• Journal of Embryo Transfer
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• v.26 no.1
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• pp.19-25
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• 2011

This study was carried out to evaluate the effect of early pregnant cow as donor for Ovum Pick-Up (OPU) derived oocyte aspiration and embryo production in Holstein heifers. Four non-pregnant and 2 pregnant Holstein heifers were used as donor and then carried out total 17 OPU session for 10 weeks (2 times per week). Recovered cumulus-oocyte-complexes (COCs) were classified into 4 grade by oocyte cytoplasm and cumulus cells and matured in vitro in TCM-199 supplemented with 10% FBS, 10 mg/ml FSH and 1 mg/ml estradiol in 5% $CO_2$ and over 99% humidity for 24 h. After 24 h co-incubation with post-thaw sperm, the presumed zygotes were cultured in CR1aa medium with 4 mg/ml BSA for 3 days and then changed CR1aa medium with 10% of FBS for another 3~4 days. The Mean number of aspirated follicles and collected oocytes in the early stage pregnant and non-pregnant heifers were $13.0{\pm}4.3$ and $10.6{\pm}3.9$, $5.4{\pm}3.4$ and $7.7{\pm}3.6$ per session, respectively. Rate of collected oocyte from aspirated follicles were 59.2% and 50.5%, respectively. The average number of good quality oocytes (Grade I and II) in the early stage pregnant and non-pregnant heifers was $3.7{\pm}2.7$ and $4.9{\pm}2.6$ (Mean${\pm}$SD). Cleavage and blastocyst developmental rates in Grade I and II were 22.2% and 25.5%, and then $1.7{\pm}0.9$ and $1.4{\pm}1.1$ blastocyst per session, respectively. In conclusion, OPU technology can be used in early stage pregnant and non-pregnant heifers without any problem and so applied OPU derived embryo production to maximize the ability of genetically valuable females.

• Journal of Embryo Transfer
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• v.13 no.1
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• pp.77-86
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• 1998

A combined technology of transvaginal ovum pick-up(OPU) system with in vitro-oocyte manipulation technique can be used for improving reproductive efficiency in the cattle. The objective of this study was to establish a newly-conceived breeding program using OPU in the pregnant cows. The OPU trial was performed in pregnant cows every 10 days from 40 through 90 days of artificial insemination (Al), and number of follicles in ovary, number of retrieved oocytes and embryo development following in vitro-fertilization, were evaluated. Reduced number of follicles in the ovaries of pregnant cows was firstly detected from 70 days after A' and a significant (P<0.05) decrease in the follicle number (5.4 follicles /donor) was found at 90 days than at 40, 50, 60 and 80 days after Al (8.0~9.2). A similar pattern was also observed in the number of oocytes retrieved by OPU apparatus during experimental period. When retrieved oocytes were matured and inseminated in vitro with frozen bull semen, development of the oocytes to the blastocyst stage was not significantly affected by the retrieval time. Four embryos (morula or blastocyst stage) derived from oocytes retrieved from pregnant cows were nonsurgically transferred to four recipient cows on day 7 of estrus cycle. For the first time in Korea, three of four transferred embryos developed to live calves with normal physiological parameters. In conclusion, an effective breeding program employing pregnant cow can be developed by use of OPU trial and in vitro culture techniques of oocytes ; OPU system could be repeated in pregnant cows with no risk of abortion and viable offsprings were borne after transfer to the recipients.

• Korean Journal of Veterinary Research
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• v.34 no.2
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• pp.395-406
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• 1994

To study the conditions to enhance success of embryo transfer in the dog, 20 mixed-breed bitches were used for the experiment along with 4 male dogs for mating. The bitches were paired according to synchronism of natural estrus, or the counterpart as donor or recipient was treated with gonadotropin as FSH (follicular stimulating hormone) or PMSG (pregnant mare serum gonadotropin) for induction of estrus to be synchronized with estrus of the other bitch in natural estrus. Embryo recovery was performed in two ways for comparison, either by flushing each uterine horn after ovariohysterectomy or by flushing each horn in the state of non-ovariohysterectomy. In addition, the result of pregnancy according to the embryo stage and the repeatability of the experimental animals as donor or recipient were also investigated. FSH or PMSG was administered to the bitches which had passed over 4 months from last estrus, resulting in estrus-positive in 3 dogs of 6 FSH-treated dogs (50.0%), and in 5 dogs of 9 PMSG-treated dogs (55.6%), determined by proestrus signs and vaginal smear test. Estrus-positive bitches induced with gonadotropin were used as donor or recipient resulting in one embryo-recovered bitch as donor and one offspring-delivered bitch as recipient in 5 PMSG-treated dogs, whereas no result was obtained from 3 FSH-treated dogs. The rate of embryo recovery to be compared with number of corpus luteum was 68.2% in ovariohysterectomized dogs and 55.2% in non-ovariohysterectomized dogs, respectively. The number of dogs from which embryo was collected were 4 dogs of 6 ovariohysterectomized dogs (66.7%) and 6 dogs of 7 non-ovariohysterectomized dogs (85.7%), respectively. The result of parturition was obtained from one dog of 5 estrus-induced recipients, whereas no result was obtained from 3 natural-estrus recipients. The only dog which delivered a male puppy had been transferred 3 morulae and 2 blastocysts. Of 6 repeat-used bitches in canine embryo transfer, 3 dogs showed repeatability either as donor or recipient. These results indicated that inducing estrus of a dog with gonadotropin is feasible in canine embryo transfer to be synchronized with that of a natural-estrus dog, that embryo recovery is also possible in non-hysterectomized dogs, that the estrus-induced dog is also usable as recipient to result in parturition, and that repeat-use of a bitch as donor or(and) recipient is possible in canine embryo transfer.

• Journal of Embryo Transfer
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• v.5 no.2
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• pp.38-44
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• 1990

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$_2$$\alpha$ 45mg on day 4 of FSH injection. Donor cows were flushed to collect embryos on day 7 or 8 of the estrus cycle. Fresh embryos collected were transferred to synchronized dairy recipients or frozen using glycerol 3 step method to he equilibrated. And 35 embryos which were frozen using glycerol 6 step method were imported from U.S.A. After glycerol dilution of frozen embryos was done by reverse density during freezing. frozen-thawed embryos were transferred to synchronized dairy or beef recipients. The results obtained were as follows; 1. Total of 24 embryos were collected from 7 donor cows flushed and transferable embryos were 18 (75.0%). 2. Among 24 embryos. morula, early blastocyst, blastocyst, expanded blastocyst and unfertilized ova were 3 (12.5%), 1 (4.2%), 10 (41.6%), 4 (16.7%) and 6 (25.0%), respectively. 3. Heat inducing rate after 1st and 2nd injections of PGF$_2$$\alpha$ 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%).

• 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%).

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.4
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• pp.585-592
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• 2017

Objective: The present study investigates pre- and post-implantation developmental competence of nuclear-transferred porcine embryos derived from male and female fetal fibroblasts. Methods: Male and female fetal fibroblasts were transferred to in vitro-matured enucleated oocytes and in vitro and in vivo developmental competence of reconstructed embryos was investigated. And, a total of 6,789 female fibroblast nuclear-transferred embryos were surgically transferred into 41 surrogate gilts and 4,746 male fibroblast nuclear-transferred embryos were surgically transferred into 25 surrogate gilts. Results: The competence to develop into blastocysts was not significantly different between the sexes. The mean cell number of female and male cloned blastocysts obtained by in vivo culture ($143.8{\pm}10.5$ to $159.2{\pm}14.8$) was higher than that of in vitro culture of somatic cell nuclear transfer (SCNT) groups ($31.4{\pm}8.3$ to $33.4{\pm}11.1$). After embryo transfer, 5 pregnant gilts from each treatment delivered 15 female and 22 male piglets. The average birth weight of the cloned piglets, gestation length, and the postnatal survival rates were not significantly different (p<0.05) between sexes. Conclusion: The present study found that the sex difference of the nuclear donor does not affect the developmental rate of porcine SCNT embryos. Furthermore, postnatal survivability of the cloned piglets was not affected by the sex of the donor cell.

• Journal of Embryo Transfer
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• v.6 no.2
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• pp.37-46
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• 1991

A field trial was performed to evaluate the effects of hormone treatment on estrus induction, ovulation, embryo transfer and reproductive performance in post-weaning sows. This trial involved 61 mixed breed sows of varying parity on a commercial pig farm. Sows were allocated to one of five trials: control group involved 25 sows that were treated with a single intramuscular injection of 5 ml physiological saline, 6 sows received 1,500 IU PMSG on the day of weanning and 500 IU HCG at the onset of estrus in trial I, 7 sows received 750 IU PMSG on the day of weanning and 500 IU HCG at the onset of estrus in trial II, 5 sows were treated with the same as trial II on day 28 after weanning in trial III. and 18 sows were treated with 10 mg PGF$_2$$\alpha$ plus 2 mg estradiol benzoate on day 31 after weanning in trial IV. Ovarian responses were checked by laparotomy and ova were recovered by oviducal flushing between 40 and l00hrs after mating. Fertilized ova were transferred into the oviduts of recipient sows synchroni- zed. The results obtained were summarized as follows: 1. Percentages of sows detected in standing estrus following treatment were 86~100% among trial groups. The interval from treatment to standing estrus(6l.7$\pm$0.5lhrs) in lOmg PGF$_2$$\alpha$ and 2mg estradial henzoate treated group was significantly earlier than in other trial groups(P<0.05). 2. Average number of ovulations was 11.5~37.8 among trial groups. The ovulation rate in 1,500 IU PMSG and 500 IU RCG treated group (37.8$\pm$ 19.87) was significantly different from other trial groups(P<0.05). 3. Ova were recovered by oviducal flushing between 40~ l00hrs after mating and recovery rates of ova wore 91.4% between 40~59hrs. 4. Fertilized ova were transferred into the oviducts of 8 recipient sows synchronized with 7 to 17 ova per animal. Three of the recipients were pregnant and delivered 25 piglets. 5. Four of the donor sows in those embryo collection was not successful were pregnant following oviducal flushing and delivered 23 piglets. 6. Recurrence of estrus and farrowing performance of experimental sows were observed following the experiment was no difference among trial groups, respectively.

• Journal of Embryo Transfer
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• v.12 no.1
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• pp.75-90
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• 1997

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.

• Journal of Embryo Transfer
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• v.6 no.1
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• pp.13-24
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• 1991

The objective of this experiment was to study some possibilities to simplify freezing, thawing and transfer procedure of one-step straw method comparing with the conventional methods using bovine embryos. The previous work are also designed to investigate the thawing effect by development stage and its quality using the embryos. Results obtained were summarized as follows: 1. A total of 87 embryos from 14 donor cows were frozen-thawed and an average of frozen embryo/donor was 6.2. 2. The survival rates of morula stage(65.4%) were higher than those of blastocyst stage(57.l%) and vice versa in rate of morphological recovery (80% vs 95.4%). However. no significant difference was denoted between them. 3. In difference between the groups of good quality and poor quality. good quality was resulted in a significantly higher embryo survival rate(75%) and recovery rates(95%) than poor quality(P<0.0l). 4. In effects of non-permeable sugar dilution in added to l.0M glycerol. higher survival rates were orderd in sucrose. lactose, raffinose and xylose. But lactose-raffinose, sucrose-trehalose and xylose in added to 2.OM glycerol. 5. The highest survival rates were obtained by direct plunge into the liquid nitrogen with 3.OM concentration both of glycerol and trehalose. 6. The survival rates in vitro condition of one-step and direct plunge methods(75%-87.5%) were significantly higher than those of multiple steps (21.4-52.6%) in in vitro (P<0.0l). However, the results of single-step were critical in comparing to other steps of final pregnant conformation.

• Korean Journal of Veterinary Research
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• v.29 no.1
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• pp.61-68
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• 1989

This study was carried out to determine suitable selection factors for recipients and embryos which could improve pregnancy rates following bovine embryo transfer. The experiment included 52 surgical transfers from February, 1985 through June, 1986 performed on Kyungpook Breeding Center in southern Korea. The pregnancy rate was highest when recipients were in estrus within 6 hours before the donor to 12 hours after the donor (78.3% versus 50% for recipients in estrus earlier or later). Pregnancy rates were acceptable following culture under field conditions for up to 17 hours. More recipients over 15 months of age (76.1%) remained pregnant than those under 15 months (66.7%). Embryos transferred during the months from February to July resulted in higher pregnancy rates than those transferred during the remaining 6 months (77.3% versus 57.1%). Transferrable embryos were classified A (best) to C (worst); those graded A or B resulted in significantly higher pregnancy rates than those graded C (81.8% and 73.3% versus 25.0%, p<.05). Pregnancy rates among recipients of the Korean native breed tended to be higher than among Holstein recipients (100% versus 71.1%). Similarly, when the embryo was transferred to the right uterine horn, pregnancy rates tended to be higher than when it was transferred to the left (81.3% versus 65%). Pregnancy rates did not differ according to the stage of development of the embryo; they were for morulae, tight morulae, blastocysts, and advanced blastocysts, respectively: 75.0%, 66.7%, 75.0%, and 77.4%.