Estabilidade aeróbia de silagens de capim-mombaça tratadas com Lactobacillus buchneri

Abstract

This study aimed to evaluate the effect of the addition of two L. buchneri strains on the aerobic stability of the Mombaça grass silages. The experiment was carried out in a completely randomized design with three replicates in split-plot in time scheme, so that the treatments (silages without inoculant and with experimental or commercial inoculants) were randomized on plot and in times of aerobic evaluation of the silages (0, 2, 8, and 10 days after the opening of the silos) as subplots. After an storage period of 90 days, the silos were opened and samples of about 2,5 kg were collected for the evaluation of the aerobic stability based on the temperature for each sample. The chemical and microbiological changes in the silages were evaluated. As soon as the silos were opened, changes in the silages were observed, with increases in the lactic acid bacteria, yeast and filamentous fungus populations. Also, the pH values increased due to the reduction in the organic acids concentration and to the increase in the DM and CP contents. The addition of L.buchneri to the silages increased their stability. The silages without inoculant was stable for 55 hours. The inoculated silages remained stable for 10 days. The improved stability was a consequence of an association of high acetic acid concentration with propionic acid and lower lactic acid concentration at the moment of silo opening, which resulted in inhibition of yeasts and molds.