Effects of microbial inoculant and fibrolytic enzymes on fermentation quality and nutritional value of BRS capiaçu grass silage

Abstract

The objective of this study was to evaluate the effect of bacterial-enzymatic inoculants with different concentrations of fibrolytic enzymes on the fermentation quality and nutritional value of the silage of BRS capiaçu grass. Two bacterial-enzymatic inoculants with different levels of enzyme complex were evaluated (Silotrato® (5%) and Biotrato® (8%)) and control silage (without additive) according to a completely randomized design with eight replicates. To evaluate the silage aerobic stability, a completely randomized split plot design was used with three treatments (plots) and seven times after opening (subplots). There was no interaction between treatments and times after opening on values of pH (P=0.79). Regarding bacterial-enzymatic inoculants, the silage pH was 21.66% and 16.16% higher in silage without additive (mean of 6.00) compared to silage with 5% and 8% enzyme complex (P < 0.01). There was no difference between treatments on pH (P = 0.08), lactic acid (p = 0.08) and acetic acid (p = 0.64), means of 3.11, 47.31 g dry matter (DM)-1 and 11.19 g DM-1, respectively. There was no difference between treatments for any of the chemical composition variables (P = 0.86). Mean values for DM, crude protein, neutral detergent fiber and total digestible nutrients were 22.31%, 6.65%, 71.15% and 42.07%, respectively. There was a higher concentration of butyric acid in the control silage compared to Silotrato® silage. The control silage and silage treated with Biotrato® presented effluent losses (P = 0.05) 13.99% higher than silage with Silotrato®. For ensiling BRS capiaçu grass, it is recommended to use lactic acid bacteria containing 5% fibrolytic enzymes.