The nutritional value of high-protein corn distillers dried grains for broiler chickens and its effect on nutrient excretion

Two experiments were conducted with a co-product of corn endosperm fermentation. The first experiment determined nutrient digestibility of high-protein corn distillers dried grains (HP-DDG; 54% CP) after feeding semi-purified diets from 15 to 22 d of age. The AME(n) of HP-DDG was 2,526 kcal/kg, whereas standardized ileal Lys, Met, and Thr digestibilities were 73.0, 84.9, and 73.0%, respectively. In a second experiment, an industry control diet (I) regimen was compared with that of either an approximate 25 or 50% replacement for the level of 48% CP soybean meal (SBM) inclusion in the diet utilizing the amino acid digestibility and AME(n) determined from the first experiment. From 0 to 14, 14 to 28, and 28 to 42 d of age, the HP-DDG in the 50% SBM replacement diet was added at 25, 23.5, and 21% of the diet, respectively. To meet digestible amino acid needs, the diet containing 50% SBM replacement with HP-DDG contained 3.2, 3.6, and 4.4% units more CP than the I diet regimen from 1 to 14, 14 to 28, and 28 to 42 d of age, respectively. Dietary replacement of up to 50% of SBM inclusion with HP-DDG had no effect on bird performance at 14 or 42 d of age or breast fillet yield at 42 d of age; however, it decreased BW gain and increased feed: gain ratio from 14 to 28 d of age. Birds consuming a diet with 50% replacement of SBM with HP-DDG consumed 17.1% more N compared with those consuming I diets. This additional N and fiber consumed resulted in birds being fed the 50% replacement for SBM diet excreting 21.9 and 31.8% more manure DM and N, respectively. Due in large part to the amino acid profile and digestibility of HP-DDG, use of this feedstuff as a large proportion of the diet is feasible but results in more manure and manure N from broilers.