Foraging behaviour and diet selection in domestic herbivores

Foraging behaviour and diet selection determine both the nutrient intake by the animals and their impact on the vegetation. They are therefore of importance for animal and vegetation management. Animals exploit the heterogeneity of resources through selective grazing, choosing a diet of better quality than the average vegetation on offer. Recent increased effort has been made to develop models of the grazing process supported by theory, which should facilitate generalisation and application to a broad range of situations. Foraging involves the interactions between the characteristics of the animal and the characteristics of food in the environment. We review some of the animals' foraging decisions within the vegetation, morpho-physiological, digestive and behavioural constraints they face. The determinants of foraging behaviour and diet selection remain, however, somewhat obscure and a matter of debate. The complexity of the animal/vegetation interactions have prompted the development of simple experimental approaches, and further research is needed to extrapolate these to larger spatio-temporal scales. (C) Elsevier/Inra.