During the past few years the production of distillers dried grains with solubles (DDGS) has increased and DDGS have become a major source of protein and energy in selected livestock rations. The purpose of this experiment was to determine if the concentration of digestible energy (DE) and metabolizable energy (ME) in DDGS produced in the Midwest. Samples of DDGS from 11 ethanol plants in Illinois, 4 ethanol plants in Indiana, 4 ethanol plants in Iowa, 2 ethanol plants in Missouri, and 2 ethanol plants in Wisconsin were obtained and used to formulate swine diets. Twenty four barrows (weighing about 28kg) were randomly allotted to 1 of 24 dietary treatments in a 24 × 8 Youden square design with 24 diets and 8 periods. Each period consisted of a seven-day diet adaptation period followed by feces and urine collection.

The results of this study indicated that the DDGS sources were highly variability; the coefficient of variation for ADF, NDF, and lignin were 18.01, 10.09, and 34.74%, respectively. There was a wide range of particle size (266 to 930 mm) and bulk density (368 to 548 g/L) among the 23 sources of DDGS. The acid hydrolyzed ether extract ranged from 5.3 to 10.6% indicating that some ethanol plants were centrifuging solubles to remove the corn oil from the solubles. The DE, ME, ATTD of GE, and ATTD of N in DDGS were different (P < 0.05) among sources. Correlation coefficients among and between chemical and physical components and DE and ME were determined. Prediction equations for DE and ME in DDGS were generated, but the accuracy with which DE and ME could be predicted was relatively low. The researchers concluded that sources of DDGS procured in the Midwest states vary in concentration of ether extract, and more research is needed to generate prediction equations for estimating these energy measurements in DDGS.