Effect of a Chemical Additive on Fermentation and Aerobic Stability of High-Moisture Corn
The objective of this experiment was to evaluate effect of a chemical additive on fermentation and aerobic stability of high moisture corn (HMC). Ground HMC (~63% DM) was untreated, or treated with 2 L of Safesil (SAFE, sodium nitrite, potassium sorbate, and sodium benzoate, Salinity Agro, Halmstad, Sweden)/t of fresh HMC, 3 L of SAFE/t, or 4 L of SAFE/t. Lab silos (7.5 L, 4 silos/treatment/time point) were prepared (density of 672 kg of DM/m3) and ensiled for 21 and 90 d at 22 ± 2 °C. Data were analyzed as a 4 × 3 factorial arrangement of treatments with main effects of Safesil (4 levels) and days of ensiling (0, 21 and 90 d), and their interaction, using the software JMP, version 10. Numbers of yeasts were similar (P > 0.05) among treatments in fresh HMC (log 6.9 to 7.1 log cfu/g) but decreased (P < 0.01) substantially after ensiling (< 3.3 log cfu/g). Numbers of yeasts were similar (P = 0.33) among treatments after 21 d of ensiling but after 90 d they were lower (P < 0.01) in HMC treated with SAFE (< 2 log cfu/g for all levels) compared to untreated HMC (3.22 log cfu/g). Compared to untreated HMC, addition of SAFE to HMC at all levels did not affect the concentrations of organic acids (lactic, acetic, and propionic) or pH at any ensiling time. In contrast, treatment with SAFE markedly decreased (P < 0.01) the concentrations of ethanol in HMC after 21 and 90 d (< 0.25% of DM for all SAFE levels) when compared to untreated HMC (1.02 and 0.76 % of DM, respectively at d 21 and 90). Treatment with SAFE markedly improved (P < 0.01) the aerobic stability of HMC after 30 d (89 h for untreated HMC vs. > 500 h for HMC treated with SAFE at all levels) and after 90 d of ensiling (77 h for untreated HMC vs. > 500 h for HMC treated with SAFE at all levels). This was the first evaluation of Safesil on HMC in North America and it showed that this additive, even when added at a relatively low level (2 L/t) effectively improved the aerobic stability of HMC and reduced concentrations of ethanol without altering the concentrations of organic acids or pH.
Keywords: high moisture corn, fermentation