Rotational Grazing

Rotational grazing means dividing pasture into fenced sections, called paddocks, and moving the animals from one to the next so each is grazed briefly and then left alone to regrow. Ground handled this way produces more feed than the same ground grazed continuously - about 20 percent more under a simple rotation, and 30 to 50 percent more where the moves are managed closely. Part of the gain is manure. Animals left in one place drop most of it around shade and water; moved on a schedule they spread it over every paddock they pass through.

The timetable belongs to the plants rather than to the calendar. Once grazed, a plant rebuilds its leaves out of stored reserves and needs time to finish before the animals come back: a cool-season grass may want two weeks in cool weather and five to seven in hot, a legume three to four throughout. How far down it is grazed matters as much as how long it rests, because the buds new growth comes from sit low - tall fescue and orchardgrass are taken from about 15 to 20 cm (6 to 8 in) down to 8 to 10 cm and no further. The number of paddocks then follows from arithmetic: a 35-day rest, with stock spending 3.5 days in each cell, needs ten.

Two things are not optional. The ground has to be subdivided, and every cell needs drinking water, the tighter constraint of the two. Cattle made to walk more than about 240 m (800 ft) to drink eat less, so a rotation built on fence lines alone with one central trough can do worse than what it replaced. The other cost is time: a move takes an experienced grazier 15 to 45 minutes, and since the cost per animal falls as the herd grows, a rotation that pays on a large herd is uneconomic on a few. Run to a fixed calendar through a dry spell, it overgrazes exactly as continuous stocking would, and a rest too short to break the cycle of internal worms can leave a paddock carrying more of them than before.