Soybean mill run is composed of soybean hulls and such bean meats that adhere to the hulls which results from normal milling operations in the production of dehulled soybean meal. (AAFCO, 2003) This is considered a cheap, poor quality, by-product filler. Soy is highly allergenic, causing problems for many animals and contains some enzyme inhibitors which impedes protein digestion. Most soy is also genetically modified (see GM), which makes its long term effects impossible to predict.