• 농업과학연구
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• 제47권3호
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• pp.657-665
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• 2020

The objective of this study was to investigate whether supplementation of pentoxifylline (PTX; phosphodiesterase inhibitor) to thawed boar semen improves the post-thaw motility of sperm and affects the efficiency of artificial insemination (AI) and further development. To determine the concentration of PTX for AI, frozen-thawed semen was incubated with 0, 5, 10, and 20 mM PTX in an extender freezing medium, respectively, after thawing. Kinematic properties of sperm were examined with a computer-assisted semen analysis (CASA) system. In addition, viability and mitochondrial activity were also tested by LIVE/DEAD and a MitoTracker kit. There were no significant differences in the kinetic parameters of thawed sperm between control and treatment groups, but overall assessment parameters such as motility and rapid progressive were higher in the 10 mM PTX group. In the viability and mitochondrial assay, there were no significant differences observed in the PTX treatment, compared to the control. For further analysis, artificial inseminations were performed using frozen semen and 10 mM PTX treated cryopreserved semen, respectively. There were no differences in pregnancy rates and fetus weights among the groups until 30 and 40 days, but litter size was reduced and relatively low-birth weight was observed in the PTX group. In summary, our findings suggest that enhancement of in vitro sperm quality or non-toxicity supplemented by PTX may have detrimental effects on fetus development.

• Journal of Animal Science and Technology
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• 제45권4호
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• pp.517-522
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• 2003

한우의 고환둘레와 정액 생산 및 번식과의 관계를 구명하기 위하여, 농협중앙회 가축개량사업소 보유 종모우 63두의 고환둘레와, 이들의 19,742번의 정액 생산기록(정액량, 농도/ml 및 총정자수) 및 이중 16두가 생산한 1,289두의 자손기록을 이용하였다. 정액량, 정액 농도와 총 정자수 모두 정액채취년도, 정액채취월, 정액 채취 순서에 따라 영향을 받았다(P<0.001). 고환 둘레의 평균은 41.2$\pm$4.54cm 이었고, 1회 평균 사정량은 5.47$\pm$0.89ml 이었으며, 정액 농도는 16.2$\pm$2.78(${\times}10^8$/ml), 사정당 총정자수는88.47$\pm$15.24(${\times}10^8$)이었다. 고환둘레와 정액량 및 총 정자수 간에는 0.14 및 0.15의 정의 상관을 나타내었으며, 임신율과는 0.39, 출산율과는 0.26의 상관을 나타내었다.

• 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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• 제30권3호
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• pp.189-193
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• 2015

Calculating break-even price of calf production is closely associated with reproductive efficiency. To determine the price, we need data from reproduction records including number of claves weaned, number of cows exposed for breeding, and annual cash coast per cow, and average weaning or market weight of claves sold and retained. Unfortunately, the data were not available in Korea native cow (Hanwoo). To evaluate the performance and the price, we collected calving interval from about 60,000 cows for last 10 years and estimated reproductive performance. Calving interval was increased 4.3% and pregnancy rate was decreased about 1.4~2.8% year-on-year. Increases in growth rates of number of cow and semen per calf supported the low reproductive performance. Finally, break-even price was calculated using estimated percent calf crop and demonstrated that growth rate of break-even price is larger than that of annual cash per cow, suggesting cow-calf profitability and financial efficiency in Korea native cow (Hanwoo) is getting worse.

• 한국수정란이식학회지
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• 제26권4호
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• pp.271-276
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• 2011

This study was focused on improvement of milk production in Mongolian dairy industry by artificial insemination (AI) technology, supported by ODA of KOICA in Republic of Korea. This program was started in January 2009 and it is in $3^{rd}$ years. This manuscript summarized the data especially on estrus synchronization and pregnancy establishment in dairy cows (Holstein) this year. A total of 81 dairy cows from 4 private farms (38 from Undarmal milk and that of 30, 8 and 5 dairy cows from Onjin (Enkhbayer), Jargalant, and BRM School farms respectively) were synchronized with 5 ml Lutalyse (i.m.) in the dump of dairy cows and then estrus was detected 2 to 3 days after $PGF_{2{\alpha}}$ injection. The synchronized dairy cows were inseminated with 0.5 ml dairy frozen semen by conventional artificial insemination (AI) techniques. Pregnancy was diagnosed about 60 days after AI by palpation method. About 96.3% (78/81) of synchronized cows were responded to single $PGF_{2{\alpha}}$ injection. Total 75 over 78 dairy cows (90.1%) inseminated were diagnosed as pregnant. The estrus induction and pregnancy rates were very effective using Lutalyse injection and conventional AI techniques in Mongolian dairy cow. The present results indicated that AI after estrus induction in Mongolian dairy cows could be applied to dairy breeding technology for improving breeding efficiency and milk production of the country.

• 농업과학연구
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• 제47권4호
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• pp.979-985
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• 2020

A wide range of techniques have been developed to separate X or Y- chromosome-bearing sperm. In particular, bovine semen sex-sorted by using flow cytometry based on differences in the amount of DNA between X and Y chromosome bearing sperm is used in dairy farms. The first piglets were produced using sex-sorted sperm 30 years ago. However, sexed sperm have not been commercially available in pigs because the flow cytometry technique is not capable of sorting the high number of sperm required for porcine artificial insemination (AI), and the prolonged exposure to an electrical filed might damage to the DNA in sperm. The purpose of this study was to evaluate a boar sperm sorting method based on magnetic nanoparticles. A flow cytometer assay verified the efficacy of the magnetic nanoparticles (> 90% of sex-sorted sperm). In addition, a duplex polymerase chain reaction (PCR) assay using sex chromosome specific genes including SRY (sex-determining region Y; male), ZFY (zinc finger protein Y-linked; male), and ZFX (zinc finger protein X-linked; female) showed that in vitro fertilized porcine embryos by X and Y-chromosome bearing sperm were 100% female (40/40) and 72% female (35/48), respectively, at 8-cell or morula stages, suggesting that the sex-sorted sperm were fertile. In conclusion, our findings suggest that the sex-sorted method based on magnetic nanoparticles can be utilized for porcine sex-sorted AI.

• 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.

• Journal of Animal Science and Technology
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• 제51권2호
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• pp.105-110
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• 2009

국내에서 동일시기에 사용된 보증종모우(한국형 보증종모우와 수입 보증종모우 포함)와 후보종모우의 능력을 비교하기 위하여 1990년부터 2004년 사이에 사용된 종모우 1,128두의 딸소 148,329두의 산유능력검정기록을 분석하였다. 유량의 경우 보증종모우의 생산능력이 후보종모우에 비해 높게 나타나고 있으나 보증종모우를 수입 보증종모우와 한국형 보증종모우로 구분하여 비교해 보면 동일 년도에 사용된 후보종모우의 능력이 한국형 보증종모우의 능력에 비해 항상 높은 것으로 나타나 우리나라 젖소개량을 위한 종모우 선발은 바람직한 방향으로 진행되고 있는 것으로 보인다. 유지방은 국내에서 선발된 종모우의 생산 능력이 수입 보증종모우에 비해 높게 나타나고 있는데 이는 우리나라에서 종모우 선발을 위한 종합지수식에서 유지방에 가장 큰 비중을 두고 있기 때문에 나타나는 결과로 사료된다. 본 연구에서는 각 종모우 딸소들의 평균 생산능력을 이용하여 종모우의 능력을 비교하였으나 수입 보증종모우의 경우 국내산 종모우에 비해 정액이 고가로 판매되고 있어 농가에서 능력이 우수한 암소에 주로 사용되고 후보종모우 정액은 무상으로 공급됨에 따라 능력이 낮은 암소에 주로 사용되는 선택적 효과(preferential effect)를 고려할 경우 국내산 종모우의 능력이 과소평가될 수도 있어 향후 이러한 효과를 고려한 분석이 추가로 이루어져야 할 필요가 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권7호
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• pp.938-943
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• 2002

This study was perfonned to detect polymorphisms of the two candidate genes, bovine BTN (Butyrophilin) and ST AT5a (Signal Transducers and Activators of Transcription) gene using 98 Holstein bulls' frozen semen, and to offer the basic information for QTL (Quantitative Trait Loci) analysis. Each BTN PCR product was digested with endonuclease restriction enzyme. The digested fragments of four BTN PCR products were observed as follows: 316,280, and 162 bp in BTN1, 568, 305 and 263 bp in BTN2, 576, 332, and 244 bp in BTN3, and 573, 291, and 282 bp in BTN4, respectively. The gene frequencies of A and B allele in four BTN loci were as follows: 0.8980 and 0.1020 in BTN1, 0.5510 and 0.4490 in BTN2, 0.8163 and 0.1837 in BTN3, and 0.8875 and 0.1122 in BTN4, respectively. And three genotypes (homotypel, heterotype, and homotype2) for STAT5a were observed by SSCP (single stranded conformational polymorphism) method and the genotype frequencies are 78.57%, 19.39%, and 2.04%, respectively. The PlC (Polymorphism Information Content) value and heterozygosity of four BTN loci were as follows: 0.1695 and 0.1870 in BTN1, 0.3713 and 0.4927 in BTN2, 0.2549 and 0.2999 in BTN3, and 0.1794 and 0.1992 in BTN4, respectively. Comparing with the reported data, PlC value of BTN2 might have the possibility to be useful marker. Other BTN loci indicated skewed allele distribution.

• 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.