Analysis of growth curves in different lineages of Caipira broiler type

The objective of this work was to identify, by means of different statistical criteria the ideal nonlinear regression model to describe the growth curve of three lineages of caipira broiler for meat production. A total of 90 birds were used, being 30 birds from each of the following lineages: Pescoco Pelado , Carijo and Pesadao Vermelho . The individual body weight of broilers (1, 7, 14, 21,28, 35, 42, 49, 56, 63, 70, 77, 84 and 91 days of age) was collected weekly for determination of growth curves by means of Models von Bertalanffy, Gompertz, Logistic, Richards and Brody. The parameters of Brody model did not converge to the weight of strains. The model that better adjusted to the data was Logistic.