When it comes to silage spoilage, mould and yeast usually get the blame. And while they certainly do damage—especially at feedout—they’re often just the tip of the iceberg. The real troublemakers might be hiding deeper in your clamp, long before you ever spot a dusty white patch or notice heating. These four unseen bacteria work quietly during fermentation, setting the stage for poor silage quality, reduced feed value, and livestock health issues.
So, let’s uncover the four bacteria in silage you really need to watch out for—and how to keep them under control.
1. Clostridia in Silage
Where does clostridia come from?
Clostridia usually come from soil or slurry contamination—think late slurry applications, low dry matter or crop sugars, or high crude protein levels. Once in the silage, clostridia thrive if the pH doesn’t drop quickly enough.
Why are they bad?
They produce butyric acid, which smells like rancid butter—and your cows agree! This foul odour signals poor feed quality, reducing intake and wasting precious energy and protein. Worse, Clostridia degrade protein and produce biongenic amines, toxic molekules making silage not feedable to animals.
What can you do?
Choosing the right silage inoculant is key. SiloSolve® MC contains a patented strain of Lactococcus lactis (SR3.54), which has been proven in trials to significantly reduce clostridia levels, outperforming even many standard inoculants. By lowering pH faster and creating conditions hostile to clostridia, it helps protect your silage before issues even start.
2. Listeria in Silage
Where does listeria come from?
Listeria is naturally present in soil, and can enter your silage through soil contamination. But it becomes a real threat when oxygen enters the silage—whether through poor sealing, damaged bales, loose clamp faces, or in feed troughs.
What does listeria do?
Listeria monocytogenes thrives in air pockets and poorly fermented silage that isn’t acidic enough. This bacteria can cause listeriosis, or “circling disease,” which can lead to abortions, loss of coordination, and death—especially in sheep and cattle.
What helps?
While SiloSolve® MC doesn’t directly kill listeria, it supports a faster, more stable fermentation, producing a silage environment that’s less welcoming to Listeria pathogens. Moreover, good bale wrapping and airtight sealing are essential to keep air out.
3. Enterobacteria in Silage (E.coli, Salmonella)
Why are they there?
Enterobacteria in silage—including E. coli and Salmonella—are present on fresh grass. They can contaminate silage through slurry application, soil contamination, poor fermentation, or oxygen exposure during ensiling or feed-out. If not controlled early, enterobacteria compete with good bacteria for sugars, slowing the crucial pH drop.
What’s the risk?
In addition to spoilage, enterobacteria can convert nitrates in plants into dangerous toxic silo gases (nitrogen oxides). These gases are not only harmful to livestock but also to people working near the clamp. Surviving strains may also cause scours, mastitis, or other infections in cows.
How to manage enterobacteria?
SiloSolve® FC helps drive a faster, cleaner fermentation, making it harder for harmful bacteria to establish. Trials have been shown it reduces E. coli O157:H7 during both fermentation and feedout, creating a safer and more stable feed.
4. Bacillus in Silage
How do bacillus enter silage?
Bacillus bacteria can enter silage through soil contamination or aerobic exposure during ensiling or feed-out.
What makes bacillus dangerous?
Bacillus in silage is tricky because these bacteria form heat-resistant spores that survive ensiling. Once oxygen enters the silage at feedout, they activate and begin heating the silage, consuming valuable lactic acid and raising the pH. This opens the door for yeasts and moulds to take hold.
How can you reduce their impact?
SiloSolve® FC, while not proven to directly target Bacillus, improves aerobic stability by limiting yeast growth and encouraging acetic acid production through Lactobacillus buchneri LB1819. This helps maintain silage quality, even at feedout.
Final Thoughts
The good news? Most of these bacterial threats can be managed with solid silage-making practices: proper wilting, chopping to the right length, tight compaction, and airtight sealing. For added protection and enhanced nutritional value, pairing good technique with the right inoculant, like SiloSolve® MC or SiloSolve® FC, can go a long way in improving your silage.
These inoculants help protect your silage by enhancing fermentation, improving aerobic stability, and promoting better dry matter retention. They’re proven to They‘re proven to improve the nutritional value, and increase protein preservation by 5%, ensuring more milk from forage and better overall quality. While they don’t completely eliminate all harmful bacteria, they make silage conditions less hospitable to unwanted microbes, boosting its overall nutritional value and stability.
Because, in the end, your silage is far too valuable to let unseen bacteria damage it.
