How to read a forage utilization map before moving cattle
A forage utilization map is just a picture of how much grass your cattle have already eaten in a pasture, broken into bands. Most ranch managers run into one for the first time through a university extension handout or a grazing consultant's report, and the legend looks straightforward until you're standing at the gate trying to decide if today's the day to open it.
What the bands actually mean
Utilization maps usually sort a pasture into five classes: light (0-20%), moderate (21-40%), full use (41-60%), heavy (61-80%), and severe (81-100%). Those percentages are how much of the current year's forage production has been grazed off, not how much grass is left standing. A pasture can look green from the truck window and still be sitting at 70% utilization if the regrowth is coming off plants that were already hit hard earlier in the season.
The number that matters more than the color is residual. Take-half-leave-half is the old rule of thumb, and it still holds: once you've removed roughly half the standing crop, the other half needs to stay for root reserves and ground cover. A map showing "full use" across most of a pasture is your cue to start planning the move over the next several days, while there's still a cushion before the readings climb into heavy.
Reading it against your rotation, not in isolation
A single utilization reading doesn't tell you much by itself. What tells you something is the trend between readings. If utilization jumped from 30% to 55% in two weeks, your cattle are working through that pasture faster than you budgeted, and the next paddock in the rotation needs to be ready sooner than planned. If it's crawling up slowly, you may have more flexibility than your grazing chart says.
This is also where grass bank reading comes in. A grass bank, a pasture or portion of a ranch held in reserve for drought years or late-season grazing, should show minimal utilization through most of the grazing season. If a bank pasture is climbing past light use before you've turned anything into it, something's wrong with your fencing, your water placement, or your assumptions about how much forage that ground is carrying.
When the map says move
Move cattle while the pasture is still reading moderate to full use, before the bands tip into heavy or severe. Waiting until a map shows 70-80% utilization to start the gather means cattle were already grazing regrowth and hammering the same plants twice, which is exactly the pattern that turns a good pasture into a weak one over two or three seasons. The better practice is to check utilization on a schedule tied to your rotation length, not just when something looks off from the truck.
For operations running cattle across open range where paddocks are too big to walk or glass in a day, that check is the hard part. A hand count from a truck tells you where the herd is standing right now, not how many head are out there or how that number lines up against what the pasture can carry. Pairing a head count with a biomass read on the same pasture, on a repeatable schedule, is what turns "the grass looks thin over there" into a stocking-rate decision you can act on. That's the gap Livestock Counting is built to close, a monthly count paired with a pasture read so you see the over- or under-stocked paddocks before the grass tells you itself.
If you're the one deciding whether to open a gate this week, get a count and a utilization read for your pastures before you decide.