thumb|upright=1.35|Diagram of rotational grazing, showing the use of paddocks, each providing food and water for the livestock for a chosen period

In agriculture, rotational grazing, as opposed to continuous grazing, describes many systems of pasturing, whereby livestock are moved to portions of the pasture, called paddocks, while the other portions rest. Each paddock must provide all the needs of the livestock, such as food, water and sometimes shade and shelter. The approach often produces lower outputs than more intensive animal farming operations, but requires lower inputs, and therefore sometimes produces higher net farm income per animal.

Approach

thumb|upright=1.2|Rotational grazing of cattle and sheep in [[Missouri with pasture divided into paddocks, each grazed in turn for a period and then rested]]

In rotational grazing livestock are moved to portions of the pasture, called paddocks, while the other portions rest. The intent is to allow the pasture plants and soil time to recover.

Rotational grazing can be used with ruminants such as cattle, sheep or goats; non-ruminants such as pigs can also be used. The herds graze one portion of pasture, or a paddock, while allowing the others to recover. The length of time a paddock is grazed will depend on the size of the herd and the size of the paddock and local environmental factors. Resting grazed lands allows the vegetation to regrow. Rotational grazing is especially effective because grazers do better on the more tender younger plant stems. These systems may or may not leave parasites behind to die off, minimizing or eliminating the need for de-wormers, depending if the rotational time is smaller or larger than the parasitic life cycle. Rotational grazing has been said to be more environmentally friendly in certain cases. Many pastures undergoing certain types of rotational grazing are less susceptible to soil erosion. Paddocks might require fewer inputs. These grazing regimes are sometimes said to be more resilient and more capable of responding to changing environmental conditions. Rotational grazing may reduce greenhouse gas emissions such as carbon dioxide, nitrous oxides, and methane. One study looking at finishing stages suggested that adaptive multi-paddock grazing could result in a net carbon sink. However, the study's authors have cautioned that the results are limited in scope as they are only looking at one stage of an experimental system. Other studies have also found some land may sequester just as much or more without any grazing.

Problems

A key element of this style of animal husbandry is that either each grazed area must contain all elements needed for the animals (water source, for instance) or the feed or water source must be moved each time the animals are moved. Having fixed feeding or watering stations can defeat the rotational aspect, leading to degradation of the ground around the water supply or feed supply if additional feed is provided to the animals. Special care must be taken to ensure that high use areas do not become areas where mud, parasites or diseases are spread or communicated.

Several problems are related to shade in pasture areas. Although shade provides relief from heat and reduces the risk of heat stress, animals tend to congregate in these areas which leads to nutrient loading, uneven grazing, and potential soil erosion.

Ruminal tympany, also known as bloat, is a common serious problem when ruminants graze on fresh, young pasture, and if left untreated can be fatal. This problem occurs when foam producing compounds in plants are digested by cows, causing foam to form in the rumen of the animal and not allowing animals to properly belch gas. Animals are especially susceptible to bloat if they are moved to new pasture sources when they are particularly hungry and especially on young, fresh and wet legumes. It is therefore important to ensure that the herd is eating enough at the end of a rotation when forage will be more scarce, limiting the potential for animals to gorge themselves when turned out onto new paddocks. The risk of bloat can be mitigated by careful management of rotations, seeding the non-bloating European legume species Lotus corniculatus in pasturelands, reducing the amount of legumes/increasing grasses, providing sufficient supplemental feeding and extra fodder when turning out on new paddocks, reducing the size of the paddock when livestock is first turned out, and daily rations of the anti-foaming agent poloxalene mixed well into the fodder. Legumes are able to fix atmospheric nitrogen, thus providing nitrogen for themselves and surrounding plants.

Although grazers remove nutrient sources from the pasture system when they feed on forage sources, the majority of the nutrients consumed by the herd are returned to the pasture system through manure. At a relatively high stocking rate, or high ratio of animals per hectare, manure will be evenly distributed across the pasture system. The nutrient content in these manure sources should be adequate to meet plant requirements, making commercial fertilization unnecessary. These systems are fertilized with on-farm sources, and are less prone to leaching as compared to commercial fertilizers. Additionally, the system is less prone to excess nutrient fertilization, so the majority of nutrients put into the system by manure sources are utilized for plant growth. If a pasture was continuously grazed in the past, likely capital has already been invested in fencing and a fencer system. Cost savings to graziers can also be recognized when one considers that many of the costs associated with livestock operations are transmitted to the grazers. For example, the grazers actively harvest their own sources of food for the portion of the year where grazing is possible. This translates into lower costs for feed production and harvesting, which are fuel intensive endeavors. Rotational grazing systems rely on the grazers to produce fertilizer sources via their excretion. There is also no need for collection, storage, transportation, and application of manure, which are also all fuel intensive. Additionally, external fertilizer use contributes to other costs such as labor, purchasing costs.

  • Virtual fencing is an emerging technology that uses GPS-enabled collars and auditory cues to influence and control livestock movement without the use of fencing. These systems allow farmers/ranchers to automate rotations and reduce labor costs, however, they still remain at low adoption rates.
  • Satellite imagery and drone-based remote sensing systems can be used by farmers/ranchers to monitor pasture health, soil moisture, and vegetation cover at a distance.
  • Grazing Planners and Software exist as a digital solution to drive insights into pasture growth, rotation schedules, and animal performance. This approach can incorporate user input, weather data, and satellite imagery to generate optimized grazing plans.

Criticism

Managers have found that rotational grazing systems can work for diverse management purposes, but scientific experiments have demonstrated that some rotational grazing systems do not always necessarily work for specific ecological purposes. This controversy stems from two main categorical differences in rotational grazing, prescribed management and adaptive management. The performance of rangeland grazing strategies are similarly constrained by several ecological variables establishing that differences among them are dependent on the effectiveness of those management models. Depending on the management model, plant production has been shown to be equal or greater in continuous compared to rotational grazing in 87% of the experiments.

Incentives

United States

In the United States, incentives for managed rotational grazing operations are found throughout the Farm Bill, an omnibus package of federal legislation passed roughly once every five years. Within this package, conservation programs such as the Environmental Quality Incentive Program (EQIP) and the Conservation Stewardship Program (CSP) focus on providing financial and technical support to working lands, such as ranches. The most common grazing practices under this program are grazing management design and identification of necessary materials, prescribed grazing that includes animal rotation and pasture resting, and mechanical treatment to improve soil and plant conditions.

In contrast, CSP is intended to provide "whole-farm" financial and technical assistance to farmers who combine basic conservation activities with more substantial interventions.

  • Management Intensive Rotational Grazing
  • Installing electrical fence offsets and wire to facilitate cross-fencing for improved grazing management
  • Grazing management that improves or maintains watersheds, pollinator habitat, or wildlife
  • Prescribed grazing that protects sensitive areas from gully erosion as well as surface or ground water from nutrients
  • Strategically planned patch burning for grazing distribution and wildlife habitat
  • Grazing to reduce wildfire risks in forests
  • Improved grazing management on pasture for plant productivity and health with monitoring activities
  • Maintaining forage quality and quantity for animal health and productivity

Other Farm Bill programs that may impact grazing incentives:

See also

  • Electric fence
  • Free range
  • Ley farming
  • Pastured poultry
  • Rangeland management
  • Soil conservation
  • Transhumance
  • Yarding

References

  • Watering systems for grazing livestock. Iowa State University Extension.
  • Greener Pastures.
  • NRCS Range and Pasture Handbook
  • Forage Resources
  • The Ins and Outs of Overwintering
  • Nitrogen Fertilization
  • Weed Control in Pastures without Chemicals
  • How does managed grazing affect Wisconsin's environment
  • Milking more than profit
  • Graze Anatomy. By Richard Manning. OnEarth Magazine, Spring 2009
  • Managed Rotational Grazing: An Overview of Farm Bill Programs to Support Regenerative Agriculture