Formula
Animal units = number of animals × average weight ÷ weight of one animal unit (1,000 lb in the US). Stocking rate = animal units ÷ area.
Example
100 head averaging 800 lb make 80 animal units. On 200 acres, the stocking rate is 0.4 AU/acre. At a target of 0.5 AU/acre, the same pasture holds 125 head, so there is room for 25 more.
Choosing the target
It depends on the forage, the rainfall and the season. Rotational grazing usually supports more animals than continuous grazing. Watch the grass height and adjust before the pasture runs out.
Frequently asked questions
Why use animal units?
A calf and a mature cow eat very different amounts. Converting by weight lets you compare herds of different sizes.
What is an AUM?
An animal unit month: the forage one animal unit eats in a month, about 780 lb of dry matter.
See also
Results are estimates for information only and are not financial, legal or medical advice. Rates, taxes and fees vary — confirm with a professional or your lender.