The effects of a (30 cm high) elevated platform as an enrichment structure on the behaviour and performance of fattening rabbits kept in groups were investigated. Three housing systems for fattening rabbits were compared using a stocking density of 15 rabbits m–2. The rabbits were housed either in large pens (3.67 m2 plus a platform of 0.39 m2; with 60 rabbits per pen) or in small pens (0.503 m2 plus a platform of 0.159 m2; with10 rabbits per pen), or in conventional standard cages (0.39 m2, with 6 rabbits and without any enrichment) from 31 to 72 days of age. The conventional cages without a platform were used as a control and reference model. Rabbits housed in each small pen or in each cage belonged to the same litter, and the 60 rabbits sharing the same large pen were from six or seven litters. At the end of fattening, rabbits reached the weight of 2,508 g in cages, 2,397 g in small pens, and 2,340 g in large pens; the only significant difference was daily weight gain which was better in cages than in both pens. There was no difference in growth parameters between the two types of pens. The mortality rate was less than 1% for all treatments. No sanitation problems or severe lesions were seen with rabbits even those reared in large pens and large groups. Neither housing systems, nor elevated platform affected activities such as dietary intake or resting. The use of the platform appears to depend upon the amount of space available; in a large pen, an elevated platform can be utilised as an exercise structure while in a small pen it was used more as simply extra space to occupy.

The possibility of improving the welfare of fattening rabbits by rearing them in pens instead of cages was investigated. Time budgets, locomotion, ear lesions, breaking strength of the femur and productivity were compared in fattening rabbits kept at the same stocking density (15 rabbits m−2) either in standard cages of 0.4m2 (6 animals) or in pens of 1.6m2 (24 animals). Behavioural observations, performed by video recording at 6 and 9 weeks of age, indicated that the frequency of rabbits walking over one another was higher in cages than in pens at 9 weeks of age. Although the time spent in locomotion did not differ significantly, the number of consecutive hops performed by animals was clearly increased in pens at 6 weeks and tended to be higher at 9 weeks. In pens (without a ceiling), rabbits were observed ‘keeping watch’ with a characteristic fully upright posture; this was not possible for rabbits in cages (with ceilings at 30cm).

Ear lesions were more frequent in caged rabbits than in penned; this might be due to the caged rabbits walking on one another, due to the lack of space to perform locomotory behaviour. Weight, diameter and breaking strength of femur tended to increase in rabbits kept in pens. In penned rabbits, body and carcase weight were significantly reduced (by 2.0% and 3.4% respectively) when compared with caged ones. However, overall, the use of wire-floor pens of 1.6m2, housing 24 animals, was considered to be beneficial to fattening rabbits’ welfare when compared to standard-sized cages holding 6 animals.

Three housing systems for fattening rabbits were compared using a stocking density of 15 rabbits m–2. The rabbits were housed in large pens (3.67 m2, 50 rabbits), small pens (0.66 m2, 10 rabbits) or in conventional standard cages (0.39 m2, 6 rabbits) from 31 to 72 days of age. Rabbits housed in each small pen or in each cage belonged to the same litter, and the 50 rabbits housed in each large pen were from six or seven litters. At the end of fattening, when rabbits were 72 days old, there was no significant difference in the weight of rabbits from the three different housing systems, even though the rabbits from small pens were slightly heavier in weight compared with rabbits from large pens. The best feed conversion ratio was found in rabbits from cages, but was only significantly different from rabbits housed in small pens. No significant differences were found in the main activities: nutrition, social behaviour, resting, and standing; however, the frequency of runs, hops and consecutive hops was significantly higher in rabbits from large pens compared with rabbits from the two other housing systems. These results confirm that the total surface area available for animals is the most important factor for such locomotory activities. This study did not reveal any significant difference in aggressive behaviours between rabbits from different litters housed in large pens and between rabbits from the same litter housed in small pens or cages.