What is controlled grazing?

Answer 1

Controlled grazing is allowing farm animals to graze a field for a brief period of time to protect the area from the damages of grazing. When some animals graze, they dig up roots and everything. This will de-grass an area and make it succeptable for erosion. By limiting graze time, fields can produce all year round instead of being a one time harvest.

Answer 2:

Controlled grazing is a management practice designed to regulate the amount of time and the amount of grazing that should take place within a particular paddock or pasture in order to either increase/optimize animal performance or forage quality or both. Controlled grazing is mainly used to control the quality, yield, consumption and persistence of forage from pasture. The area of fresh pasture provided to a set number of animals for a given period (known as stock density or carrying capacity) is changed to control the amount of forage eaten, its quality, and how long each pasture or paddock is rested between grazing periods. In this way, it's possible to match pasture growth with the animals' requirements. Surplus growth is conserved as hay or silage, while growth shortages are made up by careful feeding of supplements.

Controlled grazing is one of many names given to the term Managed Intensive Grazing or MIG. Other names include Mob Grazing, Rotational Grazing, Intensive Grazing, etc.

From the first answer above, Time Controlled Grazing is what occurs when you, "[allow] farm animals to graze a field for a brief period of time..." TCG is very important for pastures/rangeland that have native grasses which are more prone to decreasing in population size than tame grasses. There is also another name for this method, and it's abbreviated as HFLI, or High-Frequency-Low Intensity. This method is also useable on tame pastures, where grazers are only allowed to take off about 10 to 20% of the forage mass before moving on to another paddock, but the return frequency is much faster than the HILF grazing, or High Intensity-Low Frequency grazing (taking ~70% cover and coming back to it 30 to 50 days later).

"...to protect the area from the damages of grazing." This statement depends on what area needs to be protected from grazing, what animals are being used for MIG and how grazing is being utilized. For instance, allowing livestock to graze in a particular area for a "brief period of time" may apply to riparian areas that are being fenced off from regular grazing areas accessed by cattle, for instance. Riparian areas are land that surrounds a body of water, be it a pond, a creek, a slough, a lake or a river. Riparian areas are critical wildlife habitat for birds, insects and mammals, as well as areas where a huge variety of indigenous and vulnerable plant life exist. Livestock that are in this area for long trample these plants, eat all the leaves off the trees as far as they can reach, and make a big mud hole where a healthy pond or slough once was. Livestock are not as careful where they step and what they eat as other native wildlife species are such as deer, elk and moose.

However, any grassland, native or tame, is susceptible to damage from grazing if it is not managed properly. Overgrazing stems from livestock grazing an area too many times too often, resulting in poorer plant vigour and root death. A few parts of one pasture can be overgrazed than other parts, simply because the livestock have been able to access the whole pasture and are not controlled to particular sections; hence controlled grazing and MIG.

Ironically, the most common type of grazing is when livestock are allowed to graze until the forage is only 3 to 4 inches in height. Hoof action, deposition of urine and feces in a more uniform area aid in increasing pasture growth. However, the cincher is that livestock are not allowed to graze a certain area until it is at least 10 to 12 inches in height. If grazed any shorter, this compromises root recovery, energy storage in the roots (decreasing this as plants are repeatedly grazed below this ideal height), and grass' ability to depend on photosynthesis alone. This is why HILF grazing stresses low frequency: to prevent overgrazing, and allow the forage plenty of time to recover.

"When some animals graze, they dig up roots and everything. This will de-grass an area and make it succeptable for erosion." It is important to define when and where some grazers will pull up roots as they graze. Pigs are bad for this, and they're best "grazed" in feilds where root crops are being grown, as well as in fields where the crop has already been taken off. Other true grazers like cattle, sheep and horses will pull up grasses in a pasture that has been reseeded that year and have not been prevented from grazing that area for a full year. Grasses and forages that are growing from seed do not have adequate root development enough to anchor the plant in the ground in defense of the pulling action of the grazers, and it is thus important to let them complete their life cycle undisturbed. Forbs in riparian areas can be established for years, but are more susceptible to being pulled up because they always grow from seed, not from tillers nor parent plants like grasses do.

Sheep and horses are the worst for grazing plants right to the dirt. These grazers don't "dig up roots and everything...[de-grassing] an area and [making] it susceptible [to] erosion," they are able to graze plants to the soil, which destroy the growth points of these plants (particularly in grasses and legumes with their growth points right at the ground level), and "de-grassing" an area to the point where it will be susceptible to erosion. That's why it is very important to manage how sheep and horses are being grazed, much more than with cattle.

"By limiting graze time, fields can produce all year round instead of being a one time harvest." This is the beauty of MIG grazing, particularly in permanent pastures. With good grazing practices, a cattle producer can graze his pastures, provided he/she has enough cattle, at least twice a grazing season. Tame pastures or temporary pastures are also able to produce quality forage twice a season with good grazing management. However, other fields are also able to be designed to be grazed only once, and this is primarily with winter grazing practices like swath grazing, bale grazing, and stockpiling.

Controlled/MIG grazing is the "new" method of grazing for grazing more livestock in an area than traditionally done, and is fast becoming the best way to manage and increase pasture productivity with very little inputs like fertilizer and herbicides.

Answer 2

Controlled grazing is managed grazing, not necessarily intensive or extensive in nature. It is a means to allow grazing animals to defoliate an area for a certain period of time before removal of the animals and allowing rest and recovery of the vegetation. Length of time animals are on a piece of land is dictated by how much foliage should be removed and how much litter should be left behind (litter comprising of both dead and trampled plants, and manure). This is affected by the area to be grazed (less is best, see below) and how many animals are available to do the job. Length of rest depends on the recovery rate (how long it takes for plants to grow back to their "pre-grazed" state) of the vegetation.

Controlled grazing is a more ecologically-agreeing alternative means to free-range grazing. Free-range or continuous grazing is pretty much just letting animals out on a large piece of land and allowing them to graze whenever, wherever and however they wish, no pressures or restrictions put on them by fences or predators. This has shown to have negative impacts on sensitive ecological areas like riparian and wetland zones because of the inherent laziness of a grazing animal to want to hang around the watering hole instead of spreading out to graze. This is reflected by the change of the behaviour of elk in Yellowstone National Park when the wolves were re-introduced: Elk would congregate around areas they would drink and stay there often when predators were absent. When wolves were put back, the elk soon changed their bad habits and would only come down to a creek or pond for a drink before quickly retreating back into the uplands for safety.

Controlled grazing puts the necessary predatory or physically restrictive pressures onto the grazing animals to control their movements and to control where, when and how they graze. Fences are not always required, but actions to mimic predatory behaviour and movement to push animals onto new land before they've severely defoliated the land they're on are required to make controlled grazing work. This commonly would mean going back to the Old West way of herding and driving cattle: by horseback.

Controlled grazing shouldn't be regarded as mob-grazing or managed intensive grazing. Not all grassland ecosystems are created equally, so they should not be grazed in the same manner. Precipitation and climate are significant factors in how controlled grazing is carried out, and must be taken into account when planning managed grazing systems for your farm or ranch. Stocking rates and carrying capacity are very important to use to determine optimal animal numbers (even if it's just a decimal) per acre per unit time to graze.

Also take into account effects on wildlife habitat, as it's not always a good thing to have uniformly grazed lands. Various wild animals need either lightly grazed or heavily grazed areas, or both, so that they can forage or hunt for food, build nests, breed/court, or hide young, such as burrowing owls, sharp-tailed grouse, gophers, antelope, deer, and grassland song-birds. Certain vegetation also requires controlled grazing for their own propagation or control. Rough fescue, for example, will decrease if grazed when it is growing, but will increase when there is no grazing at all and take over other vegetation. Controlled grazing manages this grass species by getting livestock to graze when this native grass is in dormancy, and disallowing grazing pressure when it is growing to maturity. Rough fescue can still grow, but grazing allows other plant species to propagate as well.