Ammonium Hydroxide Treatment on Wheat Straw

Abstract

Water was added to chopped wheat straw to result in final levels of about 10, 20, 30, 40 and 50% of dry matter (DM). Ammonia, 3.3% of DM as ammonium hydroxide (NH₄0H), was sprayed onto the straw. Straw samples were then sealed in double plastic bags and stored at room temperature for 10, 20, 30, 40 or 50 days (Experiment I) or 1, 5, 10, 20, 40 or 60 days (Experiment II) before being frozen and ground with dry ice to pass a 1 mm screen. DM, total nitrogen, in vitro dry matter digestibility (IVDMD), free ammonia nitrogen (NH₃-N) vs fiber-bound nitrogen (ADF-N), solubilization and changes in in vitro digestibility of NDF, ADF, ADL, hemicellulose and cellulose fractions were measured. Days post-treatment (P<.05) and water level (P<.0001) had significant linear effects on both IVDMD and total N content. A large percentage of the improvement in IVDMD of treated straw occurred by 1 day post-treatment, and further improvements in IVDMD after 10 days were small. Total N content of treated straw continued to increase as days post-treatment increased. Both IVDMD and total N content of treated straw increased as moisture content increased. The overall means (e.g., means of all day × moisture treatment combinations) for IVDMD and total N content of untreated (underscored values) and treated straw were: 39.8, .78; 52.0, 1.73 (Experiment I); 36.8, .69; 49.6, 1.79 (Experiment II). Ammonia-nitrogen and ADF-N accounted for 43.4 and 12.6%, respectively, of the total nitrogen retained when averaged across all day × moisture treatment combinations. NH₄0H treatment decreased straw hemicellulose and NDF fractions by 42.7 and 8.6%, respectively, and increased digestibility of NDF, ADF and cellulose fractions that remained after NH₄ OH treatment. Copyright © 1979. American Society of Animal Science . Copyright 1979 by American Society of Animal Science.