Abstract: A process for improving the nutritional quality of a feed co-product, resulting from the fermentation of a grain, sugar beets, or sugar cane to produce ethanol. The process comprises combining water, a source of nitrogen, a source of phosphorus, a feed co-product comprising a cellulose and/or a hemi-cellulose, and a microbe to form a fluid fermentation mixture suitable for submerged fermentation, wherein the feed co-product is derived from the fermentation of a grain, sugar beet, or sugar cane to produce ethanol and wherein the microbe is a microbe capable of breaking down the cellulose and/or the hemi-cellulose to one or more sugars and then utilizing the sugars to proliferate; fermenting the fluid fermentation mixture such that the microbe converts at least a portion of the cellulose and/or the hemi-cellulose into at least one sugar and uses the sugar to proliferate thereby increasing the concentration of microbes in the fermentation mixture.