Traditional and alternative nonlinear models for estimating the growth of Morada Nova sheep

• Autor(a) principal: Souza,Laaina de Andrade
• Data de Publicação: 2013
• Outros Autores: Carneiro,Paulo Luiz Souza, Malhado,Carlos Henrique Mendes, Silva,Fabyano Fonseca e, Silveira,Fernanda Gomes da
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Revista Brasileira de Zootecnia (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982013000900007
• topic: cluster analysis; growth curve; naturalized breed

In the present study, alternative and traditional nonlinear models to describe growth curves of Morada Nova sheep reared in the state of Bahia, Brazil, were applied. The nonlinear models were: Schnute, Mitscherlich, Gompertz, Logistic, Meloun I Meloun II, III Meloun, Gamito and Meloun IV. The model adjustment was evaluated by using: Adjusted Coefficient of Determination (R²aj), Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC), Mean Squared Error of Prediction (MEP) and Coefficient of Determination of Prediction (R²p). The selection of the best model was based on cluster analysis, using the evaluators as variables. Six out of the nine tested models converged, while Meloun I and Meloun IV were equally effective in explaining animal growth, without significant influence of sex or type of parturition over the curve parameters. The models Meloun I and IV have the best adjustment and reveal a remarkable reduction of weight gain after 150 days of age, which indicates special attention should be given to feeding at this stage.