ABSTRACT
This chapter provides an overview of modeling as a systems research method and to describe how computer simulation models can be used in livestock production research and development. Simulation models can be used for what to do questions by setting up simulation experiments exploring a certain response surface. Simulation models can be classified by the following three dichotomies Static versus dynamic, Deterministic versus stochastic and Empirical versus mechanistic. Although there is a history of modeling biological and physiological systems in animal science, the technique has had limited use at higher levels of aggregation such as applied livestock production science. A deterministic livestock herd model uses classes of animals as the simulation unit to deal with discrete events such as conception, sex of offspring, death, and culling. Livestock herd simulation models are typically mechanistic in the sense that they simulate the production of the herd indirectly by simulation of subsystems.
