Comparison of nonlinear functions using partial growth data at different lengths of growth period in awassi lambs

Abstract

The aim of this study was to comparatively evaluate some nonlinear functions i.e. Brody, Negative Exponential and Bertalanffy in order to describe the growth of Awassi male lambs (n=120) at the age of 10 months. The coefficient of determination values estimated for Brody, Negative Exponential and Bertalanffy models were 0.9523, 0.6094, and 0.9428 R2 for the first-time interval (0-90 days of age), 0.9866, 0.9743 and 0.9797 R2 for the second time interval (0-180 days of age) and 0.9924, 0.9853 and 0.9902 R2 for the third time interval (0-300 days of age), respectively. Pearson correlation coefficients between the observed and predicted weight values of the Awassi lambs were found as 0.9417, 0.9255 and 0.9203 for 0-90 days of age, 0.9741, 0.9501 and 0.9634 for 0-180 days of age and 0.9824, 0.9765 and 0.9790, for 0-300 days of age, respectively. Brody, Negative Exponential and Bertalanffy models were found to be useful models to describe the growth of Awassi lambs raised in Turkey. In conclusion, it could be suggested that the nonlinear functions might allow breeders to achieve remarkable information in practice in terms of determining managerial problems, slaughtering age, ideal feed amounts, and the studied breed’s growth standards.