Silage Loss & Count the Dry Matter You Keep
Conserves grass
Ensiling always costs dry matter to fermentation, effluent and spoilage — enter the fresh tonnes, dry-matter percent and expected loss to get the dry matter retained, dry matter lost and silage out.
Estimate your silage losses
Next: budget feed on the 8.2 t of dry matter you actually keep, not the 9.6 t you ensiled; tightening compaction and sealing can claw back much of the 1.4 t lost.
Losses come from field wilting, fermentation, aerobic spoilage and feed-out; well-managed clamps lose ~10–15%, poorly sealed ones can exceed 25%.
Silage loss — key facts
- DM in
- fresh weight × DM%
- DM retained
- DM in × (1 − loss%)
- DM lost
- DM in × loss%
- Silage out
- retained DM ÷ silage DM%
- Typical loss
- ≈ 10–15% well-made
- Loss causes
- fermentation, effluent, spoilage
- Measured on
- dry-matter basis
- Privacy
- Runs in your browser; nothing uploaded
Every point of loss is feed that never reaches the trough
Silage is forage preserved by fermentation, and fermentation costs dry matter — sugars are burned to acids, effluent drains nutrients, and trapped air feeds spoilage. The dry matter you put in the clamp is never all the dry matter you take out. Measuring on a dry-matter basis matters because that, not the water, is what feeds the animal. A simple balance shows how much feed each percent of loss really costs.
This tool gives the silage out, dry matter retained, dry matter lost and loss percent from the fresh weight and dry-matter percent. Use it to budget winter feed, compare clamp management, and put a tonnage on better sealing and compaction. Pair it with the Bypass Fat Supplement, Cattle Cooling Water and Milk Standardization tools for a full herd-feeding plan.
See the real cost
Turn a loss percent into tonnes of lost feed.
Budget winter feed
Know the dry matter that actually survives.
Justify better clamps
Value the feed that sealing and packing save.
Works any crop
Same balance for grass, maize or wholecrop.
Frequently Asked Questions
How is the dry-matter loss calculated?+
The tool first finds the dry matter going in: fresh weight × dry-matter percent. It then applies the loss: dry matter retained = DM in × (1 − loss%), and dry matter lost = DM in × loss%. The silage coming out as fresh tonnes is the retained dry matter scaled back up by the silage dry-matter percent. Every figure follows directly from those balances.
Why does silage lose dry matter at all?+
Ensiling is a controlled fermentation, and fermentation burns sugars to make the acids that preserve the crop, releasing carbon dioxide and heat — that is real dry matter gone. On top of that, effluent can carry away soluble nutrients, and any air left in the clamp lets spoilage organisms eat more. So some dry-matter loss is unavoidable; the goal is to keep it small.
What is a typical dry-matter loss for silage?+
Well-made silage in a sealed clamp or bale often loses around 10–15% of its dry matter from field to feed-out. Poorly compacted, slowly sealed or badly fed-out silage can lose 20–30% or more. The figure you enter should reflect your system; the tool then shows the tonnes of feed that loss actually costs you.
What drives higher losses?+
Slow filling and sealing, loose compaction that traps air, ensiling too wet (which increases effluent) or too dry (which prevents good packing), warm weather, and a slow feed-out face that re-heats. Each of these lets more dry matter be respired away or spoiled. Reducing them is the cheapest way to put more feed in front of stock.
What is dry matter and why measure it?+
Dry matter is what is left after all the water is driven off — the actual feed substance. Fresh forage is mostly water, so two clamps of equal fresh weight can hold very different feed if their dry-matter percent differs. Losses are measured on a dry-matter basis precisely because that is what feeds the animal, not the water.
Do I need to know the silage dry-matter percent separately?+
To convert retained dry matter back into silage tonnes, yes — the silage out depends on the dry-matter percent of the conserved feed, which is usually close to the crop you put in. If you only want the dry-matter figures you can read those directly; the silage-out tonnes is the extra step that turns dry matter back into a clamp weight.
Does this work for grass and maize silage?+
Yes — grass, maize, wholecrop and legume silages all follow the same dry-matter balance. Only the numbers change: maize ensiles at a higher dry matter and often lower loss, while wet grass can lose more to effluent. Enter the values for your crop and the calculation holds.
How can I reduce the loss this shows?+
Fill and seal fast, compact hard in thin layers, ensile at the right dry matter, use an effective film or inoculant, and feed out across a tight, fast-moving face. Each step cuts the dry matter that ferments away or spoils, so the retained tonnes the tool reports go up.
Are the figures precise?+
They are solid planning figures from your inputs. Actual loss depends on the season, the harvest and how the clamp is managed, so treat the result as a working estimate. Weigh loads and sample dry matter where you can, and use the tool to compare scenarios and set realistic feed budgets.