Título:	Bayesian analyses of heterogeneous variances among generations of brazilian Canchim beef calves.
Autoria:	MARTINS, E. N. ENGLER, E. O. SAKAGUATI, E. S. FREITAS, A. R. de ALENCAR, M. M. de NIETO, L. M. FALCÃO, A. J. S.
Afiliação:	E. N. MARTINS, UEM; E. O. ENGLER, UEM; E. S. SAKAGUTI, UEM; ALFREDO RIBEIRO DE FREITAS, CPPSE; MAURICIO MELLO DE ALENCAR, CPPSE; L. M. NIETO, UEM; A. J. S. FALCÃO, UEM.
Ano de publicação:	2002
Referência:	In: WORLD CONGRESS APPLIED TO LIVESCTOCK PRODUCTION, 7., 2002, Montpellier, France. Abstracs... Montpellier: INRA, 2002. p.197.
Conteúdo:	In the genetic evaluations, the models usually assume homogeneous variance through subclasses of identified factors. However, several studies have reported heterogeneous genetic and residual variances in analyses of many animal production traits (Weigel and Gianola, 1993). Different regions, birth years, feeding systems, genetic variability within herds and production levels can have heterogeneous variance among their subclasses (Ibáñez et al., 1996; De Veer and Van Vleck, 1987). Synthetic breeds are usually formed from selection of crossbred animals. Crossbred populations in general have relatively high genetic variability. However, selection changes gene frequencies and consequently it tends to reduce the genetic variability. Furthermore, the herds have had their environment modified over time by improvement in feeding and management. Therefore, data from different generations of a single population can have heterogeneous variances. Ignoring heterogeneity of variance can reduce the efficiency of genetic evaluation procedures and consequently response to selection (Hill, 1984). Thus, the aim of this study was to evaluate the occurrence of heterogeneous variance of yearling live weight among the first six generations of Brazilian Canchim breed
Palavras-chave:	Variances Heterogeneous genetic Residual variances Brazilian Canchim breed
Tipo do material:	Resumo em anais e proceedings
Acesso:	openAccess
Aparece nas coleções:	Resumo em anais de congresso (CPPSE)