The impact of data structure on genetic (co)variance components of early growth in sheep, estimated using an animal model with maternal effects

Maniatis, Nikolas; Ge, Pollott

doi:10.2527/2003.811101x

Cited by 117 publications

(92 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In this study, however, the numbers of dams and grand dams with records were few (Table 1). It has been noted that such kind of data structure makes the estimation of maternal effects and the correlation between maternal and direct additive effects delicate (Meyer, 1992;Hermesch et al, 2000b;Maniatis & Pollot, 2003;Solanes et al, 2004).…”

Section: Resultsmentioning

confidence: 99%

“…Table 2 shows the various random effects fitted for each trait in the univariate analyses. The data structure (number of offspring per dam) and the number of dams and grand dams with records are important determinants in estimating maternal effects (Meyer et al, 1992;Hermesch et al, 2000a;Maniatis & Pollot, 2003;Solanes et al, 2004). Due to limitations in the pedigree and performance data structure (Table 1), maternal environment effects and covariance between maternal and direct genetic effects were not considered in the models to estimate variance components.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Genetic parameter estimates for growth traits of Large White pigs in Kenya

Ilatsia¹,

Githinji²,

Muasya³

et al. 2008

SA J. An. Sci.

View full text Add to dashboard Cite

________________________________________________________________________________ AbstractVariance components and genetic parameter were estimated for piglet growth traits of Large White (LW) pigs managed under intensive production systems in Kenya. Data were on piglet performance of LW pigs born between 1982 to 1996. Growth performance traits of the piglets that were considered, were body weight (BW, in kg) at birth (BW0), three weeks (BW3), eight weeks at weaning (BW8), 12 weeks ( BW12), 24 weeks (BW24) and 36 weeks (BW36); and average daily gain (g/day) from birth to eight weeks (DG 0-8 ) and from weaning to 24 weeks ). Variance components and genetic parameters were estimated using univariate and multivariate animal models. Direct heritability estimates from univariate analyses were 0.38, 0.24, 0.47, 0.39, 0.36 and 0.26 for BW0, BW3, BW8, BW12, BW24 and BW36, respectively. Maternal heritabilities were 0.42, 0.25 0.15 and 0.18 for BW0, BW3, BW8 and DG 0-8 , respectively. Genetic correlations among growth traits were positive and ranged from 0.45 to 0.98 while phenotypic correlations ranged from 0.54 to 0.95. Early piglet growth was highly heritable and under the influence of maternal effects. Selection programmes for genetic improvement of early growth performance should be based on models that account for direct and maternal genetic and litter effects. ________________________________________________________________________________

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Genetic parameter estimates for growth traits of Large White pigs in Kenya

Ilatsia¹,

Githinji²,

Muasya³

et al. 2008

SA J. An. Sci.

View full text Add to dashboard Cite

show abstract

“…Similar estimates have been reported by Eler et al (1995 and for WW (−0.13) and for BW and WW (−0.33 to −0.14) of Nelore cattle, respectively, and by De Mattos et al (2000) for WW of Hereford cattle in the United States, Canada and Uruguay (−0.51 to −0.31). According to Maniatis and Pollott (2003), the negative estimates obtained for the correlation between direct and maternal genetic effects in the present study might be because of the small number of dams with weight records (18% and 19% for BW and WW, respectively). In this respect, some authors suggest to define the covariance between direct and maternal genetic effects as zero (Meyer, 1995).…”

Section: Resultsmentioning

confidence: 54%

Genotype by production environment interaction for birth and weaning weights in a population of composite beef cattle

Júnior

Eler

Bignardi

et al. 2014

Animal

View full text Add to dashboard Cite

The objectives of the present study were: (1) to evaluate the importance of genotype × production environment interaction for the genetic evaluation of birth weight (BW) and weaning weight (WW) in a population of composite beef cattle in Brazil, and (2) to investigate the importance of sire × contemporary group interaction (S × CG) to model G × E and improve the accuracy of prediction in routine genetic evaluations of this population. Analyses were performed with one, two (favorable and unfavorable) or three (favorable, intermediate, unfavorable) different definitions of production environments. Thus, BW and WW records of animals in a favorable environment were assigned to either trait 1, in an intermediate environment to trait 2 or in an unfavorable environment to trait 3. The (co)variance components were estimated using Gibbs sampling in single-, bi-or three-trait animal models according to the definition of number of production environments. In general, the estimates of genetic parameters for BW and WW were similar between environments. The additive genetic correlations between production environments were close to unity for BW; however, when examining the highest posterior density intervals, the correlation between favorable and unfavorable environments reached a value of only 0.70, a fact that may lead to changes in the ranking of sires across environments. The posterior mean genetic correlation between direct effects was 0.63 in favorable and unfavorable environments for WW. When S × CG was included in two-or three-trait analyses, all direct genetic correlations were close to unity, suggesting that there was no evidence of a genotype × production environment interaction. Furthermore, the model including S × CG contributed to prevent overestimation of the accuracy of breeding values of sires, provided a lower error of prediction for both direct and maternal breeding values, lower squared bias, residual variance and deviance information criterion than the model omitting S × CG. Thus, the model that included S × CG can therefore be considered the best model on the basis of these criteria. The genotype × production environment interaction should not be neglected in the genetic evaluation of BW and WW in the present population of beef cattle. The inclusion of S × CG in the model is a feasible and plausible alternative to model the effects of G × E in the genetic evaluations.

show abstract

“…Mercadante & Lôbo (1997), trabalhando com dados de bezerras Nelore, bem como Mello et al (2002), trabalhando com dados de bezerros machos e fêmeas da raça Canchim, obtiveram valores próximos a zero para esta correlação. Essas diferenças podem ser atribuídas, em parte, às diferenças na estrutura dos dados, no número de mães e de avós com seus próprios dados de desempenho, sendo que, quanto maior for o número de mães e avós com seus próprios dados e o número de filhos por mãe, melhores serão as estimativas (Maniatis & Pollott, 2003).…”

Section: Resultsunclassified

Modelagem de efeitos genéticos e ambientais que influenciam o peso à desmama de bezerros mestiços Charolês-Zebu

Toral

Júnior²,

Lopes

et al. 2011

R. Bras. Zootec.

View full text Add to dashboard Cite

RESUMO -Este trabalho foi realizado com o objetivo de avaliar alternativas para modelagem de efeitos genéticos e ambientais que influenciam o peso à desmama de bezerros mestiços Charolês-Zebu. Foram utilizados os dados de peso à desmama de 56.965 bezerros, com percentuais de alelos de origem da raça Charolesa variando entre 23% e 66%. Os modelos considerados diferiram quanto à inclusão de efeitos genéticos aditivos e não-aditivos médios, individuais e maternos, bem como quanto à maneira de modelar estes efeitos (regressão múltipla ou variável classificatória). Também foi avaliada a inclusão da interação entre o grupo genético do bezerro e seu grupo de contemporâneos, como um efeito aleatório não correlacionado. De acordo com os critérios de ajuste utilizados, a interação entre o grupo genético e o grupo de contemporâneos representa parte significativa da variação observada para o peso à desmama de bezerros Charolês-Zebu e os efeitos dos percentuais de alelos de origem da raça Charolesa e de heterozigoses, individuais e maternos, podem ser modelados por meio da utilização de regressão múltipla.Palavras-chave: avaliação genética multirracial, bovinos de corte, cruzamento, heterozigose, modelo estatístico Modeling of genetic and environmental effects affecting the weaning weight of Charolais-Zebu crossbred calvesABSTRACT -This study was carried out to evaluate some alternatives for modeling of genetic and environmental effects influencing the weaning weight of Charolais-Zebu crossbred calves. The weaning weight data of 56,965 calves with alleles'percentage from the Charolais breed varying from 23% to 66% were used. The models under comparison differed for the inclusion of the individual and maternal additive and non-additive genetic effects, as well as the way to model those effects (multiple regression or discrete variable). The inclusion of the interaction between the calf genetic group and its contemporary group was also evaluated as a random uncorrelated effect. The adjustment criteria pointed out the interaction between the calf genetic group and its contemporary group to represent a significant part of the variation observed for the weaning weight of the Charolais-Zebu crossbred calves, and the effects of alleles' percentage from the Charolais breed and the heterozygosity, individual and maternal, can be modeled by using the multiple regression.

show abstract

The impact of data structure on genetic (co)variance components of early growth in sheep, estimated using an animal model with maternal effects

Cited by 117 publications

References 20 publications

Genetic parameter estimates for growth traits of Large White pigs in Kenya

Genetic parameter estimates for growth traits of Large White pigs in Kenya

Genotype by production environment interaction for birth and weaning weights in a population of composite beef cattle

Modelagem de efeitos genéticos e ambientais que influenciam o peso à desmama de bezerros mestiços Charolês-Zebu

Contact Info

Product

Resources

About