Handling effects on body weight and behaviour of group-housed male rabbits in a laboratory setting

In the study described in this paper we focus on the behaviour of male rabbits under modified housing conditions. We investigated whether handling has an effect on the behavioural stress response and whether this response is related to the coping strategy of the rabbits. Furthermore we studied the effect of handling from birth onwards on body weight and dominance.To assess the rabbit's coping strategy we performed a tonic immobility test, human-approach test, open-field test and a novel-object test. The results are that handling has no effect on body weight during the experimental period. Handling led to a more social and stable hierarchy among rabbits. Handled animals are less sensitive to tonic immobility, approached and made contact with the novel object and test-person's hand more often and longer, and moved around more freely in the open field than non-handled rabbits. This suggests that handled animals are proactive copers, while non-handled animals are reactive copers. However, in the second tonic immobility test handling depressed the tonic immobility response to such a level that nearly all handled animals did not react in a pro- or reactive manner at all.Altogether we provide evidence that handling pups form birth onwards, independent of nursing time, can be very effective in providing tame, less emotional and more cooperative animals.