Paddock Rotation Planner NZ
This works out the round length your paddocks and grazing days give you, the break a mob needs each day, and whether the growth rate you are getting can actually sustain that round. The round length is the number that matters most, and it is easy to think of it as a decision about the stock when it is really a decision about the plant: it is how long a paddock gets to recover before the mob comes back. In spring, when pasture is growing fast, a short round works because the paddock has regrown by the time it is needed. In autumn the same round brings stock back to a paddock that has not recovered, covers fall away across the whole farm at once, and by the time it is obvious it takes weeks to climb back out. Lengthening the round is how a farm slows its demand to match what the pasture can supply, which is why the growth check here compares the two directly rather than leaving you to feel your way. The break size is the other half. It is the area that supplies the mob for a day at the cover you are grazing, and the residual you leave behind is a real decision inside it: grazing lower makes every break go further and takes more out of the plant.
A round of regrowth only takes a paddock to 2,558 kg DM a hectare against the 2,900 the plan assumes, so every pass starts lower than the last. The round length is a decision about the plant, not the stock. It is how long a paddock gets to recover before the mob returns.
How it works
The round is the paddock count multiplied by the days spent in each. The break size divides the mob's daily demand by the dry matter available a hectare, which is the pre grazing cover less the residual you intend to leave rather than the whole cover, because the residual is not eaten. Regrowth in a round is the growth rate multiplied by the round length, which is what a paddock will have put on by the time the mob comes back to it, and comparing that against the cover you want to graze is the check the page exists to make.
The check that matters
If regrowth over a round does not bring a paddock back up to your target cover, the round is too short for the growth you are getting, and every pass around the farm will start from a lower cover than the last. That is the mechanism behind a farm falling behind in autumn, and it happens gradually enough to be invisible for a fortnight and then obvious all at once. The fix is a longer round, fewer stock, or bought feed, and it is much cheaper when the arithmetic says so in March than when the paddocks say so in May.
Worked example
A farm with 24 paddocks grazed a day each is on a 24 day round. A mob of 320 cows eating 16 kilograms of dry matter a day needs 5,120 kilograms, and at a pre grazing cover of 2,900 kilograms a hectare grazed to a residual of 1,550, each hectare supplies 1,350 kilograms, so the break is 3.79 hectares a day. Across 96 hectares the farm grows 4,032 kilograms a day at 42 kilograms a hectare, which is less than the mob eats. Over the 24 day round each paddock regrows 1,008 kilograms a hectare on top of the 1,550 residual, reaching 2,558 rather than the 2,900 the plan assumes: the round is too short for this growth rate and the farm is going backwards.
Related calculators
- Farm Feed Budget: the same question over a season.
- Stock Units: converting the mob into demand.
- Silage Stack Yield: what is on hand to fill a gap.
- Lifestyle Block Stocking: the same logic on a small block.