• Title/Summary/Keyword: Genetic Improvement

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Biodiversity and Conservation of Indian Sheep Genetic Resources - An Overview -

  • Bhatia, S.;Arora, R.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.10
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    • pp.1387-1402
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    • 2005
  • Indian subcontinent is a rich source of diverse ovine germplasm, and only very few countries have such a large number of breeds with wide genetic diversity. This vast ovine biodiversity in India is being eroded rapidly and more than 50% of sheep breeds are currently under threat. It is noteworthy that the characterization of Indian sheep breeds was last done in the first half of the century since then no recent estimates are available and surveys in majority of the regions/breeds are far from complete. Starting in 1985 National Bureau of Animal Genetic Resources (NBAGR), Karnal, India, therefore, initiated activities aimed at determining the status and compiling information on indigenous farm animals including sheep. This report represents attempts made to date on the basis of field/literature surveys and additional activities on molecular characterization to ascertain their status including distribution, population changes, breed diversities and risk status. The need, mode and mechanisms of conservation are also described. Involvement of several agencies for evaluation, improvement, conservation programmes and recommendations made for effective characterization and conservation of sheep biodiversity are highlighted. This publication would promote action particularly at national level to improve the information base on domestic Indian breeds of sheep and provide input into national domestic sheep diversity conservation policy decisions.

Estimation of Genetic Parameters for Wool Traits in Angora Rabbit

  • Niranjan, S.K.;Sharma, S.R.;Gowane, G.R.
    • Asian-Australasian Journal of Animal Sciences
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    • v.24 no.10
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    • pp.1335-1340
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    • 2011
  • Different genetic parameters for weaning weight and wool traits were estimated using restricted maximum likelihood (REML) in Angora rabbits. Total wool yield of first (I), second (II) and third (III) clips were taken as a separate trait under study. The records from more than 2,700 animals were analysed through fitting six animal models with various combinations of direct and maternal effects. A log likelihood ratio test was used to select the most appropriate model for each trait. Direct heritability estimates for the wool traits were found to be moderate to high across different models. Heritability estimates obtained from the best model were 0.24, 0.22, 0.20 and 0.21 for weaning weight, clip I, II and III; respectively. Maternal effects especially due to permanent environment had higher importance at clip I and found to be declining in subsequent clips. The estimates of repeatability of doe effect on wool traits were 0.44, 0.26 and 0.18 for clip I, II and III; respectively. Weaning weight had moderately high genetic correlations with clip I (0.57) and II (0.45), but very low (0.11) with clip III. Results indicated that genetic improvement for wool yield in Angora rabbit is possible through direct selection. Further, weaning weight could be considered as desirable trait for earliest indirect selection for wool yield in view of its high genetic correlation with wool traits.

Genetic diversity and phenotype variation analysis among rice mutant lines (Oryza sativa L.)

  • Truong, Thi Tu Anh;Do, Tan Khang;Phung, Thi Tuyen;Pham, Thi Thu Ha;Tran, Dang Xuan
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.22-22
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    • 2017
  • Genetic diversity is one of fundamental parameters for rice cultivar improvement. Rice mutants are also a new source for rice breeding innovation. In this study, ninety-three SSR markers were applied to evaluate the genetic variation among nineteen rice mutant lines. The results showed that a total of 169 alleles from 56 polymorphism markers was recorded with an average of 3.02 alleles per locus. The values of polymorphism information content (PIC) varied from 0.09 to 0.79. The maximum number of alleles was 7, whereas the minimum number of alleles was 2. The heterozygosity values ranged from 0.10 to 0.81. Four clusters were generated using the unweighted pair group method with arithmetic mean (UPGMA) clustering. Fourteen phenotype characteristics were also evaluated. The correlation coefficient values among these phenotye characteristics were obtained in this study. Genetic diversity information of rice mutant lines can support rice breeders in releasing new rice varieties with elite characterisitics.

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Genetic Parameter Estimates for Backfat Thickness at Three Different Sites and Growth Rate in Swine

  • Kim, J.I.;Sohn, Y.G.;Jung, J.H.;Park, Y.I.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.3
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    • pp.305-308
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    • 2004
  • The purpose of this study was to estimate the genetic parameters for backfat thickness at shoulder, mid back and loin and days to 90 kg using a derivative-free REML procedure. Data were collected from 6,146 boars and gilts of purebred Durocs, Landraces and Large Whites performance tested at breeding farms of National Agricultural Cooperatives Federation in Korea from 1998 to 2001. Estimated heritability for backfat measurements at shoulder, mid-back and loin and an average of those backfat measurements were 0.14, 0.32, 0.22 and 0.25 in Durocs, 0.34, 0.50, 0.42 and 0.46 in Landraces and 0.33, 0.52, 0.43 and 0.49 in Large Whites. Heritabilities of backfat measurements estimated were hightest in mid-back and lowest at shoulder. Phenotypic variances of backfat measurements estimated were largest at shoulder and smallest at mid-back. Estimated heritabilities for days to 90 kg were 0.37 in Durocs, 0.42 in Landraces and 0.54 in Large Whites. Genetic correlations among backfat measurements at shoulder, mid-back and loin and an average of those backfat measurements estimated were positive and very high. Genetic correlations of days to 90 kg with the backfat measurements estimated were _0.19 ~ _0.30 in Durocs, _0.04 ~ _0.17 in Landraces and _0.10 ~ _0.13 in Large Whites.

Identification of Genetic Relationships Among Morus alba Genotypes Based on RAPD and ISSR Fingerprinting

  • Kalpana, Duraisamy;Cha, Hyo-Jung;Choi, Tae-Ki;Lee, Yang-Soo
    • Korean Journal of Plant Resources
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    • v.24 no.6
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    • pp.675-687
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    • 2011
  • Mulberries have importance in the sericulture industry as food for Bombyx mori, silkworm reared for its silk. Korean Morus alba have many cultivars and, for the protection of these cultivars and for utilization in plant-breeding programs, genetic information and the diversity among cultivars are essential. This study with 14 mulberry genotypes was undertaken using RAPD and ISSR fingerprinting to discover the genetic divergences between cultivars. Polymorphism rate among the cultivars produced by RAPD primer was found to be 64.48% and 66.29% relative to ISSR primer. The genetic relationships among the cultivars were identified using a dendrogram constructed with the UPGMA clustering method. Nei's method was used to calculate the genetic dissimilarity coefficients between each pair of genotypes, and the highest dissimilarity coefficient of 0.246 was exhibited between Suwon and Hwanggum cultivars. To determine the efficiency of each primer, a polymorphic index was calculated, and the robustness of the dendrogram was checked using cophenetic correlation coefficient. The results of this study can be utilized for the improvement of mulberry varieties in plant-breeding programs.

Global sensitivity analysis improvement of rotor-bearing system based on the Genetic Based Latine Hypercube Sampling (GBLHS) method

  • Fatehi, Mohammad Reza;Ghanbarzadeh, Afshin;Moradi, Shapour;Hajnayeb, Ali
    • Structural Engineering and Mechanics
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    • v.68 no.5
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    • pp.549-561
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    • 2018
  • Sobol method is applied as a powerful variance decomposition technique in the field of global sensitivity analysis (GSA). The paper is devoted to increase convergence speed of the extracted Sobol indices using a new proposed sampling technique called genetic based Latine hypercube sampling (GBLHS). This technique is indeed an improved version of restricted Latine hypercube sampling (LHS) and the optimization algorithm is inspired from genetic algorithm in a new approach. The new approach is based on the optimization of minimax value of LHS arrays using manipulation of array indices as chromosomes in genetic algorithm. The improved Sobol method is implemented to perform factor prioritization and fixing of an uncertain comprehensive high speed rotor-bearing system. The finite element method is employed for rotor-bearing modeling by considering Eshleman-Eubanks assumption and interaction of axial force on the rotor whirling behavior. The performance of the GBLHS technique are compared with the Monte Carlo Simulation (MCS), LHS and Optimized LHS (Minimax. criteria). Comparison of the GBLHS with other techniques demonstrates its capability for increasing convergence speed of the sensitivity indices and improving computational time of the GSA.

Estimation of Genetic Parameters for Direct and Maternal Effects on Litter Size and Teat Numbers in Korean Seedstock Swine Population

  • Song, Guy-Bong;Lee, Jun-Ho;Lee, Deuk-Hwan
    • Journal of Animal Science and Technology
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    • v.52 no.3
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    • pp.187-190
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    • 2010
  • The objective of this study was to estimate genetic parameters for total number of born (TNB), number of born alive (NBA) and teat numbers (TN) of Landrace and Yorkshire breeds in Korean swine population using multiple trait animal model procedures. Total numbers of 4,653 records for teat numbers and 8,907 records for TNB and NBA collected from 2004 to 2008 on imported breeding pigs and their litter size records were used in this study. To find the appropriate model for estimation of genetic parameters (heritabilities and genetic correlations), five statistical models (two models for reproductive traits, two models for teat numbers, one model for combining these traits) considering only direct additive genetic effects, including maternal effects were used and Akaike information criteria (AIC) of each two models for reproductive traits and teat trait were compared. The means and standard deviations of TNB, NBA, and TN were $11.52{\pm}3.34$, $10.55{\pm}2.96$ and $14.30{\pm}0.83$, respectively. Estimated heritabilities for TNB and NBA traits using the model which considered only additive genetic effect were low (0.06 and 0.05, respectively). However, estimated heritabilities considering maternal genetic effects were a little bit higher than that of the model considering only additive genetic effect (0.09 for TNB and NBA, respectively). Estimated heritability for TN using the model which considered only additive genetic effect was 0.40. However, estimated heritability of direct genetic effects from a model considering maternal genetic effect was high (0.60). All results of AIC statistics, the models considering maternal effect was more appropriate than the models considering only additive genetic effect. Genetic correlations of direct additive genetic effect between litter size (TNB, NBA) and teat numbers were low (-0.18 and -0.14, respectively). However, genetic correlations of maternal effect between litter size (TNB, NBA) and teat numbers were a little bit higher than those of direct additive genetic effect (0.08 and 0.16, respectively).

A Whole Genome Association Study to Detect Single Nucleotide Polymorphisms for Carcass Traits in Hanwoo Populations

  • Lee, Y.-M.;Han, C.-M.;Li, Yi;Lee, J.-J.;Kim, L.H.;Kim, J.-H.;Kim, D.-I.;Lee, S.-S.;Park, B.-L.;Shin, H.-D.;Kim, K.-S.;Kim, N.-S.;Kim, Jong-Joo
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.4
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    • pp.417-424
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    • 2010
  • The purpose of this study was to detect significant SNPs for carcass quality traits using DNA chips of high SNP density in Hanwoo populations. Carcass data of two hundred and eighty nine steers sired by 30 Korean proven sires were collected from two regions; the Hanwoo Improvement Center of National Agricultural Cooperative Federation in Seosan, Chungnam province and the commercial farms in Gyeongbuk province. The steers in Seosan were born between spring and fall of 2006 and those in Gyeonbuk between falls of 2004 and 2005. The former steers were slaughtered at approximately 24 months, while the latter steers were fed six months longer before slaughter. Among the 55,074 SNPs in the Illumina bovine 50K chip, a total of 32,756 available SNPs were selected for whole genome association study. After adjusting for the effects of sire, region and slaughter age, phenotypes were regressed on each SNP using a simple linear regression model. For the significance threshold, 0.1% point-wise p value from F distribution was used for each SNP test. Among the significant SNPs for a trait, the best set of SNP markers were selected using a stepwise regression procedure, and inclusion and exclusion of each SNP out of the model was determined at the p<0.001 level. A total of 118 SNPs were detected; 15, 20, 22, 28, 20, and 13 SNPs for final weight before slaughter, carcass weight, backfat thickness, weight index, longissimus dorsi muscle area, and marbling score, respectively. Among the significant SNPs, the best set of 44 SNPs was determined by stepwise regression procedures with 7, 9, 6, 9, 7, and 6 SNPs for the respective traits. Each set of SNPs per trait explained 20-40% of phenotypic variance. The number of detected SNPs per trait was not great in whole genome association tests, suggesting additional phenotype and genotype data are required to get more power to detect the trait-related SNPs with high accuracy for estimation of the SNP effect. These SNP markers could be applied to commercial Hanwoo populations via marker-assisted selection to verify the SNP effects and to improve genetic potentials in successive generations of the Hanwoo populations.

Establishment of Hanwoo(Korean Cattle, Bos taurus, Linn.) Traceability System Using Radio Frequency Identification(RF-ID) (전자식별칩(RF-ID)을 이용한 한우 생산이력추적시스템 도입)

  • Seo, K. S.;Kim, S.;Lee, J.G.;Sohn, Y.G.;Salces, A.J.;Choi, T.J.
    • Journal of Animal Science and Technology
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    • v.50 no.1
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    • pp.1-8
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    • 2008
  • This study was conducted to develop a traceability system for systematic animal identifi- cation to increase efficiency of animal production, post production and processing to ensure that quality and sanitary meat products reach the consumers of the entire country. The new animal identification traceability system was designed for easy management, data collection and storage considering bar code, registration number and farm number.Specifically the system aimed 1) To provide standard radio frequency technology identification (RF-ID) for livestock management, standard of ear tag, microchip and ear tag identification equipment, 2) To guarantee meat product label thereby safeguarding the consumers 3) To give incentives to farmers for producing quality meat products and 4) To provide unified system for national livestock management.Results of the research which started in July 2003 which was used by several farmers’ cooperatives and Department Store revealed the feasibility of using the RF-ID system although much will be done to conform to global nomenclatures.

Optimum Design of Steel Frames Using Genetic Algorithms (유전자 알고리즘을 이용한 강 뼈대 구조물의 최적설계)

  • 정영식;정석진
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.13 no.3
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    • pp.337-349
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    • 2000
  • Genetic Algorithms(GA) together with simulated annealing are often called methods of last resorts since they can be applicable to any kind of problems, particularly those to which no sophisticated procedures are applicable or feasible. The design of structures is primarily the process of selecting a section for each member from those available in the market, resulting in the problem of combinatorial nature. Therefore it is usual for the design space to include astronomical number of designs making the search in the space often impossible. In this work, Genetic Algorithms and some related technique are introduced and applied to the design of steel frameworks. In problems with a small number of design variables, GA found true global optima. GA also found true optima for the continuous variable test problems and proved their applicability to structural optimization. For those problems of real size, however, it appears to be difficult to expect GA to find optimum or even near optimum designs. The use of G bit improvement added to ordinary GA has shown much better results and draws attention for further research.

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