Magnesium oxide
A mineral product, dosed in grams per head per day rather than fed by the kilogram. Supplies magnesium at 55% of its dry matter.
Also called mag oxide, causmag.
Composition
Every figure is a percentage of dry matter. A mineral product carries no meaningful energy, protein or fibre, so those measures are left out rather than printed as zeroes.
Macro-minerals, % of dry matter
- Dry matter
- 99%
- Magnesium
- 55%
Where these numbers come from
Feed-grade magnesium oxide (causmag) specification.
What it costs
There is no cost per megajoule here: a mineral product is bought for what it supplies, not for energy. 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.
Work out the dose
Mineral products are dosed in grams per head per day. Open the calculator with Magnesium oxideadded to the diet, set the dose, and it will show what that does to the diet's mineral balance.
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.