1 March 2007

3 minute read

Every bushel of corn processed produces 2.65 gallons of ethanol and 17 pounds of distiller’s grains. Since billions of gallons of ethanol are produced each year, a tremendous amount of co-product is also being produced.

Distiller’s grains can come from either the production of alcohol for human consumption (whiskey) or from ethanol production for fuel. This can be fed as a high-moisture product without drying (sometimes referred to as “slop feeding”). This form of feeding is typically done close to the source because the high percentage of water makes this product expensive to haul more than a few miles.

More commonly, distiller’s grains are partially dried to a product that is 35 to 50 percent moisture or more completely dried to a product that is about 10 percent moisture. The dried product is called distiller’s dried grains (DDG). Another co-product of the industry is distiller’s solubles, which can be dried and sold as distiller’s dried solubles (DDS). If the solubles are added to the dried grain, the product is called distiller’s dried grains and solubles (DDGS).

DDGS is relatively high in protein (28 – 30 percent) and, since it is fairly high in fat (11 to 14 percent), the energy is as high as corn (or maybe slightly higher). Another component that makes it a desirable feed stuff is the fiber. DDGS is up to 45 percent neutral detergent fiber (NDF) which makes it desirable for feeding in a forage-based diet.

The protein in distiller’s grains has relatively low rumen degradability but is readily digested in the lower gut. This “bypass” characteristic makes it nutritionally superior to other protein sources, particularly in the diet of growing calves.

The mineral profile is a slight concern. Calcium is low (0.1 to 0.3 percent) while phosphorus is high (0.9 to 1.3 percent). This calls for supplemental calcium if significant amounts are used. Another problem is sulfur, which can be as high as 0.7 percent. This level of sulfur is one reason for limiting the amount of distiller’s grains included in the diet.

Distiller’s dried grains have a range of potential uses in beef cattle rations. First consideration would be to feed it as a source of protein. For example, cows being fed a poor quality hay are likely to be short of protein. Feeding 1.5 pounds of DDGS would provide about 0.4 pound of protein.

For cows on lower quality forages, up to 20 percent of the ration dry matter can be fed as DDGS. At 3 to 5 pounds of DDGS per head, the cows are not only getting protein but are also receiving a significant amount of fat. Providing fat at 4 to 6 percent of the diet has been shown to improve reproductive efficiency in heifers and cows.

DDGS may have a role in stretching forage supplies. Nebraska researchers fed DDGS to heifers at either 0, 1, 2, 3 or 4 pounds per head per day. They found that for each pound of DDGS consumed, the heifers consumed 1.72 pounds less forage.

Distiller’s dried grains are often used in the diets of growing calves to provide a portion of the protein and as an economical source of energy. Inclusion rates of 20 to 40 percent are common. Concerns at the higher rates include the calcium to phosphorus ratio as well as possible copper and selenium deficiency due to excess sulfur. These problems can be addressed by balancing the ration with supplemental minerals.

March 2007