Modelling of body weight in meat-type white quails and dual-purpose quails with nonlinear growth curves

Abstract

This study aimed to determine the best nonlinear growth model to explain variation in live weights of meattype white quails (Texas White) and dual-purpose quails (Japanese quails). A total of 96 quail chicks were used, including 48 Texas White quails and 48 Japanese quails. The experiment was continued for 42 days, and the live weights of the quails were measured weekly. The data obtained were analyzed with different nonlinear growth models (Brody, Lundqvist-Korf, Gompertz and von Bertalanffy). The coefficient of determination (R- 2 ), mean squared error (MSE), root mean squared error (RMSE), Akaike's information criterion (AIC) and Bayesian information criterion (BIC) were used as criteria for determining the model that best describes growth. Coefficients of determination (R- 2 ) for meat-type male quails in Brody, Lundqvist-Korf, Gompertz, and von Bartalanffy models were 0.981, 0.994, 0.998 and 0.996, respectively, whereas MSE values in these models were 202.064, 47.36, 17.434 and 37.635, respectively. For meat-type female quails, coefficients of determination were 0.987, 0.998, 0.999 and 0.998, respectively, and MSE values were 196.705, 23.852, 23.038 and 29.913, respectively. In the same models, R (2 )values for male dual-purpose quails were 0.981, 0.994, 0.999 and 0.997, respectively, and MSE values were 150.434, 34.222, 9.83 and 25.499, respectively. R- 2 values for female dualpurpose quails were 0.988, 0.997, 0.999, 0.999, respectively, and MSE values were 133.779, 20.536, 3.388 and 16.043, respectively. Thus, the Gompertz model was the one that best described growth in meat-type white quails and dual-purpose quails.