ABSTRACT
This chapter describes the energy budget concept with a simple computer simulation of a representative large herbivore, the wapiti. To serve the needs of an industry, agricultural scientists have developed feeding standards, simple factorial models for estimating the level and balance of energy and nutrients to support predetermined target levels of production. Major tracking variables are summarized in graphic screens monitoring general parameters, activity budgets, feeding constraints, digestive kinetics, energy balance, and body pools of nonprotein and amino acid nitrogen. Pregnancy calculates daily requirements for energy and nitrogen for conceptus growth while lactation executes similar calculations for milk production. Computer simulation models usually are tested in two ways. First, they are exposed to sensitivity analysis to determine how precisely parameters must be known. Secondly, predictions are tested against empirical data or at least the subjective knowledge of experience. The paucity of good estimates of many bioenergetic parameters for wapiti required use of crude approximations.
