Potassium (K)
Almost never deficient here, and the usual cause of the two mineral problems that look like something else — staggers and a stubbornly positive DCAD.
Often searched as high potassium pasture, K:Na.
What it changes in the tools
- Grass staggers index
- Potassium is the numerator: K ÷ (Ca + Mg) in milliequivalents, danger above 2.2. High-potassium spring pasture is what pushes it there.
- Source: Kemp & 't Hart (1957).
- DCAD
- Potassium is the largest positive term in (Na + K) − (Cl + S), which is why pasture is the hardest thing to write a low-DCAD transition diet around — the published prepartum goal is below +50 meq/kg DM or negative, and NZ pasture measures about +200 to +900. For everything that is not a cow about to calve, a positive DCAD is simply what pasture is, and needs no action. Note too that DairyNZ report ordinary pasture potassium (1.0–4.5% of DM) does not by itself raise milk-fever risk — it is effluent and heavily fertilised paddocks that lift the odds.
- Source: Equivalent weights: standard atomic equivalents. Prepartum goal: Beede 2007 (Michigan State / DAIReXNET). Pasture potassium and milk-fever risk: DairyNZ.
Which feeds carry the most potassium
From the cited composition of every feed in our library, as a percentage of dry matter. Useful when the answer is a feed change rather than a mineral product.
| Feed | % of dry matter |
|---|---|
| Chicory | 3.64% |
| Molasses (cane) | 3.5% |
| Pasture — autumn (medium) | 3.2% |
| Pasture — summer (stemmy) | 3.2% |
| Pasture (leafy spring) This is pasture at its spring best, not a year-round average. For the rest of the year the seasonal pasture entries will be closer. | 3.2% |
| Pasture (NZ spring midpoint) | 3.2% |
Read it for your farm
Build the diet and it works the mineral balance out for you — including the indices below.
These are published reference bands, not a diagnosis. Mineral deficiencies and toxicities are diagnosed from the animal — blood, liver or tissue — not from a pasture test alone, and the treatment rates are veterinary decisions. Talk to your vet before dosing stock.