ABSTRACT
The plant/animal interface is one of many subsystems of a grazing system. It is a key element but is subject to a number of forward and backward interactions with the other subsystems. This chapter reviews integrated approaches to obtain an adequate definition of the plant/animal interface in a systems context. From the viewpoint of whole grazing systems, it is clear that the plant/animal interface is not completely represented if the consequences of grazing and other nutritional management practices on the animal are not modeled. It is widely recognized that stocking rate is one of the major determinants of animal production from pastures and the sustainability of the grazing system. Intake prediction is one of the most important elements in grazing systems models because the prediction of animal responses to nutrients are largely dependent on it. Diet selection is one of the crucial elements in grazing systems models for appropriate prediction of animal performance.
