Quality and fermentation of enzyme-treated alfalfa silages at three moisture concentrations

Abstract

Second harvest alfalfa was cut at the early bud stage, wilted in the field to approximately 45% moisture, and chopped to a theoretical length of 0.95 cm. Herbage was reconstituted to moisture concentrations of 50, 60, and 70% prior to enzyme treatment. Treatments consisted of control, 0.5 or 1 g kg −1 of an enzyme preparation having cellulolytic and amylolytic activity. Herbage was ensiled in small experimental silos for 1, 7 or 21 days. Organic acid content and pH reflected both the time of fermentation and moisture concentration of alfalfa. Rapid acidification occurred by Day 7 in the 70% moisture silage and remained constant to Day 21 of fermentation. Lactate concentrations remained relatively high and butyrate low in high moisture silages. Lactate concentration in alfalfa silages was apparently affected by moisture and enzyme treatment. Increases in lactate concentration were noted in the 60 and 70% moisture silages treated at a rate of 1 g kg −1 enzyme preparation. Crude protein and in vitro dry matter digestibility of alfalfa silages were not affected by moisture concentration or addition of enzyme. Cell wall components remained fairly stable during ensiling. The cellulase preparation did not have a beneficial effect in this experiment.