How long a pasture lasts — forage pounds × allowable utilization ÷ herd demand.
Grazing days
15.0 days
Total standing forage
7,500 lb DM
Usable forage
at 50% utilization
3,750 lb DM
Daily herd consumption
250 lb DM
The "take half, leave half" rule keeps enough residual leaf area for regrowth — over-grazing past that point cuts regrowth rate in half and invites weeds. 50% utilization is conservative; rotational grazers may push to 60–70% on short stays with long rest.
Forage availability is reported on a dry matter (DM) basis. Fresh pasture is about 25% DM, so 1500 lb DM per acre is roughly 6000 lb of green standing grass.
total_forage = acres × lb_per_acre
usable = total × utilization_pct
grazing_days = usable ÷ (head × daily_intake)