Ad Libitum Feeding and Growth Functions

Abstract

Chapter 1 discussed all growth functions so far developed for animals as systems with output only, empirical in nature despite the appeals to various theories of growth. The animal is best considered as a black box with input and output not whitened by any theories of growth. It was shown that the rate of growth (dW/dt) of an animal is the product of the true growth efficiency (dW/dF) and the food intake (dF/dt) whether an animal is fed ad libitum or on a controlled feeding regime. Since the animal is considered a black box with input F(t) and output W(t), only experimental data can reveal acceptable functions W(F) and F(t) so that the true growth efficiency (dW/dF) and the food intake (dF/dt) can be calculated. These functions will be acceptable if the W(t) function possesses the three mathematical properties discussed in Chap. 1 and if the parameters of the W(F) and F(t) functions are interpretable in physical terms.