Experimental Data for Evaluating Broiler Models

A study was conducted to compare the performance of two distinct broiler strain-crosses and to provide genetic descriptions of them for modelling. Ross x Arbor Acres (RxAA) and Steggle x Arbor Acres (SxAA) broiler strain-crosses were reared on corn-soybean meal diets exceeding the minimum NRC nutrient recommendations. Diets were fed from 0 to 4 (starter), 4 to 8 (grower), and 8 to 16 (finisher) wk of age. Birds and feed were weighed at 2, 4, 6, 8, 12, and 16 wk of age. Carcass and feather compositions were determined on sample birds at 0, 2, 4, 6, 8, 12, and 16 wk of age. Lower body weights, better feed efficiency, and less feed intake per period, with the exception of the last period, were exhibited by the SxAA broilers vs. the RxAA broilers. Lower weights, feed consumption, poorer feed efficiency, and more carcass fat were evident for the female broilers vs. male counterparts. Strain-cross and sex initially influenced breast meat yield, but after day 14, the primary influence was strain-cross or sex. The RxAA broilers contained more carcass fat on a dry matter basis than the SxAA broilers, reflective of the selection for lean mass in the Steggle breed. Generally, feather yield was greater for male broilers than for females. Protein, fat, and ash content of feathers varied. Overall information attests that broiler strains and their sexes differ in their demands for growth.