Embryo transfer (ET) technology is of high importance in modern cattle breeding programs. ET is one step in the process of removing one or more embryos from the reproductive tract of an outstanding donor female and transferring them to one or more recipient females. Embryos also can be produced in the laboratory via techniques such as in vitro fertilization (IVF). But the actual transfer of an embryo is only one step in a series of processes that may include some or all of the following: superovulation and insemination of donors, collection of embryos, isolation, evaluation and short-term storage of embryos, micromanipulation and genetic testing of embryos, freezing of embryos and embryo transfer. Cryopreservation and direct transfer of frozen-thawed embryos is common-place with pregnancy rates near that of fresh embryos. Polymerase chain reaction (PCR) technology is currently being used for sexing embryos, and this technology will be used for “embryo diagnostics” and “embryo genomics” in the future. Although, many limitations and problems remain to overcome, these and other new technologies promise to change livestock breeding drastically in the next decade.

The study was conducted to investigate the comparison of pregnancy rate and transferable embryos produced by genetically superior Korean cows (Hanwoo) of livestock farms. Eighteen Hanwoo donors were superovulated with gonadotropin for 4 days combined with Progesterone Releasing Intravaginal. Embryos were recovered 7 days after the second insemination by flushing the uterus with embryo collection medium. No differences were observed in the efficiency of rate of superovulation in groups A (low nutrition) and B (highnutrition) it was observed to be 100.0% and 87.5%, respectively. The mean numbers of total embryos were 10.8±3.4 and 8.9±2.5, and transferable embryos were 7.5±3.3 and 4.0±1.5 in groups A and B, respectively. The pregnancy rates after embryo transfer were 23.5%, 20.0%, C 80.0% and 55.6% in farm A, B, C, and D, respectively. In conclusion, results suggest that superovulation could be used quite effectively to raise superior Hanwooembryos. However, physical and biological condition of recipients greatly affects the rate of pregnancy.

The objective of this study was to investigate the comparison of transferable embryos and pregnancy rate between Hanwoo and Chickso. The results obtained were as follows: No differences were observed in the efficiency of superovulation rates on Hanwoo 78%, and Chickso 85%, respectively. The mean number of total embryos are each 14.76± 2.16 and 6.23±1.07. So the mean number of transferable embryos are each 10.94±1.91 and 4.58±1.05. In addition, the mean number of total Hanwoo embryo from <10 and 10≤ of corpora luteum was 0.50±0.50, 11.56±1.92, respectively. In case of Chickso, The mean number of transferable embryo from <10 and 10≤ of CL was 2.75±1.39, 6.00±1.00, respectively. The pregnancy rates were Hanwoo 40%, and Chickso 37% following transfer of fresh embryos produced in vivo. Also, the pregnancy rates of Chickso 60% were significantly greater (p<0.05) than the Hanwoo 42.48% following transfer of following transfer of frozen embryos, respectively. In conclusion, these results suggest that Chickso may be effectively used for transferable embryos production in Hanwoo. Although the transferable embryos number was not enough, it seems the Chickso greatly affect pregnancy rate. The results indicated that the possibility of transferable embryos from Chickso for embryo transfer could be confirmed in this study. Based on the present findings, it was suggested that it is very important to evaluate in vivo embryo production and pregnancy rate of embryo transfer following superovulation for effective Hanwoo and Chickso production.

Embryo transfer (ET) is the final procedure for getting pregnancy through assisted reproductive technology such as IVF (in vitro fertilization), SCNT (somatic cell nuclear transfer). In our laboratory, the porcine cloned embryos loaded in ET medium are carried for 3 hours by portable incubator because of the great distance from the laboratory to the experimental farm. Thus, before transferring into recipient, porcine cloned embryos are exposed in vitro condition for long time. Medium which is used in this process is the TALP (Tyrode’s medium supplemented with 10 mM HEPES), but it includes little nutrients for embryo. Thus, the aim of this study is to determine whether ET media containing nutrients affect the in vitro development of embryos compared to TALP. For the experiment, porcine zygote medium (PZM)-5 which has amino acids for developing embryo was chosen as ET medium containing nutrients, added 10 mM Hepes as PZM-5 does not contain buffering system. For experiment, we carried out parthenogenesis through a chemical method using Thi/DTT. Parthenogenetic embryos were cultured in PZM-5 for 2 days, and then they were randomly divided into two group; loaded in a straw with TALP or PZM-5-Hepes, respectively. They were stored in a portable incubator for 3 hours to simulate the time consumed in ET, thereafter embryos in both TALP and PZM-5-Hepes groups were respectively cultured in PZM-5 for additional 5 days. All experiments were repeated 5 times. In result, blastocyst formation rate were 22.46%±1.47 and 23.17%± 2.13, respectively and total cell number were 32.9±2.22 and 37.09±2.18, respectively. There is no significant difference between TALP and PZM-5-Hepes groups. * Further study will investigate effect of PZM-5-Hepes on in vivo development of porcine cloned embryo. This study was supported by IPET (#311011-05-1-SB010), RNL Bio (#550-20120006), Institute for Veterinary Science, the BK21 program and TS Corporation.

A study was conducted to investigate the efficiency of recipient for Embryo Transfer (ET) in Holstein Heifers. A total of 193 heifers (Age 14-20 months and body weight, 250-400 Kg) was assigned in 2 groups (natural ovulation cycle group and Hormone-induced ovulation synchronization group) based on the development of corpus luteum (CL) and uterus where 28.49% (55/193) heifers were in normal estrous. The ET technique was applied in both of the groups to transfer the embryo in the recipients and evaluated their efficiency. In vivo frozen embryos were used for ET at the blastocyst stage. Results showed that according to recipient preparation method the conception rates were 22.72% (10/44) and 40.26% (60/149) in hormone-induced ovulation synchronization group and natural ovulation cycle group, respectively. The pregnancy rate of heifers was significantly higher (p<0.05) during the first time ET compared to repeat ET; however, recipient showed no significant difference in CL development in both side. The conception rate were 31.03% (9/29), 37.75% (57/151) and 15.38% (2/13) at day 6, 7 and 8, respectively after the CL development of the heifers. The conception rate was significantly higher (p<0.05) in the right side compared to left side of the CL development. In addition, during ET anesthesia group and non anesthesia group conception rate of the recipient were 27.63% (21/76) and 41.88% (49/117), respectively.

Artificial insemination and embryo transfer is one of the most important factors affecting to the production of fawn from deer nuclear transfer in the field of deer farms. This study* was conducted to establish the production technology of nuclear transfered embryo in deer. For estrus synchronization or superovulation tretments in flower deer and elk, each 10 does were inserted into the vagina for 14 days with CIDR (Pfizer New Zealand Ltd., NZ) for elk and Ring-CIDR (Bioculture Co., Ltd., Korea) for flower deer, and then those inserted devices were removed. The estrus synchronization of each 6 does were induced by the intramuscular injection of PGF2α (25 mg/head) and PG600 (hCG 200IU + PMSG 400IU, Intevet, Holland). Then, the superovulation of each 4 does of flower deer and elk was induced by additional injection of FSH (200 mg/ head) twice with an interval of 24 hours , respectively. Follicular oocytes were collected from each 2 does superovulated after 48 hours since the injection of PG600 and FSH. In the meantime, the ovarian response and the number of the collected ovarian follicles were investigated with the surgical operations. As a result, the average number of the collected ovarian follicles were 8.5 and 9.0 in flower deer and elk, respectively. The ovarian follicles collected from each two does were cultured in vitro for 48 hours with m-DMEM medium, and then the cell fusion was carried out after the nuclear transfer by the antler cell. As a result, 5 out of 18 ovarian follicles collected from 2 elk does were reached on the MII stage, but there was no generation resulting from the nuclear transferred embryos by the antler cell after enucleation. In 2 flower does, 7 out of 17 ovarian follicles were reached to the MII stage, but one of them was developed to parthenogenetic embryo as well despite a case of fusion from the nuclear transferred embryo. Embryos were collected in a surgical way on the 7th day after artificial insemination, numbers of average embryos collected were 2.5 and 3.0 in each 2 flower deer and elk does superovulated, respectively. The collected two embryos were transplanted to each 2 does synchronized. As a result, a head of fawn was produced from only one elk doe, where as a head of fawn were delivered from one out of 4 elk does artificial inseminated. Given these findings, we consider that more or less of problems might have occurred in vitro culture system of ovarian follicles in the production of nuclear transfered deer embryos. In addition, the greatest reason why both the aetificial insemination and embryo transfer failed was considered attributable to stress due to anesthesia and catching.

Embryo transfer has been used in Japan for several years to produce bulls and cows of high genetic value, to produce beef calves from dairy cows. The average size of Japanese cattle farming is not very large. An efficient embryo transfer program is important to facilitate adoption of these technologies in the field. The fixed‐time embryo transfer programs allow for systematic embryo transfer under field conditions. The objective of this paper was to evaluate the practical utility of fixed‐time embryo transfer programs in cattle under field conditions. Two fixed‐time embryo transfer programs were used for dairy or beef cattle: 1) the ovysync program and the 2) progesterone and estradiol program. 1) Ovysync Program Dairy cattle (cows, n = 146; heifers, n = 107) were randomly allocated to a natural estrus control group (cows, n = 63; heifers, n = 47) or an ovulation synchronization (ovysync) group (cows, n = 83; heifers, n = 60), which was treated with an intramuscular (IM) injection of 100 μg GnRH at a random stage of the estrus cycle. Seven days later, the cattle received PGF2α (Cows; 25 30 mg) or PGF2α analog (Heifers; 0.5 mg) to regress the corpora lutea (CL). Forty‐eight hours later, the cows and heifers received a second injection of 100 μg GnRH. Embryo transfer was carried out 6 or 7 days after the second GnRH injection. There were no differences in the proportion of acceptable embryo transfers in the control (cows, 81.0%; heifers, 91.4%) and ovysync groups (cows, 83.1%; heifers, 91.7%). Pregnancy rates did not differ between groups. 2) Progesterone and Estradiol Program All beef heifers and beef or dairy cows received CIDR and estradiol benzoate (EB, beef heifers and cows, 1 mg; dairy cows, 2 mg) IM on Day 0, PGF2α at the time of CIDR removal (beef heifers and cows, Day 7; dairy cows, Day 8), 1 mg EB IM on Day 8 (beef heifers and cows) or 9 (dairy cows). Embryo transfer was carried out on Day 16 (beef heifers and cows) or Day 17 (dairy cows). The pregnancy rates were 80.0% (12/15) for beef heifers, 46.7% (7/15) for beef cows and 68.4% (13/19) for dairy cows. These results suggest that both fixed‐time embryo transfer programs can be effectively applied to cattle programs under field conditions.

This study was carried out to confirm the effects of luteotrophin, human chorionic gonadotrophin (hCG), and an anti-luteolytic agent, flunixin meglumin (FM), on pregnancy rates in Hanwoo with in vitro produced (IVP) embryo transfers (ET), and to research the effects on the estrus cycle. Treatments included hCG and FM administration 3~10 minutes prior to ET. Also, pregnancy rates were compared with lidocane treatment and FM treatment prior to ET. The results are shown below. 30-day pregnancy rate was 76.7% in the hCG-treated group and 75.7% in the FM-treated group. Both rates were higher than the 70% rate for the control group. 42-day pregnancy rate was 76.7% in the FM-treated group. This was higher than 66.7% recorded for both the hCG-treated and control groups. The pregnancy rate of the hCG-treated group was high at Day 30 (76.7%) but low at Day 40 (66.7%), and there were no differences from the FM-treated and control groups. The recurrent estrus rate of infertile individuals at 2 weeks after ET was 36.4% in the hCG-treated group, under 71.4% in the FM-treated group and 80.0% in the control group. The non-pregnancy rate of individuals without recurrent estrus was 18.2% in the hCG-treated group, which was higher than the 0% rate in both the FM-treated and control groups. The pregnancy rates were higher in the FM-treated group than the Lidocane-treated group with 72.3% versus 67.5% in the heifers and 48.9% versus 43.6% in the cows. From the above results, the FM treatment proved more effective than the hCG treatment and no treatment whatsoever in increasing pregnancy rates after ET. In addition, hCG treatment was shown to be undesirable due to the deviations it caused in the reproductive physiology of the hCG-treated recipients. Therefore, in our study, the FM treatment resulted in a higher pregnancy rate than either lidocaine treatment or no-treatment in the trials of ET.