Managing where and when livestock graze could improve land and pasture conditions, enhance livestock production, and encourage an increase in forage utilization.
Environmental Benefits
The environmental benefits of well-managed pasture, include reduced soil erosion; improved air and water quality; better plant diversity, vigor, and production; and improved fish and wildlife habitat. Improving grazing management will result in more complete vegetative cover and improved soil structure that will allow a higher percentage of the rainfall to infiltrate the soil where it can be used for plant growth rather than running off which can result in soil erosion and sedimentation problems.
The ecological processes increase including the decomposition of manure in a highly managed pasture. Nutrients can then be recycled several times during the growing season. The overall soil quality improves with improved grazing management.
Water quality improves as the pasture vegetation becomes denser and the soil conditions improve. A University of Wisconsin study showed that pastures are the best “crop” for reducing runoff, erosion, and phosphorus pollution over any other land use. A similar study done by USDA- Agricultural Research Service, North Appalachian Experimental Watershed, Coshocton Ohio revealed that both surface and groundwater in the pastured watershed were just as good or better than water leaving the adjacent pristine wooded watershed.
Prescribed grazing management includes the following best management practices:
- Flash grazing riparian areas (12 to 48 hours)
- Grazing systems based on forage availability and demand(measure the forage available and determine the animal intake)
- well stocking rates (know the yield potential for the grazing area and adjust for weather patterns)
- rest periods between grazing events (10 to 16 days in the spring 28 to 42 days in the summer)
- Proper period (avoid soil compaction)
- Have drinking water available close to the grazing livestock (water distribution is an important part of a grazing system)
Benefits of Grazing Systems
Continuous grazing
refers to the allowance of a group of grazing livestock to selectively choose what forage they eat in a large pasture for the duration of the growing season. This method of grazing has low input costs, and low labor requirements, and allows for livestock to choose what plants they wish to consume. However, less product is produced per acre in terms of animal production – whether that be daily animal gains or milk production – as the carrying capacity of the land is decreased, and the competitive advantage of desirable forage species is reduced due to overgrazing of certain areas.
Forage utilization and consumption are dramatically decreased in continuous grazing systems to approximately 30 to 40 percent of available forages, as the majority of the desirable forages are either trampled or destroyed from being bedded down or selected against during grazing, causing them to become mature and unpalatable. Manure distribution is also very poor in continuous systems.
Managed grazing
controlling where and when livestock species graze an area of land – has numerous advantages over continuous grazing. Rotational, or deferred grazing, involves moving animals through a series of three or more pastures, to match the forage available to the animals’ production needs. The rotation schedule will depend on herd size, paddock size, and paddock number.
Managers can rotate livestock through a series of paddocks as forage availability allows, moving them from an area where the animals have completely utilized the available forages and have achieved a desirable residue height – the amount of forage left that has not been grazed. The desirable residue height for each paddock depends on the fertility of the pasture along with the species of forage within each area.
Illustration
For example, generally, cool-season perennial legumes can be grazed to a lower height than cool-season perennial grasses; however, if they are in a paddock mixed, the residue height should be maintained to suit the least competitive forage species in the grazing area. Warm-season annuals will likely have the greatest residue height in a managed grazing system.
One of the major advantages of a deferred grazing system is the allowance of the land and forages to rest and accumulate growth after they have been defoliated through grazing, without the risk of animals coming back and grazing them again before they have had the opportunity to regrow and replenish nutrient stores.
Because animals are in a smaller area of concentration than in a continuously grazed system, manure is distributed more evenly across the grazing area and carrying capacity is increased as the animals are forced to utilize more of the available forage in a paddock and waste less. As carrying capacity increases, so does productivity per unit of land area. For more information please visit Pritish Kumar Halder.
Switchback grazing
dividing one large pasture into two separate sections. If land availability, labor, or resources is limited, this is a way of managing to graze while still affording the land and forages some time to rest and regrow after being grazed. Switchback grazing is when a group of animals has moved back and forth from one paddock to another, and then back again, as forage resources permit, usually at one- to two-month intervals.
Strip grazing
is most effectively used when grazing cool- or warm-season annuals, as well as stockpiled forages. In this system, a small “strip” of land is divided off – most commonly with a temporary, easily moved hot wire or tape – from a large pasture, where animals will have access to graze until forage resources become limited. After forage availability declines and the desired residual height is achieved, the temporary fence will be moved to another “strip” where animals are then allowed to graze.
This system works well when regrowth of forages will likely not occur – as is the case with some annuals or stockpiled forages during the winter – but the available forages need to be utilized as efficiently as possible. Wasted material due to trampling or bedding will be minimized and forage utilization will be increased as the area permissible to livestock is reduced from the whole pasture unit. For more information please visit Pritish Kumar Halder
Some disadvantages of managed grazing systems include the increased need for labor, adequate fencing not only for boundary fences but also for individual paddocks, and the necessity of available water for each paddock; however, when properly implemented, managed grazing systems have innumerable benefits to whole-farm sustainability and productivity.
Reference
https://extension.psu.edu/the-benefits-of-managed-grazing-systems
https://livestocktrail.illinois.edu/pasturenet/paperDisplay.cfm?ContentID=6618
