A SIMULATION-MODEL OF GRAZING SHEEP .2. WHOLE FARM MODEL

This paper presents the implementation of a farm management model of sheep grazing systems and demonstrates how the model can be used to gain incremental information about the system being investigated. The structure of the model is presented in detail, including a description of the data structures used to represent paddocks, mobs, pasture and animal production, and a flexible management component which controls the operation of the model. An experiment is presented that explores potential carrying capacities, requirements for pasture conservation, and appropriate levels of winter feeding for dryland and irrigated properties in the Canterbury Plains of New Zealand: The results of this experiment are then used as inputs to a second experiment that evaluates the effects of stocking rate on animal performance, meat and wool production and profitability.