• Journal of Embryo Transfer
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• v.17 no.3
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• pp.235-238
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• 2002

The present study was undertaken to find out possibilities for superovulation and recovery of freezable/transferable embryo from repeat breeding crossbred cows. For this study a total of 10 Holstein crossbred cows having history of failure of conception even after more than 4~5inseminations were taken and superovulated using Folltropin-V at 100 to 140% dose schedule. The results indicated that out of 10 donors, 8 responded to superovulatory treatment and yielding a total of 94 embryos, out of which 45 were of transferable/freezable quality. The mean ovulations and mean transferable embryos were 11.5$\pm$2.91 and 4.5$\pm$1.66, respectively. These observations suggests that the repeat breeding cows having conception failure after several artificial inseminations can be used as donors for production of embryos and calves through embryo transfer technology.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.6
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• pp.554-564
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• 2006

It is important to understand pedigree of rice cultivars commonly used for breeding. In this paper, pedigree tables for tracking the pedigree of 17 representative rice cultivars recommended by Rural development Adminstration (RDA) were completed and analyzed using two kinds of web database system; 'IRIS' and 'RRDB'. Seven cultivars, namely, 'Sangmibyeo', 'Ilpumbyeo', 'Saegewhabyeo', 'Surabyeo', 'Shindongjinbyeo', 'Ilmibyeo' and 'Jungwhabyeo' had 'Koshihikari' on the pedigree of their ancestor. Besides 'Koshihikari', the most feguently used ancestral germplasms among the high quality rice cultivars were 'Fujisaka 5', 'Kameno o' and 'Asahi', 'Fujisaka 5' was used as ancestral parent in 12 out of 17 cultivars. Interestingly, 'Kameno o' was used in pedigree of 16 out of 17 high quality varieties and 'Asahi' was used in the ancestral pedigree of all 17 varieties. 'Hwayeongbyeo' was used as one of parent in the breeding of 'Dongjin 1', 'Hwabongbyeo', 'Saegewhabyeo' and 'Junambyeo'. 'Ilpumbyeo' was used in the breeding pathway of 'Junambyeo' and 'Saegewhabyeo', 'Mangeumbyeo' itself was not enlisted as one of high quality rice cultivars, but was used as a breeding parent of three high quality varieties, namely, 'Saegewhabyeo', 'Hwabongbyeo' and 'Nampyeongbyeo'. Incorporated with evaluation data, pedigree will provide a valuable chance to genealogical tracking of agronomic traits such as disease resistance, grain quality and etc.

• Korean Journal of Veterinary Service
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• v.46 no.3
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• pp.203-210
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• 2023

Breeding ducks are susceptible to fungal infections due to being bred in confined spaces for long periods. The objective of this study was to show the real state of the clinical fungal contamination of 22 duck breeding farms in Chungcheongbuk-do, South Korea. Out of the 430 carcasses obtained from the 22 duck breeding farms, 80 were diagnosed with invasive pulmonary aspergillosis (IPA). Aspergillus spp. were detected as the causative agents, including 26 cases of A. fumigatus, 35 cases of A. flavus, and 19 cases of A. terreus. The clinical lesions in the breeding ducks had circumscribed cream-and-yellow-colored plaques and/or white-to-greenish mycelium. Septate hyphae with parallel walls and dichotomous branching were observed in the histopathological lesions. AGMAg ELISA was performed to determine the overall positive rate of Aspergillus spp. in duck breeding farms. These results showed a positive rate of 58.97% for Aspergillus spp. Additionally, the positive rate increased with the age of the host.

• The Korean Journal of Ecology
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• v.28 no.5
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• pp.237-243
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• 2005

To study entering and exiting routes of male and female Hynobius leechii to a breeding site and staying time of them within the breeding site, we monitored a breeding population located in the research forests of Kangwon National University. The breeding site was surrounded by a drift fence associated with nine pitfall traps. The breeding season of this population was about one month, from 16 March to 13 April, 2005. Breeding males arrived earlier at the breeding pond than females did. The operational sex ratio (OSR), defined as the ratio of males to females which are ready to mate, over a breeding season was female-biased as 0.67 male vs 1 female (57 males vs 87 females), but daily OSRs, OSR in a particular day, within the breeding pond were male-biased with $1.36\sim7.5$ male vs f female in six days out of seven investigated days. While breeding males stayed in the breeding pond for about 11 days, breeding females left the pond as soon as they completed oviposition. However, the females stayed at terrestrial areas near the pond for about seven days before completely leaving the breeding site. Entering and exiting routes to the breeding site were different between males and females, and between ovulated and oviposited females. Both males and females arrived earlier at the breeding site stayed longer within the site. Males stayed longer within the breeding site lost more body weight.

• Journal of Animal Science and Technology
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• v.47 no.2
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• pp.147-158
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• 2005

The purpose of this study was to find out the effects that daughters' incomplete lactation records affect sire's breeding values through genetic evaluation using RRTDM(random regression test-day model). First, we estimated genetic parameters and breeding values on sires having complete lactation records of daughter by RRTDM, second, we changed complete lactation records of specific sires into incomplete records by various methods. Third, the breeding values were compared between complete and incomplete records. Finally, this study aimed to find out the methods to minimize the estimation errors of young bulls' breeding values. Data used in this study were collected from the dairy herd improvement program, and a total of 97,562 records were composed of 10,929 first parity with both parents known, since 1999. Breeding values on the daughters from randomly chosen sires were calculated and compared with among 90 day, 150day, and 200 day's incomplete records. For milk yields, sire's ranks of breeding values used by complete lactation records were very different from sire's ranks of breeding values obtained by incomplete lactation records(Rank_90 cut, 150cut, 200 cut).The differences were also obtained between complete lactation records(per305_full) and incomplete lactation record (per_90 cut, 150cut, 200 cut) in breeding values regarding persistency. Especially, the differences between per_90 cut and per305_full were very large(from 1.8 kg to 145kg).

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.2
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• pp.203-211
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• 2020

Objective: Staphylococcus aureus (S. aureus) is one of the major microorganisms responsible for subclinical mastitis in dairy cattle. The present study was designed with the aim to explore the DNA methylation patterns using the Fluorescence-labeled methylation-sensitive amplified polymorphism (F-MSAP) techniques in a S. aureus-infected mouse model. Methods: A total of 12 out-bred Institute of Cancer Research female mice ranging from 12 to 13 weeks-old were selected to construct a mastitis model. F-MSAP analysis was carried out to detect fluctuations of DNA methylation between control group and S. aureus mastitis group. Results: Visible changes were observed in white cell counts in milk, percentage of granulocytes, percentage of lymphocytes, CD⁴⁺/CD⁸⁺ ratio (CD⁴⁺/CD⁸⁺), and histopathology of mice pre- and post-challenge with S. aureus. These findings showed the suitability of the S. aureus-infected mouse model. A total of 369 fragments was amplified from udder tissue samples from the two groups (S. aureus-infected mastitis group and control group) using eight pairs of selective primers. Results indicated that the methylation level of mastitis mouse group was higher than that in the control group. In addition, NCK-associated protein 5 (Nckap5) and transposon MTD were identified to be differentially methylated through secondary polymerase chain reaction and sequencing in the mastitis group. These observations might play an important role in the development of S. aureus mastitis. Conclusion: Collectively, our study suggests that the methylation modification in Nckap5 and transposon MTD might be considered as epigenetic markers in resistance to S. aureus-infected mastitis and provided a new insight into S. aureus mastitis research in dairy industry and public health.

• Asian Journal of Turfgrass Science
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• v.11 no.1
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• pp.73-85
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• 1997

Although zoysia grass (Zoysia spp.) has a lot of excellent chracteristics as warm-season grass, it have been limited in use due to slow establishment, low seed production, poor shade tolerance and other factors. Breeding trials have been continued from 1900's, much attentions have been paid especially in U.S.A., Korea and Japan recently. In U.S.A., more than 24 varieties had been evaluated at National Turfgrass Evaluation Program(NTEP) from 1991 to 1995 and some were regsistered as commercial. After the 6th International Turfgrass Research Conference at Japan in 1989, Japan Turfgrass In-corporation (JTI) sponsored by private companies and government carried out breeding programs for pest, salt, and shade tolerant and herbicide resistant varieties. JTI also has been trying to im-prove vigor and breed evergreen zoysia Korean breeders collected germplasms since 1960's. After USDA breeders came to Korean penesula in 1982, Korean breeders joined with USDA zoysia breeding project for several years. Many interspecific hybrids and natural selected varieties were breeded that period both in U.S.A and Korea. Breeding objectives were to extend green color period, improve leaf quality and density, and better leaf color at dormant stage. Since 1990's, zoysia grass breeding trials are getting more diverse in many points such as random amplified polymorphic DNA (RAPD) assay for ecotype identification. The objectives of this study are to evaluate germplasms in Korea, and also review the present status and future prospect in zoysia grass breeding in the world.

• Korean Journal of Poultry Science
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• v.22 no.1
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• pp.15-31
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• 1995

This study was carried out to develop a computer software system for poultry breeding by using microcomputer(PC). Through this study, SPPB(Statistical Package for Poultry Breeding) was designed and developed, which can help poultry breeder collect and analyse the chick records. A main feature of the system was the application of user-oriented procedure, for example, choice of the flock file, selection of the family size and the desired traits. Creation of the data files and the breeding files. calculation of the elementary statistics, estimation of the heritability and the genetic and phenotypic correlation coefficients can be obtained by user's choice of the sire and dam family size. Also, it is possible to estimate the various selection indices through this system. Easiness of using this system and the flexibility of the file management could help increasing the efficiency of related practical poultry breeding jobs. Correctness and relationships between the unit programs in the system were proved through the run-test of the SPPB using sample data. Because it wasn't able to collect breeding records at the commercial breeding farm, effectiveness of the system was not proved totally. Also. it will be necessary to develop the integrated software system which make possible to computerize the general works at breeding farm and the genetic analyses of the records from chick breeders.

• Development and Reproduction
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• v.18 no.4
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• pp.275-286
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• 2014

To successful molecular breeding, identification and functional characterization of breeding related genes and development of molecular breeding techniques using DNA markers are essential. Although the development of a useful marker is difficult in the aspect of time, cost and effort, many markers are being developed to be used in molecular breeding and developed markers have been used in many fields. Single nucleotide polymorphisms (SNPs) markers were widely used for genomic research and breeding, but has hardly been validated for screening functional genes in olive flounder. We identified single nucleotide polymorphisms (SNPs) from expressed sequence tag (EST) database in olive flounder; out of a total 4,327 ESTs, 693 contigs and 514 SNPs were detected in total EST, and these substitutions include 297 transitions and 217 transversions. As a result, 144 SNP markers were developed on the basis of 514 SNP to selection of useful gene region, and then applied to each of eight wild and culture olive flounder (total 16 samples). In our experimental result, only 32 markers had detected polymorphism in sample, also identified 21 transitions and 11 transversions, whereas indel was not detected in polymorphic SNPs. Heterozygosity of wild and cultured olive flounder using the 32 SNP markers is 0.34 and 0.29, respectively. In conclusion, we identified SNP and polymorphism in olive flounder using newly designed marker, it supports that developed markers are suitable for SNP detection and diversity analysis in olive flounder. The outcome of this study can be basic data for researches for immunity gene and characteristic with SNP.

• Korean Journal of Veterinary Service
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• v.36 no.2
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• pp.133-137
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• 2013

The purpose of this study was to investigate the seroprevalence of paratuberculosis in Korean cattle in western Jeonbuk area. From February 2012 to January 2013, blood samples were collected from 2,606 Korean cattle of 263 farms. As a result, 60 (2.3%) heads of 46 (17.5%) farms were positive on the ELISA test for paratuberculosis. Based on regional analysis, 18 (19.6%) out of 92 farms and 24 (2.5%) out of 941 heads in Iksan area, 28 (22.0%) out of 127 farms and 36 (2.8%) out of 1,291 heads in Kimje area were positive but samples from Gunsan area were all negative. According to scale breeding, small scale (below 50 heads) breeding showed the most high prevalence rate compared to middle (50 to 99 heads) or large (over 100 heads) scale breeding. To clarify the relation between number of heads and paratuberculosis prevalence, some additional analysis would be required in further, though.