Resumen de The effect of housing conditions on Biceps femoris muscle fibre properties, fatty acid composition, performance and carcass traits of slow-growing rabbits

Zdenek Volek, Darina Chodova, Eva Tumova, Lenka Volkova, Elena Marounek, Milan Marounek

• The aim of the present work was to evaluate the effect of stocking density on the biceps femoris (BF) muscle fibre properties, meat quality, the growth performance and carcass traits of Czech White rabbits.  A total of 20 rabbits (40 days old, 10 rabbits per treatment, sex ratio 1/1) were reared in cages at different stocking densities (10 rabbits/m2 or 4 rabbits/m2) for 49 days. Stocking density had no significant effect on the growth performance. There were no significant differences between groups with regard to hot carcass weight (HCW) or dressing-out percentage. The proportions of both perirenal (9.5 vs. 15.9 g/kg HCW; P=0.010) and total dissectible fat (14.9 vs. 25.1 g/kg HCW; P=0.001) were lower in rabbits reared at the lower stocking density. No significant differences in ultimate pH values, meat colour or proximate composition were observed. The hind leg meat of rabbits reared at the lower stocking density contained significantly less lauric (4.6 vs. 6.7 mg/100 g of muscle; P=0.008) and myristic acid (52.2 vs. 64.4 mg/100 g of muscle; P=0.033). Significantly higher percentages of βR fibres (16.3 vs. 6.5 %, P=0.001) and αR fibres (24.5 vs. 14.2 %; P=0.001) and a significantly lower percentage of αW fibres (59.2 vs. 79.3 %; P=0.001) were also observed in these rabbits. The mean cross-sectional area (1882 vs. 2744 μm2; P=0.001) and diameter (47.9 vs. 58.5 μm; P=0.001) of βR fibres were smaller in rabbits reared at the lower stocking density. Thus, the lower stocking density favourably affected the medium-chain fatty acid profile of meat and fibre characteristics of the rabbits' biceps femoris muscle.