[The evaluation of animal welfare of housing systems for small and large groups of fattening rabbits].

In the present study three new group housing systems for fattening rabbits kept in smaller and larger units were evaluated with respect to the animal welfare as stated in the Swiss Regulations about animal protection. Judgement of animal welfare was based on the results of two practical examinations in which abnormal behaviour and injuries were elevated. To determine proper keeping evaluation criteria and their limits were set. In the examined housing systems no problems concerning locomotory and occupation behaviour, resting and hiding places were found. But in a few larger groups social problems occurred by the end of the fattening period. Hence heavy injuries were found before day 80 of life. These problems concerning aggressive behaviour and injuries may be explained by the accelerated sexual development (determined by strain, by housing conditions or by the presence of adult females) or the difficulty for the young rabbits to establish steady dominance hierarchies in this social environment and under the given conditions. These findings raise the question which factors are responsible for the difficulties.