Growth, livability, feed consumption, and carcass composition of the Athens Canadian Random Bred 1955 meat-type chicken versus the 2012 high-yielding Cobb 500 broiler

A flock of the Athens Canadian Random Bred (ACRB), a 1955 meat-type chicken control strain, was raised alongside a flock of 2012 Cobb 500 fast feathering high-yielding broilers to determine selection changes over the past 57 yr. All birds were reared under management practices appropriate for the Cobb 500. Birds were weighed weekly and processed at 6, 8, and 10 wk. Whole carcass, carcass parts, and organs were weighed. Modern broilers outweighed ACRB at every age, ranging from 3.7 to 4.7 times the size of the ACRB. All parts and organs were compared as a percentage of live fasted BW. The ACRB had significantly heavier feet, wings, internal organs, and feathers. The modern Cobb broiler had double the breast and larger leg muscles and had a significantly greater fat pad. Despite the larger muscle mass, the supply organs, the heart and lungs, were significantly smaller in the Cobb broiler than the ACRB as a percentage of BW. Relative size of supply and other vital organs should be given consideration for genetic selection of the future broiler. Comparisons of ACRB weights and organ percentages with past published data indicates that the ACRB remains a consistent control strain.