An ethanol unit and anaerobic digestion/bio-fertilizer unit are integrated with a cattle feedlot (or dairy operation), wherein a continuous, balanced process yields a sanitary, low- to zero-pollution, and economically efficient production of “clean beef” (or milk), fuel ethanol, and bio-gas/bio-fertilizer. Fossil fuel consumption is substantially reduced, even eliminated, and 100% of the cattle waste is treated in digesters wherein it is converted into medium-BTU gas (bio-gas), organic fertilizer and bio-compost. The ethanol unit serves the purposes of ethanol production, grain pretreatment to produce feed for the cattle and production of a thin stillage which is fed to the digesters. The grain is first processed in the ethanol unit, where the starch portion is converted into ethanol and CO2. The remaining portion is separated into the thin stillage and a wet cake which is fed directly to cattle as a superior ruminant animal ration which displaces certain traditional feed components, alters the standard starch to protein ratio, and significantly improves conversion efficiencies and meat/milk quality.