Rumen-protected fat (Ca salts)
97% dry matter, 33 MJ of metabolisable energy per kg of dry matter, 0% crude protein and 0% fibre (NDF) — the cited reference values behind our calculators.
Also called bypass fat, calcium salts of fatty acids.
Composition
Energy is MJ ME per kg of dry matter. Everything else is a percentage of dry matter.
| Measure | Value |
|---|---|
| Dry matter | 97% |
| Energy (ME) | 33 MJ/kg DM |
| Crude protein | 0% |
| Fibre (NDF) | 0% |
| Starch | 0% |
| Sugar | 0% |
| Fat | 84% |
Macro-minerals, % of dry matter
- Calcium
- 9.3%
Chloride is left out on purpose: standard lab digestion doesn't recover it, so published feed tables leave it blank and ours would be an estimate. A mineral left out here is one the source table didn't report — not a measured zero.
Where these numbers come from
Volac/Megalac and GP Feeds datasheets — calcium salts of palm fatty acids; digestibility basis from NASEM 2021 Dairy, Table 4-1.
Pure energy: it supplies no protein at all. Being rumen-inert is what lets a small daily amount approach the dietary fat ceiling safely — but total diet fat above about 6–7% DM still depresses fibre digestion and intake.
What it costs
Cents per megajoule is the figure that actually ranks feeds, because it is the only one that accounts for both water and energy density — a cheap wet feed and an expensive dry one can land in the same place. These prices are indicative starting points from mid-2026, not quotes: they move with region, volume and season, and every one of them is editable in the calculator.
How it compares
Other concentrates & by-products in the library, ordered by how close they sit to Rumen-protected fat (Ca salts) on energy.
| Feed | DM % | ME | Protein | Fibre | c/MJ |
|---|---|---|---|---|---|
| Rumen-protected fat (Ca salts)this page | 97 | 33 | 0% | 0% | 6.9c |
| Maize grain | 88 | 13.5 | 9% | 12% | 4.4c |
| Wheat grain | 88 | 13.5 | 12.5% | 13% | 4.2c |
| Field peas | 87 | 13.4 | 23.9% | 14.2% | 4.7c |
| Barley grain | 88 | 13 | 11% | 20% | 3.9c |
A dash under c/MJ means the feed isn't bought — grazed pasture and standing crops carry no purchase price, and showing them at zero would read as free.
Does it feed the animal?
A composition on its own can't tell you that. Open the calculator with Rumen-protected fat (Ca salts) added to the diet, set your stock and how much of it they're getting, and it will tell you what the diet actually supports — and which of energy, protein or gut fill runs out first.
Feedwise gives indicative models for decision support. It is not a substitute for a nutritionist or veterinarian — for animal-health decisions, talk to your vet.