EFFECT OF MOLDY AND NONMOLDY WHEAT STRAW TREATED WITH OR WITHOUT AMMONIA ON PERFORMANCE AND BLOOD SERUM CONSTITUENTS IN STEERS

Mold growth decreased nutritive value of wheat straw (WS). Mold increased DM (94 vs 98%) and ADF (51 vs 56%) contents and had no effect on natural detergent fiber (NDF). Crude protein and N values were decreased in moldy wheat straw, Mold increased insoluble N content of wheat straw (WS) from 21 to 27%. Ammoniation increased the CP of nonmoldy straw from 3.8 to 8.3% and moldy straw from (3.3 to 6.2%). Aspergillus and zygomycetes fungal species were most prevalent and total numbers were higher on moldy straw. Ammoniation decreased total numbers of fungal spores on nonmoldy and moldy WS. Ammoniation of moldy WS increased (p < 0.10) feed in take (1.8%) as compared with nonmoldy, ammoniated, nonmoldy and moldy WS. Steers fed moldy WS had lowest (p < 0.10) feed intake (1.3% of BW daily) compared with other diet. There was little difference (p < 0.10) in intake of nonammoniated vs. ammoniated WS. Steers fed moldy straw lost 6 kg BW. Ammoniated, nonmoldy straw elevated Blood Urea Nitrogen (BUN) (10.5 mg/dl). Alkaline Phosphatase (ALK) was greater in steers fed moldy VS nonmoldy straw (148 VS 95 U/liter. p < 0.10).