Nutritional value and utilization of wheat dried distillers grain with solubles in pigs and poultry

Dried distillers grain with solubles (DDGS) are a co-product of ethanol production from starch cereals (mainly maize in North America and wheat in Europe), which contains approximately the non-starch or non-fermentable fractions of the grain. As more becomes available with increasing bio-ethanol production, DDGS is being included not only in diets for ruminants but also in pig and poultry diets. This review paper considers the introduction possibilities of wheat DDGS in poultry and pig diets. Nutrients content in wheat DDGS and digestibility vary among ethanol plants, reflecting the starch extraction process and drying of the residues after starch extraction. Most of the variability concerns amino acid (AA) contents and their standardized ileal digestibility (SID), affected by the occurrence of Maillard reactions, reflected in the lightness score (L) of wheat DDGS. Samples with low L values (<50) are dark and have the lowest nutritional value, both in pigs and in poultry. Lysine is the most affected AA, with contents ranging between 0.9 (dark) and 3.0 percent of crude protein (CP; N×6.25) for wheat DDGS. In parallel, lysine SID is also variable, with the lowest values observed in DDGS with low lysine level in CP. For the darkest products,lysine SID is close to zero. Energy digestibility varies in parallel with changes in lysine content and L values, but is more related to other nutrients such as dietary fibre, fat and residual starch contents. In addition, wheat DDGS can supply significant amounts of available phosphorus. DDGS from wheat can be used in diets for poultry and pigs; however, in relation with nutritional value variability, practical use should take into account correct energy values or lysine SID content in order to prevent any performance deterioration. Finally, only the light-coloured productsare recommended for non-ruminants, and their introduction at high inclusion rates will contribute to reducing the energy value of the diet.