The objectives of this study were to analyze the effects of wilting and bacterial-enzimatic additive (BEA) and buffered propionic acid (BPA) on the microbial profile, physical parameters and aerobic stability of Tifton 85 (Cynodon spp.) silages stored as squared bales (140 x 120 x 70 cm) wrapped with plastic bags. Treatments were based on five forage dry matter (DM) contents (250, 350, 450, 550 and 650 g/kg DM) without BEA. Other three forage dry matter contents (250, 450 and 650 g k/g DM) were associated with BEA while a wilted forage (650 g/kg DM) was sprayed with BPA. Silage samples were taken at ensiling time, and after 6 and 12 hours and 1, 2, 4, 8, 16, 32, 90 and 180 days of fermentation. The experimental design was completely randomized with three replications; with DM levels set as the main factor and fermentation time as a split-plot feature of the design. Silages containing higher DM contents (> 450 g/kg DM) showed lower bacterial counts, intermediary values of water activity (Aw) and silage N-NH3, and improved values of electrical conductivity (EC), pH and higher aerobic stability as compared to the wet silages. Results suggest a decrease in Aw followed by an inibition on microorganism growth and silage fermentation as the silage DM increased. The BEA had positive effect on the silage with dry-matter content of 450 g/kg, mainly on the 32nd day of storage, whereas BPA addition had no benefit.
bacterial-enzymatic additive; propionic acid; wilting
