MECHANISTIC MODELLING OF DAIRY PRODUCTION SYSTEMS
- nitrogen use and its associated environmental effects;
- grassland production;
- milk production; and
- economic factors to determine the viability of the system.
At this stage, the model is being developed to describe the linkages between forage production, the grazing dairy cow and animal production, and its associated effects on the environment and the viability of the dairy enterprise. The starting point for this integrated model was the development of a mini system model that described grass growth, grazing and milk production under climate change conditions (Topp and Doyle, 1996a and 1996b).
To improve the environmental aspects, a description of nitrogen cycling within the soil and herbage is being included. Similarly, to evaluate farm profitability impacts, an economic component is also being added. Consequently, the integrated model will be used to determine what areas of the system require further knowledge and thus indicate what areas of research are required to further enhance the model. The ultimate aim of the project is to develop a decision