Higher rates of Lactobacillus buchneri inoculum, which increases acetic acid levels, will likely be more effective in reducing aerobic spoilage in silage than lower concentrations, according to researchers.
Studies have shown that corn silage treated with L. buchneri at less than 100,000 colony forming units/gram (cfu/g) resulted in a 10-fold reduction in the number of yeasts that can cause spoilage. That treatment was compared to silage treated with greater than 100,000 cfu/g. That higher level decreased yeast counts by 100-fold, says Limin Kung, University of Delaware dairy nutritionist.
Both treatments brought improvements in aerobic stability, but those improvements were markedly greater in silage treated with higher L. buchneri rates, he says.
In other research, higher applications of the bacterium only increased dry matter losses in corn silage by one percentage point compared to untreated silage. “Relative to the potential beneficial effects of improved stability during storage and feeding, these losses are small,” Kung says.
Other studies also indicate that ruminants fed L. buchneri-treated silages consumed the same amount of dry matter compared to those fed untreated silages.
Silage inoculants aren't always effective, adds Kung, because they don’t necessarily react the same to the same stressors. “The ability of specific bacterial strains to withstand a multitude of stressors can be a key determinant for a successful inoculant.”