Uso de bactérias lácticas da microbiota autóctone como inoculante na ensilagem de palma forrageira

Abstract

The objective of this work was to evaluate the use of lactic acid bacteria of the autochthonous microbiota as an inoculant in ensiling forage cactus and its effect on ensiling losses, fermentative characteristics and bromatological composition of forage cactus silage. A completely randomized design was used with the following treatments: Control (without inoculant), 5 major lactic acid-producing lactic cultures (GP21, GP22, GP23, GP24 and GP31) and 5 major acetic acid producers (GP1; GP2; GP3, GP5 and GP15), with three replicates per treatment. The fermentative losses of forage cactus silages treated and not treated with inoculants presented no significant differences (P> 0.05) and ranged from 3.55 to 9.27% for gas losses (GL) and 3.95 to 10, 47 g / kg for effluent losses (EL). There was significant effect of the inoculation on the dry matter recovery (DMR) of the silages (P <0.05). The control silage (untreated) and silages treated with GP2 (Lactobacillus plantarum) had lower dry matter recovery values (89.30 and 88.49%, respectively) when compared to the other silages. There was no difference (P> 0.05) for the concentrations of lactic acid (LA), acetic acid (AA), propionic acid (PA), butyric acid (BA), lactic acid:acetic acid ratio, pH and buffer capacity (BC) of the treated and untreated forage cactus silages. Was observed mean values ranging from 0.98 (GP24) to 1.40% in DM (Control) to AA; 0.04 (GP21; GP22) at 0.12% in MS (Control) for AP; 0.007 (GP15, GP21) at 0.011% in DM (GP3) for BA; the lowest AL/AA ratio was presented by GP2 treatment (Lactobacillus plantarum) with different behavior and the highest relation was observed for the treatment GP31 (Lactobacillus plantarum). Averages of BA and PA were below 0.5%. Mean pH values ranged from 3.87 (GP22) to 4.19 (GP1). For buffer capacity of the ensiled mass, the mean values ranged from 0.073 (Control) to 0.147 e.mg / 100 g DM (GP24), with no effect (P>0.05) among the treatments studied. For dry matter (DM) and neutral detergent fiber (NDF) values, there was no effect due to the use of the inoculant. The crude protein (CP) levels obtained in the evaluated treatments (GP1, GP2, GP3 and GP5) presented significant differences, observing the lowest values in the silages with the presence of homofermentative inoculant. Both microbial (homo and heterolytic) inoculants provided a suitable fermentative standard, and demonstrated beneficial particularities. Probably due to the lower protein degradation (proteolysis) during the fermentation process, the silages inoculated with heterolactous bacteria had a CP value, similar to the original forage, with higher proportions of CP compared to the homoláticas strains. Based on this, it would be interesting to carry out studies with the combination of homofermentative and heterofermentative LABs in forage cactus silage.