Industry Resources: Co-products

While ethanol production consumes the grain's starch, the protein, minerals, fat and fiber are concentrated during the production process to produce a highly valued and nutritious livestock feed. For dry mill ethanol refineries, which make up the majority of production, most feed is dried and sold as Distillers Dried Grains with Solubles (DDGS).  A modern dry-mill ethanol refinery produces approximately 2.8 gallons of ethanol and more than 17 pounds of distillers grains from a bushel of corn.

In 2013, ethanol biorefineries produced 35.5 million metric tons of high quality feed. This amount of feed would rank as the world's fourth-largest corn crop. The feed produced last year would be enough to produce nearly 45 billion quarter-pound hamburger patties - or six patties for every person on the planet.

Historic Distillers Grains Production from U.S. Ethanol Biorefineries:

Year Metric Tons
1999 2.3 million
2000 2.7 million
2001 3.1 million
2002 3.6 million
2003 5.8 million
2004 7.3 million
2005 9.0 million
2006 12.0 million
2007 14.6 million
2008 23.0 million
2009 30.5 million
2010 32.5 million
2011 39.0 million
2012 34.4 million
2013 35.5 million


Roughly one-third of every 56-pound bushel of grain that enters the ethanol process is enhanced and returned to the animal feed market, most often in the form of distillers grains, corn gluten feed and gluten meal.  These co-products are fed to beef cattle, dairy cows, swine, poultry, and fish in nations around the world.  Feed co-products represent an increasingly important share of profit opportunities for ethanol producers. A typical dry mill earned 27% of its gross revenue from the sale of distillers grains and corn distillers oil in 2013.

"The use of wet distillers grains has been tremendously positive with regard to the average daily gain of our high stress cattle. The greatest benefit has been the ability to get them on the growing ration in half the time as previously."

Greg Gleue, Neosha Valley Feeders, LeRoy, Kansas

"Research conducted at several universities as well as the University of Minnesota has shown that corn DDGS contributes several valuable nutrients in poultry diets including energy, amino acids and phosphorous. In Minnesota, DDGS is used regularly in turkey diets as an economical feed ingredient and high quality products are in demand."

Dr. Sally Noll, Professor of Poultry (Turkeys) Science, Department of Animal Science, University of Minnesota

Exports:  Internationally, distillers grains are gaining widespread acceptance as a high quality livestock feed component.  These markets are particularly important to the U.S. as domestic co-products markets near saturation. 

Investing to Improve Quality
Ethanol producers are investing in new technologies to improve the quality and quantity of the livestock feed they produce. A number of dry mills are installing technology that allows them to separate crude corn oil from the stillage at the back end of the process. This crude corn oil can be sold into the feed market (particularly for poultry), further refined and sold into the human food market, or used as a feedstock for biodiesel.

Guidelines are also available for analyzing DDGS. A year-long study funded jointly by RFA, the National Corn Growers Association, and the American Feed Industry Association (AFIA) offers recommended test methods for determining the moisture, crude protein, crude fat, and crude fiber content of DDGS. These factors are often viewed as the key determinants of the market value of the product. Historically, the lack of “standard” empirical DDGS test methods has led to results that vary significantly from laboratory to laboratory, causing product uncertainty for producers, marketers, nutritionists, regulatory bodies and — most importantly — distillers grains customers. RFA believes the widespread voluntary adoption of recommended test methods will reduce market confusion and add more structure to the DDGS marketplace. Click here for the report

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Feed Associations



Last updated March 2014