Since managed grazing is such a profit-maker, and such an enabler for management techniques that make more profit, this primer is intended to help newcomers with terminology and understanding basic principles.
Mob grazing, planned grazing, cell grazing, Savory grazing, MIG grazing, AMP grazing – All these terms and more have been coined to describe managed grazing. When we say managed grazing, it means cattle are being moved to fresh pasture often enough that the manager has some control over consumption level of the cattle, as well as the graze and recovery times for plants. It also implies the manager has a plan (planned grazing) for grazing that meets certain goals of both the soil-plant complex and the livestock.
MIG is management intensive grazing. AMP is adaptive multi-paddock grazing. Savory grazing was a colloquialism based on consultant Allan Savory’s early advocacy for multi-paddock grazing in the U.S.
Cell grazing refers to the once-common label of a grazing unit as a “cell,” with a grazing unit being the area where one herd is managed. This is less common terminology today. Mob grazing refers to very-high-stock-density grazing and has either Australian or South African origins.
Paddock -- is the term defining an enclosure where cattle are contained for a brief grazing period. This might be a week, or more, or less. It might be a few hours. It could be made with permanent, semi-permanent, or temporary fencing.
Stocking rate – Typically refers to the number of cattle that can be run on a ranch, or more specifically the total pounds of a livestock type and class that can be run year-around. It is typically based on the number of animals that can be grazed on one-half of one-half (or 25%) of the total forage grown in a year. Arguably, this carrying capacity would not include additional animals dependent on purchase of hay and other supplemental feeds. It can be a way to measure ranch productivity, but improvements in consumption, regrowth and soil health under well-managed grazing should improve stocking rate immediately and long-term.
Stock density – Stock density is a measurement of the amount of animals on a paddock at one time, usually expressed in pounds per acre. Using pounds per acre allows reasonable comparison across livestock species of the consumption and herd effects such as trampling, and urine and feces distribution.
Why does stock density matter?
Stock density is inversely related to grazing time. The higher the stock density, the fewer pounds of forage will be available for each animal and therefore the shorter must be the grazing time. The longer you graze livestock in a paddock under any circumstances, the less residual forage you leave in the paddock and the more forage animals will consume. High stock density also increases trampling. Managing stock density also helps determine the evenness of grazing and of urine and feces distribution, and whether less-desirous plants will be grazed or left behind.
Further, high stock density is directly correlated to length of recovery time and to number of paddocks needed. Put another way, higher stock density requires more paddocks and increases length of forage recovery. In turn, that allows greater forage production and the chance to leave more forage behind, preferably much of it trampled onto the soil surface to make more available for consumption by soil life while still protecting the soil.