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 two 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 two slaughter seasons (SS: Spring, Summer) in an organic production system. The effect of storage time (ST) at frozen state (2 months at -20 °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* color 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) SB x P, SB x G and P x G 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 reversed result has been obtained for LL meat (P<0.01). The 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), however 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 to the farming environmental conditions needs to be paid.