Dairy focus: Ethanol production byproducts nutritious animal feed

By J.W. Schroeder, NDSU Extension Service Dairy Specialist

Thursday, December 6, 2007 3:13 PM MST

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: the starch is removed; it’s a product of fermentationhigh fiber content; it contains dried yeast cells; has been developed in an all-natural process considered Food and Drug Administration food grade; it’s a highly digestible protein source (85 percent); has concentrated grain nutrients; is a good source of bypass protein and 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 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.