• Asian-Australasian Journal of Animal Sciences
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• 제19권4호
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• pp.468-474
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• 2006

Real time ultrasound data was generated on 10,596 live Hanwoo cows to study genetic variation on ultrasonic beef quality traits and to assess the best model to estimate genetic parameters on these traits. Pedigree stacking and data validation was done using the SAS statistical software and the genetic parameter estimates were obtained by EM-REML algorithm. Out of the five different multi-trait mixed animal models constructed, the optimal model included fixed effects of herd, year-season-appraisal, body condition score, linear and quadratic covariates for chest girth, the linear covariate effect of age and the random animal and residual effect of the five models studied. The heritability of longissimus muscle area (LMA), $12^{th}$ rib measurement of back fat thickness (BF) and marbling score (MS) was 0.11, 0.17 and 0.15, respectively. Genetic correlation of LMA vs. BF, LMA vs. MS and BF vs. MS was -0.15, 0.06 and 0.61, respectively. The results showed presence of genetic variation in these ultrasonic beef quality traits in Hanwoo cows and suggest that the selection of Hanwoo cows may be possible by performing ultrasonic scans on live animals, which will ultimately be helpful in reducing the generation interval and the cost of selection procedure.

• International Journal of Industrial Entomology and Biomaterials
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• 제13권2호
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• pp.85-95
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• 2006

Seveval Chinese and Japanese varieties with good characters were used in the breeding. After 5 years (15 generations), a pair of robust and high quality silkworm variety with NPV resistance was bred by means of a combination of crossing and pedigree selection complemented by the selection of NPV resistance. The variety was identified jointly nationwide in 2003 and 2004, and appraised by National Mulberry and Silkworm Appraising Committee. Results are as follows: its cocooning rate is over 93%, shell rate 23-25%, filament length 1200-1300 meters, reelability 75-88%, Length of non-broken cocoon filament 900-1100 meters, raw silk rate 17-19%, neatness 95-97 points, and cocoon crop, cocoon shell weight and raw silk weight per 10000 larvae is higher than those of the control variety by 7-10%, 14-19% and 14-18%, respectively. The variety is not only robust, resistant to high temperature and NPV, easy to rear, uniform in hatching, molting and maturing, but also lays more eggs, and its fecundity is high. It is suitable to rear in the Yangtze River Basin, the Yellow River basin and the Pearl River basin of China.

• Asian-Australasian Journal of Animal Sciences
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• 제28권9호
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• pp.1244-1251
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• 2015

A herd of Berkshire pigs was established in 2003 and subjected to selection without introduction of any genetic resources until 2007. The complete pedigree, including 410 boars and 916 sows, as well as the records from 5,845 pigs and 822 litters were used to investigate the results obtained from the selections. The index of selection for breeding values included days to 90 kg (D90kg), backfat thickness (BF) and number of piglets born alive (NBA). The average inbreeding coefficients of pigs were found to be 0.023, 0.008, 0.013, 0.025, 0.026, and 0.005 from 2003 to 2007, respectively. The genetic gains per year were 12.1 g, -0.04 mm, -3.13 days, and 0.181 head for average daily gain (ADG), BF, D90kg, and NBA, respectively. Breeding values of ADG, BF and D90kg were not significantly correlated with inbreeding coefficients of individuals, except for NBA (-0.21). The response per additional 1% of inbreeding was 0.0278 head reduction in NBA. The annual increase of inbreeding was 0.23% and the annual decrease in NBA due to inbreeding was 0.0064 head. This magnitude could be disregarded when compared with the annual gain in NBA (0.181 head). These results suggest that inbreeding and inbreeding depression on ordinary farms can be controlled with a proper breeding scheme and that breeding programs are economical and safe relative to the risks associated with importation of pigs.

• Asian-Australasian Journal of Animal Sciences
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• 제18권8호
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• pp.1075-1079
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• 2005

The main objective of this study is to examine genetic changes in growth rate and carcass composition traits in group housed, ad libitum fed pigs, from lines of Large White divergently selected over four years for high and low post-weaning daily gain on a fixed but restricted ration. Genetic parameters for production and carcass traits were also estimated by using average information-restricted maximum likelihood applied to a multivariate individual animal model. All analyses were carried out on 1,728 records of group housed ad libitum fed pigs, and include a full pedigree of 5,324 animals. Estimates of heritability (standard errors in parentheses) were 0.11 (0.04) for lifetime daily liveweight gain (LDG), 0.13 (0.04) for daily carcass weight gain (CDG) and 0.28 (0.06) for carcass backfat (CFT). Genetic correlations between LDG and CDG were highly positive and between LDG and CFT negative, suggesting that selection for lifetime daily gain under commercial conditions of group housing with ad libitum feeding would result in favourable improvement in carcass traits. CFT showed negative genetic correlations with CDG. Correlated genetic responses evaluated as estimated breeding values (EBVs) were obtained from a multivariate animal model-best linear unbiased prediction analysis. After four years of divergent selection for 6 week post-weaning growth rate on restricted feeding, pigs performance tested on ad libitum feeding in groups exhibited changes in EBVs of 6.77 and -9.93 (g/d) for LDG, 4.25 and -7.08 (g/d) for CDG, and -1.42 and 1.55 (mm) for CFT, in the high and low lines, respectively. It is concluded that selection for growth rate on restricted feeding would significantly improve genetic performance and carcass composition of their descendants when group housed and ad libitum fed as is a common commercial practice.

• 한국수산과학회지
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• 제55권5호
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• pp.549-556
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• 2022

The aim of this study was to evaluate the genetic parameters of growth traits for improvement breeding in olive flounder Paralichthys olivaceus at the 8^th generation of selective breeding in April 2021. Growth traits such as total length, body weight and condition factor at 11 months of age were measured for 7,508 individuals with confirmed paternity. Data were analyzed using the restricted maximum likelihood method applied to a multiple traits animal model. The effects of sex and family were significantly different across traits (P<0.05). The heritability values of total length, body weight and condition factor were estimated to be high as 0.479, 0.457, and 0.466, respectively. Correlation analysis between phenotypic and breeding values, indicated that the selection accuracy was 75.9-85.2% for all traits. To increase the selection accuracy for parent fish selection, the sex and pedigree characteristics that affect each trait should be considered. Moreover, further improvement of multiple traits can be achieved if the correlation between each trait is appropriately considered.

• 한국작물학회지
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• 제25권1호
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• pp.39-46
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• 1980

영남작물 시험장에서는 우리 나라 남부지방의 답이작에 적합한 조숙 안전 다수성 보리 신품종을 보다 효율적으로 육성하기 위하여 1975년부터 보리의 웅성불임을 이용한 누환선발육종을 실시한 결과 1978년에 보리의 순환선발집단인 RSPYB#1을 육성하였는데 그 결과를 요약하면 다음과 갈다. 1. 집단육성에 이용된 재료는 미국 California 와 Idaho 및 Montana 지방에서 육성된 Composite cross F_2 집단과 우리 나라 육성계통의 혼합집단을 사용 하였다. 2. 집단육성 과정에서 각 Cycle의 F_1 세대에서는 종자증식만 하고 F_2 세대에서는 웅성불임과 웅성임성을 인공교배 하였다. 3. 웅성불임 재료에 우리 나라 육성계통의 혼합집합이 2회 교잡되므로서 이론적으로 75%의 적응률을 가졌으며 남부지방의 답이작하에서 그 Cycle 이 반복되어 왔으므로 답이작에 대한 적응도가 높은 것으로 인정된다. 4. 각 Cycle의 F_2 세대에서는 우량개체를 주별로 선발하였고 선발된 계통은 계통 육종법에 따라 재배하였으며 유망한 계통은 생산력 검정시험에 공시하여 수량과 특성을 검정하였다. 5. 보리순환선발집단 RSPYB# 1에서 선발된 계통들은 기존장여 품종들에 비하여 조숙 다수성으로 답이작에 적응도가 높은 경향이었다. 6. 보리순환선발집단 RSPYB# 1은 Cycle이 진전될수록 답이작에 더욱 우수한 계통들이 선거될 것으로 기대된다.

• International Journal of Industrial Entomology and Biomaterials
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• 제9권1호
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• pp.101-105
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• 2004

A number of Chinese, Japanese and European silkworm strains with coarse size filament were used for breeding the coarse size variety. Through cross breeding combined with pedigree selection within thirteen generations, a pair of coarse size silkworm variety, named ${CU_1}{\times}{CU_2}$, was obtained after five years. Laboratory trials showed that the filament size of its 4F_1$ hybrid was over 4.3 D, and the other economic characters were also good.

• Journal of Animal Science and Technology
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• 제52권5호
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• pp.357-366
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• 2010

한우의 유전체 전장의 정보를 Illumina BeadArray$^{TM}$ Bovine SNP50 assay를 이용하여 단일염기다형 현상을 조사한 결과, 유전적 다양성을 보이는 좌위가 약 32,567 좌위 이상에서 다양성을 보이고 있었으며 약 5,554 좌위에서 다양성이 조사되지 않았다. 이는 조사된 자료의 가계집단의 수가 크게 제한되었기 때문에 기인될 수 있으며 또 다른 원인으로는 한우 종축집단의 크기가 작을 수 있다는 현상을 반증한다고 사료된다. 유전분석의 기초가 되는 혈통기록에 의한 개체간 혈연관계를 유전체 정보에 의한 혈연관계와 비교하여 본 결과, 유전체 정보에 의한 혈연관계의 크기가 혈통기록에 의한 혈연관계보다 좀 더 정확하게 추정될 수 있다는 장점이 있으며 혈통기록상의 오류로 그릇된 혈연관계의 크기를 유전체 정보를 통하여 보완할 수 있다는 장점이 있다. 이러한 장점을 활용하면 유전체정보를 이용한 유전능력 평가의 정확성을 크게 향상시킬 수 있을 것으로 사료되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권12호
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• pp.1836-1843
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• 2019

Objective: Social genetic effects (SGE) are an important genetic component for growth, group productivity, and welfare in pigs. The present study was conducted to evaluate i) the feasibility of the single-step genomic best linear unbiased prediction (ssGBLUP) approach with the inclusion of SGE in the model in pigs, and ii) the changes in the contribution of heritable SGE to the phenotypic variance with different scaling ${\omega}$ constants for genomic relationships. Methods: The dataset included performance tested growth rate records (average daily gain) from 13,166 and 21,762 pigs Landrace (LR) and Yorkshire (YS), respectively. A total of 1,041 (LR) and 964 (YS) pigs were genotyped using the Illumina PorcineSNP60 v2 BeadChip panel. With the BLUPF90 software package, genetic parameters were estimated using a modified animal model for competitive traits. Giving a fixed weight to pedigree relationships (${\tau}:1$), several weights (${\omega}_{xx}$, 0.1 to 1.0; with a 0.1 interval) were scaled with the genomic relationship for best model fit with Akaike information criterion (AIC). Results: The genetic variances and total heritability estimates ($T^2$) were mostly higher with ssGBLUP than in the pedigree-based analysis. The model AIC value increased with any level of ${\omega}$ other than 0.6 and 0.5 in LR and YS, respectively, indicating the worse fit of those models. The theoretical accuracies of direct and social breeding value were increased by decreasing ${\omega}$ in both breeds, indicating the better accuracy of ${\omega}_{0.1}$ models. Therefore, the optimal values of ${\omega}$ to minimize AIC and to increase theoretical accuracy were 0.6 in LR and 0.5 in YS. Conclusion: In conclusion, single-step ssGBLUP model fitting SGE showed significant improvement in accuracy compared with the pedigree-based analysis method; therefore, it could be implemented in a pig population for genomic selection based on SGE, especially in South Korean populations, with appropriate further adjustment of tuning parameters for relationship matrices.

• Journal of Animal Science and Technology
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• 제44권3호
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• pp.279-288
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• 2002

본 연구는 국내 홀스타인 젖소 보증종모우 16두와 후보종모우 93두를 이용하여 선천성 장애 유전자의 검색을 통하여 불량 유전자의 존재 유무를 판별함과 동시에 가축의 선발 및 육종, 개량시 기초자료로 제공하고자 하는데 그 목적이 있으며, 본 연구의 결과를 요약하면 아래와 같다. 공시재료(홀스타인 젖소 보증종모우 16두, 후보 종모우 93두) 109두에 대하여 DUMPS (deficiency of uridine monophophate synthase)의 검색결과 모든 개체에서 DUMPS 유전자를 보유하는 개체는 없는 것으로 판명되었다. 또한 PCR-RFLP(Ava I) 방법에 의해 조기 검색이 가능하게 되었다. 한편, BLAD(bovine leukocyte adhesion deficiency) 검색결과, 보증종모우 16두에서는 검출되지 않았으나, 후보우 93두중 5두에서 BLAD 잠재성 보유개체(carrier)로 판명되었고, 혈통확인을 통하여 BLAD 유전자의 전이 경로를 추정할 수 있었으며, PCR 증폭산물에 대한 제한효소 처리시 HaeⅢ 보다는 TaqⅠ 제한효소를 사용하였을 때 더 효율적으로 판명할 수 있는 것으로 나타났다. Citrullinemia 검색결과 보증종모우 16두 및 후보종모우 93두 모두에서 잠재성 보유개체는 없는 것으로 판명되었으나 citrullinemia에 대한 폭넓고 다양한 조사 및 분석이 이루어져야 할 것으로 사료된다. 본 연구의 결과로 미루어 볼 때 가축의 유전성 질환에 대한 다양하고 폭넓은 연구가 이루어 져야 할 것으로 사료되며, 가축의 선발과 육종, 개량에 있어서 지속적이며 혈통의 철저한 관리를 통한 개량의 방향을 설정하여야 할 것으로 판명되었다.