USE OF ALKALINE TREATED CROP RESIDUES AS PARTIAL GRAIN REPLACEMENTS FOR FINISHING CATTLE

Abstract

Recently, corn has become expensive and this has led to high feed costs and decreased profitability. High priced corn has allowed for the consideration of other ingredients as replacements to reduce diet cost. In much of the Corn Belt, supplies of wet or modified distillers grains and crop residues are abundant. These ingredients were investigated as corn replacements. Studies were conducted to identify methods for treating crop residues to improve digestibility and value in finishing diets based on corn grain and corn wet distillers grain with solubles (WDGS). Digestibility and value of crop residues were improved by mild chemical treatment. Moisture and temperature affected treatment response and extending reaction times beyond 7 days did not improve digestibility. The magnitude of response to chemical treatment depends on the type of residue (i.e., straw vs. stover) and plant part within corn residue (i.e., husk vs. stalk). Treating crop residues at 50% DM with 5% calcium oxide fed in conjunction with wet or modified distillers grains can replace up to 15 percentage units of corn without hindering performance. It appears that moisture, storage time, and plant part affect response to chemical treatment. Feeding chemically treated crop residues and wet or modified distillers grains is an effective strategy for replacing a portion of corn grain in feedlot diets. Replacing 15% units of corn and all of the untreated roughage with treated crop residue resulted similar nutrient supply to the animal. Reducing grind size, feeding a maximum of 20% treated crop residue, and maintaining at least 25% corn in the diet are strategies for optimizing cattle performance for replacing corn with treated crop residues and distillers grains. Collectively, these studies demonstrate corn replacement options which should reduce diet costs, maintain performance and ultimately increase profitability. Advisers: Galen E. Erickson and Terry J. Klopfenstei