• 현장농수산연구지
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• 제25권4호
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• pp.111-117
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• 2024

Reproductive research such as artificial insemination and embryo transfer is necessary to produce high-quality riding horses. In this study, we investigated the effects of estrus synchronization and ovulation induction methods, which can be considered the basis of artificial insemination in horses, on the hormone concentration and artificial insemination pregnancy rate of mares. For the purpose of synchronization of estrus in horses, Cidr-plus insertion method, Regumate feeding method, and 150mg progesterone + 10mg estradiol mixed administration method were used. In the Cidr-plus insertion method and the Regumate feeding method, the progesterone concentration reached the appropriate level for ovulation induction on the 8th day of administration. The mixed administration method of 150mg progesterone + 10mg estradiol maintained the progesterone concentration at an appropriate level immediately after administration. With the administration of PGF2a and hCG, progesterone concentration decreased rapidly, making ovulation induction possible. As a result of comparing the pregnancy rate between natural estrus and estrus synchronization, the pregnancy rate was found to be higher in estrus synchronization and ovulation induction. From the results of this study, it is insufficient to judge the effect of the pregnancy rate due to the small number of tests, but in terms of usability, estrus synchronization and ovulation induction were useful. Therefore, it is expected to contribute to improving the efficiency of future roadster production.

• Asian-Australasian Journal of Animal Sciences
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• 제22권6호
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• pp.774-780
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• 2009

The objectives of this study were to test the efficacy of induction of estrus and determine the timing of ovulation in relation to preovulatory LH and estrogen surges in cycling Murrah buffaloes subjected to Heatsynch protocol (GnRH-$PGF_2{\alpha}$-Estradiol benzoate). In experiment 1, the buffaloes (n = 10) were treated with Heatsynch protocol and observed for estrus and ovulation. In experiment 2 and 3, 30 cycling Murrah buffaloes were used to investigate the efficacy of Heatsynch protocol in terms of conception rates in summer (experiment 2) and winter (experiment 3) seasons. Fixed time A.I. was performed in all the buffaloes at 48 and 60 h post-estradiol benzoate (EB) injection. All buffaloes responded to the Heatsynch protocol with expression of estrus for which ovulations were induced in 8 buffaloes (80%). Mean time interval from the EB injection to ovulation was 50.0${\pm}$2.0 h (range 44.0 to 60.0 h). The interval from the end of LH surge to ovulation was 18.5${\pm}$2.47 h (range 8 to 26 h). The interval from end of estrogen surge to ovulation was 26.75 ${\pm}$2.07 h (range 22 to 36 h). Mean LH peak after EB injection occurred at 20.81${\pm}$1.61 h (range 14 to 28 h) and mean estrogen peak after EB injection occurred at 9.62${\pm}$1.03 h (range 7 to 16 h). Hence, the mean estrogen peak preceded the mean LH peak by 11 h. It was observed that the percentage of conceptions to total number of estruses for control buffaloes was 18 and 30 in summer and winter, respectively, whereas it increased to 26 and 40 in Heatsynch treated buffaloes in respective seasons. The results suggest the possibility of using Heatsynch treatment followed by fixed time A.I. in buffaloes for fertility improvement, especially since the incidence of silent heat in buffaloes is very high.

• 한국수정란이식학회지
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• 제26권2호
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• pp.105-109
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• 2011

Ovulation synchronization (ovsynch) has proved to increase the number of insemination in cattle by overcoming the problems of heat detection. The aim of this study was to do ovsynch in water buffaloes where heat detection is a major reproductive problem and to determine the conception rates after timed artificial insemination (TAI). Twenty cyclic buffaloes at ${\geq}$ 60 days postpartum were selected by examining 24 unobserved estrus buffaloes based on milk progesterone assay (progesterone concentration ${\geq}$ 1.0 ng/ml) from the Mymensingh district of Bangladesh. Ovsynch treatment regimen was started irrespective of the stage of estrous cycle. Gonadorelin (500 ${\mu}g$) was injected intramuscularly at Day 0 followed by Alfaprostol (8 mg) at Day 7. A second injection of Gonadorelin was given at Day 9 and TAI was done with frozen semen from Mediterranean buffalo bulls at 16~20 hours of the second Gonadorelin injection. Milk progesterone ELISA at Day 10~12 post AI confirmed ovulation in 16 out of 20 (80%) buffaloes (progesterone concentration ${\geq}$ 1.0 ng/ml). High progesterone concentration (${\geq}$ 1.0 ng/ml) at Day 10~12 and Day 22~24 of AI showed pregnancy in six out of 20 (30%) buffaloes. Pregnancy was further confirmed by ultrasonography at Day 40 in these six buffaloes. In conclusion, ovsynch followed by TAI could be applied in cyclic buffaloes for overcoming the estrus detection problems; however, more studies are needed to increase the conception rate.

• 한국수정란이식학회지
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• 제18권3호
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• pp.187-193
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• 2003

본 연구는 한우에 GnRH ＋ PGF$_2$$\alpha$＋GnRH (Ov-synch)를 처리하여 배란동기화를 시켰으며, 2차 GnRH 투여후 배란시간, 수태율, 계절별 수태율, 산차별 수태율을 조사하였으며, 시험축은 2산 이상의 개체를 무작위로 선발하여 실험에 공시하였으며, 배란동기화 처리후 1회 인공수정을 실시하고 수태율을 환산하였다. 호르몬 처리방법으로는 GnRH ＋ PGF$_2$$\alpha$ ＋ Gn-RH(Ov-synch)법을 이용하였으며, 배란시간의 조사는 초음파를 이용하여 2차 GnRH 투여 후 24시간부터 31시간까지 2시간 간격으로 난소를 촬영하여 배란 여부를 조사하였다. 1. 배란동기화 처리후 24시간부터 31시간까지 2시간 간격으로 난소의 상태를 확인한 결과 28∼30시간 사이에 80%(20/25)로 가장 많이 배란된 것으로 나타났다. 2. 수태율에 있어서는 계통별 1회 수정 수태율은 고급육 계통이 48.1%(38/79)로 다소 높게 나타났다. 3. 산차에 따른 수태율은 1∼2, 3∼4산차에서 각각 44.3, 55%로 나타났다. 4. 계절별로는 여름보다는 봄과 가을에서 47.3%로 다소 높은 경향이였다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권8_spc호
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• pp.1284-1295
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• 2019

Considerable progress in reproduction of dairy goats has been made, with advances in reproductive technology accelerating dairy goat production since the 1980s. Reproduction in goats is described as seasonal. The onset and length of the breeding season is dependent on various factors such as breed, climate, physiological stage, male effect, breeding system, and photoperiod. The reproductive physiology of goats was investigated extensively, including hypothalamic and pituitary control of the ovary related to estrus behavior and cyclicity etc. Photoperiodic treatments coupled with the male effect allow hormone-free synchronization of ovulation, but the kidding rate is still less than for hormonal treatments. Different protocols have been developed to meet the needs and expectations of producers; dairy industries are subject to growing demands for year round production. Hormonal treatments for synchronization of estrus and ovulation in combination with artificial insemination (AI) or natural mating facilitate out-of-season breeding and the grouping of the kidding period. The AI with fresh or frozen semen has been increasingly adopted in the intensive production system, this is perhaps the most powerful tool that reproductive physiologists and geneticists have provided the dairy goat industry with for improving reproductive efficiency, genetic progress and genetic materials transportation. One of the most exciting developments in the reproduction of dairy animals is embryo transfer (ET), the so-called second generation reproductive biotechnology following AI. Multiple ovulation and ET (MOET) program in dairy goats combining with estrus synchronization (ES) and AI significantly increase annual genetic improvement by decreasing the generation interval. Based on the advances in reproduction technologies that have been utilized through experiments and investigation, this review will focus on the application of these technologies and how they can be used to promote the dairy goat research and industry development in the future.

• 한국수정란이식학회지
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• 제23권2호
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• pp.81-86
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• 2008

This study compared the pregnancy rates of Korean native donor cattle after either a timed artificial insemination (TAI) or embryo transfer (TET) following the synchronization of ovulation using a controlled internal drug release (CIDR) device together with estradiol benzoate (EB) and prostaglandin $F_{2{\alpha}}$ ($PGF_{2{\alpha}}$). Fifty five cows and 8 heifers which had been previously used for embryo production were assigned to two treatments: (1) Thirty-two cattle received a CIDR device and 2 mg EB (Day 0), 25 mg $PGF_{2{\alpha}}$ injection at the time of CIDR removal on Day 7, and 1 mg EB injection on Day 8. All of the cattle received a TAI 30 h (Day 9) after the second EB injection (TAI group). (2) Thirty-one cattle received the same hormonal treatments as in the TAI group. The cattle with corpus luteum (CL) received a TET on Day 16 using frozen-thawed embryos (TET group). Ultrasonographic observations demonstrated that the proportion of cattle with synchronized ovulation on Day 10 and the concomitant formation of new CL on Day 13 did not differ between groups (p>0.05); the overall mean rates were 65.1 and 73.0%, respectively. The conception and pregnancy rates did not differ (p>0.05) between the TAI (12.5% and 12.5%) and TET groups (13.0% and 9.7%), respectively. We conclude that the pregnancy rate following TAI or TET in Korean native donor cattle was poor, which might be due in part to a poor synchrony of ovulation and concomitant CL formation.

• 한국수정란이식학회지
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• 제2권1호
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• pp.33-35
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• 1987

This study was carried out to investigate the seasonal effect on the recovery rate of embryos in donors and on the conception rate in recipients following embryo transfer. The results obtained from this experiment were summarized as follows: 1. The ovulation point in winter and summer was 28.6 and 28.6, respectively. There was no difference in ovulation point between two seasons. More embryos recovered in the winter (27,0) than the summer (20.9). 2. The number of CL, unruptured follicle, hemorrhagic follicle, young born and pregnancy rate in the winter were 6.0,4.8,1.5,1.8 and 75%, and those in the summer were 2.9,5.7, 3.8, 2.2 and 46.7%, respectively. The rate of synchronization of recipients in the winter showed better results than that in the summer.

• 한국가축번식학회지
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• 제27권3호
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• pp.207-213
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• 2003

본 연구는 한우에 PGF$_2$$\alpha$와 GnRH+PGF$_2$$\alpha$+GnRH(Ov-synch)를 처리하여 발정 및 배란을 동기화 시켰으며, 2차 GnRH 투여후 배란시간, 2차 GnRH 투여후 시간 경과에 따른 수태율과 발정ㆍ배란 동기화법에 의한 수태율을 조사하고자 실시하였다. 시험축은 총 4개 농가에서 경산우 150두를 무작위로 선발하여 시험에 공시하였으며, 발정ㆍ배란동기화 방법에 따라 발정을 유기한 후 1회 인공수정을 실시하고 수태율에 미치는 영향을 조사하였다. 호르몬처리 방법으로는 GnRH+PCF$_2$$\alpha$+GnRH(Ov-synch)와 PGF$_2$$\alpha$를 이용한 발정동기화 방법을 사용하였다. 2차 GnRH 투여 후 배란시간을 알아보기 GnRH 투여 후 24시간 후부터 32시간까지 2시간 간격으로 초음파 Sonovet-600(Medison. Korea)를 이용하여 난소를 촬영하였다. 1. 호르몬 투여후 발정동기 화율은 PGF$_2$$\alpha$ 투여구에서 40.0%와 GnRH+PGF$_2$$\alpha$+GnRH(Ov-synch)처리구에서 91.3%로 나타났다. 2. 2차 GnRH 주사후 24시간에 배란이 시작되어 32시간에 배란이 종료되었으며, 배란율은 28시간째에 46.6%가 배란되어 가장 높게 나타났다. 3. 2차 GnRH주사후 6∼24시간에 수정한 군이 6시간 이전과 30시간 이후에 수정시킨 군에 비해 높은 수태율을 나타냈다. 4. 호르몬 처리별 수태율은 PGF$_2$$\alpha$, CIDR 및 GnRH+PGF$_2$$\alpha$+GnRH(Ov-synch)에서 각각 50.0, 36.0와 76.9%로 GnRH+PGF$_2$$\alpha$+CnRH(Ov-synch)군에서 가장 높은 수태율을 나타냈다.

• 한국가축번식학회지
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• 제27권3호
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• pp.241-248
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• 2003

본 연구는 한국재래산양에서 프로게스타겐(Synchromate-B, Veramix 및 CIDR)과 성선자극호르몬(PMSG, FSH 및 hOG)의 병용처리가 발정동기화 및 과배란유기에 미치는 영향을 구명하고자 수행하였는 바, 그 결과를 요약하면 다음과 같다. 1. 프로게스타겐과 PMSG을 이용한 재래산양의 발정동기화 유기율은 Synchromate-B는 52.9%, Veramix는 72.9% 그리고 CIDR는 75.2% 로써 Veramix 및 CIDR처리구가 Synchromate-B 처리구보다 유의적으로 높게 나타났다(P<0.05). 또한, 프로게스타겐을 이용한 발정동기화유기시 배란점에 미치는 영향을 조사한 결과, 평균배란점수는 Synchromate-B는 2.11$\pm$1.89개, Veramix는 1.34$\pm$0.87개 및 CIDR는 1.42$\pm$0.96개로써 Synchromate-B 처리구에서 유의적으로 높은 결과를 나타냈다(P<0.05). 2. 프로게스타겐인 Synchromate-B, Veramix 및 CIDR로 성주기를 조절하고 FSH, PMSG와 hCG로 과배란처리를 유기하였을 때 프로게스타겐에 따른 과배란유기율은 각각 98.6%, 99.45% 및 98.8%로서 상호간에 유의성이 인정되지 않았고, 평균배란점수는 각각 12.58$\pm$16.52개, 12.91$\pm$7.27개 및 11.28$\pm$6.33개로 CIDR 처리구에 비하여 Synchromate-B 처리구와 Veramix 처리구에서 유의적으로 높았다(P<0.05). 3. CIDR로 성주기를 조절하고 성선자극호르몬으로써 FSH, PMSG와 hCG를 처리한 시험구와 PMSG를 투여하지 않은 시험구의 배란점은 각각 11.16$\pm$6.00개 및 10.79$\pm$6.46개로서 유의적 차이가 인정되지 않았다.

• 한국가축번식학회지
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• 제11권3호
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• pp.223-229
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• 1987

This study was carried out to investigate effects of superovulation and time of embryo recovery on ovarian response, recovery rate and developmental stage of embryo in donor and effects of methods of synchronization, number of corpus luteum (CL), stage of embryo and time of embryo transfer on ovarian response, conception rate and number of newborn in recipients which were transferred on 2.5, 3.5 and 4.5 days after synchronization. The results obtained are as follows; 1. The ovulation point of superovulated donor on 2.5, 3.5 and 4.5 days after copulation was 23.3, 35.3 and 23.3, respectively. The number of embryos recovered from the donors on 2.5, 3.5 and 4.5 days after copulation was 23.3, 25.8 and 19.8, respectively. The ovulation point and number of embryos recovered on 3.5 days were greater than those of 2.5 and 4.5 days. Among 232 embryos recovered on 3.5 days after copulation, 84 were blastocyst and 62 were hatching blastocyst. 2. The number of CL in recipients on 2.5, 3.5 and 4.5 days after synchronization was 3.2, 2.9 and 3.8 and showed no difference among the days. 3. When the number of CL was 0, 2-3, 4-6 and more than 7 the pregnancy raet of recipients was 0, 37.5, 66.7 and 75%, respectively. The pregnancy rate of recipients increased as the number of CL increased. 4. The pregnancy rate of transferred morula, blastocyst and hatching blastocyst was 32.0, 37.2 and 24.7%, respectively. The blastocyst nhowed highest pregnancy rate. 5. When the recipients were synchronized by HCG, the number of CL, unruptured follicle, hemorrhage, pregnancy rate and number of young were 5.5, 6.4, 3.3, 72.7% and 3.3, whereas that of GnRH were 2.3, 4.4, 2.8, 25.0% and 1.2, respectively. Recipients synchronized by HCG showed better results than GnRH. 6. When the embryos were collected on 2.5 days after copulation and transferred to the synchromized recipients, the pregnancy rate and the number of young born was 62.58% and 3.1, respectively. Those of 3.5 and 4.5 days after copulation was 57.1% and 1.3, and 37.5% and 1.6. The 2.5 days showed higher pregnancy rate and number of young born than 3.5 and 4.5 days.