Vrarance and covarance components were estimated by a restricted maximum likelihood (REML)approach for the 6 traits, and heritability estimates of which were 0.24, 0.215, 0.29,0.48 and 0.36 resp.

用约束最大似然估计法(REML:Restricted maximum likelihood)估计方差组分,得到以上6性状的遗传力分别为0.24,0.215,0.29,0.48和0.36。

Genetic analysis was carried out on reproduction traits in large white sows both in Zhenghong and Yinong swine breeding farm in Hunan Province. Multiple traits derivative free Restricted maximum likelihood(MTDFREML) were used to estimate 7 736 records from the year of 1998 to 2004,including total number born(TNB),number born alive(NBA),litter weight born(LWB) and litter weight of 21 days(LW21).

运用多性状非求导约束最大似然法(multiple traits derivative free restricted maximum likelihood,MTDFREML),对湖南正虹种猪场和益阳市农科所种猪场(益农种猪场)大白母猪1998-2004年的共7 736胎次的繁殖性状育种记录进行遗传参数估计.

The study analyzed the non-genetic factors influencing the main traits of Aohan Merino Sheep, selected different models and estimated variance components and genetic parameters of twelve traits using animal model Best Linear Unbiased Prediction(BLUP) and Multiple Trait Derivative-Free Restricted Maximum Likelihood(MTDFREML).

Eight simulated data sets are generated by Monte Carlo simulation to compare the relative accuracy of methods for estimating variance components. These methods selected are Analysis of variance ( ANOVA ) which does not take the fixed herd-year-season effects into account, Henderson method 1 , Henderson method 3, Maximum Likelihood ( ML ) , Modified Maximum Likelihood(MOML ) and Restricted Maximum Likelihood ( REML ) .

A random regression model with Legendre polynomials of age as independent variables was used to estimate the covariance functions by restricted maximum likelihood employing the average information algorithm (AIREML).

Based on the sequence data of 1660 and 2326 molecular markers, blastn software were used to search identical sequences on internet chicken genomic DNA database and some useful bionformations were derived.

The simulation results indicate that the estimates of REML are most accurate and the estimates of ANOVA are most biased, compared with those of the other methods.

WOMBAT-A tool for mixed model analyses in quantitative genetics by restricted maximum likelihood (REML)

WOMBAT is a software package for quantitative genetic analyses of continuous traits, fitting a linear, mixed model; estimates of covariance components and the resulting genetic parameters are obtained by restricted maximum likelihood.

In comparing the mean proportions for different levels of a factor, such as time of day, the method uses restricted maximum likelihood (REML), an algorithm which can account for the sampling variance as well as for missing data.

Restricted maximum likelihood estimation of heterogeneous variances and covariances via the expectation-maximization algorithm is presented.

Estimates were obtained by restricted maximum likelihood (REML) computed under a derivative free algorithm (DFREML).

Eight simulated data sets are generated by Monte Carlo simulation to compare the relative accuracy of methods for estimating variance components. These methods selected are Analysis of variance ( ANOVA ) which does not take the fixed herd-year-season effects into account, Henderson method 1 , Henderson method 3, Maximum Likelihood ( ML ) , Modified Maximum Likelihood(MOML ) and Restricted Maximum Likelihood ( REML ) . The simulation results indicate that the estimates of REML are most accurate and the estimates...

Eight simulated data sets are generated by Monte Carlo simulation to compare the relative accuracy of methods for estimating variance components. These methods selected are Analysis of variance ( ANOVA ) which does not take the fixed herd-year-season effects into account, Henderson method 1 , Henderson method 3, Maximum Likelihood ( ML ) , Modified Maximum Likelihood(MOML ) and Restricted Maximum Likelihood ( REML ) . The simulation results indicate that the estimates of REML are most accurate and the estimates of ANOVA are most biased, compared with those of the other methods.

Single and multiple trait BLUP estimates were obterned from 13 Qinchuan bulls for birth weight, weaning weight, daily weight gain, height at withers, body length and heart girth using the best linear unbiased prediction method ( BLUP). Vrarance and covarance components were estimated by a restricted maximum likelihood (REML)approach for the 6 traits, and heritability estimates of which were 0.24, 0.215, 0.29,0.48 and 0.36 resp. The genectic trends of the 6 traits during the 10 years were calculated from the...

Single and multiple trait BLUP estimates were obterned from 13 Qinchuan bulls for birth weight, weaning weight, daily weight gain, height at withers, body length and heart girth using the best linear unbiased prediction method ( BLUP). Vrarance and covarance components were estimated by a restricted maximum likelihood (REML)approach for the 6 traits, and heritability estimates of which were 0.24, 0.215, 0.29,0.48 and 0.36 resp. The genectic trends of the 6 traits during the 10 years were calculated from the regression of the weighted average transmitting ability (WATA) on time series, which averaged 0.1859, 0.04364, 1.74 (kg/yr) and 0.2304, 0.231 and 0.1716 (cm/yr) resp. The problems of rationality for bull utilization were discussed. The study showed that the BLUP method was suitable and effective in selecting Qinchuan bulls.

以最佳线性无偏预测法(BIUP:Best Linear unbiased prediction)估测了13头秦川种公牛的初生重、断奶重、日增重、体高、胸围、体斜长6性状的育种值和复合育种值。用约束最大似然估计法(REML:Restricted maximum likelihood)估计方差组分,得到以上6性状的遗传力分别为0.24,0.215,0.29,0.48和0.36。由公牛加权平均传递力(WATA,weight average transmitting ability)对时间序列的回归估计群体的年平均遗传进展分别为0.1859,0.0436,1.74(kg/yr)和0.2304,0.231,0.1761(cm/yr)。分析了以往种公牛利用的合理性问题。研究表明用BIUP法选择秦川公牛是适用和有效的。

Components of variance for sire, litter nested within sire andresidual effects were estimated by restricted maximum likelihood(REML)for multifoetal animal. The age in days at 105kg of body weight(D105)and average backfat thickness (ABF) of swine was taken for example.Both D105 and ABF were adjusted to a 105kg basis. A mixed modelincluding the fixed effects of birth-year-month(BYM), sex of the pig andparity of the dam(gilt vs. sow) was used for estimating components ofvariance. Random effects in the model were...

Components of variance for sire, litter nested within sire andresidual effects were estimated by restricted maximum likelihood(REML)for multifoetal animal. The age in days at 105kg of body weight(D105)and average backfat thickness (ABF) of swine was taken for example.Both D105 and ABF were adjusted to a 105kg basis. A mixed modelincluding the fixed effects of birth-year-month(BYM), sex of the pig andparity of the dam(gilt vs. sow) was used for estimating components ofvariance. Random effects in the model were sire, litter nested withinBYM and sire, and residual error. REML was used to estimate thecomponents of variance for sire , litter nested within BYM and sire, and residual error, with the assumption that each random effect within these sources of variance was distributed independently andidentically, i. e, var(s)=Iσ_s~2 var(I)=Iσ_i~2, var(e)=Iσ_e~2, with no co-variances among the radom effects, i.e. cov=0, coy=0,coy =O.Heritability(h~2) and common envirnmental effect of litter-mates (c~2) were estimated as h~2=respectively.

本文研究对于多胎动物利用约束最大似然法(REML)估计父畜、父内窝间和剩余误差的方差组分。以猪达到105公斤体重的日龄(D105)和背膘厚度(ABF)为例,把D105和ABF的记录都调整到以105公斤为基础。采用的混合模型包括出生一年一月(BYM)、猪的性别和母猪产次的固定效应,随机效应是父畜、BYM和父畜内的窝及剩余误差。利用REML来估计父畜的方差组分(0 0,BYM和父畜内的窝方差组分和剩余误差。假定这些方差来源内的每个随机效应相互独立和同一分布,即Var=Iσ_s~2,VasIσ_1~2Var(e)=Iσ_e~2;随机效应间不存在协方差,即COV=0,Cov=0,COV=0。遗传力(h~2)和同窝小猪的共同环境效应(C~2)的估值分别按=和=计算。 C