• Asian-Australasian Journal of Animal Sciences
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• 제28권4호
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• pp.476-484
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• 2015

The objective of this study was to estimate genetic and phenotypic parameters for linear type traits, as well as milk yield (MY), fat yield (FY) and protein yield (PY) in 18,831 Holstein cows reared in 495 herds in Brazil. Restricted maximum likelihood with a bivariate model was used for estimation genetic parameters, including fixed effects of herd-year of classification, period of classification, classifier and stage of lactation for linear type traits and herd-year of calving, season of calving and lactation order effects for production traits. The age of cow at calving was fitted as a covariate (with linear and quadratic terms), common to both models. Heritability estimates varied from 0.09 to 0.38 for linear type traits and from 0.17 to 0.24 for production traits, indicating sufficient genetic variability to achieve genetic gain through selection. In general, estimates of genetic correlations between type and production traits were low, except for udder texture and angularity that showed positive genetic correlations (>0.29) with MY, FY, and PY. Udder depth had the highest negative genetic correlation (-0.30) with production traits. Selection for final score, commonly used by farmers as a practical selection tool to improve type traits, does not lead to significant improvements in production traits, thus the use of selection indices that consider both sets of traits (production and type) seems to be the most adequate to carry out genetic selection of animals in the Brazilian herd.

• Journal of Animal Science and Technology
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• 제55권6호
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• pp.501-508
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• 2013

This study was conducted to determine genetic correlations among carcass traits measured by ultrasound and real carcass measurements and to estimate indirect selection responses for real carcass traits based on ultrasound measurements in Hanwoo cows. To accomplish this, 22,080 ultrasound measurement records from 17,926 cows collected from 2001 to 2012 and 11,907 carcass records obtained from fattened cattle from 2008 to 2012 were used. Genetic parameters were estimated based on eye muscle area (EMA), backfat thickness (BF) and marbling score (MS) measured by ultrasound-scanning of live cows and using the official technique on chilled bovine half-carcasses after slaughtering. Heritability and genetic correlation for carcass traits were estimated using a mixed model equation that consisted of environmental effects as fixed parameters and additive genetic effects and residual effects as random parameters, assuming that traits were different between ultrasound and carcass measurements. This statistical method was applied to the average information restricted maximum likelihood method. The heritability of EMA, BF and MS measured by ultrasound were 0.33, 0.61 and 0.46, respectively, while the heritability estimates of the corresponding traits based on carcass measurements were 0.29, 0.40 and 0.38, respectively and the genetic correlation between ultrasound and carcass traits for EMA, BF and MS were 0.41, 0.78 and 0.67, respectively. The genetic correlation between ultrasound and carcass traits was highly positive. Additionally, the selection response for marbling score was estimated to be 0.42 per generation if the cows were selected based on the ultrasound scan marbling score with an assumed selection intensity of 0.8. Overall, these results indicate that the ultrasound scan technique would be applicable to judging cow selection for genetically improved meat quality.

• 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.

• 한국수산과학회지
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• 제54권6호
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• pp.974-981
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• 2021

The aim of this study was to evaluate genetic parameters of growth traits for improving selective breeding in olive flounder Paralichthys olivaceus produced in April 2019. The total length and body weight at 11-, 18-, and 22-months-old were measured for 7,479, 2,831 and 1,904 individuals, respectively. Since 2004, we have been conducting a selective breeding program to improve growth traits in the olive flounder. Data were analyzed using the restricted maximum likelihood method using the multiple traits animal model. The effect of sex and production period showed significant differences in all traits (P<0.05). The heritability of all traits was 0.428-0.520, which is relatively high by measurement month. Therefore, it is considered that individual selection will be more advantageous than family selection. However, to maintain an appropriate degree of inbreeding and genetic diversity for future generations, it is necessary to consider family selection adequately. Results of the correlation analysis between the same traits according to the measurement period indicated that considering production costs such as feed cost, selection at 18-months-old will be advantageous. Olive flounder is a major aquaculture species in Korea, and continuous selective breeding research is essential to improve productivity.

• 한국수정란이식학회지
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• 제31권3호
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• pp.243-247
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• 2016

Growth traits, such as body weight, directly influence productivity and economic efficiency in the swine industry. In this study, we estimate heritability for body weight traits usinginformation from pedigree and genome-wide single nucleotide polymorphism (SNP) chip data. Four body weight phenotypes were measured in 1,105 $F_2$ progeny from an intercross between Landrace and Jeju native black pigs. All experimental animals were subjected to genotypic analysis using PorcineSNP60K BeadChip platform, and 39,992 autosomal SNP markers filtered by quality control criteria were used to construct genomic relationship matrix for heritability estimation. Restricted maximum likelihood estimates of heritability were obtained using both genomic- and pedigree- relationship matrix in a linear mixed model. The heritability estimates using SNP information were smaller (0.36-0.55) than those which were estimated using pedigree information (0.62-0.97). To investigate effect of common environment, such as maternal effect, on heritability estimation, we included maternal effect as an additional random effect term in the linear mixed model analysis. We detected substantial proportions of phenotypic variance components were explained by maternal effect. And the heritability estimates using both pedigree and SNP information were decreased. Therefore, heritability estimates must be interpreted cautiously when there are obvious common environmental variance components.

• Asian-Australasian Journal of Animal Sciences
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• 제21권10호
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• pp.1395-1403
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• 2008

The objective of the present study was to estimate genetic parameters for economic traits in Markhoz goats. Data collected from 1993 to 2006 by the Markhoz goat Performance Testing Station in Sanandaj, Iran, were analyzed. The traits recorded as body weight performance at birth (BW), weaning (WW), six month (6MW), nine month (9MW), yearling (YW) and yearling fleece weight (YFW) were investigated. Least square analyses were used for estimation of environmental effects. Genetic parameters were estimated with single and multi trait analysis using restricted maximum likelihood (REML) procedures, under animal models. By ignoring or including maternal additive genetic effects and maternal permanent environmental effects, five different models were fitted for each trait. The effects of sex, type of birth, age of dam and year of birth on the all body weights were significant (p<0.01), but had no effects on YFW except year of birth. Age of kids had significant influences on WW and 6MW (p<0.01). A log likelihood ratio test was carried out for choosing the most suitable model for each trait. Total heritability estimates for YFW and growth traits varied from 0.16 for YFW and WW to 0.41 for YW. For all traits, maternal heritability was lower than direct heritability, ranging from 0.06 for BW to 0.01 for 6MW and 9MW. The magnitude of $c^2$ was more substantial for BW than the others, and relative importance was reduced from 0.12 for BW to 0.04 for 9MW. The direct additive genetic correlations estimates were positive and varied from 0.21 between BW-YW to 0.96 between WW-6MW. Direct additive genetic correlations between YFW and body weight traits were positive and ranged from 0.14 between BW-YFW to 0.67 between 6MW-YFW. For all traits, the corresponding estimates for phenotypic correlation were positive and lower than genetic correlations. The maternal additive genetic correlations between various traits were varied and ranged from -0.19 between 9MW-YFW to 0.96 between 6MW-9MW. The estimates of the maternal permanent environmental correlations between various traits were positive and ranged from 0.33 between WW-YFW to 0.93 between WW-6MW. Also, the environmental correlations between various traits ranged from 0.01 between BW-YFW and WW-YFW to 0.70 between 9MW-YW. Estimates of genetic parameters for various traits in this study confirm that selection should be applied on WW for genetic improvement in Markhoz goats.

• 한국패류학회지
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• 제23권2호
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• pp.217-225
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• 2007

본 연구는 국립수산과학원에서 2004년도부터 시작된 전복 육종 프로그램 개발의 일환으로서, 전복 집단에서 개체에 대한 유전적 평가를 바탕으로 우량전복을 효과적으로 선발하기 위해 전복 성장 형질에 대한 초기 성장시기에 있어 각 종별 유전모수를 추정하였다. 실험에 사용한 한국산 북방전복과 둥근전복은 동해안, 남해안, 서해안 및 제주연안의 전국 11 개소로부터 자연산과 양식산으로 구분하여 수집한 후, DNA 분석에 의한 원거리 유연관계를 기초로 F1 세대의 반형매군을 생산하고 채묘후 5개월간 사육을 실시하였다. 이중 임의로 추출한 북방전복 76가계 (3,795 마리), 둥근전복 8가계 (399 마리) 에 대해 각장 (mm), 각폭 (mm) 및 중량 (g) 에 대해 측정을 실시하고, 유전모수는 성장관련형질인 각장, 각폭, 중량, 체형 및 비만도에 대해 추정하였다. 개체에 대한 성장형질에 영향을 미치는 효과분석을 위해 animal model에 의한 선형 혼합모형을 이용하여 SAS 통계 프로그램으로 통계분석을 실시하였다. 또한 EL-REML (restricted maximum likelihood) method를 전산 프로그램화한 REMLF90 (Misztal, 1990) 을 이용하여 다형질 혼합모형으로 유전모수를 추정하였다. 분석모형은 sire와 dam의 수집해역효과, 자연산 혹은 양식산 sire와 dam의 교배 효과, 생산시기 및 사육밀도를 고정효과로 하였다. 분석결과 초기성장시기인 채묘후 5개월령에서의 성장관련 형질은 북방전복에서 평균 $\pm$ 표준편차가 각각 각장 15.11 $\pm$ 4.04 mm, 각폭 10.64 $\pm$ 2.70 mm 및 중량 0.44 $\pm$ 0.33 g이었으며, 둥근전복에서는 각각 각장 14.56 $\pm$ 4.01 mm, 각폭 10.19 $\pm$ 2.67 mm 및 중량 0.40 $\pm$ 0.30 g 이었다. 채묘후 5개월령에서의 북방전복의 유전력은 각장, 각폭, 중량, 체형 및 비만도에서 각각 0.76, 0.78, 0.73, 0.20, 0.17로 추정되었다. 둥근전복의 각장, 각폭, 중량, 체형 및 비만도에 대한 유전력은 각각 0.89, 0.87, 0.89, 0.45, 0.01로 추정되었다. 이러한 결과로 보아, 북방전복과 둥근전복 모두 각장, 각폭 중량에서 고도의 유전력이 추정되어 개체선발만으로도 높은 육종효과가 기대되는 것으로 판단된다. 한편 북방전복과 둥근전복의 성장관련형질에 대한 유전상관은 각장과 각폭, 각장과 중량 및 각폭과 중량 간에 각각 0.99, 0.96, 0.96, 0.99, 0.99, 0.98로 추정되어 두 종 모두에서 형질들 간의 높은 유전상관을 나타내었다.

• 한국패류학회지
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• 제24권2호
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• pp.121-130
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• 2008

양식 대상 종들에 있어 성장형질에 대한 개량은 선발 육종을 통하여 이루어져 왔다. 북방전복과 둥근전복은 아시아에서는 매우 중요한 전복종이 지만 그동안 이들에 대한 선발 육종연구는 활발하지 못하였으나, 최근 들어 이들 전복에 대한 선발 육종연구가 신중히 수행되고 있다. 본 연구는 12개월 령의 북방전복과 둥근전복에 대한 다형질 개체모형을 이용하여 유전력, 유전상관 및 표형형상관 등 유전모수 추정을 목적으로 수행되었다. 실험에 사용한 한국산 북방전복과 둥근전복은 동해안, 남해안, 서해안 및 제주연안의 전국 11개소로부터 자연산과 양식산으로 구분하여 수집한 후, DNA 분석에 의한 원거리 유연관계를 기초로 F1세대의 전형매 혹은 반형매군을 각각 생산하고 1년간 사육을 실시하였다. 이중 임의로 추출한 북방전복 26가계(1,509 마리), 둥근전복 6가계(297 마리)에 대해 각장(mm), 각폭(mm) 및 중량(g)에 대해 개체별 측정하고, 유전모수 추정은 성장관련형질인 각장, 각폭, 중량, 체형 및 비만도에 대해 각각 실시하였다. 개체의 성장형질에 영향을 미치는 환경효과분석을 위해 animal model에 의한 선형모형을 이용하여 SAS 통계 프로그램 package(ver. 9.1)로 통계분석을 실시하였다. 또한 유전모수 추정을 위해서는 EL-REML(restricted maximum likelihood) method를 전산 프로그램화한 REMLF90(Misztal, 2001)을 이용하여 다형질 혼합모형으로 유전모수 추정을 실시하였다. 분석모형에서 교배 sire와 dam의 자연산 혹은 양식산에 의한 교배타입을 고정효과로 하였다. 분석결과 12개월 령에서의 성장관련 형질은 북방전복에서 평균$\pm$표준편차가 각장 $29.86{\pm}5.89$ mm, 각폭 $20.70{\pm}4.09$ mm 및 중량 $3.47{\pm}2.05$ g, 둥근전복은 각장 $31.80{\pm}6.15$ mm, 각폭 $21.97{\pm}4.13$ mm 및 중량 $4.23{\pm}2.42$ g으로 각각 성장하였다. 12개월 령 북방전복의 유전율은 각장, 각폭, 중량, 체형 및 비만도에서 각각 0.43, 0.43, 0.40, 0.19, 0.09로 추정되었다. 12개월 령 둥근전복의 각장, 각폭, 중량, 체형 및 비만도에 대한 유전율은 각각 0.33, 0.26, 0.51, 0.23, 0.10으로 추정되었다. 이러한 결과로 보아, 북방전복과 둥근전복 모두 각장, 각폭 및 중량에서 중고도의 유전율이 추정되어 높은 육종효과가 기대된다. 한편 북방전복과 둥근전복의 성장관련형질에 대한 유전상관은 각장과 각폭, 각장과 중량 및 각폭과 중량 간에 각각 0.92-0.97, 0.96-0.99로 추정되어 두 종 모두에서 형질들 간의 높은 유전상관을 나타내었으며, 이들 성장관련 형질 중 어느 것을 기준으로 선발을 실시하여도 다른 관련형질에 대한 높은 개량효과가 추정되어졌다.

• Journal of Animal Science and Technology
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• 제48권1호
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• pp.39-48
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• 2006

본 연구는 1999년 1월부터 2004년 12월까지의 체세포점수의 검정일 자료를 이용하여 124,635개의 초산자료와 134,308개의 2산자료, 37,412개의 3산자료, 41787개의 4산자료, 37412개의 5산 자료를 이용하였다. 분석에 사용된 방법은 체세포 점수에 영향을 미치는 분만연도, 연령, 비유단계, 산차, 계절의 효과를 추정하기 위하여 GLM을 이용하여 최소자승법으로 분석하였으며, 검정일 모형을 이용한 분산성분 추정은 EM-REML 분석방법을 전산 프로그램한 REMLF90을 이용하였다. 각 산차별로 연령에 대한 효과는 연령이 낮은 군에서 체세포 점수가 낮게 나타났으며, 연령이 높은 군에서는 다소 높게 나타났다. 비유단계별 효과는 1산과 2산에서는 비유초기에서 체세포 점수가 낮게 나타났으며 비유말기에 3.151, 3.696로 높은 체세포 점수를 나타났으나, 3산, 4산, 5산에서는 비유중기에 높은 체세포 점수를 나타내었으며, 대체로 피크기에 체세포 점수가 높게 나타나는데 4산과 5산에서는 비유말기에 체세포 점수가 낮게 나타났다. 분만계절별 환경효과는 1산～5산 모두 대체로 9～11월에 체세포 점수가 낮게 나타났으며, 대체로 유량이 낮게 추정되는 6～8월 사이에는 체세포 점수가 대체로 높게 나타났다. 각 산차별 유전력은 1산에서 5산까지 각각 0.05, 0.09, 0.10, 0.05, 0.05를 나타냈으며, 유전분산값은 비유초기의 경우 2, 3, 5산에서 높게 나타났으며, 1산과 4산의 경우는 대체로 낮게 추정되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제21권8호
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• pp.1109-1115
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• 2008

The reproduction component traits are important components of sow efficiency. The objective of this study was to evaluate the phenotypic and genetic parameters of four reproduction component traits (age at puberty (AP), preweaning number dead (PND), weaning to service interval (WSI), and intra-individual SD in litter size (IISDLS)) of sows in two Chinese indigenous pig breeds. Available reproductive records including 22,591 piglets born from 2,054 litters by 574 Jiangquhai sows and 464 Meishan sows were used in this investigation. A set of mixed models and restricted maximum likelihood methodology were used for the multiple trait analyses of these traits. The results showed that the estimates of heritabilities (${\pm}$standard error) for AP, PND, WSI and IISDLS were $0.40{\pm}0.05$, $0.06{\pm}0.03$, $0.20{\pm}0.02$ and 0.09{\pm}0.03 in Jiangquhai sows, and $0.35{\pm}0.06$, $0.05{\pm}0.03$, $0.18{\pm}0.03$ and $0.10{\pm}0.04$ in Meishan sows, respectively. There was moderate genetic correlation between AP and WSI, while there were low genetic correlations between the other pairwise traits. The genetic correlations were positive for most of the pairwise traits, except for the one between AP and IISDLS. The results indicated that all traits except for AP were difficult to make genetic improvement by traditional selection methods due to low heritabilities and the favorable improvement of AP might result in unfavorable changes of IISDLS due to the trend of genetic antagonism.