MODELOS DE REGRESÃO NÃO LINEAR EM CURVA DE CRESCIMENTO DE PINTAINHAS POEDEIRAS

Abstract

The objective of this study with weighing laying hens from 1 to 35 days old was due to the need for studies regarding growth curves in the initial phase. The data used were obtained from 32 birds that were housed with another 300 in a shed with a concrete floor lined with shavings bedding and heated with electric and gas hoods. These birds were weighed at the ages of 1, 7, 14, 21, 28 and 35 days using a precision scale and a digital platform scale. From these weighings, averages, standard deviations and coefficient of variation were calculated to evaluate the homogeneity of the birds' growth. Also carried out, being the main objective, studies with mathematical models to describe growth curves such as the model of Gompertz, Logistic, von Bertalanffy and Richards and finally made the qualification of adjustment of these models, that is, which adjusts better to the data of the curve with evaluators such as the percentage of convergence (C%), the coefficient of determination R2, adjusted coefficient of determination (R2aj), the mean squared error of prediction (MEP), the Akaike information criterion (AIC) and the Bayesian criterion of Schwarz (BIC).