Your browser doesn't support javascript.
loading
Modeling genetic differences of combined broiler chicken populations in single-step GBLUP.
Bermann, Matias; Lourenco, Daniela; Breen, Vivian; Hawken, Rachel; Brito Lopes, Fernando; Misztal, Ignacy.
Afiliação
  • Bermann M; Department of Animal and Dairy Science, University of Georgia, Athens, GA, USA.
  • Lourenco D; Department of Animal and Dairy Science, University of Georgia, Athens, GA, USA.
  • Breen V; Cobb-Vantress Inc., Siloam Springs, AR 72761, USA.
  • Hawken R; Cobb-Vantress Inc., Siloam Springs, AR 72761, USA.
  • Brito Lopes F; Cobb-Vantress Inc., Siloam Springs, AR 72761, USA.
  • Misztal I; Department of Animal and Dairy Science, University of Georgia, Athens, GA, USA.
J Anim Sci ; 99(4)2021 Apr 01.
Article em En | MEDLINE | ID: mdl-33649764
ABSTRACT
The introduction of animals from a different environment or population is a common practice in commercial livestock populations. In this study, we modeled the inclusion of a group of external birds into a local broiler chicken population for the purpose of genomic evaluations. The pedigree was composed of 242,413 birds and genotypes were available for 107,216 birds. A five-trait model that included one growth, two yield, and two efficiency traits was used for the analyses. The strategies to model the introduction of external birds were to include a fixed effect representing the origin of parents and to use unknown parent groups (UPG) or metafounders (MF). Genomic estimated breeding values (GEBV) were obtained with single-step GBLUP using the Algorithm for Proven and Young. Bias, dispersion, and accuracy of GEBV for the validation birds, that is, from the most recent generation, were computed. The bias and dispersion were estimated with the linear regression (LR) method,whereas accuracy was estimated by the LR method and predictive ability. When fixed UPG were fit without estimated inbreeding, the model did not converge. In contrast, models with fixed UPG and estimated inbreeding or random UPG converged and resulted in similar GEBV. The inclusion of an extra fixed effect in the model made the GEBV unbiased and reduced the inflation. Genomic predictions with MF were slightly biased and inflated due to the unbalanced number of observations assigned to each metafounder. When combining local and external populations, the greatest accuracy can be obtained by adding an extra fixed effect to account for the origin of parents plus UPG with estimated inbreeding or random UPG. To estimate the accuracy, the LR method is more consistent among scenarios, whereas the predictive ability greatly depends on the model specification.
Assuntos
Palavras-chave

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Galinhas / Modelos Genéticos Idioma: En Ano de publicação: 2021 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Galinhas / Modelos Genéticos Idioma: En Ano de publicação: 2021 Tipo de documento: Article