Simulation of a swine nursery to facilitate economical management

Two deterministic simulation models were developed to assess the economics of swine nurseries. The first model assessed the emergency needs of swine nurseries by simulating the temperature response during a short term power failure. The failure model accounted for heat exchange by conduction, convection, radiation, and air infiltration. An existing sub-model was used to predict swine heat and moisture loss.

The failure model was validated using a nursery constructed of concrete block. It performed well for cases with constant solar load, but tended to overpredict temperature changes during periods of no solar load. Validation indicated accurate wall-characteristic and wind velocity estimations were crucial to obtain accurate model results.

The second model was developed to describe the normal operation of swine nurseries by predicting pig growth and feed consumption, building fuel consumption, and cost per unit of gain produced. lt was based on an existing swine model that was converted to an hourly basis. An optimization option was incorporated into the operational model to allow minimization of the cost per unit of gain.

The operational model was validated and found to accurately predict feed consumption and growth during a one week time frame. Fuel consumption was less accurate. The optimization mode predicted considerable cost savings for operation at lower temperatures.