Calcium Oxide (CaO) treatment of cornstalks, oat hulls, wheat straw or drought stressed corn plants when added at five percent of the feed dry matter will reduced neutral detergent fiber (NDF) levels of these feedstuffs and improve NDF digestibility and in-vitro digestibility to varying degrees due to the strong base reacting with the plant fiber. Ammoniated whey when added to the above mentioned feedstuffs likewise improves these same measures but does so in an additive manner since the ammonia level in these products is not high enough to initiate the desired reaction seen with the CaO. Therefore the rate at which the ammoniated product is added should be done so based on final desired outcome in terms of crude protein.