Data/hora: 10/06/2024 06:53:22

Provedor de dados: | 96
País: | Brazil
Título: | Modeling the effect of the age of dam at calving on the weaning weight of Charolais-Zebu crossbred calves
Autores: | Toral,Fábio Luiz Buranelo; Torres Júnior,Roberto Augusto de Almeida; Lopes,Paulo Sávio; Silva,Luiz Otávio Campos da; Reis Filho,João Cruz.
Data: | 2009-07-01
Ano: | 2009
Palavras-chave: | Beef cattle; Environmental effects; Genetic evaluation; Least square.
Resumo: | The objective of this study was to evaluate alternatives for modeling the age of dam at calving (AOD) effect on the weaning weight of Charolais-Zebu crossbred calves. Data from 56,965 calves were analyzed, using statistical models considering the fixed effects of the contemporary groups, sire and dam genetic groups, and AOD. The AOD effect was fitted to models using annual age classes, and ordinary quadratic to quintic-ordered polynomials (OP) or segmented polynomials (SP) with two, three, four, six and twelve evenly spaced intervals. In the case of segmented polynomials, general linear and quadratic effects and only one quadratic additional term from each knot were considered. The AOD effects were nested within sex of calf in all cases. According to the fitting criteria, the F-test for the reduction of residual sum of squares, coefficient of determination, residual sum of squares and mean of squared residuals, the three interval segmented polynomial (two knots) fitted to the data as well as the more complex polynomials.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982009000700011
Editor: | Sociedade Brasileira de Zootecnia
Relação: | 10.1590/S1516-35982009000700011
Formato: | text/html
Fonte: | Revista Brasileira de Zootecnia  v.38 n.7 2009
Fonte: | info:eu-repo/semantics/openAccess