Genetic parameters and alternatives for evaluation and ranking of Nellore young bulls in pasture performance tests

Revista Brasileira de Zootecnia

Breno De Oliveira Fragomeni²  Daiane Cristina Becker Scalez¹  Fábio Luiz Buranelo Toral²  José Aurélio Garcia Bergmann²  Idalmo Garcia Pereira²  Paula Souza Teixeira Da Costa² 

[1] ,Universidade Federal de Minas Gerais

关键词: breeding value;    heritability;    least square;    mixed models;    selection;   

DOI  :  10.1590/S1516-35982013000800004

来源: SciELO

【 摘 要 】

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 more appropriate than the least squares method and should be utilized in the evaluation of young bulls in performance tests.

【 授权许可】

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