How this calculator works
Forage production is expressed as dry matter per area over the relevant grazing period. The usable share accounts for residual forage, trampling and other losses. Divide usable forage by each animal's demand over the entered months. Manitoba Agriculture uses a 1000 lb cow as one animal unit and rounds monthly demand to 355 kg; the demand field is editable. Cow equivalents scale with weight, while the heifer, steer and bull examples follow the Manitoba table. A clipped sample measures standing forage only unless the sampling plan also captures regrowth.
Formula
Usable forage = area (ha) × dry-matter production (kg/ha) × utilization. Cattle capacity = usable forage/(kg per AU-month × AU per head × grazing months).
Worked example
Ten hectares producing 2000 kg dry matter/ha with 50% utilization provide 10000 kg usable forage. At 400 kg per head per month for five months, capacity is five cattle.
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Frequently asked questions
Can rainfall alone predict stocking rate?
Not reliably across regions and pasture types. Use measured forage or locally calibrated production guidance instead of a universal rainfall rule.
Is this instantaneous stocking density?
No. The cattle-per-area result applies to the entire entered grazing period. A short rotational paddock occupation can have a much higher instantaneous density.
Should I use fresh clipped weight?
No. Dry the sample or convert it to dry matter before entry. Water content can make fresh forage mass misleading.