Growth, livability, and feed conversion of 1957 versus 2001 broilers when fed representative 1957 and 2001 broiler diets.

Body weight, feed consumption, and mortality were measured in the 1957 Athens-Canadian Randombred Control (ACRBC) strain and in the 2001 Ross 308 strain of broilers when fed representative 1957 and 2001 diets. The dietary regimens were chosen to be representative of those used in the industry in 1957 vs. 2001. The 1957 diets were fed as mash, the 2001 starter was as crumbles, and the grower and finisher diets were pellets. Feed consumption and BW were recorded at 21, 42, 56, 70, and 84 d of age to cover the two broiler strains normal span of marketing ages. Mortality was low, and the mortality of the ACRBC was approximately half that of the modem strain. Average BW for the ACRBC on the 1957 diets were 176, 539,809, 1,117, and 1,430 g vs. 743, 2,672, 3,946, 4,808, and 5,520 g for the Ross 308 on the 2001 diets at 21, 42, 56, 70, and 84 d of age, respectively. The 42-d feed conversion (FC) on the 2001 and 1957 feeds for the Ross 308 were 1.62 and 1.92 with average BW of 2,672 and 2,126 g and for the ACRBC were 2.14 and 2.34 with average BW of 578 and 539 g, respectively. The Ross 308 broiler on the 2001 feed was estimated to have reached 1,815 g BW at 32 d of age with a FC of 1.47, whereas the ACRBC on the 1957 feed would not have reached that BW until 101 d of age with a FC of 4.42.