Efeitos do inoculante microbiano e das enzimas fibrolíticas na qualidade fermentativa e no valor nutricional da silagem de capimBrs capiaçu

Abstract

The cultivar BRS Capiaçu is an elephant grass clone, developed for bulky supplementation in the form of silage or green chop. Due to its high fibrous fraction, the use of bacterialenzymatic inoculants has been tested as an alternative. The objective of this study was to evaluate the effect of commercial bacterial-enzymatic inoculants with different concentrations of fibrolytic enzymes on the fermentative quality and nutritional value of BRS Capiaçu grass silage. 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 aerobic stability of the silage, a completely randomized split plot design was used with three treatments (plots) and seven times after opening (subplots). Regarding bacterial-enzymatic inoculants, the pH of the silage was 21.66% and 16.16% higher in the silage without additive (mean of 6.00) compared to the silage with 5% and 8% of enzymatic 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 the silage with Silotrato®. The control silage and the silage treated with Biotrato® presented effluents losses (P = 0.05) 13.99% higher than the silage with Silotrato®. For ensiling of BRS Capiaçu grass, it is recommended to use lactic acid bacteria containing 5% of fibrolytic enzymes.