A method for the production of ethanol and a modified animal feed is provided. The method replaces the starch in known corn-based animal feed with biomass fiber treated to make it more digestible by animals. The process includes wherein the pericarp and germ are removed from the corn kernel and processed for by-products. The starch and protein are also removed and separated. The starch is then fermented and distilled to ethanol and stillage. The bioavailable modified animal feed comprises the pericarp and germ removed from corn kernels and optionally by-products of the pericarp and germ processing, and lignocellulosic materials. The modified animal feed may optionally include energy materials such as animal and vegetable fats, vegetable soapstocks, or glycerin, and combinations thereof.