Variation in the Composition of Distillers Dried Grains

University of Illinois researchers determined the concentration of true ileal digestible (TID) lysine and relative bioavailable lysine in seven sources of distillers dried grains with solubles (DDGS) when fed to poultry. The TID of amino acids in DDGS were measured using cecectomized roosters and relative bioavailable lysine was measured using standard curve methodology. The seven DDGS sources were analyzed for reactive lysine using the guanidination procedure and Hunterlab L, a, and b scores were measured to determine the degree of lightness, redness, and yellowness in the samples. Results showed that the TID for lysine among the seven DDGS sources varied (P < 0.05) from 52.7 to 70.4%, with an average value of 61.4%. The concentration of relative bioavailable lysine did not differ among the seven sources of DDGS. The average concentration of TID lysine in DDGS was not different from the concentration of bioavailable lysine (0.47% and 0.53%, respectively). The concentration of TID lysine was correlated (r2=0.84, P < 0.05) with the concentration of reactive lysine in the samples. Hunterlab L scores of DDGS was correlated (r2=0.90, P <0.05) with the concentration of bioavailable lysine. In conclusion, the concentration of TID lysine in DDGS is close to the concentration of bioavailable lysine for chicks. The researchers concluded that values for reactive lysine and Hunterlab L may be used to estimate the concentration of TID lysine and bioavailable lysine in DDGS, respectively.

Pahm, A. A. and co-workers. 2008. True ileal amino acid digestibility in cecectomized roosters and lysine bioavailability in chicks fed distillers dried grains with solubles. J. Anim. Sci. 86:180/J. Dairy Sci. 91:180 (Abstract 210).