Effect of environmental enrichment on carcass and meat quality in growing rabbits reared in collective pens

To evaluate the effect of the presence and the type of environmental enrichment in different collective housing systems, 504 crossbred rabbits were weaned at 33 d of age and housed in 16 pens (1.68 m2) with plastic slatted floor. Half of the pens were equipped with a plastic slatted platform (50 × 120 cm; 30 cm above the plastic floor). Within pens with or without the platform, half of the pens were additionally equipped with a plastic tube (ϕ 20 cm; length: 50 cm) for hiding. Within housing system, rabbits were slaughtered at 68 or 75 days of age. The presence of the platform increased slaughter weight (2495 vs. 2424 g; P<0.10) and the occurrence of rabbits injured at genitals (20.6 vs. 11.7%; P<0.01). Slaughter results were not affected, but dissectible fat was higher in rabbits kept in pens with the platform compared to those without (3.0 vs. 2.6%; P<0.01). Ultimate meat pH did not change whereas the lightness index of both l. lumborum (53.7 vs. 51.3) and b. femoris (50.7 vs. 49.8) was higher in rabbits reared in presence of the platform (P<0.01). The presence of the tube decreased slaughter weight (2403 vs. 2515 g; P<0.01) and reference carcass weight (1217 vs. 1276 g; P<0.10), but did not affect other carcass traits. The pH and colour of main muscles were not affected, but significantly higher shear force was measured on l. lumborum (4.63 vs. 4.30 kg/g; P<0.05) and b. femoris (3.15 vs. 2.83 kg/g; P<0.01) of the rabbits kept with the tube compared to those without. In conclusion, the presence of enrichment may affect both positively (platform) or negatively (tube) slaughter results and carcass traits in rabbits kept in collective pens. Further investigations are needed to ascertain the effects of the platform on aggression frequency.