Quality of meat from two 1970s and Ross 308 broiler strains fed drug-free low- and recommended-protein diets

Abstract

SUMMARY A study was conducted to compare the quality of meat from a modern broiler strain (Ross 308; RS) with that of two 1970s strains fed drug-free low-protein (LP) and recommendedprotein (RP) diets from 1 to 30 d of age. The RP and LP starter and grower diets were fed from 1 to 16 d and from 16 to 30 d of age, respectively. The LP grower diet was fed to all birds from d 31 to 63. Breast and thigh meats were less (P < 0.05) fibrous for the RS strain than for the 1970s strains. The breast meat of the RS strain was also juicier (P < 0.05) than that of the 1970s strains when the LP diet was fed. Thigh meat from 7-wk-old birds was less fibrous (P < 0.05) than that from 9-wk-old birds. The LP diet improved (P < 0.05) the tenderness of breast and thigh meats, but the improvement in breast meat tenderness was significant (P < 0.05) only for 7-wk-old birds. Breast and thigh meats from RS birds had higher (P < 0.05) pH and water-holding capacity than those from the 1970s strains. Breast meat from the RS birds had a higher (P < 0.05) percentage of fat (1.23 vs. 0.55 and 0.73%) and a lower (P < 0.05) percentage of protein (24.17 vs. 24.90 and 24.78%) than the 1970s strains. Meat from the RS strain had better sensory attributes and quality characteristics than meat from the two 1970s strains. Meat from the 1970s strains had a higher protein content and lower fat content than meat from the RS birds. The LP diet can improve meat sensory attributes if the birds are slaughtered at 7 wk of age, but not at 9 wk of age.