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

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 g...

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Detalles Bibliográficos
Autores: Ferreira, Jorge Luis, Borjas, Arcadio de los Reyes, Carvalheiro, Roberto, Lôbo, Raysildo Barbosa
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2011
País:Brasil
Institución:Universidade Federal de Goiás (UFG)
Repositorio:Ciência animal brasileira (Online)
Idioma:portugués
OAI Identifier:oai:ojs.revistas.ufg.br:article/5503
Acceso en línea:https://revistas.ufg.br/vet/article/view/5503
Access Level:acceso abierto
Palabra clave:Breeding
bovinos
simulação
correlação genética direta-maternal
estimativas de (co)variâncias.
Descripción
Sumario: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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