Ethanol plants make more than just ethanol. The ethanol production process results in additional co-products that have market value in livestock production and food processing:

Distillers grains are a valuable co-product of dry grind ethanol production. This feed is used in livestock rations, primarily for ruminant animals such as dairy and beef cattle-but it is also fed to swine and poultry. Distillers grains are high in protein, fiber and fat-providing an excellent source of nutrition and energy for livestock. The Heron Lake BioEnergy plant will have the capacity to produce 160,000 tons of dried distillers grains annually for feeding to local and nationally grown livestock.

Carbon dioxide (CO₂) is another co-product of ethanol production that, after further processing, is marketable to soft drink bottlers, food processors and other industries.