Cattle Feed Ration Calculator

Work out cattle feed ration instantly with clear inputs, formula shown and shareable results.

About Cattle Feed Ration Calculator

Dry matter intake is 2.5-3.5% of body weight for a dairy cow and up to 4% for a high yielder. The ration splits between forage and concentrate; a forage share below about 40% risks rumen acidosis. The production allowance is roughly 400 g of concentrate per litre of milk above maintenance.

Formulas

Dry matter intake

DMI (kg) = body weight x DMI %

Ration split

Forage DM = DMI x forage share; concentrate DM = DMI - forage DM; production concentrate = 0.4 kg per litre of milk

Worked example

With the default values below, Cattle Feed Ration Calculator returns Total Dry Matter Intake of 13.50. Change any input above and every figure here is recalculated in your browser.

Inputs used

Body Weightminimum 10 kg: 450 kg
Dry Matter Intakeaccepts 0.5–6 % of body weight: 3 % of body weight
Forage Share Of Rationaccepts 10–100 %: 60 %
Daily Milk Yieldminimum 0 L: 12 L

Results

Total Dry Matter Intake: 13.50
Forage Dry Matter: 8.10
Concentrate Dry Matter: 5.40
Concentrate For Milk Production: 4.80

Step by step

1Values used
2Dry matter intake
3Ration split
4Total Dry Matter Intake= 13.50
5Forage Dry Matter= 8.10
6Concentrate Dry Matter= 5.40
7Concentrate For Milk Production= 4.80

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why work in dry matter rather than fresh weight?

Green fodder is 75-85% water and silage 65-70%. Only dry matter carries nutrients, so rations balanced on fresh weight can be wildly wrong.

What happens if the forage share is too low?

Rumen pH falls, fibre digestion suffers and the cow risks subacute acidosis, laminitis and a drop in milk fat. Keep effective fibre above the minimum for the animal's stage.