Glossary · Silage
Fermentation Loss
Dry matter lost during the fermentation phase of ensiling, primarily from microbial activity converting sugars to volatile compounds.
Fermentation loss is the dry matter lost during the fermentation phase of ensiling — typically the first 1–3 weeks after a pile is sealed.
Fermentation is a biological process. Lactic-acid bacteria consume sugars and produce lactic acid, dropping the pH and preserving the silage. Some dry matter is consumed in this process and lost as carbon dioxide. A well-fermented silage loses 2–5% of its dry matter to fermentation. A poorly-fermented silage can lose double that.
The biggest drivers of fermentation loss are:
- Oxygen exposure during filling and packing — which fuels aerobic yeasts and molds that consume sugars instead of producing acid.
- Initial moisture — too wet, you get clostridial fermentation (which is bad); too dry, you get incomplete fermentation.
- Sugar availability — lactic-acid bacteria need fermentable sugar to do their work.
Fermentation loss is a subset of total silage shrink. The other subsets — surface spoilage, feedout loss, hauling loss — happen at different stages and have different remediations.