Enzyme, bacterial inoculant, and formic acid effects on silage compositionof orchardgrass and alfalfa

We evaluated the effects of cellulase (from Trichoderma longibrachiatum) ap plication rates on neutral detergent fiber (NDF) concentration and fermenta tion products of orchardgrass (Dactylis glomerata L.) and alfalfa (Medicago sativa L.) silages harvested with decreasing dry matter (DM) digestibility . Additionally, the impacts of inoculant (Lactobacillus plantarum and Pedio coccus cerevisiae), pectinase (from Aspergillus niger), or formic acid on s ilage composition were studied. Forages wilted to a DM content of about 320 g/kg were ensiled in laboratory silos for 60 d. Cellulase, combined with i noculant, was applied at 2, 10, and 20 ml/kg of herbage (at least 2500 IU/m l). Cellulase at 10 ml/kg was also applied alone or in combination with pec tinase and inoculant or formic acid. The NDF concentration of orchardgrass silage decreased with increasing cellulase up to 20 ml/kg, at which NDF con tent was decreased by 30%. The NDF concentration of alfalfa silage decrease d with increasing cellulase application up to 10 ml/kg, at which NDF conten t was decreased by 13%. Immature plants were more responsive to cellulase t reatment than mature plants. Cellulase at 2 ml/kg combined with inoculant i mproved fermentation characteristics of the silages but generally, there wa s no effect on silage fermentation by higher cellulase applications, result ing in an accumulation of sugar. The improved fermentation of orchardgrass treated with cellulase and inoculant was mostly related to the effect of in oculant, whereas cellulase alone improved fermentation characteristics of a lfalfa silage and this effect was enhanced by addition of inoculant. Decrea sed NDF and increased sugar concentrations did not improve the in vitro DM digestibility of cellulase-treated silages.