Effect of genotype, housing system and hay supplementation on performance and ear lesions of growing rabbits

There is growing demand by consumers for meat produced in alternative systems. Since its market share is quite small, but is growing, it could be important to deal with this issue. The aim of the experiment was to examine the effects of genotype (terminal line or traditional giant breed), housing system (cage or pen) and feeding method (only pelleted diets or pelleted diets plus hay) on production and ear lesions of growing rabbits. The crossbred rabbits (n=336) Pannon Large×Pannon Ka (Large) and Hungarian Giant×Pannon Ka (Hung) were weaned at 5 wk of age. Half were randomly housed in cages (3 rabbits/cage) and the other half in pens (14 rabbits/pen). Two other subgroups were formed, rabbits that received only pelleted commercial diets (Pellet) or pelleted commercial diets plus grass hay (P+Hay), ad libitum. Differences were found in body weight at 12 wk of age and in weight gain and pellet intake between 5 and 12 wk in favour of the Large rabbits (3170 vs 2935 g, P<0.001; 42.3 vs 39.5 g/d, P<0.001; 147 vs 132 g/d, P<0.01, respectively). There were no significant differences in feed conversion ratio or mortality. The caged rabbits achieved better results for body weight at 12 wk and daily weight gain than the rabbits housed in pens (3123 vs 2982 g, P<0.001; 42.5 vs 39.4 g/d, P<0.001): while differences in pellet intake, feed conversion ratio and mortality were not significant. The rabbits that consumed only pelleted diets had higher body weights at 12 wk and weight gains than group P+Hay (3093 vs 3017 g, P<0.05; 41.6 vs 40.3 g/d, P<0.05, respectively). Ratios of ear lesions in the Large and Hung rabbits were not significantly different but were affected by housing system (0 and 34%; P<0.001, in cage and pen, respectively) and feeding method (20.6 and 8.3%; P<0.003, in the groups Pellet and P+Hay, respectively). It can be concluded that the alternative systems negatively influenced the production; the genotype had the greatest, while the feeding method had the lowest impact. Housing of rabbits in large groups was contrary to animal welfare (more ear lesions), although the hay supplementation reduced the aggressiveness.