• Asian-Australasian Journal of Animal Sciences
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• 제10권3호
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• pp.329-332
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• 1997

A study on the conception rate of 885 cows and heifers bred under artificial insemination (AI) and natural service was carried out at AI sub-centers. A high conception rate was observed at first service in all breeding methods. It was revealed that the conception rates in AI with liquid semen (LS) were found to be 25.08, 18.58, 12.69, and 2.48% after 1, 2, 3 and 4 services, respectively. Inseminations of cattle with frozen semen (FS) were found to achieve 42.15, 14.46, 5.85, and 2.46% conception rates after 1, 2, 3, and 4 services, respectively. In natural service, conception rates were found to be 62.45, 6.75, 5.91, and 4.64%, respectively, after 1, 2, 3, and 4 services. Insemination of cows and heifers at mid-cycle had significantly (p < 0.05) higher conception rate as compared to early and late cycles. The existing AI machineries and breeding management need to be improved to achieve higher conception rate of dairy cattle under AI.

• Clinical and Experimental Reproductive Medicine
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• 제20권1호
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• pp.57-63
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• 1993

From September 1988 to August 1992, two different methods of preparing human sperm before intrauterine insemination(IUI) were compared using the semen samples of seventy-three infertile couples. The sperms were prepared by a swim-up after sperm washing or by a continuous percoll gradient technique. Fourteen of 35 women conceived during IUI cycles using a sperm washing and swim-up method (40%), and 12 of 38 women conceived during IUI cycles using a percoll gradient technique(31.6%). Among the group with male infertile etiologic factor only, one of 5 women conceived during sperm washing and swim-up cycles(20%); one of 4 women conceived during percoll gradient cycles(25%). On the contrary, among the group with cervical factor only, six of 10 women conceived during sperm washing and swim-up cycles (60%) ; Five of 17 women conceived during percoll gradient cycles(29.4%). It is suggested that sperm separation by sperm washing ar -up is a useful technique for intrauterine insemination in cervical infertility, and sperm separation in percoll gradient appears to be more valuable for intrauterine insemination of male subfertility.

• Animal Bioscience
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• 제34권7호
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• pp.1100-1104
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• 2021

Objective: The objective of present study was to estimate heritability of non-return rate (NRR) and success of first insemination (SFI) by using the Bayesian approach with Gibbs sampling. Methods: Heifer Traits were denoted as NRR-h and SFI-h, and cow traits as NRR-c and SFI-c. The variance covariance components were estimated using threshold model under Bayesian procedures THRGIBBS1F90. Results: The SFI was more relevant to evaluating success of insemination because a high percentage of animals that demonstrated no return did not successfully conceive in NRR. Estimated heritability of NRR and SFI in heifers were 0.032 and 0.039 and the corresponding estimates for cows were 0.020 and 0.027. The model showed low values of Geweke (p-value ranging between 0.012 and 0.018) and a low Monte Carlo chain error, indicating that the amount of a posteriori for the heritability estimate was valid for binary traits. Genetic correlation between the same traits among heifers and cows by using the two-trait threshold model were low, 0.485 and 0.591 for NRR and SFI, respectively. High genetic correlations were observed between NRR-h and SFI-h (0.922) and between NRR-c and SFI-c (0.954). Conclusion: SFI showed slightly higher heritability than NRR but the two traits are genetically correlated. Based on this result, both two could be used for early indicator for evaluate the capacity of cows to conceive.

• 한국수정란이식학회지
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• 제9권3호
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• pp.235-241
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• 1994

The study was conducted to determine the optimal hormone and glucose levels during the in vitro culture of bovine oocytes matured and fertilized in vitro for blastocyst development. Oocytes matured in TCM 199 + 10% FCS + hormones and glucose were fertilized in vitro in a TALP medium with swim up separated and heparin-treated epididymal cauda spermatozoa. Oocytes were cultured for 2~5 days in synthetic oviduct fluid medium (SOFM) supplemented with 10% FGS and with different hormone and glucose levels, and further cultured 5 days same medium in SOFM. The results are summarized as follows : The in vitro maturation and penetration rates of porcine oocytes cultured in TCM 199 media containing PMSG, hCG, PMSG + hCG, hCG + $\beta$ estradiol, PMSG + $\beta$ estradiol 0 to20 hours after insemination were 88.0% and 81.8%, 82.6% and 68.4%, 80.0% and 75.0%, 80.0% and 65.0%, 77.3% and 64.7%, respectively. The in vitro maturation and penetration rates of porcine oocytes cultured in TCM 199 media containing PMSG, hCG, PMSG + hCG, hCG + $\beta$ estradiol, PMSG + $\beta$ estradiol 20 to 40 hours after insemination were 92.0% and 87.0%, 92.0% and 82.6%, 91.3% and 81.0%, 85.2% and 73.9%, 87.5% and 81.0%, respectively. The cleavage and in vitro developmental rates to blastocyst of porcine oocytes cultured in TCM 199 media containing 0.05 mM, 0.10 mM, 0.30 mM, 0.50 mM, 1.00 mM, and 3.00 mM glucose lelvels 0~3 days after insemination were 31.5~48.1% and 10.0~16.7%, respectively. The cleavage and in vitro developmental rates to blastocyst of porcine oocytes cultured in TCM 199 media containing 0.05 mM, 0.10 mM, 0.30 mM, 0.50 mM, 1.00 mM, and 3.00 mM glucose levels 4~8 days after insemination were 30.0~53.8% and 8.7~19.2%, respectively. The cleavage and in vitro developmental rates to blastocyst were higher in TCM 199 media containing various glucose levels 0~3 days after insemination than 4~8 days.

• 한국수정란이식학회지
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• 제28권2호
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• pp.87-93
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• 2013

The efficiency of artificial insemination (AI) for horses remains unsatisfactory. It is mainly because each process of AI causes a detrimental effect on semen quality. To sustain quality of semen properly, several factors including libido of stallions and sperm damage during sperm processing and preservation should be considered. Stallions with decent libido produce a high ratio of sperm to seminal plasma in their ejaculates, which is the ideal semen composition for maintaining sperm quality. Thus, to maximize the fertility rate upon AI, stallions should be appropriately managed to enhance their libido. Seminal plasma should have a positive effect on horse fertility in the case of natural breeding, whereas the effects of seminal plasma on both sperm viability and quality in the context of AI remain controversial. Centrifugation of semen is performed during semen processing to remove seminal plasma and to isolate fine quality sperm from semen. However, the centrifugation process can also result in sperm loss and damage. To solve this problem, several different centrifugation techniques such as Cushion Fluid along with dual and single Androcoll-E$^{TM}$ were developed to minimize loss of sperm and to damage at the bottom of the pellet. Most recently, a new technique without centrifugation was developed with the purpose of separating sperm from semen. AI techniques have been advanced to deliver sperm to optimal region of female reproductive tract at perfect timing. Recombinant equine luteinizing hormone (reLH) and low dose insemination techniques have been developed to maximize both fertility rate and the efficiency of AI. Horse breeders should consider that the entire AI procedure should be optimized for each stallion due to variation in individual horses for a uniformed AI protocol.

• 한국임상수의학회지
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• 제37권5호
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• pp.235-241
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• 2020

We aimed to determine the effect of timed artificial insemination (TAI) protocols on the pregnancy rate per insemination and pregnancy loss compared with AI performed at detected estrus in dairy cows and Korean Hanwoo cattle under heat stress. In dairy cattle, 1,250 sets of data that underwent AI during heat stress (temperature-humidity index ≥ 72) were categorized according to their TAI protocols or as controls: 1) PGF_2α-36 h-estradiol benzoate (EB)-36 h-TAI (PG-EB group, n = 113); 2) GnRH-7 days-PGF_2α-56 h-GnRH-16 h-TAI (Ovsynch group, n = 455); or 3) GnRH-6 days-Ovsynch (G6G group, n = 136). The remaining cows underwent AI at detected estrus (AIDE group, n = 546). The probability of pregnancy per AI 45 days after AI was higher (P < 0.01) in the PG-EB (odds ratio [OR]: 1.68), Ovsynch (OR: 1.48), and G6G (OR: 1.79) groups than in the AIDE group. However, the prevalence of pregnancy loss between 30 and 45 days after AI did not differ among the groups. In Hanwoo cattle, 617 sets of data inseminated artificially under heat stress were categorized into AIDE (n = 281), PG-EB (n = 194), and combined Ovsynch or G6G (n = 142) groups. The probability of pregnancy per AI 45 days after AI and the prevalence of pregnancy loss between 30 and 45 days after AI did not differ among the groups. Thus, implementation of a TAI protocol (PG-EB, Ovsynch, or G6G) in dairy cows under heat stress improves the pregnancy rate per AI versus AIDE, whereas there is no beneficial effect of TAI on the pregnancy rate of Hanwoo cattle under heat stress.

• 한국수정란이식학회지
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• 제9권1호
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• pp.15-21
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• 1994

This experiment was investigated the effect of cell stage of embryos at 48 hours post-insemination On in vitro development of IVF embryos. The ovaries of Korean native cows or heifers were obtained from an abattoir and kept on 25 to 28$^{\circ}C$ and transported to laboratorty within 2 hrs. The oocytes were matured in vitro(IVM) for 24 hrs. in TGM-199 supplemented with 35 $\mu$g/$m\ell$ FSH, 10 $\mu$g/$m\ell$ LH, 1 $\mu$g/$m\ell$ estradiol-17$\beta$ and granulosa cells at 39$^{\circ}C$ under 5% $CO_2$ in air. They were fertilized in vitro(IVF) by epididymal spermatozoa treated with heparin for 24 hrs. , and then the zygotes were co-cultured in vitro(IVC) with bovine oviductal epithelial cells for 7 to 9 days. At 48 hrs. post-insemination, the embryos were classfied into 5 to 8-cell, 3 to 4-cell or 2-cell stage and then were co-cultured in vitro(IVC) with bovine oviductal epithelial cells until the embyos reached blastocyst stage. Embryos developed to blastocyst stage were stained with Hoechst 33342 for cell counting. The embryos of 5 to 8-cell stage at 48 hrs. post-insemination with grade I oocytes were significantly (P<0.05) better developed to blastocysts(63.0%) than 3 to 4-cell(42.0%) and 2-cell stage(2.7%) embryos which delayed in the early cleavage, and those embryos cleaved faster in the very early stage seemed to develop to blastocysts earlier. These results indicate that the embryos cleaved faster at 48 hrs. post-insemination seemed to develop to blastocysts earlier.

• 한국동물생명공학회지
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• 제36권4호
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• pp.194-202
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• 2021

In this study the effect of vitamin C administration on pregnancy rates during summer heat stress in dairy cows was examined. A total of 80 Holstein-Friesian cows were divided into control and treatment groups (n = 40 each). Control group animals were given 10 mL isotonic normal saline, and treatment group, Vitamin C (4 mg/kg) on artificial insemination day (day 0) and 4^th, 8^th and 12^th day post insemination. Pregnancy diagnosis was performed on 30^th day post insemination by ultrasonography. Blood samples were randomly taken from 11 animals from each group. Serum P₄, GSH, MDA and plasma 8-OHdG levels were determined by using ELISA method. Results showed that 8-OHdG levels were lower in treatment group on day 4, 8 and 12 (p < 0.05) compared with the control group. Similarly, pregnancy rate was higher in treatment group (32.5%) than control (22.5%), respectively. However, MDA, P₄ and GSH levels were similar in both groups at 4^th, 8^th and 12^th day. A gradual increase in P₄, and MDA levels, and a strong positive correlation between 0, 4^th (r = 0.54), 4, 8^th (r = 0.59) and 8, 12^th (r = 0.51) day was found. Similarly, GSH levels also showed positive correlation at days 0, 4^th (r = 0.47) and 4, 8^th (r = 0.56). However, a strong negative correlation (r = -0.56) between MDA day 0, and GSH day 8 was found. In conclusion, vitamin C application during insemination period in postpartum cows increases pregnancy rate, and reduces oxidative stress metabolite 8-OHdG levels.

• 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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• 제24권2호
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• pp.209-216
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• 2000

본 연구는 1996년부터 1999년까지 다비 AI 센타에서 사육되는 종모돈 199두와 종빈돈 4,181두를 가지고 종모돈의 정액생산과 번식성적에 미치는 품종, 연령, 계절, 산차 및 교배방법의 영향을 구명하고자 실시한 바, 그 얻어진 결과는 다음과 같았다. 1. 정액량은 Landrace (L) 종이 266.8 $m\ell$로 제일 많았고, Yorkshire (Y) 종이 그 다음으로 많았으며, Duroc (D) 종이 제일 적었다. 정자 운동성은 품종간에 차이가 없었다. 정자농도는 Landrace 종이 4.7$\times$109 sperm/$m\ell$로 제일 낮았고, 정액량이 제일적은 Duroc 종이 5.7$\times$$10^{9}$ sperm/$m\ell$ 로 제일 높았다. 종모돈의 연령에 따른 정액량은 2세 때가 213.3 $m\ell$로 제일 많았고, 4, 3 그리고 l 세의 순서로 정액량이 감소하였다. 2. 종모돈의 계절에 따른 정액량은 겨울철이 228.6 $m\ell$로 제 일 많았고, 가을, 여름, 봄의 순서로 정액량이 감소하였다. 정자농도는 봄철이 5.9$\times$109 sperm/$m\ell$로 제일 높았으며, 여름, 겨울, 그리고 가을의 순서로 낮았다. 3. 교배방법에 따른 복당 생시체중은 품종간 처리구간에 차이점을 인정할 수 없었으나 복당 출생시 생존수에 있어서는 자연종부후 인공수정을 실시한 처리구에서 9.5두로 제일 많았으며, 인공수정을 실시한 처리구에서는 9.2두, 그리고 자연종부를 실시한 처리구에서는 8.9두로 처리구간에 유의성 (P＜0.01)이 인정되었다. 4. 교배그룹간에서는 L (우)$\times$Y (♂) 교배조합과 L (♀)$\times$L (♂) 교배조합이 Y (♀)$\times$ L (♂) 교배조합 Y (♀)$\times$Y (♂) 교배조합보다 복당 생시체중이 무거웠으며, 복당 출생시 생존 자돈수에 있어서도 비슷한 경향을 나타내었다. 자연종부와 인공수정간에 복당 생시체중과 복당 출생시 생존자돈수는 유의차가 없었다. 5. 산차간에 있어서는 2~6 산차의 복당 생시체중과 복당 출생시 생존 자돈수가 각각 13.5 kg 과 9.5 두로 1산차와 7~9 산차에 비하여 우수하였다.