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

Revista Brasileira de Zootecnia

Fragomeni, Breno de Oliveira¹  Scalez, Daiane Cristina Becker²  Toral, Fábio Luiz Buranelo¹  Pereira, Idalmo Garcia¹  Costa, Paula Souza Teixeira da¹  Bergmann, José Aurélio Garcia¹ 

[1] Universidade Federal de Minas Gerais;Universidade Federal de Mato Grosso

关键词: breeding value;    heritability;    least square;    mixed models;    selection    Introduction The Brazilian cattle herd consists of 176;   

DOI  :  10.1590/S1516-35982013000800004

学科分类：兽医学

来源: Universidade Federal de Vicosa

【 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】

CC BY-NC