Slaughter Performance of Four Different Turkey Strains, with Special Focus on the Muscle Fiber Structure and the Meat Quality of the Breast Muscle

Abstract

The increase in human consumption of turkey meat and the shift in the poultry market from whole birds to further processed meat products increases the visibility of meat alterations (e.g., heterogenic color, drip loss, petechial hemorrhages) at retail. Changes in poultry meat quality have been related to the intensive growth of the current turkey strains. Considering this, the main objective of this investigation was to evaluate the meat quality and muscle structure of commercially available turkey strains with different growth properties but similar breast yields. Toms (n = 120) of 4 different turkey strains (British United Turkeys Big 6, Kelly Broad-Breasted Bronze, Kelly Wrolstad, Kelly Super Mini; n = 30 per strain) were reared in an experimental barn under similar environmental and feeding conditions and were slaughtered at 22 wk of age in a commercial slaughterhouse. The strains Big 6 and Broad-Breasted Bronze belong to the fast-growing (FG) turkey strain and the other 2 to the slow-growing (SG) turkey strain. The carcass weights, as estimated by video imaging, differed significantly (P < 0.05) between the SG and FG groups. The breast yields (percentage of carcass weight) of the investigated strains were similar. Except for the significantly (P < 0.05) greater protein concentration in the musculus pectoralis superficialis of the SG birds, the musculus pectoralis superficialis had nearly similar fat and ash contents. Plasma lactate concentrations were similar in the investigated turkey strains but the creatine kinase activities were greater in the FG turkeys at the time of slaughter. Determination of the different meat quality parameters [pH, electrical conductivity, color (L*a*b*), drip loss, shear force] did not result in clear differences between the SG and FG turkey strains. There were larger muscle fibers in the FG in comparison with the SG strains, but no differences could be determined in the capillary density and incidence of degenerated or giant fibers, except for a higher rate in the Wrolstad strain. The present results are contradictory to the opinion that turkeys with faster growth have worse meat quality.