In the same way that you need to understand stocking rate and carrying capacity, when it comes to making grazing decisions it is useful to understand feed budgeting.
Season to season, year to year, each paddock and pasture system offers a finite resource that determines how many animals you can stock. In turn, the quality and quantity of feed that animals need changes throughout the year.
Like any budget, feed budgeting is about reconciling supply and demand. To be able to meet stock needs you must know what they need and what’s available. This sum can identify if there is a surplus or deficit, and what the consequences of either may be. It can answer a question in the paddock: how long will it support this particular mob of animals?
The calculation is:
(the feed in kilogram of dry matter available per ha – what you’ll leave behind) x ha (+ growth for longer graze periods) / (the intake target per head per day x the number of stock) = how long the paddock will last and meet these targets
A similar calculation can estimate whether there is enough feed for a set number of days, say over winter to the start of spring, to a target like lambing, or to the so-called magic spring day, when growth finally matches demand.
Whether you have an excess of feed or a deficit, knowing the situation by pasture budgeting is useful. It can help you to reduce your risks and exploit opportunities when they present themselves.