• Journal of Embryo Transfer
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• v.11 no.2
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• pp.137-144
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• 1996

The present study was carried out to obtain the pregnancy and delivery rate following transfer of fresh and frozen-thawed Korean native cattle(KNC) blastocysts(1~4 em-bryos / head) produced in vitro to Holstein recipients. The pregnancy rate of fresh and frozen-thawed KNC blastocysts produced in vitro was 50%(7 /14 heads) and 38.5%(5 /13 heads), respectively. The pregnancy rate of frozen-thawed KNC blastocysts produced in vitro frozen using 1.5M ethylene glycol and 1.4M glycerol for cryoprotectant was 33.3%(2 /6 heads) and 42.9 %(3 /7 heads), respectively. Seven calves including 2 sets of twin were born fiom 5 pregnant recipients receiving eleven fresh blastocysts. Three pregnant recipients were aborted among four pregnant recipients receiving twelve frozen-thawed blastocysts and one calf was born from the rest of one pregnant recipient.

• Journal of Embryo Transfer
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• v.25 no.2
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• pp.89-92
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• 2010

We report herein the successful results of estrus induction, sperm cryopreservation and kids born by transcervical insemination of frozen-thawed semen in a Saanen goat. Flugestone acetate (FGA: 60 mg) was inserted into vagina for 15 days. The goat was intramuscularly injected with 400 IU PMSG and 200 IU hCG ($PG600^{(R)}$: Intervet, Korea) a day before withdrawal of the FGA sponge. Follicles and corpora lutea were identified on both ovaries by laparoscopy. Artificial insemination was performed 46 hours after removal of FGA sponge. The concentration of frozen-thawed semen was $3.975{\times}10^8/ml$ and 0.5 ml of frozen-thawed semen was transcervically inseminated into uterine body under anesthesia. Three kids, all females, were born 144 days after artificial insemination. This is the first report producing kids by transcervical insemination of frozen-thawed semen in a Saanen goat of which the estrus was induced by FGA sponges, PMSG and hCG during non-breeding season in Korea.

• Journal of Embryo Transfer
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• v.12 no.3
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• pp.315-324
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• 1997

This study was undertaken in an effort to develop a cryopreservation system of immature and mature porcine oocytes. For this aim, the experiments were designed to examine the effect of cryoprotectants and equdibration time on the viability of frozen-thawed oocytes by using trypan blue(TB) and fluorescene diacetate(FDA) test. The viability of frozen immature oocytes evaluated by TB test was slightly higher than that of frozen mature oocytes. The viability(25.O%) after IVM of frozen-thawed immature oocytes greatly decreased that(42.9%) of oocytes just after thawing, but it was higher than frozen-thawed mature oocytes(15.8%). When immature oocytes were equilibrated for 10, 20 and 30 minutes before freezing the oocyte viability was 20.0, 31.3 and 42.9%, respectively. There was a tendency for long equilibration before oocyte freezing to be more effective for the immature oocytes and a short equilibration time for mature oocytes. Although there was no difference in viability index of frozen oocytes hetween the viability test methods, the index of TB test was slightly higher than that of FDA test. The viability(FDA test) of frozen-immature oocytes with 3 different crtoprotectants was 22.2% for propylene glycol(PG), 9.3% for polyehtylene glycol(PEG) and 65.6% for PG+PEG, in which PG+PEG was more protective against freezing effect.

• Korean Journal of Animal Reproduction
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• v.15 no.2
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• pp.97-101
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• 1991

This study was carried out to investigate the survival rate of in vitro culture after frozenthawed, to used DMSO(dimethyl sulfoxide), glycerol and ethylene glycol of cryorpotective agents at the zona pellucida removed and intact on the morulae and blastocysts. The results obtained from this study were as follows : 1. The survival rate of in vitro culture after frozen-thawed to used cryoprotective agents of three kinds at the morulae was 86.0%, 87.1% and 83.3%, total or mean were 85.5%, respectively. 2. The survival rate of in vitro culture after frozen-thawed to used cryoprotective agents of three kinds at the zona pellucida removed morulae was 53.2%, 42.3% and 37.5%, total or mean were 44.3%, respectively. 3. The survival rate of in vitro cultrue after frozen-thawed to used cryoprotective agents of three kinds at the blastocysts was 89.4%, 86.2%, total or mean were 86.7%, respectively. 4. The survival rate of in vitro culture after frozen-thawed to used cryoprotective agents of three kinds at the zona pellucida removed blastocysts was 55.8%, 51.6% and 40.6%, total or mean were 49.3%, respectively.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.1
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• pp.59-65
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• 2000

Objective: The purpose of this study was to determine the important factors affecting survival and pregnancy rate in frozen-thawed embryo transfer cycles. Methods: we performed retrospective analysis in 738 cycles of frozen-thawed embryo transfers, in relation to the insemination methods, the freezing stage of embryo, patient's age, infertility factors and the origin of injected sperm in ICSI cycles. After conventional IVF or ICSI, the supernumerary PN stage zygotes or multicellular embryos were cryopreserved by slow freezing protocol with 1,2-propanediol (PROH) as a cryoprotectant. Results: The survival rates of thawed embryos were 69.3% (1585/2287) in conventional IVF group and 71.7% (1645/2295) in ICSI group. After frozen-thawed embryo transfers, 27.0% (92/341) and 32.0% (109/341) of pregnancy rates were achieved in conventional IVF and ICSI group, respectively. There were no significant difference in the survival and pregnancy rates according to the insemination methods, the freezing stage and patient's age. However, the pregnancy rate (36.2%) of male factor infertility was significantly higher than the tubal (27.2%) and other female factor infertility (22.9%). In ICSI group, the origin of injected sperm did not affect the outcome of frozen-thawed embryo transfer cycles. Conclusion: The present study demonstrates that acceptable clinical outcomes can be achieved after the transfer of frozen-thawed embryos regardless of the stage of embryos for freezing, the patient's age and the origin of injected sperm.

• Journal of Embryo Transfer
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• v.15 no.3
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• pp.219-230
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• 2000

This study was carried out to determine the factors on achieving good viability of embryos biopsied fur sexing, to investigate pregnancy rate following embryo transfer(ET) with sexed embryos, and to confirm the accuracy for the calves bort following ET with sexed embryos by polymerase chain reaction(PCR). To investigate viability of Hanwoo embryos after biopsy for sexing, fresh and frozen/thawed embryos were biopsied according to different developmental day of blastocysts, different stage of blastocysts, and different biopsy grade and the embryos themselves were incubated for 2 hours in TCM199 after microsection to be evaluated morphologically for recovery as blastocyst. The results obtained were as follows : 1. The rate of oocytes cleaved in vitro and the rate of blastocyst of the cleaved oocytes were 52.5% and 21.6%, respectively. The rate of blastocyst on day 8 was 11.2%, denoting the highest rate during whole culture period posterior to in vitro fertilization(IVF) 2. After biopsy for sexing, the viability rate of blastocyst on day 7, 8 and 9 was 75.0%, 88.4%, and 100.0%, respectively and the viability of early, mid, and expanded blastocyst after biopsy was 75.0%, 88.9%, and 91.1%, respectively The viability rate of fresh and frozen/thawed embryos was 89.9%, 71.4%, respectively. And the viability of expanded, hatching, and hatched blastocyst of frozen/thawed embryos was : 75.0%, 75.0%, and 50.0%, respectively. The viability of embryos according to biopsy grade of 10∼20%, 21∼30%, and 31∼40% was 85.7%, 91.5%, and 71.4%, respectively. 3. Pregnancy rate after transfer with biopsied embryo between flesh and frozen/thawed embryos was 22.6% and 20.0%, respectively. 4. In comparison between sex by PCR method and sex of calves born after embryo transfer, the accuracy of sex deterimination was 92.3% (12/13).

• Korean Journal of Animal Reproduction
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• v.7 no.1
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• pp.19-23
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• 1983

Present studies were conducted to investigate the developmental stage and the location of embryos in the reproductive tract at various times after ovulation, the morphologically normal after thawing of embryos preserved in liquid nitrogen, and the survival after transferring frozen-thawed embryos. The results obtained were as follows: 1. Embryo stage and location in the reproductive tract after hCG administration. For the investigation of embryo stage and location in the reproductive tract after ovulation, rabbits were laparotomized at 24, 40, 48, 72 and 120 hrs post hCG injection, simultaneously with mating. the oviducts and uteri were flushed out with PBS medium containing 50% rabbit serum, respectively. 1) Most of embryos was remained in the oviduct within 48 hrs, with the lapse of time, embryos were started to move to uterus and shifted in uterus at 72 hrs after hCG injection. 2) The representatives of embryos stage collected at 24, 40, 48, 72 and 120 hrs were 1-cell(60.4%), 8-cell to early morula (52.3, 39.3%), late blastocyst (95.5%) stages, respectively. 2. Morphological normality and survival of the frozen-thawed embryos. For the evalution of the quality and viability on the frozen-thawed embryos, immediately after thawing, embryos were assessed by morphologically normal under a dissecting microscope, and a further test of frozen-thawed embryos was made by transferring the morphologically normal embryos to the uteri of recipient rabbit induced pseudopregnancy by the injection of hCG at the time of hCG injection in donor rabbits. 1) The propotions of embryos which a, pp.ared morphologically normal was higher when 8-cell (85.7%) and morula(90.5%) were used for freezing than when 4-cell (66.7%) and blastocyst (75.8%) were used. 2) Preganacies were observed at Day 15 after transfer of frozen-thawed 8-cell (7/13), morula (19/42) and blastocyst (3/19) but not after transfer of embryos at 4-cell stage.

• Journal of Embryo Transfer
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• v.13 no.2
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• pp.147-157
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• 1998

This study was conducted to investigate the effects of in vitro fertilization, culture and embryo development according to in vitro maturation rate, protectant composition and equilibrium time after frozen /thawing of bovine immature oocytes. This results obtained in studies on the effect of different cryoprotectants on the viability, maturation and development of in vitro bovine oocytes were as follow: 1.The post-thawing of immature oocytes matured to metaphase II during culture time for 0 to 26 h, and those group (62~3%) were low than control group (76.7%). The optimal maturation time of frozen-thawed immature oocytes was at 24 h. 2.The viability of cryopreserved immature oocytes was not affected by sort of cryoprotectants. The developmental competence of frozen4hawed oocytes was not affected by cryoprotectants. These results indicate that an optimal maturation time of frozen /thawed immature oocytes was at 24h. Furthermore the viability of cryopreserved immature oocytes was not affected by sort of cryoprotectants and developmental competence of frozen /thawed oocytes.

• Journal of Embryo Transfer
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• v.8 no.2
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• pp.105-109
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• 1993

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%).

• Journal of Embryo Transfer
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• v.26 no.1
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• pp.13-17
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• 2011

Research in the area of equine artificial insemination (AI) has led to its increased application in field trials. However, procedures for equine semen collection, cooling and freezing of semen and artificial insemination need further improvement. In experiment 1, we investigated the percentage of total motility (TM) and progressive motility (PM) of sperms at after-collection, cooled-diluted, cooled-transported or frozen-thawed semen. In experiment 2, mares were inseminated with either cooled-diluted, cooled-transported or frozen-thawed semen. In experiment 3, we examined the effect of buffer (skim-milk extender), which was infused into the uterus at the time of AI with frozen-thawed semen. In experiment 4, we compared AI pregnancy rates for mares ovulating spontaneously versus after treatment with hCG. In experiment 1, the average percentage of TM was decreased from 75.3% to 14.4% at the stage of after-collection to frozen-thawed semen (p<0.05). The average percentage of PM was 58.2% and 59.6% at after-collection and cooled-diluted, but it was significantly increased 71.7% after frozen-thawed (p<0.05). In experiment 2, the pregnancy rates after AI using cooled-diluted, cooled-transported and frozen-thawed semen were 60%, 50% and 37.5%, respectively, and similar among treatments. In experiment 3, the pregnancy rate of mares infused with buffer at AI was 40% which was higher than that with no buffer (10%). In experiment 4, the pregnancy rates of mares were similar between ovulated spontaneously (25%) and ovulated with hCG (50%). The results suggest that equine semen that has been cooled-diluted, cooled-transported or frozen can be successfully used to establish AI, pregnancy and foal production. Also, the pregnancy rates after AI can be increased by infusing buffer into the uterus at AI or by inducing ovulation with hCG, but further study is need.