Cattle Ration Calculator: Dry Matter, UFL Energy and PDI
Determine daily feed requirements in Dry Matter (DM), Net Energy (UFL), and Digestible Protein (PDI) using the INRAE feed unit system.
Dairy cow ration: UFL energy, PDI protein and dry matter needs
The tool adds to the animal's maintenance needs an allowance per kilo of milk or per 100 g of daily gain: 0.44 UFL and 50 g of PDI per kilo of milk for a dairy cow. A Holstein giving 28 kg of milk therefore needs about 17.8 UFL, 1,780 g of PDI and 19.8 kg of dry matter a day, then split between forage and concentrate.
Calculated needs
| Animal | Maintenance | Production allowance | Intake (kg DM/day) |
|---|---|---|---|
| Dairy cow | 5.5 UFL, 380 g PDI | 0.44 UFL and 50 g PDI per kg of milk | 10 + 0.35 × milk |
| Suckler cow | 6 UFL, 420 g PDI | 0.42 UFL and 45 g PDI per kg of milk | 11 + 0.2 × milk |
| Young bull | 4.8 UFL, 350 g PDI | 0.38 UFL and 35 g PDI per 100 g of daily gain | 5 + 0.012 × weight |
| Ewe, goat | 0.8 or 0.85 UFL, 60 or 65 g PDI | 0.40 UFL and 55 g PDI per litre | 0.02 × weight + 0.4 × milk |
Dry matter is split according to the forage share you choose; concentrate is converted to fresh weight at 88% DM and priced per tonne over 30.5 days.
Worked example
60 cows of 650 kg giving 28 kg of milk, 65% forage, concentrate at €340/t: 5.5 + 28 × 0.44 = 17.82 UFL, 380 + 28 × 50 = 1,780 g PDI, 10 + 28 × 0.35 = 19.8 kg DM, of which 12.9 kg forage and 6.9 kg DM concentrate (7.9 kg as fed). The herd eats 36.2 t DM a month and about €4,900 of concentrate.
Limits
Maintenance needs are fixed per species: the live weight you enter changes neither maintenance nor intake for cows; it only matters for the young bull, ewe and goat. Butterfat, lactation stage, pregnancy and the actual feed value of your forage are ignored. The result is an order of magnitude to refine with a feeding plan drawn up by a livestock adviser.
Sources and dates: maintenance, production and intake coefficients are indicative values of the tool expressed in the French INRAE UFL/PDI system, not verified; 88% DM for concentrate is an indicative value (checked 14/10/2026).
Frequently Asked Questions
How many UFL are needed per kilo of milk?
The tool uses 0.44 UFL and 50 g of PDI per kilo of milk for a dairy cow, on top of 5.5 UFL and 380 g of PDI for maintenance. A cow giving 30 kg of milk therefore needs about 18.7 UFL a day.
How much dry matter does a dairy cow eat per day?
The tool estimates intake at 10 kg + 0.35 kg per kilo of milk: 19.8 kg of dry matter for 28 kg of milk, 20.5 kg for 30 kg. An actual ration also depends on forage quality and lactation stage.
How do I convert dry matter into the fresh weight of concentrate?
Divide the dry matter by the concentrate's DM content; the tool uses 88%. So 6.9 kg of concentrate DM equals 7.9 kg to feed as is.
What share of forage should the ration contain?
The tool's slider sets the forage share of dry matter, 65% by default; the rest comes from concentrate priced per tonne. The right balance depends on yield and the forage you have, so check it with your livestock adviser.
Is this tool really free?
Yes, all tools on Kristools are 100% free and accessible without registration.
Is my data protected?
Yes. All processing is performed directly and securely inside your browser. No personal data is sent to our servers.