• Title/Summary/Keyword: Genetic Improvement

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Estimation of Growth Curve Parameters for Body Weight and Measurements in Castrated Hanwoo (Bostaurus Coreanae) (한우 거세우의 체중 및 체형에 대한 성장곡선 모수 추정)

  • Choi, Te-Jeong;Seo, Kang-Seok;Kim, Si-Dong;Cho, Kwang-Hyun;Choi, Jae-Gwan;Hwang, In-Ho;Choi, Ho-Sung;Park, Chul-Jin
    • Journal of Animal Science and Technology
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    • v.50 no.5
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    • pp.601-612
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    • 2008
  • This study was conducted to figure out how the shape of Hanwoo changes over time, examine the rank correlations between the carcass traits which are the selection traits and parameters of growth curve, and determine the correlation between body shape and carcass. Body weight, body measurements and carcass traits were measured from 161 castrated Hanwoo, and 12 growth traits and 5 carcass traits were investigated in total. The logistic model(Nelder, 1961) used for the estimation of growth curve parameters and growth characteristics at inflection point were calculated by these growth curve parameters. The value of this parameter was greatest for pinbone width, which suggests that it is an early ripening trait, while it was lowest for chest girth, suggesting it to be a late ripening trait. The rank correlations of chest depth, chest width, and hip width with backfat thickness steadily increased from 6 to 24 months, while the rank correlations of other traits decreased after 18 months until 24 months of age. Only phenotypic records were analyzed in this study, but for examine the genetic changes over growth phase in Hanwoo, if another additional genetic analysis like as estimation of genetic parameters should achieve, body measurements may be useful traits in proven bull selection.

Genetic Structure and Differentiation of Three Indian Goat Breeds

  • Dixit, S.P.;Verma, N.K.;Aggarwal, R.A.K.;Kumar, Sandeep;Chander, Ramesh;Vyas, M.K.;Singh, K.P.
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.9
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    • pp.1234-1240
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    • 2009
  • Gene flow, genetic structure and differentiation of Kutchi, Mehsana and Sirohi breeds of goat from North-Western India were evaluated based on 25 microsatellite markers so as to support breed conservation and improvement decisions. The microsatellite genotyping was carried out using an automated DNA sequencer. The gene diversity across the studied loci for the Kutchi breed varied from 0.57 (ILST 065) to 0.93 (OarFCB 304, OMHC 1, ILSTS 058) with an overall mean of 0.79${\pm}$0.02. The corresponding values for Mehsana and Sirohi breeds were 0.16 (ILST 008) to 0.93 (OMHC 1, ILSTS 058) with an average of 0.76${\pm}$0.04, and 0.50 (ILSTS 029) to 0.94 (ILSTS 058) with an average of 0.78${\pm}$0.02, respectively. The Mehsana breed had lowest gene diversity among the 3 breeds studied. All the populations showed an overall significant heterozygote deficit ($F_{is}$). The Fis values were 0.26, 0.14 and 0.36 for Kutchi, Mehsana and Sirohi goat breeds, respectively. Kutchi and Mehsana were more differentiated (16%) followed by Mehsana and Sirohi (13%).The measures of standard genetic distance between pairs of breeds indicated that the lowest genetic distance was between Kutchi and Sirohi breeds (0.73) and the largest genetic distance was between Mehsana and Kutchi (1.0) followed by Sirohi and Mehsana (0.75) breeds. Mehsana and Kutchi are distinct breeds and this was revealed by the estimated genetic distance between them. All measures of genetic variation revealed substantial genetic variation in each of the populations studied, thereby showing good scope for their further improvement.

Development of International Genetic Evaluation Models for Dairy Cattle (홀스타인의 국제유전평가를 위한 모형개발에 관한 연구)

  • Cho, Kwang Hyun;Park, Byoungho;Choi, Jaekwan;Choi, Taejeong;Choy, Yunho;Lee, Seungsu;Cho, Chungil
    • Journal of Animal Science and Technology
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    • v.55 no.1
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    • pp.1-6
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    • 2013
  • This study was aimed to solve the problems of current national genetic evaluation systems in Korea and its development to pass the verification processes as required by International Bull Evaluation Service (Interbull). This will enable Korea to participate in international genetic evaluation program. A total of 1,416,589 test-day milk records with calving dates used in this study were collected by National Agricultural Cooperative Federation from 2001 to 2009. Parity was limited up to fifth calving and milk production records were adjusted to cumulative 305 day lactation. The pedigree consisted of 2,279,741 animals where 2,467 bulls had 535,409 parents. A newly developed multiple trait model was used in calculation of breeding values for milk yield, milk fat, and protein yield. Data were edited with SAS (version 9.2) and R programs, and genetic parameters were estimated using VCE 6.0. Results showed a continuous increase in genetic potentials, in general, and no remarkable differences were found between performances by parity. Except fat yield, potentials in milk yield and protein yield were well calculated. We found an increased number of daughters per each top ranked 1,000 bulls in recent years of calf births compared to the cases of previous evaluations. Of the bulls ranked top 100 by our new models (multiple-trait models) we found that increased numbers of bulls were included. Of twenty eight bulls born in 2006, twenty bulls born in 2007 and eight bulls born in 2008 that were listed by new models, only 23, 12, and 2 bulls born in respective years were represented on top 100 by old single-trait models. Re-ranking of the daughters or sires by multiple-trait models suggest that this new multiple trait approach should be used for dairy cattle genetic evaluation and seed-stock selection in the future to increase the accuracy of multiple trait selection. Breeding values for these traits should also be calculated by new method for international genetic evaluation.

A whole genome sequence association study of muscle fiber traits in a White Duroc×Erhualian F2 resource population

  • Guo, Tianfu;Gao, Jun;Yang, Bin;Yan, Guorong;Xiao, Shijun;Zhang, Zhiyan;Huang, Lusheng
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.5
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    • pp.704-711
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    • 2020
  • Objective: Muscle fiber types, numbers and area are crucial aspects associated with meat production and quality. However, there are few studies of pig muscle fibre traits in terms of the detection power, false discovery rate and confidence interval precision of whole-genome quantitative trait loci (QTL). We had previously performed genome scanning for muscle fibre traits using 183 microsatellites and detected 8 significant QTLs in a White Duroc×Erhualian F2 population. The confidence intervals of these QTLs ranged between 11 and 127 centimorgan (cM), which contained hundreds of genes and hampered the identification of QTLs. A whole-genome sequence imputation of the population was used for fine mapping in this study. Methods: A whole-genome sequences association study was performed in the F2 population. Genotyping was performed for 1,020 individuals (19 F0, 68 F1, and 933 F2). The whole-genome variants were imputed and 21,624,800 single nucleotide polymorphisms (SNPs) were identified and examined for associations to 11 longissimus dorsi muscle fiber traits. Results: A total of 3,201 significant SNPs comprising 7 novel QTLs showing associations with the relative area of fiber type I (I_RA), the fiber number per square centimeter (FN) and the total fiber number (TFN). Moreover, one QTL on pig chromosome 14 was found to affect both FN and TFN. Furthermore, four plausible candidate genes associated with FN (kinase non-catalytic C-lobe domain containing [KNDC1]), TFN (KNDC1), and I_RA (solute carrier family 36 member 4, contactin associated protein like 5, and glutamate metabotropic receptor 8) were identified. Conclusion: An efficient and powerful imputation-based association approach was utilized to identify genes potentially associated with muscle fiber traits. These identified genes and SNPs could be explored to improve meat production and quality via marker-assisted selection in pigs.

The Studies on The Development of 305-day Adjustment Factors and Formulas for Production Traits in Dairy Cattle (젖소의 생산형질에 대한 305일 보정계수 및 함수식 개발에 관한 연구)

  • Cho, Kwang-Hyeon;Lee, Joon-Ho;Na, Seung-Hwan;Son, Sam-Kyu;Seo, Kang-Seok;Kim, Si-Dong;Choi, Jae-Gwan
    • Journal of Animal Science and Technology
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    • v.51 no.2
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    • pp.111-122
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    • 2009
  • This study was performed to make it possible to adjust milk production records which are changing with days in milk more accurately as developing new 305-day adjustment factors considering current circumstance and to offer easier application by converting adjustment factors to formulas. Total 4,264,347 records were used in this analysis after eliminating unusual value and data was classified by first parity and over second parity. Herd-year effects were classified with 2,878 and 19,783 classes in first parity and over second parity, respectively and number of subclass of age-calving season-lactation stage effects were 136 (age 2, calving season 4, lactation stage 17). For calculation of least square mean, SAS GLM was used and multiplicative adjustment factors were developed. The result of error analysis, deviations between means of adjusted yields and cumulated yields were the lowest in new adjustment factor which was developed in this study comparing with other adjustment factors which were developed in the past (94', 02') in first parity and in over second parity, results of adjustment factors which were developed in 2002 and this study were similar. For easier application, formulas of 305-day adjustment factors were developed using SAS NLIN.

In vitro Plant Regeneration from Apical Bud and Nodal Segments of Anthocepahalus Cadamba - An important sacred and medicinal tree

  • Kavitha, M.;Kalaimagal, I.;Mercy, S.;Sangeetha, N.;Ganesh, D.
    • Journal of Forest and Environmental Science
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    • v.25 no.2
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    • pp.111-118
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    • 2009
  • Multiple shoot induction and plant regeneration using apical bud and nodal explants of 100 year old tree of Anthocephalus cadamba, an important sacred and medicinal tree in India was achieved for the first time. Aseptic explants cultured in Murashige and Skoog (MS) medium augmented with different concentrations of BAP (0.1, 0.5, 1.0, 2.5, 5.0 and 10 mg/l), when maintained for 60 days, healthy shoots were induced in presence of BAP (1 mg/l). Lower concentrations of BAP (0.1 - 0.5 mg/l) induced only one shoot per explant. Increase in number of shoots per explant was observed in presence of higher concentrations of BAP (2.5, 5.0 and 10 mg/l). However, elongation of shoots was completely inhibited. Bud break and shoot regeneration was largely associated with seasonal factors. Apical buds cultured during June to August exhibited early bud break within two weeks of initial culture. In rest of the months, bud break and shoot regeneration was very slow irrespective of the various concentrations of BAP used in the medium. Explants sourced from three different maturity levels of shoots indicated that actively growing shoots from the mother plant with 1 - 2 nodal segments was more suitable for culture initiation than the explants collected from mature shoots at dormant stage. Regenerated shoots with 2 - 3 pairs of leaves when transferred to half strength MS medium fortified with IBA (1 mg/l), 60% of the shoots induced healthy roots, indicating the possibility of large scale micropropagation.

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Estimation of Genetic Parameters for Milk Production Traits in Holstein Dairy Cattle (홀스타인의 유생산형질에 대한 유전모수 추정)

  • Cho, Chungil;Cho, Kwanghyeon;Choy, Yunho;Choi, Jaekwan;Choi, Taejeong;Park, Byoungho;Lee, Seungsu
    • Journal of Animal Science and Technology
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    • v.55 no.1
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    • pp.7-11
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    • 2013
  • The purpose of this study was to estimate (co) variance components of three milk production traits for genetic evaluation using a multiple lactation model. Each of the first five lactations was treated as different traits. For the parameter estimation study, a data set was set up including lactations from cows calved from 2001 to 2009. The total number of raw lactation records in first to fifth parities reached 1,416,589. At least 10 cows were required for each contemporary group, herd-year-season effect. Sires with fewer than 10 daughters were discarded. Lactations with 305d milk yield exceeding 15,000 kg were removed. In total, 1,456 sires of cows were remained after all the selection steps. A complete pedigree consisting of 292,382 records was used for the study. A sire model containing herd-year-season, caving age, and sire additive genetic effects was applied to the selected lactation data and pedigree for estimating (co) variance components via VCE. Heritabilities and genetic or residual correlations were then derived from the (co) variance estimates using R package. Genetic correlations between lactations ranged from 0.76 to 0.98 for milk yield, 0.79~1.00 for fat yield, 0.75~1.00 for protein yield. On individual lactation basis, relatively low heritability values were obtained 0.14~0.23, 0.13~0.20 and 0.14~0.19 for milk, fat, and protein yields, respectively. For the combined lactation heritability values were 0.29, 0.28, and 0.26 for milk, fat, and protein yields. The estimated parameters will be used in national genetic evaluations for production traits.

Screening of Genetic Variations in Korean Native Duck using Next-Generation Resequencing Data

  • Eunjin Cho;Minjun Kim;Hyo Jun Choo;Jun Heon Lee
    • Korean Journal of Poultry Science
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    • v.50 no.3
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    • pp.187-191
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    • 2023
  • Korean native ducks (KNDs) continue to have a high preference from consumers due to their excellent meat quality and taste characteristics. However, due to low productivity and fixed plumage color phenotype, it could not secure a large share in the domestic market compared to imported species. In order to improve the market share of KNDs, the genetic characteristics of the breed should be identified and used for improvement and selection. Therefore, this study was conducted to identify the genetic information of colored and white KNDs using next-generation resequencing data and screening for differences between the two groups. As a result of the analysis, the genetic variants that showed significant differences between the colored and white KND groups were mainly identified as mutations related to tyrosine activity. The variants were located in the genes that affect melanin synthesis and regulation, such as EGFR, PDGFRA, and DDR2, and these were reported as the candidate genes related to plumage pigmentation in poultry. Therefore, the results of this study are expected to be useful as a basis for understanding and utilizing the genetic characteristics of KNDs for genetic improvement and selection of white broiler KNDs.

Heterosis and Percent Improvement in Survivability, Reproduction and Production Performance of Various Genetic Groups of Temperate x Zebu Crosses in Tropics

  • Singh, Kuldeep;Khanna, A.S.;Sangwan, M.L.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.6
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    • pp.794-799
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    • 2003
  • A study was conducted on 2102 records of 808 crossbred cows of various genetic groups maintained under 'All India Coordinated Research Project on Cattle' at C C S Haryana Agricultural University, Hisar, over 25 years period (1968-1993) with an objective to assess and compare the amount of percent improvement and heterotic effect for different performance traits in various genetic groups produced under this programme. Survivability sharply and significantly declined from 1/2 to $3/4^th$ bred and further from $3/4^th$ to inter-se bred. This may be due to periodic and management differences in addition to the higher level of exotic inheritance and decreased heterotic effect over the filial generations. Jersey and Holstein Friesian crosses among 1/2 breds and their 50% inheritance among $3/4^th$ and inter-se breds had highest improvement and heterosis in reproduction and production traits respectively. Among inter se bred genetic groups, BFH (I) had no recombination loss in SP and CI, while FJH (I), JFH (I) and FBH (I) had on recombination loss in AFC, LY, LL and PE. The crossbreeding of zebu cows with exotic breeds brings about spectacular improvement in comparison to the performance of zebu breed, while conventional selection over several generation would lead to only modest improvement. In addition to additive effect, there was sufficient heterosis in Jersey crosses for reproduction and Holstein Friesian crosses for production performance. Three breed crosses with exotic inheritance between 50 and 75 percent incorporating genes (25 to 50%) from both of these breeds is the best combination for stabilization.