexual multiplets had a very low frequency of drumstick in the nucleus of neutrophils irrespective of genetic sex. Diameters of drumstick fund in freemartin and male cotwin did not differ from those of normal cows. Examinations of drumstick in 800 neutrophils for both female and male siblings are concluded to be the best way to aid the detection of freemartinism of heterosexual twins at early life.

• Journal of Embryo Transfer
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• v.23 no.3
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• pp.167-175
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• 2008

This study was performed to investigate the result that in-vivo or in-vitro embryos of Hanwoo cows were transferred to Holstein cows. Seventeen Hanwoo cows were used as donors for production of in-vivo embryos and fresh hanwoo in-vivo embryos were transferred to 1,150 Holsteins. And 2 embryos were transferred to 188 Holstein recipients to produce twin calves. Diagnosis on pregnancy was performed by rectal palpation at $60\sim90$ days after transfer. The pregnancy rate of Holstein recipients was 55.8% after transfer with Hanwoo in-vivo embryos and 38.2% after transfer with Hanwoo in-vitro embryos. The delivery rate of pregnant Holstein recipients was 88.4% after transfer with Hanwoo in-vivo embryos and 75.6% after transfer with Hanwoo in-vitro embryos. The rate of delivery of Holstein recipients transferred with two Hanwoo embryos was 36.2% and the rate of twin production was 25.9%. The rate of twin production by embryo transfer with in-vivo embryos was 30.4%, whereas the fate with in-vitro embryos was 15.6%. The pregnancy rate according to the grade of corpus luteum of Holstein recipients transferred with Hanwoo in-vitro embryos was 41.5 and 36.0% for A and B grade, respectively. The pregnancy rate according to the transfer in site in the uterine lumen of recipients was 40.9 and 32.7% for anterior and middle site, respectively. The pregnancy rate according to day of embryo transfer after estrus of recipients was 45.5, 38.8 and 39.7% for day 6, day 7 and day 8, respectively. There was difference of pregnancy rate according embryo transfer technician ($30.5\sim45.8%$) individual dairy farm ($21.1\sim51.0%$). These results are supposed to indicate that the rate of pregnancy after transfer with Hanwoo embryos to Holstein recipients was similar to that within the same breed, and consequently that this method would be beneficial to enhance the productivity in Hanwoo reproduction.

• Journal of Embryo Transfer
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• v.6 no.2
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• pp.1-17
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• 1991

It is widely recognized that the embryonic or fetal loss after breeding is common in the cattle and that it is an important factor affecting reproductive efficiency. The causes of this loss have been subject of extensive researches and the results indicate that the embryonic mortality may he primary factor responsible for low pregnancy rates in non-embryo transfer bovine populations as well as embryo transfer programs. However, it's causes are still not clearly understood. The embryonic mortality or pregnancy rate has been influenced by various embryonic and maternal effects related to genetic and environmental factors. The timing and extent of embryonic mortality vanes greatly according to authors and estimating methods, because it is difficult to make direct measurements. The major important factors that may influence the embryonic losses or pregnancy rates after embryo transfer can be summeirized. 1.When an embryo is transferred to unmated recipients, the contralateral transfer to corpus luteum results in a lower survival rate than ipsilateral deposition. When the embryos are transferred for the production of twin calves, their survivals and twin pregnancies have quite inconsistent according to the transfer methods either to the unmated-synchronized or already mated recipients and more works are needed to accurrately clarify the previous results. 2.Although embryos can be cultured in vitro some hours without the great declines in pregnancy rates, the rates differ markedly among culture times and media but may be improved by co-transfer systems. 3.Embryo developmental stages and quality grades clearly affect the survival rate following freezing and the pregnancy rate after transfer and the selection of embryos without chromosome abnormalities and of high fertile semen may also be considered to increase the pregnancy rates. 4.Many researches have attempted to relate the plasma progesterone levels to pregnancy rates and others have done either direct progesterone supplementation or luteal stimulation by hCG treatment in order to increase the pregnancy rates. However, these effects on pregnancy rates are inconsistent and also contradictory. 5.The asynchrony between donors or embryos and recipients may he a major cause of embryo death and low pregnancy rate and the sensitivity to uterine asynchyony differs in according to the quality and stages of embryos. 6.The extremes of poor or over nutrition during early pregnancy in the recipients are detrimental to the survival of embryos and the good body condition is required to prevent a reduejion of pregnancy rates. The uterine pathogens in embryonic mortality or fertility have been questioned but the infection of C.pyogenes and Campylobacter fetus is still important pathogens. 7.The heat stress during early pregnancy may reduce conceptus weight and possibly increase the embryonic mortality.

• Korean Journal of Veterinary Research
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• v.46 no.1
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• pp.63-66
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• 2006

This case was found in Holstein cow suffering from dystocia. The twin calves in uterus were dead and removed by fetotomy. Gross anatomical analysis of thoracopagus siamese calf was carried out. Two normal heads were present on two necks, however, the twins were fused in the thoracic region. There were four forelimbs and an abnormal orientation of ribs. Two separate vertebral columns along the length of the animal ended with two tails. A single pericardium lay on the midline when opening the thorax. However, there were two almost completely hearts within the pericardial sac. Two heart were joined by a common cavernous venous sinuous. There were two sets of lungs. Each twins had a separate esophagus that entered a separated stomach. A large liver was fused and connected into two duodenums. The pelvis, large intestines and urinary tracts were separated. The twins are female and have a full complement of limb.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.8
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• pp.1188-1195
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• 2001

A tetraparental chimeric bull was successfully produced by aggregating bovine IVF embryos of F1 (female Holstein${\times}$male Japanese Black) and F1(female Japanese Brown${\times}$male Limousin) and culturing in vitro without the zona pellucida at Yamaguchi Research Station in Japan. In the microsatellite genotyping, 12% (28/228) microsatellite primer sets ware potentially useful for this parentage analysis in the chimeric bull, 78.6% (22/28) of microsatellite present in the chimeric bull were uniquely contributed from the Japanese Black and 21.4% (6/28) from Limousin. This chimeric bull semen was used in producing IVF embryos. The chromosome preparations were made from peripheral lymphocytes. Based on chromosome analysis the Chimera had apparently normal chromosomes (29 acrocentric pairs, one large sub metacentric X chromosome and one small sub metacentric Y chromosome). The proportion of acrosome reacted spermatozoa after 1 h of incubation was higher (p<0.01) with the Chimera than with the Holstein and in Japanese Brown bulls. But did not differ from Japanese Black and Limousin bull sperm. Fertilization rates observed after 5 h of sperm-oocyte incubation with Chimera sperm were higher (p<0.05) than with Japanese Brown and (p<0.01) than with Holstein sperm, but did not differ from Japanese Black and Limousin sperm. The cleavage rates of IVF oocytes inseminated with Chimera sperm were also higher (p<0.001) compared with Holstein, (p<0.01) Japanese Brown and (p<0.05) Limousin, but did not differ from Japanese Black sperm. The blastocyst rates of IVM oocytes inseminated with sperm were higher (p<0.05) than in Limousin, Japanese Brown and Holstein, but did not differ from Japanese Black. Chimeric cattles were produced by aggregation of parthenogenetic (Japanese Brown) and in vitro fertilized (Holstein) bovine embryos at the Yamaguchi Research Station in Japan and by aggregation of parthenogenetic (Red Angus) and in vitro fertilized (Holstein) embryos at the St. Gabriel Research Station in Louisiana. The aggregation rate of the reconstructed demi-embryos cultured in vitro without agar embedding was significantly lower than with agar embedding. The aggregation was also lower when the aggregation resulted from a whole parthenogenetic and IVF-derieved embryos cultured without agar than when cultured with agar. The development rate to blastocysts, however, was not different among the treatment. To verify parthenogenetic and the cells derieved from the male IVF embryos in blastocyst formation, 51 embryos were karyotyped, resulting in 27 embryos having both XX and XY chromosome plates in the same sample, 14 embryos with XY and 10 embryos with XX. The viability and the percentage of zonafree chimeric embryos at 24 h following cryopreservation in EG plus T with 10% PVP were significantly greater than those cryopreserved without PVP. Pregnancies were diagnosed in both stations after the transfer of chimeric blastocysts. Twin male and single chimeric calves were delivered at the Yamaguchi station, with each having both XX and XY chromosomes detected. Three pregnancies resulted from the transfer of 40 chimeric embryos at the Louisiana station. Two pregnancies were Jost prior to 4 months and one phenotypically chimeric viable male born.