EFFECTS OF AN ENZYME ADDITIVE ON COMPOSITION OF CORN-SILAGE ENSILED AT VARIOUS STAGES OF MATURITY

Corn forage at the milk, soft dough, and black layer stages of maturit y (22, 28, and 44% DM, respectively) was treated with an enzyme additi ve at 1, 10, or 100 times the recommended dose and ensiled in laborato ry silos at 26 degrees C. By in vitro assay, the additive contained a full complement of cellulase and hemicellulase activities. The pH and temperature optima for cellulase and hemicellulase activities were 4.8 and 50 degrees C, respectively. Regardless of dose, the additive had no effect on fermentation acids or nitrogenous compounds in silage at any maturity; however, high doses increased the glucose content of sil age at the milk stage of maturity and increased ethanol content at the soft dough stage. Across maturities, addition of the enzyme additive resulted in a linear decrease in ADF, NDF, and hemicellulose content o f corn silage but decreased the acid detergent lignin content of silag e only at the milk and black layer stages of maturity. The enzyme addi tive had no consistent effect on in vitro NDF digestion.