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Scalez,Daiane Cristina Becker; Fragomeni,Breno de Oliveira; Santos,Dalinne Chrystian Carvalho dos; Passafaro,Tiago Luciano; Alencar,Maurício Mello de; Toral,Fabio Luiz Buranelo. |
ABSTRACT The objective of this study was to estimate genetic parameters for body weight of beef cattle in performance tests. Different random regression models with quadratic B-splines and heterogeneous residual variance were fitted to estimate covariance functions for body weights of Nellore and crossbred Charolais × Nellore bulls. The criteria −2 residual log-likelihood (−2RLL), Akaike Information Criterion (AIC), and consistent AIC (CAIC) were used to choose the most appropriate model. For Nellore bulls, residual variance was modeled with six classes of age, and direct additive genetic and permanent environment effects were modeled with quadratic B-splines with two and one intervals, respectively. For crossbred bulls, quadratic B-splines with one... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Animal breeding; Bos indicus; Genetic correlation; Heritability. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982018000100407 |
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Fragomeni,Breno de Oliveira; Scalez,Daiane Cristina Becker; Toral,Fábio Luiz Buranelo; Bergmann,José Aurélio Garcia; Pereira,Idalmo Garcia; Costa,Paula Souza Teixeira da. |
The objective of this study was to estimate (co)variance components for weight at 550 days, average daily gain and an index with both traits, and to compare alternatives for evaluation and ranking of Nellore young bulls in pasture performance tests. The heritability estimates were 0.73, 0.31 and 0.44 for weight at 550 days, average daily gain and index, respectively. Animals were ranked according to their predicted breeding values or the phenotypic deviations in relation to the mean of the test. Although the correlations between breeding values and phenotypic deviations were high, there were differences in the number of animals selected in common when the selection criteria were the predicted breeding values or the phenotypic deviations. Mixed models are... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Breeding value; Heritability; Least square; Mixed models; Selection. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982013000800004 |
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