Genomic evaluation by including dominance effects and inbreeding depression for purebred and crossbred performance with an application in pigs - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Genetics Selection Evolution Année : 2016

Genomic evaluation by including dominance effects and inbreeding depression for purebred and crossbred performance with an application in pigs

Tao Xiang
  • Fonction : Auteur correspondant
Ole Fredslund Christensen
  • Fonction : Auteur
Zulma Gladis Vitezica
Andres Legarra

Résumé

AbstractBackgroundImproved performance of crossbred animals is partly due to heterosis. One of the major genetic bases of heterosis is dominance, but it is seldom used in pedigree-based genetic evaluation of livestock. Recently, a trivariate genomic best linear unbiased prediction (GBLUP) model including dominance was developed, which can distinguish purebreds from crossbred animals explicitly. The objectives of this study were: (1) methodological, to show that inclusion of marker-based inbreeding accounts for directional dominance and inbreeding depression in purebred and crossbred animals, to revisit variance components of additive and dominance genetic effects using this model, and to develop marker-based estimators of genetic correlations between purebred and crossbred animals and of correlations of allele substitution effects between breeds; (2) to evaluate the impact of accounting for dominance effects and inbreeding depression on predictive ability for total number of piglets born (TNB) in a pig dataset composed of two purebred populations and their crossbreds. We also developed an equivalent model that makes the estimation of variance components tractable.ResultsFor TNB in Danish Landrace and Yorkshire populations and their reciprocal crosses, the estimated proportions of dominance genetic variance to additive genetic variance ranged from 5 to 11%. Genetic correlations between breeding values for purebred and crossbred performances for TNB ranged from 0.79 to 0.95 for Landrace and from 0.43 to 0.54 for Yorkshire across models. The estimated correlation of allele substitution effects between Landrace and Yorkshire was low for purebred performances, but high for crossbred performances. Predictive ability for crossbred animals was similar with or without dominance. The inbreeding depression effect increased predictive ability and the estimated inbreeding depression parameter was more negative for Landrace than for Yorkshire animals and was in between for crossbred animals.ConclusionsMethodological developments led to closed-form estimators of inbreeding depression, variance components and correlations that can be easily interpreted in a quantitative genetics context. Our results confirm that genetic correlations of breeding values between purebred and crossbred performances within breed are positive and moderate. Inclusion of dominance in the GBLUP model does not improve predictive ability for crossbred animals, whereas inclusion of inbreeding depression does.
Fichier principal
Vignette du fichier
12711_2016_Article_271.pdf (1.27 Mo) Télécharger le fichier
Origine : Publication financée par une institution

Dates et versions

hal-01479227 , version 1 (28-02-2017)

Licence

Paternité

Identifiants

Citer

Tao Xiang, Ole Fredslund Christensen, Zulma Gladis Vitezica, Andres Legarra. Genomic evaluation by including dominance effects and inbreeding depression for purebred and crossbred performance with an application in pigs. Genetics Selection Evolution, 2016, 48 (1), pp.92. ⟨10.1186/s12711-016-0271-4⟩. ⟨hal-01479227⟩
27 Consultations
71 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More