Behaviour and use of space in fattening rabbits as influenced by cage size and enrichment

In the few previous studies on the effects of space allowance on fattening rabbit behaviour, space allowance was confounded with group size. This is the first study of fattening rabbit behaviour in which space allowance was varied whilst group size was stable (8 animals per pen), although this meant that stocking density and total cage size were altered simultaneously. Behaviour was studied at 6 and 9 weeks of age during artificially created dawn, daytime and dusk phases, and compared between cages with and without a wooden enrichment structure.Although a wide range of space allowances was studied (seven different cage sizes between 0.40 and 1.60 m2) the observed effect on behaviour was limited: only sternal lying increased consistently with decreasing space allowance. In the larger cages, grooming was performed when animals had more free space around them. However, grooming did not decrease in smaller cages, suggesting that this behaviour was important enough to be performed under non-preferred conditions.The wooden enrichment structure decreased lateral lying and cage manipulation. Effects on lying behaviour and cage manipulation have previously been reported for gnawing sticks. However, in contrast to findings on gnawing sticks, the enrichment structure also decreased social contact. Although social contact is generally seen as positive, the rabbits may have used the structure as a visual or physical barrier to protect themselves from unwanted interactions with conspecifics.As expected, rabbits were generally more active during dawn and dusk than during daytime. Specific behaviour patterns varied between dawn and dusk, and future studies may use this information to pinpoint the most favourable observation time.In summary, providing fattening rabbits housed in groups of eight with more space had a limited effect on their behavioural time budget. Thus, only minimal support was found for the suggestion that decreased cage size impedes welfare in this species, although rabbits did seem to prefer more space during grooming. In contrast, provision of a wooden structure improved welfare, as shown by a decrease in cage manipulation and interactions with conspecifics.