• Journal of Embryo Transfer
• /
• v.21 no.3
• /
• pp.191-198
• /
• 2006

The objectives of this study was to produce valuable offsprings of Hanwoo and Jeju black cattle using in vivo embryo production and embryo transfer techniques during 5 years ($2001{\sim}2005$) in Jeju. Two hundred and eighty six Hanwoo and sixty nine Jeju black cattles, at random stages of the estrous cycle, received a CIDR. Seven days later, the animals were superovulated with a total of 400 mg pFSH ($Folltropin^{(R)}-V$) administered twice daily in constant doses (each 50 mg) over 4 days. On the 6th administration of FSH, CIDR was withdrawn and 25 mg $PGF_{2{\alpha}}$ was administered. Cows were artificially inseminated thrice after estrous detection at 12 hr intervals. The cows received $250{\mu}g$ GnRH at the time of 2nd insemination. Embryos were recovered 7 or 8 days after the 1st insemination. Recipients were synchronized with donors by insertion of a CIDR for 7 days and administration of 25 mg $PGF_{2{\alpha}}$ at the time of CIDR removal. The collected embryos were transferred to 1,219 recipients by 6 transfer persons. The mean numbers of total ova and transferable embryos from Hanwoo and Jeju black cattle donors were 7.4 and 4.7, respectively The number of transferable embryos differed between Hanwoo (5.0) and Jeju black cattle (3.5, p<0.05), while that of total ova did not differ. Repeated superovulation treatments decreased (p<0.05) the ratio of numbers of the flushed animals vs. superovulated animals in Jeju black cattle, and the numbers of total ova and transferable embryos in Hanwoo. More transferable embryos were collected at summer (5.6) than winter (2.9, p<0.01). The mean pregnancy rate was 40%. The pregnancy.ate was affected by transfer year (2001<2004, p<0.05) and transfer person ($33.0{\sim}41.9%$, p<0.01), while not by donor (embryo) breed. These results showed that in vivo embryo preduction and embryo transfer techniques using CIDR for Hanwoo and Jeju black cattle donors as well as recipient, regardless of their estrous cycle, may enable a stable embryo production and recipient preparation.

• Asian-Australasian Journal of Animal Sciences
• /
• v.32 no.11
• /
• pp.1673-1685
• /
• 2019

Objective: To evaluate the efficacy of treatments based on gonadotrophin-releasing hormone (GnRH), GnRH-prostaglandin $F2{\alpha}$ ($PGF2{\alpha}$), and/or intense exposure to novel rams to induce fertile estrus without the use of steroid hormones in seasonally anestrous Suffolk ewes. Methods: In the first experiment, ewes were treated with one injection of GnRH, two injections of GnRH administered 7 days apart, or a sequence of GnRH-$PGF2{\alpha}$-GnRH (GPG). In the second experiment anestrous ewes were exposed, for 36 days starting on the day of weaning, to groups of four rams of three different breeds that were alternated every day. Besides exposure to the male effect (ME), the ewes were injected with saline solution (ME group, n = 20), with GnRH (ME-GnRH group, n = 20) or with a sequence of GnRH-$PGF2{\alpha}$-GnRH (ME-GPG group, n = 20). The rams used for male-effect were fitted with aprons to prevent mating, and ewes detected in estrus were bred to selected fertile rams. Ovarian activity was monitored by progesterone determinations in both experiments. Results: In the first experiment sustained induction of ovarian activity was not achieved and no ewe was detected in estrus. In the second experiment induction of sustained ovarian activity was achieved in all groups. Most of the ewes were detected in estrus, 76.7% of the ewes were mated during a 36-d breeding period and 71.7% of all the ewes became pregnant during that period. No significant differences between groups were found for any of these variables. However, estrus detection efficiency was higher in the ME-GnRH group than in the ME group (p<0.05). Conclusion: An intense male-effect, that included the continuous presence and frequent alternation of several rams of different breeds, was sufficient to induce ovarian activity and fertile estrus in Suffolk ewes during the period of deep anestrus without the use of hormones, although addition of GnRH improved the efficiency of estrus detection.

• Clinical and Experimental Reproductive Medicine
• /
• v.15 no.1
• /
• pp.17-24
• /
• 1988

Follicular fluid(FF) prostaglandin $E_2$(PG$E_2$) and $PGF_{2{\alpha}}$ levels were compared in 3 groups of spontaneously ovulatory women undergoing ovulation induction with clomiphene citrate (CC) alone or with human menopausal gonadotropin(hMG) (14 patients), hMG(9 patients), or pure FSH/hMG(11 patients) for the purpose of in vitro fertilization. FF volume aspirated did not differ significantly according to the maturity of the oocyte. According to hyperstimulation regimens, the volume of FF from which preovulatory occytes were obtained was significantly less in the hMG-treated group than in the other groups. In follicles of preovulatory oocytes, FF PG$E_2$ values were significantly lower in the FSH treated group than in the Cc.treated or hMG-treated group, and FF $PGF_{2{\alpha}}$ values were significantly higher in the hMG-treated group than in the CC-treated or FSH-treated group. In follicles of immature or atretic oocytes, there was no significant difference in FF PG$E_2$ and PG$F_{2{\alpha}}$ concentrations of the similar morphology of the oocyte according to hyperstimulation regimens. In all cycles, FF PG$E_2$ and PG$F_{2{\alpha}}$ values of preovulatory oocytes were not significantly different from those of immature oocytes, but those of atretic oocytes were relatively lower than those of fertilizable oocytes and it was statistically signifincant in PG$E_2$ values of CC-treated group. In all treatment groups, FF PG$E_2$ and PG$F_{2{\alpha}}$ levels did not show and close relationship with the success of fertilization in vitro and of pregnancy after embryo transfer. Above results suggested that FF PG$E_2$ and PG$F_{2{\alpha}}$ be involved in oocyte maturation and ovulation, but their relationship with the success of in vitro fertilization was not found.

• Journal of Embryo Transfer
• /
• v.1 no.1
• /
• pp.59-68
• /
• 1986

산양의 발정주기의 생리와 조절에 관한 최근 연구 보고들과 한국 재래산양의 대한 이들 연구 결과를 모아 고찰하였다. 온대지역에서 산양의 번식계절은 분명하나 한국재래산양의 경우는 비번식계절이 비교적 짧거나 계절적 무발정율이 낮은 편이며, 비번식계절에는 기능적 황체가 유지되지 않는다. 한국재래산양의 발정주기와 발정지속기간은 타품종과 비슷하며, 발정지속기간의 반복력은 매우 낮으며, 발정주기중의 progesterone과 estradiol-17$\beta$의 소장을 규명하였다. 한국재래산양의 경우 황체기에 PGF2 1-3mg을 투여하면 항체퇴행을 유기할 수 있으나 주기중의 투여시기에 따라 투여후 발정개시 시간에 차이가 있었다. 그리고 pro-gesterone priming후 PGF$\alpha$를 투여함으로써 효과적인 발정동기화를 이룰 수 있었다. 분만후 1개월경과 유상후 12일경에 발정이 재귀되었으며, 첫 발정 후 80%의 산양에서 5-7일의 단발정주기를 나타냈으며, 대부분의 과배란유기 산양에서도 단발정주기를 나타냈는데 이는 황체의 조기퇴행 때문이었다. 초발정후 3-5일에 GnRH를 연속 주사하면 단발정주기의 발생율이 유의적으로 감소되었다.

• Journal of Embryo Transfer
• /
• v.22 no.1
• /
• pp.47-51
• /
• 2007

The objective of this study was to improve the reproductive ability of Thoroughbred mares with artificial estrous regulation by hormone treatments and artificial illumination. The results were as follows; Estrous detection in cycling mares which were treated $PGF_2{\alpha}$ or altrenogest administration was all 100%, and pregnancy rates were 95.2% and 71.4%, respectively. Estrous detection was 100% within March when altrenogest was administered alone or together with estradiol for non-pregnant mares in the previous year. Interval to estrous detection after altrenogest administration was 4.3 days in single administration of altrenogest and 3.7 days in combined administrations of altrenogest and estradiol, respectively Interval to ovulation after estrous detection were 2.7 and 2.5days, respectively. Pregnancy rate following single altrenogest administration was 80.0%. Estrous detection and pregnancy rates by artificial illumination in non-pregnant mares were 92.9% and 46.9%, respectively. These results show that estrous synchronization of mares during breeding season will be able to improve the pregnancy rate, and altrenogest administration in non-pregnant mares in the previous year will be able to induce early reproduction and improve pregnancy rate In racing horses.

• Journal of Veterinary Clinics
• /
• v.27 no.4
• /
• pp.397-401
• /
• 2010

This study was to evaluate the usefulness of a programmed reproductive management including Presynch-Ovsynch-Resynch protocol in lactating dairy cows. Nine hundred and thirty four cows calved during February to May 2008 were used for this study. Cows received im injections of 25 mg $PGF_{2{\alpha}}$ at $45{\pm}3$ and $59{\pm}3$ days in milk (DIM). Fourteen days later, Ovsynch was initiated with an im injection of $100\;{\mu}g$ GnRH ($73{\pm}3$ DIM), 25 mg $PGF_{2{\alpha}}$ 7 days later ($80{\pm}3$ DIM), $100\;{\mu}g$ GnRH 56 h later and timed artificial insemination (TAI) 16 h after the GnRH injection. Cows showed estrus during the Presynch-Ovsynch, were inseminated artificially according to am-pm rule. Pregnancy was determined on 32 days after AI using ultrasonography. Cows diagnosed pregnant were re-examined for pregnancy by rectal palpation at 60 days after AI. Non-pregnant cows were resynchronized by receiving $100\;{\mu}g$ GnRH, 25 mg $PGF_{2{\alpha}}$ 7 days later, $100\;{\mu}g$ GnRH 56 h later and TAI 16 h after. Cows with estrus since the first AI before the completion of Resynch protocol were also inseminated artificially according to am-pm rule. Pregnancy was determined by the same manner as following the first AI. Fifty five percents of the cows treated showed estrus and received AI before completion of the Presynch-Ovsynch protocol, while 45% received TAI, regardless of estrus exhibition following the completion of the protocol. The pregnancy rate following the first AI was higher in cows that showed estrus and received AI (43.3 and 38.5%) during the Presynch-Ovsynch than cows with TAI (34.6 and 29.6%) on 32 and 60 days after AI (P < 0.01). Sixty six percents of cows diagnosed non-pregnant following the first AI showed estrus before the completion of Resynch protocol and received AI, while 34% received TAI, regardless of estrus exhibition following the completion of the protocol. The pregnancy rate following the second AI was higher in cows that showed estrus before the completion of Resynch protocol and received AI (40.2 and 36.8%) than cows with TAI (21.2 and 18.2%) on 32 and 60 days after AI (P < 0.01). The cumulative pregnancy rates following the first and second AIs were 60.8 and 53.9% on 32 and 60 days after AI, respectively. These data suggest that inclusion of Presynch-Ovsynch-Resynch protocol and estrus detection into the programmed reproductive management might be an alternative option to control dairy cattle breeding.

• The Korean Journal of Pharmacology
• /
• v.23 no.2
• /
• pp.143-149
• /
• 1987

We determined the maternal peripheral lymphocyte response to mitogen during the period of implantation and evaluated the effects of hormones, which are known to be involved in the process of implantation, on the lymphocyte activity in rabbits. As compared with peripheral lymphocyte activity in non-pregnant rabbits, lymphocyte activity was significantly depressed on days 6, 7 and 9 of pregnancy. Although concentrations of serum progesterone were gradually increased during the implantation period, progesterone did not inhibit lymphocyte activity at physiological concentration. Serum $PGF_{2{\alpha}}$ was significantly increased on day 7 while PGE was slightly increased. $PGF_{2{\alpha}}$ did not modify lymphocyte activity even with greater concentrations than physiological level. However, lymphocyte activity was significantly inhibited by PGE even with physiological doses. The treatment of indomethacin at doses of 0.1 or $1.0\;{\mu}g/ml$ tended to enhance lymphocyte response, which was depressed on day 8 of pregnancy, 28% or 23% respectively. Although in non-pregnant rabbit, enhancement of lymphocyte response was also shown after the treatment of indomethacin, this enhancement was much less than that in pregnant rabbits. These results strongly suggest that maternal immune response was depressed during the process of implantation and PGE might be one of factors for immunomodulation during this period.

• Journal of Embryo Transfer
• /
• v.24 no.4
• /
• pp.289-292
• /
• 2009

Mongolia has 80% livestock of total agriculture industry, 170,000 farms are engaged, 2,500,000 of cows that were beef and dairy cows are raised. Despite of Mongolian has great application with milk, there are not clear differences between cow and dairy cattle, and the production of milk is also low. But the milk suppliers are varied (horse, sheep, goat, etc), so that the total milk production is 500 thousand ton per year. It's really considerable to improve the breed of owing to many problems with big differences among milk qualities. For carrying out for first year project, artificial insemination project was operated with 3rd grade Holstein semen that were imported from S. Korea, and initiation and field training were also carried out through appropriate AI technique we developed for Mongolia environment. Local information research and MOU conclusion were done with professor D. Altangerel in May $10^{th}{\sim}13^{th}$, 2009, and development for AI technique and AI equipments were supplied for Mongolia breeding and natural environment in July $10^{th}{\sim}17^{th}$ in 2009. All cows were treated by synchronization for AI. To do this, $PGF_{2\alpha}$ injection were treated for luteal phase cow, if it wouldn't work, try again after 11 days. After confirmation of estrus, AI and AI training were carried out with sperm injection in the uterus or cervix by rectum-vagina method which is common worldwide, the most effective artificial insemination technique. If cows were return to next estrus cycle, second AI was carried out about approximately 21 days after artificial insemination. After 2 months, all cows not showing return estrus should be taken pregnancy test. Every pregnant cow will be cared thoroughly. Total 48 cows administrated by $PGF_{2\alpha}$ for synchronization and after 48 hours 45 cows (93.8%) showing estrus were detected and then artificial inseminate them within who 8 cows (27.8%) showed return estrus. Therefore, Using $PGF_2{\alpha}$ for synchronization is effective to use for Mongolia breeding conditions. There are possibility of base for food production after all, including increase of livestock production in Mongolia by improvement of breeding cow with AI and embryo transfer project.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.17 no.2
• /
• pp.461-466
• /
• 2003

The primary mechanism of smooth muscle contraction is phosphorylation of the 20 kDa myosin light chains(LC20) by a myosin light chain kinase(MLCK). Relaxation, then, is generally the result of dephosphorylation of LC20 by myosin phosphatase(MP). Changes in MP activity is one of the important mechanisms in the regulation of Ca2+-sensitivity. Inhibition of MP activity is linked to an increase in phosphorylated myosin light chain(MLC) without an increase in [Ca/sup 2+/]i-levels. It is now generally accepted that Rho-kinase phosphorylates 130 kDa regulatory and myosin binding subunits(M130, MYPT) of MP, which results in an inhibition of MP activity. In addition Rho-kinase can also directly phosphorylate MLC. In the present study, LC20 phosphorylation and MP subunits translocation to the cell membrane were investigated in freshly isolated ferret portal vein smooth muscle single cells treated with PGF2α. We also examined the effect of Y27632(10-5mol/L), Rho-kinase inhibitor, in the MP subunits localization to compare with butanol fraction of Fructus Crataegi in its effect. Butanol fraction of Fructus Crataegi(BFFC; 1㎎/㎖) was more effective in PGF2α induced contraction than those of phenylephrine in its vasodilation effect. It significantly(P<0.05) dephosphorylated the LC20 at time indicated. In addition, the dissociation of subunits are inhibited by BFCF treatment. The results indicate that, in the smooth muscle cells, the relaxation effect of BFFC is associated with increase of MP activity based on inhibition of dissociation of the catalytic and targeting subunits of the phosphatase, and thus decrease the sensitivity of LC20 phosphorylation for Ca/sup 2+/.

• Korean Journal of Veterinary Research
• /
• v.29 no.4
• /
• pp.589-599
• /
• 1989

A total of 13 synchronized dairy cattle(Holstein) were used to determine pregnancy rates in relation to plasma progesterone, estradiol-$17{\beta}$ levels and serum chemical values on the day of last $PGF_{2{\alpha}}$ injection and day of frozen/thawed bovine embryo transfer. The pregnancy rate of recipients with 1.0~4.0ng/ml of progesterone levels at the day of last $PGF_{2{\alpha}}$ injection was higher than that of recipients with below 1.0ng/ml or above 4.0ng/ml of progesterone levels. On the day of transfer, optimal progesterone levels were between 1.0ng/ml and 4.0ng/ml coinciding with a pregnancy rate of 88.9%. Pregnancy rate decreased when progesterone levels were below 1.0ng/ml(33.3%) or above 4.0ng/ml(0%). Corpus luteum grade did not affect pregnancy rate and this result revealed that manual palpation of corpus luteum was not valid criterion of corpus luteum function. Progesterone levels as well as pregnancy rate did not significantly differ whether the corpus luteum was on the right($1.62{\pm}1.33ng/ml$; 63.5%) or left ovary($1.99{\pm}0.61ng/ml$; 85.0%). Estradiol-$17{\beta}$ levels were not significantly different between pregnant and nonpregnant recipients, but estradiol-$17{\beta}$ levels($82.2{\pm}13.5$ VS. $72.3{\pm}10.1pg/ml$) were higher at below 1.0ng/ml of progesterone, and pregnancy rates(33.3 VS. 80%) tended to be lower than above 1.0ng/ml of progesterone. Total cholesterol levels on the day of last $PGF_{2{\alpha}}$ injection and day of transfer did not affect pregnancy rate. Calcium and inorganic phoshorus levels belonged to normal range in most of the recipients. These range did not affect pregnancy rate. In reviewing above results, plasma progesterone levels(1.0~4.0ng/ml) at the time of transfer are diagnostic value for screening recipients prior to transfer of frozen/thawed bovine embryos.