Glicerina bruta na ensilagem de Urochloa brizantha cv. Piatã

Abstract

The expansion of Brazilian biodiesel production has caused a growing concern with the recycling of crude glycerin produced during this process. In order to find an alternative use for this byproduct, the objective of this study was to evaluate the improvements in fermentation and nutritional value of the silage of Urochloa brizantha cv BRS Piata harvested at three cutting ages and ensiled with different levels of crude glycerin. The experiment was conducted in a completely randomized design in a 4x3 factorial scheme, four doses of crude glycerin (0, 10, 20 and 30% DM silage) and three cutting ages (30, 45 and 60 days) with three replicates per treatment (silos). The parameters of dry matter losses (DML), gas losses (GL), pH, microbial population and nutritional value of the silage were evaluated. There was no difference in pH among the tested doses of glycerin. However, reductions in DML and GL were observed in function of glycerin doses. Bacterial populations of lactic acid and facultative mesophilic anaerobes were increased in function of glycerin doses as well. Crude glycerin increased EE levels and reduced NDF and ADF contents, improving the chemical composition of the produced silage. In conclusion, crude glycerin can be used in the ensiling of Piata grass and the dose of 30% was the one that showed the best results.