On the interpretation of feeding behaviour measures and the use of feedingrate as an indicator of social constraint

This paper highlights a number of issues associated with the use and interp retation of feeding behaviour measures using examples from the literature o n rats, cows and pigs. The inter-relatedness of six feeding behaviour varia bles is illustrated. Different meal patterns adopted to achieve similar int akes are briefly discussed in the context of flexibility of feeding behavio ur. The relative constancy of feeding rate of an individual in a given envi ronment is described, and the notion of a preferred rate of eating is intro duced. It is suggested that an animal kept individually will eat a given am ount of food at a preferred rate of eating. Changes in feeding rate by indi viduals are examined and different causes discussed. These include increase d feeding motivation (hunger), and influences from the social environment. It is proposed that changes in the feeding rate of individual group housed animals may reflect concomitant changes in the social environment, and coul d thus be used as an indicator of social constraint. In addition, it is pro posed that the depression in daily food intake seen in group housed animals compared to single kept individuals may reflect a shift in behavioural pri orities. (C) 1999 Elsevier Science B.V. All rights reserved.