EFFECTS OF NON-INCLUSION OF GENETIC DIRECT-MATERNAL COVARIANCE IN THE MODEL AND REAL VALUES OF (CO)VARIANCES ON THEIR ESTIMATES FOR WEANING WEIGHT IN BEEF CATTLE

Authors

  • Jorge Luis Ferreira
  • Arcadio de los Reyes Borjas Universidade Federal de Goiás
  • Roberto Carvalheiro Gensys Consultores
  • Raysildo Barbosa Lôbo Faculdade de Medicina de Ribeirão Preto- USP

DOI:

https://doi.org/10.5216/cab.v12i3.5503

Keywords:

Breeding

Abstract

This study aimed to compare estimates of (co)variances considering the effect of direct maternal genetic correlation (-0,50; -0,25; +0,25; +0,50); the ratios between the direct and maternal genetic variances (75:75; 50:100; 100:50) and two models which included (M2) or not (M1) the direct maternal genetic covariance. Stochastic simulation of twenty replicates of a closed and randomly mated herd of cattle was carried out for twenty years of selection. The base population was not related, non-selected and randomly sampled. (Co)variance estimates were obtained under single trait animal model using MTDFREML application. The model was not significant on estimates of maternal permanent environmental variance. The genetic direct-maternal correlation influenced all (co)variance estimates significantly (P<0,05). The ratios of genetic direct and maternal variances significantly affected (P<0,05) only estimates of genetic direct and maternal variances. Regarding negative direct-maternal genetic correlation, M1 underestimated direct and maternal variances while overestimated both when that correlation was positive. Reliable and accurate (co)variance estimates for weaning weight in beef cattle depend on the adequacy of the model as well as their actual values.
KEYWORDS: cattle; direct-maternal genetic correlation; co-variance estimates; simulation.

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Author Biographies

Jorge Luis Ferreira

Escola de Medicina Vterinaria e Zootecnia Setor de Genetica e Melhoramento Animal

Arcadio de los Reyes Borjas, Universidade Federal de Goiás

Professor Titular do Departamento de Produção Animal, da Escola de Veterinária da Universidade Federal de Goiás.

Roberto Carvalheiro, Gensys Consultores

Pós-doutor Gensys Cosultoria. Porto Alegre, Rio Grande do Sul, Brasil.

Raysildo Barbosa Lôbo, Faculdade de Medicina de Ribeirão Preto- USP

Professor Associado da FMRP-USP. Diretor-Presidente da ANCP, Ribeirão Preto, São Paulo, Brasil.

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Published

2011-09-29

How to Cite

FERREIRA, J. L.; BORJAS, A. de los R.; CARVALHEIRO, R.; LÔBO, R. B. EFFECTS OF NON-INCLUSION OF GENETIC DIRECT-MATERNAL COVARIANCE IN THE MODEL AND REAL VALUES OF (CO)VARIANCES ON THEIR ESTIMATES FOR WEANING WEIGHT IN BEEF CATTLE. Brazilian Animal Science/ Ciência Animal Brasileira, Goiânia, v. 12, n. 3, p. 435–442, 2011. DOI: 10.5216/cab.v12i3.5503. Disponível em: https://revistas.ufg.br/vet/article/view/5503. Acesso em: 22 nov. 2024.

Issue

Vol. 12 No. 3 (2011)

Section

Animal Production

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