Corn and wheat are two of the most common basal energy sources used in swine diets in North America. However, due to the high cost of energy in pig diets, the use of high-fiber ingredients, such as distillers dried grains with solubles and wheat middlings, has increased. Those fiber-rich ingredients are usually co-products from grain milling or processing industries; thus they are often more cost-effective than their parent cereal grains.