Dairy Focus: Ethanol Production Byproducts Nutritious Animal Feed

By J.W. Schroeder, Dairy Specialist

NDSU Extension Service

Editor’s note: This is the 13th article in a series on the issues facing the region’s dairy farmers, particularly the impact of the growing ethanol industry.

Distillers grain has long been recognized as a nutritious feed ingredient for animals, including dairy cows.

It is unique in that it is the only fermented feed ingredient from the dry-mill fuel or beverage ethanol process. Its features are:

• starch is removed
• it’s a product of fermentation
• high fiber content
• contains dried yeast cells
• developed in an all-natural process
• considered Food and Drug Administration food grade
• it’s a highly digestible protein source (85 percent)
• concentrated grain nutrients
• good source of bypass protein
• contains essential minerals

The handling characteristics of distillers grains also are unique. Here are some key points about these products and how they should be fed to dairy cattle:

Dried Distillers Grain with Solubles

• It’s a byproduct from the fermentation of grain for the production of ethyl alcohol.
• Solubles in dried distillers grain are left over from the fermentation and are added to the grains before they are dried (most common product).
• Corn, milo, barley, rye, wheat or sorghum are the grains used to make distillers grain. Usually corn is the predominant grain used.
• It’s a good source of bypass (undegraded) protein if properly dried.
• It contains 10 percent to 12 percent fat. Remember to include the amount of fat from dried distillers grain when calculating the amount of fat found in the diet.
• It’s low in calcium and high in phosphorus and potassium. Proper mineral supplementation is required.
• Crude protein will vary between 23 percent and 28 percent on an as-fed basis.
• It’s generally included at the following rates: 20 percent to 35 percent of the grain mix, 15 percent to 25 percent of the total ration dry matter or 6 to 10 pounds per cow per day.

Wet Distillers Grain

• It contains approximately 65 percent to 75 percent moisture. It is produced by straining out the coarser particles found in the stillage and then being pressed to remove some moisture.
• It’s low in calcium.
• Feeding large amounts may reduce dry-matter intake, especially on corn silage diets.
• Limit intake to 15 percent to 25 percent of the total ration dry matter or 9 to 10 pounds of dry matter per cow per day.
• Store in a clean, dry place. It may be stored in a concrete or asphalt bunker silo or plastic bag.
• The product deteriorates rapidly in hot weather. It needs to be fed within two to five days in the summer. During cold weather, it will last five to seven days.
• It can be ensiled in silage bags to extend its shelf life.
• Usually price limits hauling to no more than 100 to 200 miles from the distillery.

Stillage (thin slop)

• It’s a byproduct from the distillery industry.
• It’s material remaining after straining, pressing or centrifuging out larger particles.
• It’s very low in dry-matter content (may average 2 percent to 6 percent dry matter).
• On a dry-matter basis, the nutrient content is similar to dried distillers grains with solubles except for bypass protein (contains very low amounts of bypass protein).
• Limit intake so dry matter or nutrient intake does not limit milk production. Limit intake to 50 to 100 pounds per cow per day or 3.5 to 7 pounds of dry matter per cow per day.
• Mineral supplementation should complement the low calcium and high phosphorus content of this byproduct.

NDSU Agriculture Communication