Simulation analysis to test the influence of model adequacy and data structure on the estimation of genetic parameters for traits with direct and maternal effects

Genetics Selection Evolution

Éric Hanocq¹  Jacques Bouix¹  Eduardo Manfredi¹  Jean-Michel Elsen¹  Étienne Verrier²  Bernard Bibé¹  Virginie Clément¹ 

[1] Station d'amélioration génétique des animaux, Institut national de la recherche agronomique, BP 27, 31326 Castanet-Tolosan Cedex, France;Département des sciences animales, Institut national agronomique Paris-Grignon, 16 rue Claude Bernard, 75231 Paris Cedex 05, France

关键词: connectedness;    simulations;    maternal effects;    animal model;    genetic parameters;   

Others  :  1094672
DOI  :  10.1186/1297-9686-33-4-369

 received in 2000-05-03, accepted in 2001-05-05,  发布年份 2001

【 摘 要 】

Simulations were used to study the influence of model adequacy and data structure on the estimation of genetic parameters for traits governed by direct and maternal effects. To test model adequacy, several data sets were simulated according to different underlying genetic assumptions and analysed by comparing the correct and incorrect models. Results showed that omission of one of the random effects leads to an incorrect decomposition of the other components. If maternal genetic effects exist but are neglected, direct heritability is overestimated, and sometimes more than double. The bias depends on the value of the genetic correlation between direct and maternal effects. To study the influence of data structure on the estimation of genetic parameters, several populations were simulated, with different degrees of known paternity and different levels of genetic connectedness between flocks. Results showed that the lack of connectedness affects estimates when flocks have different genetic means because no distinction can be made between genetic and environmental differences between flocks. In this case, direct and maternal heritabilities are under-estimated, whereas maternal environmental effects are overestimated. The insufficiency of pedigree leads to biased estimates of genetic parameters.

【 授权许可】

   
2001 INRA, EDP Sciences