Effect of Ammoniation on the Chemical Composition of Alfalfa Hay Baled with Varying Concentrations of Moisture

Abstract

Alfalfa that contained 25 to 45% moisture was baled (large rectangular bales) and treated with 2% anhydrous NH3 (percentage of DM). The alfalfa was damaged by rain prior to ammoniation. Hay remained sealed under plastic for 21 d after ammoniation. During this time, 18 bales that represented a wide range of DM contents were sampled at 7, 14, and 21 d after ammoniation. Ammoniation increased N from 3.26 to 4.16% and decreased NDF from 59.0 to 56.2%. Neutral detergent insoluble N increased from 0.71 to 0.87% of DM. When NDF was expressed on a CP-free basis, ammoniation decreased concentrations from 54.4 to 50.7%. Most of the decrease in NDF was caused by the loss of hemicellulose. Most of the changes caused by ammoniation were completed by 11 d after ammoniation. The magnitude of the changes that were caused by ammoniation was related to DM content of the bales. Drier bales (ca. 75% DM) had greater increases in N that was bound to NDF and greater decreases in NDF than did wetter bales (ca. 60% DM). The change in total N was not affected by DM content.