[Behaviour and well-being (author's transl)].

The question how problems of behaviour and well-being of (farm) animals can be studied by ethological methods is central in the present paper. An ethologist uses basic concepts such as behaviour element, behaviour system and 'Umwelt' of an animal; these concepts are described. The normal course of all sorts of processes of behaviour can be readily accounted for by regulating systems. These regulating systems are directed towards homeostasis of several environmental aspects of the organism. Regulation of these aspects is based on criteria which may be regarded as genetic and ontogenetic memory images or those resulting from experience. Well-being may be defined as conformity of environmental characteristics and accompanying criteria. However, not all criteria are of equal biological importance. This model concept renders it plausible that animals also have some awareness of their environment and must experience sensations while functioning. The present paper concludes with a discussion of these points.