The effects of buffered propionic acid-based additives alone or combined with microbial inoculation on the fermentation of high moisture corn and whole-crop barley.

Buffered propionic acid-based additives (BP) alone or in combination with a microbial inoculant containing lactic acid bacteria (MI) were mixed with ground, high moisture corn or whole-crop barley and ensiled in triplicate laboratory silos to investigate their effects on silage fermentation and aerobic stability. The inoculant and chemicals were applied separately for treatments that included both additives. The addition of MI alone had no effect on DM recovery, fermentation end products, or aerobic stability of high moisture corn. However, treatments with 0.1 and 0.2% BP (alone and the combination) had more than 10- and 100-fold fewer yeasts, respectively, and they also had greater concentrations of propionic acid than did untreated corn. Corn treated with only 0.1 (161 h) and 0.2% (218 h) BP tended to be more stable when exposed to air than untreated corn (122 h). Treatment with MI + 0.2% BP markedly improved the aerobic stability (>400 h) of high moisture corn. With whole-crop barley, the addition of MI alone, BP alone, and combinations of MI and BP prevented the production of butyric acid that was found in untreated silage (0.48%). All barley silages that had MI in their treatments underwent a more efficient fermentation than treatments without MI, as evident by a greater ratio of lactic:acetic acid and more DM recovery than in untreated silage. Increasing levels (0.1 to 0.2%) of BP added together with MI improved the aerobic stability of barley (190 and 429 h) over the addition of MI alone (50 h). These data show that buffered propionic acid-based products are compatible with microbial inoculants and, in some circumstances when used together, they can improve the fermentation and aerobic stability of silages.

The effect of a dry or liquid application of Lactobacillus plantarum MTD1 on the fermentation of alfalfa silage.

Alfalfa was wilted to 30 and 54% dry matter and was untreated or treated with Lactobacillus plantarum MTD1 applied either as a liquid or dry inoculant to determine whether form of inoculation affected silage fermentation. In silages with 30% dry matter, both forms of inoculation resulted in silages with more lactic acid and a lower pH than in untreated silage after 2 d of ensiling. In addition, both forms of inoculation resulted in silages with lower concentrations of acetic acid between 8 and 45 d of ensiling than in untreated silage. The ammonia-N content was also lower in silages that had been treated with both forms of inoculation during the early and intermediate stages of ensiling, but not after 45 d of ensiling. In silages containing 54% dry matter, dry and liquid inoculation produced a more rapid decrease in pH from d 4 to 14 when compared with untreated silage, but the effect was greater when the inoculant was applied in water. In contrast to findings from 30% silages, the inoculated silages with 54% dry matter had lower concentrations of ammonia-N than untreated silage from d 8 to 45, and both forms of inoculation were equally effective. The results of this study agree with previous research that shows that microbial inoculation can improve the fermentation of alfalfa silage. However, this report shows that a microbial inoculant was more effective when applied in a liquid- rather than a dry-form to alfalfa with a high DM content.