The 12th annual Distillers Grains Symposium, hosted by the Distillers Grains Technology Council, was held May 21-22, 2008, in Kansas City, Missouri.
Among the 210 attendees were representatives from the beverage and fuel ethanol industries, university researchers and nutritionists. Four countries, including 31 U.S. states and five Canadian provinces, were represented at the symposium. The two-day meeting consisted of 14 presentations on the role of distillers grains (DG) in animal nutrition, new technological developments in ethanol production and regulations regarding DG. The symposium also included the awarding of seven scholarships totaling $4,750 to graduate students involved in DG research.
Symposium presentations and highlights
• Dr. Terry Klopfenstein of the University of Nebraska reviewed research by Kansas State University and Nebraska that did not consistently show any effect of diet in general, or DG in particular, on E. coli O1572:H7 prevalence in beef cattle.
• Storage options for wet DG were discussed in presentations by Dr. Larry Berger of the University of Illinois and Dr. Rick Rasby of the University of Nebraska. Storage of wet grains up to one year is possible when grains are handled similar to silage – cover, pack, limit runoff and water contamination (principles of good silage-making apply). Combining wet grains with dry byproducts or forages can improve storage and be complementary in terms of nutrient content. With straight wet DG, covering piles with 1 pound of salt per square foot and plastic can improve stability and increase storage life. Dr. Berger also reported on feeding studies with dairy beef that found wet DG could be fed at up to 30 percent of diet dry matter (DM) without affecting carcass quality or yield. The optimum level of DG will depend on cost of alternative ingredients.
• The impact of lower starch in lactating dairy rations was reviewed by Dr. David Schingoethe of South Dakota State University. As DG replaces corn, dietary starch levels decrease while digestible fiber increases. Though high DG diets will have lower starch levels than traditional corn-based diets, milk yield tends to be maintained or increased on high DG diets. Digestible fiber in DG may provide adequate carbohydrates for ruminal microbes. Milk fat depression in higher DG is not expected unless effective fiber is lower than recommended.
• The impact of corn fractionation prior to fermentation was discussed by Jeff Scharping of ICM, Inc. Advantages of fractionation include higher plant capacity (not fermenting the non-fermentables), increased efficiency in fermentation and lower energy costs (burning bran and syrup). The resulting co-product differs from traditional DG – higher protein and lower fat content.
General comments
• New co-products from fractionation and cellulosic fermentations will require new AAFCO definitions and research to evaluate feeding value. The market value of these new products is still to be determined, but new co-products will certainly provide nutritionists with more formulation options.
• DG consistency is still an issue (more so for swine and poultry), but the debate over the market value of a consistent product continues.
• Economics may force new plants to move to fractionation unless they are located in areas with strong markets for wet grains. PD
G. Alan Harrison for Progressive Dairyman
