Corn DDGS is a co-product of ethanol production, and has high energy, protein, and fiber. It can be used in livestock feed, but the nutritional content can vary widely and this needs to be accounted for when formulating diets. Reasons for the varying quality include corn quality, yeast use, fermentation and distillation variation, drying process, amount of solubles blended, the facility, and pre-factioning. Despite the high protein content, the amino acid balance in DDGS is poor and the usable lysine percent can vary greatly, so additional supplementation may be necessary. A rough indicator of amino acid content is the colour, as darker colours indicate burning or over-drying. Mycotoxins are a concern in DDGS because the processing concentrates nutrients, so a low level in the starting corn can become a significant problem in the final DDGS. Corn DDGS can be included up to 20% in swine diets, although fat firmness decreases over 10%. Flowability can possibly be an issue with DDGS in storage facilities, and clumps can form which will inhibit proper mixing. If the nutritional content is monitored, and storage and fat firmness considered, corn DDGS can be included in swine diets and provide some cost savings.