• 한국수정란이식학회지
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• 제26권2호
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• pp.91-96
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• 2011

The purpose of this study was to evaluate the effects of days open on subsequent reproductive performance following to estrus synchronization in the 114 lactating dairy cows. The animals were divided into two groups according to the time of estrus synchronization; viz, ${\leq}$ 85 days, and > 85 days postpartum, respectively. The estrus synchronization protocol consisted of insertion of a controlled internal drug release (CIDR) device containing 1.9 g progesterone with an injection of 250 ${\mu}g$ gonadorelin (Day 0), an injection of $PGF_2{\alpha}$ and removal of the device on Day 7, an injection of 250 ${\mu}g$ GnRH on Day 9, and TAI 17 h later. Pregnancy diagnosis was determined at 30 to 60 days after TAI using both ultrasonography and rectal palpation. The body condition score (BCS) gradually increased over the postpartum period. In estrus synchronized cows until 85 days, conception rate on first service, number of service per conception, interval from estrus synchronization to conception, and interval from calving to conception were not significantly different among two farms (P>0.05). In estrus synchronized cows after 85 days postpartum, conception rate on first service, number of service per conception and interval from calving to conception were significantly different ($P{\leq}0.05$) between herds A and B (26.8 vs 50.0%; $2.1{\pm}1.35$ vs $1.37{\pm}0.54$ times, $237.3{\pm}97.8$ vs $164.7{\pm}69.3$ days, respectively). In estrus synchronized cows after 85 days postpartum interval from estrus synchronization to conception was greater (P<0.01) in herd B than in herd A ($63.6{\pm}57.4$ vs $26.1{\pm}24.9$). These results indicate that the time of estrus synchronization for maximized the reproductive performance is before 85 days postpartum and feeding and management is important factor for high reproductive performance.

• 한국수정란이식학회지
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• 제27권2호
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• pp.87-92
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• 2012

A study on estrus synchronized dairy cows using progesterone intravaginal device was done to classify each cow's reproductive status from calving to synchronization and to evaluate the reproductive performance according to ovarian and uterine status, and calving season. From calving to estrus synchronization, silent heat or error of estrus detection among ovarian status and endometritis among uterine disorders were exposed in the most distribution (75.4% and 48.3%, respectively). The pregnancy rate of cows with inactive ovaries was lower than those in the follicular and luteal phase. And according to the uterine status before estrus synchronization, the pregnancy rate was similar in three groups; normal, endometritis, and pyometra (70.9, 69.1 and 100%, respectively). The interval from calving to conception was shorter (p<0.05) in cows calved during autumn than in cows calved during spring and winter.

• 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.

• 한국가축번식학회지
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• 제19권2호
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• pp.147-152
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• 1995

본 연구는 돼지의 발정 동기화를 시키는데 있어 Altrenogest와 PG600간의 효과를 비교하기 위해 축산기술연구소에서 1994년부터 1995년 사이에 실시하였다. 먼저 시험돈은 자연 발정주기를 매일 2회씩 관찰하였고(Control), 한 group은 발정주기의 15일경에 PG600을 피하 주사했으며(PG600), 나머지 한 group은 발정주기와 관계없이 9일 동안 20mg의 Altrenogest를 사료에 첨가 급여하였다(Altrenogest). 그후 대조구를 제외한 두 그룹은 각각 PMSG 1500 IU를 PG600 처리후 16일째에, Altrenogest 처리구는 Altrenogest 처리후 24시간에 각각 근육주사하였으며, 약3일후 hCG 750 IU를 각 처리별로 근육주사하였다. 이 결과 대조구에서는 85%, Altrenogest는 90.1%, PG600구에서는 100%의 발정 발현율이 나타남으로써 전체 발현율로써는 처리간에 별차이가 없었으나, hCG주입후 9일내에 발정 발현정도는 대조구(25/53)에 비하여, PG600구 (47/47)가 높았다. 또한 황체수 및 회수난자수에서는 각각 대조구 12.9$\pm$1.8, 12.7$\pm$3.9, Altrenogest구 25.5$\pm$0.7, 15.0$\pm$4.2, PG600구 25.4$\pm$13.1, 19.0$\pm$12.8로 호르몬 처리간에는 별차이가 없다. 그러나 대조구에 비해서는 호르몬 처리구에서 유의적으로 (P<0.05) 높았으며, 정상 난자율에서는 호르몬 처리구보다 대조구에서 약간 높은 경향을 보였다. 따라서 본 연구에서 호르몬 처리에 의한 발정동기화가 효율적으로 가능하다는 것이 입증되었으며 이러한 발정동기화기술은 노동력 및 비용절감측면에서 효과가 있는 것으로 사료된다.

• 한국수정란이식학회지
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• 제13권1호
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• pp.69-76
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• 1998

This study was carried out to establish an effective system for embryo transfer techniques by analyzing several factors affecting in-vivo embryo transfer in Korean cattle Embryos were transferred into a toral of 301 recipients. The results obtained in studies on the factors affecting pregnancy rate after embryo transfer by condition of transfer time were as follows ; 1. The pregnancy rate by the seasons of transferred fresh and frozen embryos were not different, but the pregnancy rate was slightly higher in summer(80.8%). 2. The pregnancy rate by the days of embryo transfer after estrus were not different when fresh embryos were transferred, but the pregnancy rate was highest at 8 days when frozen embryos were transferred(P<0.01, 40.0%). 3. The pregnancy rate at estrus synchronization was remarkably higher with PGF$_2$$\alpha$ treated than natural (P<0.05, 70.4%, 43.4%). 4. The pragnancy rate by the degree of estrus synchronization was best when the estrus was synchronized in both fresh and frozen embryos (83.3% and 29.7%, respectively), but the pregnancy rate was not different among $\pm$2 days. But the pregnancy rate of frozen embryos were slightly higher when the recipients exhibited estrus earlier than donors.

• 농업과학연구
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• 제34권1호
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• pp.61-65
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• 2007

본 연구에서는 유산양에서 비번식계절과 번식계절에 각각 발정동기화를 유도하여 인공수정을 1차와 2차에 걸쳐 실시한 후 분만율을 조사하였다. 자아넨 유산양 암컷을 대상으로 5월과 6월 사이에 CIDR-S를 이용하여 발정을 유도하였고, 액상정액과 동결정액을 이용하여 인공수정을 실시하였다. CIDR-S를 이용한 발정유도시험에서는 유산양의 발정동기화가 90%이상을 기록하여 아주 양호한 것으로 나타났다. 그러나 분만 성적은 1차 인공수정에 의해서는 25%, 2차 인공수정에 의해서는 20%로 낮하게 나타났으며, 자연종부에 의해서는 100%의 분만율을 기록하였다. 본 연구의 결과 비번식계절에서 번식주기를 인위적으로 조절할 수 있는 가능성과 정액을 주입하는 적정한 시기를 예측할 수 있는 점을 시사해 주었으나 인공수정 방법과 정액의 저장방법에 대한 연구가 필요한 것으로 나타났다.

• Reproductive and Developmental Biology
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• 제37권1호
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• pp.29-33
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• 2013

The objective of this work was to analyze the concentrations of progesterone (P4) and estrogen (E2) hormones changed during estrus synchronization in dairy heifers. Estrus synchronization was carried out with CIDR$^{(R)}$ (Controlled Intravaginal Drug Release) devices. Corpus luteum (CL) was classified into three grades based on its size and palpable characteristics. The concentrations of P4 and E2 were measured by enzyme-amplified chemiluminescence. Serum P4 concentration was markedly low at the estrus stage (36 hrs after removal of CIDR) compared to other stages, while E2 concentration was kept high during estrus stage. The serum P4 concentration was highest in the CL classified into grade I. These results indicate that P4 concentration could be used as a criteria for determining recipients for artificial insemination or embryo transfer in dairy cattle.

• 한국수정란이식학회지
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• 제32권3호
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• pp.159-163
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• 2017

The artificial insemination (AI) is one of the best assisted reproductive technologies for increasing reproductive capacity and facilitating the genetic improvement in farm animals. AI has been used in Uganda for over 60 years, but a small population of the total herd has been used. This study was conducted to investigate the efficacy of AI with estrus synchronization technique and to propose ways of improving the productivity of dairy farms through AI services in Uganda. In total, 78 cows from 11 dairy farms were selected for timed-AI. Synchronization was performed according to the ovsynch programs followed by AI using frozen semen from Korean Holstein (0.5 ml straws). Pregnancy rate was varying among farms (0-50%) and the overall pregnancy rate was 28.2%. Cows in luteal phase at the time of treatment was 40.0% whereas that in follicular phase was 20.8%. After treatment, cows that showed normal estrus signal were 45.5% (25/55). Abnormal estrus was categorized into pre-estrus (9.1%), cystic ovaries (21.8%), anestrus (18.2%) and delayed ovulation (5.5%), respectively. These results imply that an assured protocol for timed-AI should be developed to improve the productivity of dairy farms through AI services in Uganda.

• 한국수정란이식학회지
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• 제29권4호
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• pp.321-325
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• 2014

The present study was performed on farm animals to test the effectiveness of progesterone-releasing intravaginal device (Cue-Mate$^{(R)}$ 1.56 g) and injection of prostaglandin $F_{2{\alpha}}$ ($PGF_{2{\alpha}}$) for synchronization estrus in Hanwoo cattle. The cattle were at random stage of the estrus cycle. The cows were artificially inseminated at day 7 after Cue-Mate withdrawal, using commercial semen from Korean native bulls. There was a season effect on the estrus synchronization rate. It was higher in spring (94.3%) followed by winter (93.3%), autumn (90.4%) and summer (67.2%). In summary, The results of this study revealed that season has influences on estrus behavior of cattle with no significant effect on pregnancy rate. In summary, we suggest summer reproductive management to alleviate the effects of heat stress. It should be based on intensive cooling combined with hormonal treatment. Given that different subgroups of cows benefit differently from the treatments, selective hormonal administration should be considered.

• 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.