Aerobic stability, chemical composition and ruminal degradability of sugarcane silage with glycerin from biodiesel

Resumo

The experiment was performed with the objective of studying the ensiled sugarcane silage with 0, 5, 10, 15 and 20% of glycerin in experimental PVC silos. The aerobic stability was assessed by measuring the pH and the temperature of the silage at 0, 24, 48, 72, 96 and 120h. The chemical composition, the levels of non-fiber carbohydrates (NFC) and the total digestible nutrients (TDN) were evaluated. The in vitro digestibility of dry matter (IVDDM) and the in vitro digestibility of the cell wall (IVDCW) in the silages were evaluated. In three fistulated cattle the in situ degradability of dry matter (DM) and the disappearance percentage of the neutral detergent fiber (NDF) in samples incubated at 0, 2, 6, 12, 24, 48, 72 and 96h were analyzed. The experimental design was completely randomized and the statistical analyzes were done using Bayesian inference. Increases were observed in DM, TDN, mineral matter, NFC and reductions in NDF, acid detergent fiber, crude protein and ether extract as the inclusion of glycerin was higher. IVDDM increased (P <0.05) in silage with 15 and 20% of glycerin in relation to those with 0, 5 and 10%. The IVDCW at levels of 10, 15 and 20% of glycerin was higher (P <0.05) compared to the other treatments. Increases were observed in the soluble portion (a), a reduction in the insoluble fraction (b), and an increase in the degradability fraction constant (c) of the silages with 5, 10, 15 and 20% of glycerin (P <0.05) compared to the control. Glycerin improved aerobic stability while maintaining a low pH and temperature during the observation period at levels of 15 and 20% of glycerin against the silage with 0, 5 and 10%. These results indicate glycerin as a promising additive for sugarcane silage, being able to enhance energy density and improve the aerobic stability of the ensiled matter when its inclusion is from 10 to 20%.