THE PRODUCTION OF MUSHROOMS AND UTILIZATION OF THE ABUNDANT, LOW COST AND BIO-FORTIFIED CORN STOVER AS CATTLE FEED RESULTING IN YEAR ROUND PROFITABILITY OF SMALL- AND MEDIUM-SIZED FARMS ARE THE MAIN GOALS OF THIS PROJECT. IN COW/CALF OPERATIONS, FEED COST INCREASES SIGNIFICANTLY DURING WINTER WHEN PASTURES ARE LESS PRODUCTIVE RESULTING IN SUPPLEMENTAL FEEDING OF HARVESTED FORAGES AND OTHER AGRO-INDUSTRIAL BY-PRODUCTS. USE OF CROP RESIDUES BY CATTLE IS LIMITED BY THE PRESENCE OF LIGNIN, WHICH A TYPE OF FIBER THAT CANNOT BE DIGESTED BY ANIMALS. HOWEVER, CULTIVATING MUSHROOM ON THESE RESIDUES RESULTS IN THE BREAKDOWN OF LIGNIN THEREBY RELEASING THE NUTRIENTS WHICH COULD BENEFIT CATTLE PRODUCTIVITY. WE ASSUME THAT COMBINING CATTLE AND MUSHROOM PRODUCTION IS A VIABLE WAY TO REDUCE THESE CHALLENGES. READY TO FRUIT MUSHROOM SUBSTRATES WILL BE DELIVERED TO PARTICIPATING CATTLE FARMERS WHO WILL FRUIT AND SELL THE MUSHROOMS ON A WEEKLY BASIS. SPENT MUSHROOM SUBSTRATE (SMS) FROM FRUITED SUBSTRATES WILL BE USED AS FEED/SUPPLEMENT TO BACKGROUND WEANED CALVES. WE WILL ADDRESS OUR ASSUMPTION BY THE FOLLOWING OBJECTIVES: 1) EVALUATE CORN STOVER AS A SUBSTRATE FOR INTENSIVE MUSHROOM PRODUCTION; 2) UTILIZE SMS AS CATTLE FEED; 3) DETERMINE NUTRITIONAL AND HEALTH BENEFITS OF FEEDING CATTLE WITH SMS; AND 4) EVALUATE ECONOMIC BENEFITS OF THIS PRODUCTION SYSTEM. DATA SUCH AS ANIMAL GROWTH PARAMETERS, CHANGES IN GUT MICROORGANISMS, BLOOD PARAMETERS, QUANTITY/VALUE OF MUSHROOM YIELD AND CHANGES IN FARM PROFITABILITY WILL BE EVALUATED. OVERALL, THIS APPROACH HAS THE POTENTIAL TO INCREASE PRODUCTIVITY PER ACRE AND NET CASH FLOW TO SMALL-SIZED FARMERS.