POULTRY SCIENCE, vol.90, no.6, pp.1313-1323, 2011 (SCI-Expanded)
To evaluate color [lightness (L*), redness (a*), and yellowness (b*)], water-holding capacity (WHC), and pH values, and for proximate analysis of breast and thigh meats from slow-growing (Bronze; B), fast-growing (Hybrid; H), and medium-growing (crosses; H x B) turkey genotypes raised with or without outdoor access, 36 turkeys (2 females and 2 males from each replicate) per housing system or 12, 16, and 8 turkeys per B, H, and H x B genotype, slaughtered at 17 and 21 wk of age, respectively, were used. Therefore, data were analyzed as a factorial arrangement (2 x 3 x 2 x 2) of treatments. All birds were provided with the same starter, grower, and finisher feeds. Muscle samples were collected at 12 h postmortem for evaluation of meat quality and proximate analysis. Outdoor access increased the a* value and protein content of the breast muscle (P < 0.05) and the b* value of the thigh muscle (P < 0.01). The B and H genotypes had higher (P < 0.01) L* values for the breast meat than did the H x B genotype, whereas the B genotype had lower a* (P < 0.01) and pH (P < 0.01) values for the breast meat or a higher (P < 0.05) pH value for the thigh muscle compared with the H genotype. The breast meat of the B genotype was more yellow (P < 0.01) than that of the H and H x B genotype. Thigh meat from the H genotype had a higher L* value and a lower a* value than did thigh meat from the other genotypes (P < 0.01). Thigh meat from the H x B genotype was higher in protein and lower in fat than was thigh meat from the B and H genotypes, respectively (P < 0.05). No interaction effect of housing system and genotype was observed on the parameters studied (P > 0.05). These results show that housing system did not affect the main quality parameters (pH, water-holding capacity, and L* values) of either muscle, and that genotype created more differences in terms of these parameters.