Meat physical quality and muscle fibre properties of rabbit meat as affected by the sire breed, season, parity order and gender in an organic production system

The aim of the study was to evaluate some meat physical quality and muscle fibre properties of rabbit meat when considering 2 sire breeds (SB: Vienna Blue [VB]; Burgundy Fawn [BF]; both coloured and slow-growing breeds), several parity orders (P: 1, 2, >= 3), gender (G), and 2 slaughter seasons (SS: spring, summer) in an organic production system. The effect of storage time (ST) at frozen state (2 mo at -20 degrees C) of Longissimus lumborum (LL) meat was also evaluated. Animals were slaughtered when they reached 2.8 kg of live weight. Then, pH and L*a*b* colour values of Biceps femoris (BF) and LL muscles, water loss and Warner-Bratzler shear force of LL and hind leg (HL) meat, and the fibre typing and enzymatic activity of LL muscle were analysed. LL meat from females showed higher b* values than males (0.04 vs. -1.25; P<0.05). Significant (P<0.05) SBxP, SBxG and PxG interactions were observed for the b* value of LL: VB and BF crossbreds presented a higher b* value when born as P >= 3 and P2 respectively, VB females showed higher b* value than VB males, and P2 and P >= 3 produced males with a significantly lower b* value. HL thawing losses were significantly (P<0.05) higher in rabbits slaughtered in summer than in those slaughtered in spring, whereas the opposite result was obtained for LL meat (P<0.01). Cooking loss of LL meat was significantly lower in P2 group than P >= 3 group (P<0.05). The lactate dehydrogenase activity in LL muscle was higher in VB than in BF crossbreds (930 vs. 830 IU; P<0.05), albeit not supported by differences in fibre type distribution. The ST significantly (P<0.01) reduced pH, a* and b* colour values, and increased lightness of LL meat. It was concluded that the crossbreeds derived from VB and BF genotypes and farmed organically did not show remarkable sexual dimorphism, considering their elder slaughter age than rabbits reared under intensive conditions. Physical quality of meat was mainly affected by slaughter season, indicating that in the organic rearing system, specific attention needs to be paid to the farming environmental conditions