Aug 2, 1978 - aBiuret and barley were used as supplemental sources of N and. DE. While extra N was not considered necessary between 5/11 and 6/16 the barley provided small amounts as indicated. TABLE 2. FEEDLOT RATIONS FOR STEERS, TRIALS 1 AND 3. Ingredient. cSm(km). DPW(kg). Straw, rye grass. Alfalfa.