Non-linear growth models for Beetal goats

Abstract

The data were taken from the "Enhancing of Mutton Production through goat breeding" a Project run at Livestock Production Research Institute Bahadurnagar (Okara); the growth performance of Beetal goats were compared by statistical non-linear models, like Exponential, Gompertz and Logistic models. These models were based to obtain the best fitted model by following the criteria of mean absolute error (MAE), root mean squared error (RMSE), and mean absolute percentage error (MAPE). Run test were used to check the independence and normality of the models and residuals were checked by Shapiro-Wilk test. Errors were found to be normal and independently distributed. Body weights of Beetal goats and Bucks were examined by shape of the curves and it revealed that the values of α, β and γ of Gompertz model were higher than that of exponential and logistics in both the district of Okara and Sahiwal. Also, values of MAE, RMSE and MAPE of Gompertz model were lower than the logistic and exponential.

Functional Analysis of Growth in Large White Male Turkeys

“…Biological implications of the model parameters and their relationship with other production features provide a sound basis for developing a breeding strategy to modify the curve of growth [4,5]. In order to describe the biological system of the growth, numerous nonlinear functions developed and used by some scientists [6][7][8][9]. The growth, influenced by genetic and environmental factors, is clarified by some non-linear models such as Brody, Von Bertalanffy, Gompertz, Logistic, and Richard's [10].…”