Chemical Composition, Carcass Yield and Tenderness of Broilers as Influenced by Rearing Methods and Genetic Strains

Experiments were conducted to determine the influence of cage and floor rearing and strains as well as the rearing of sexes separately or in equal numbers on chemical composition, yield and tenderness. The sexed birds were processed at 6, 7 and 8 weeks of age with measurements made at these ages. The shear values from the iliotibialis of the males were higher than those of the same muscle from the female. This difference in shear values was the only one noted. The second slice of the pectoralis muscle from birds reared in cages produced lower shear values than the corresponding slice from floor reared birds. The shear values from the broilers reared separately by sex or combined were influenced by both the sex of the individual bird as well as rearing method. Shear values from males grown separately were lower than those obtained from the females or those values from birds grown with equal numbers of sexes per pen. Shear values from the 8 week old broilers were lower than either 6 or 7 week old birds. The highest values were obtained from the 7 week old broilers. Females had a higher percentage of total meat as well as a greater meat-to-bone ratio for light meat, but no statistical difference was found between sexes for the dark meat portions. Yield of the sex separated birds increased as they increased in age.