The effect of cellulase and hemicellulase plus pectinase on the aerobic stability and fibre analysis of peas and wheat silages

Abstract

The effect of applying increasing levels of cellulase and hemicellulase plus pectinase (Celluclast ® and Viscozyme ®, Novo, Denmark) to peas and wheat silages was studied under laboratory conditions. The enzymes were applied at 0.02, 0.1 and 0.2% each, corresponding to 0.3, 1.5 and 3.0 NCU (Novo cellulase units) of Celluclast, and 0.024, 0.12 and 0.24 FBG (fungal β-glucanase units) of Viscozyme per gram of fresh crop. All treatments were enriched with a lactic acid bacteria inoculum, applied at 10 4 colony-forming units per gram of forage. The following parameters of final silages (45 days) had a significant ( P < 0.05) linear regression on log (enzyme concentration + 1): pH, residual sugars, lactic acid, NDF (neutral detergent fibre) and ADF (acid detergent fibre). When enzyme levels increased from 0 to 0.2%, the NDF and ADF contents decreased from 355 and 317 to 303 and 255 g kg −1, respectively, in the pea silages, and they decreased from 568 and 357 to 522 and 340 g kg −2, respectively, in the wheat silages. Enzyme treatments resulted in enhanced aerobic deterioration in both pea and wheat silages. This was evident from higher yeast and mould counts, more intensive CO 2 production and visible mould growth during exposure to air for 5 days.