COMPARISON OF NONLINEAR GROWTH MODELS OF NATIVE CHICKENS (Gallus gallus domesticus L., Atak-S) REARED IN ORGANIC PRODUCTION

This study aimed to compare the Logistic, Gompertz, and Von Von Bertalanffy growth models to determine which best fits the data for the native chicken (Gallus gallus domesticus, Atak-S) breed.A total of 120 male and 120 female Atak-S chicks were included, with weekly body weight data recorded from hatch to 18 weeks of age.Statistical analysis was performed using the SPSS version 15 program, incorporating three distinct models: Logistic (L), Gompertz (G), and Von Von Bertalanffy (V).The estimated asymptotic weights (A) of male chicks were 2365 189.40 g for the Logistic model, 2999 329.36 g for the Gompertz model, and 3684 515.60 g for the Von Von Bertalanffy model.The corresponding growth rate (k) values were 0.22, 0.11, and 0.74 for the L, G, and B models, respectively.The Von Bertalanffy model outperformed the others with the lowest AIC (150.02) and BIC (156.24),indicating the best fit in terms of model selection criteria.It also demonstrated the lowest MSE (3139.60)and RMSE (56.08), signifying the smallest prediction error among the three models.The Von Bertalanffy model provided the most accurate and efficient fit for the data, with the highest R (99.30) and adjusted R (99.20) in Atak-S chicks.