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In animal agriculture, grazing is the practice of allowing animals to roam across land. Grazing allows animals to behave naturally but it also comes with many environmental downsides.
Words by Grace Hussain
Grazing is the practice of allowing farmed animals to roam across land feeding on wild vegetation, most often grass. Considered natural behavior for animals like cows and sheep, grazing is better for their welfare than confinement. But grazing can also have environmental downsides, like wiping out biodiversity and destroying ecosystems.
In rural areas you see fenced-off fields with a group of cattle, sheep or other animals munching away at a field of pasture. These animals are grazing. Within animal agriculture, grazing means allowing animals outdoors to consume wild vegetation. In other words, the animals are allowed to search for and consume the foods that they prefer within a given area, instead of having food brought to them as happens on feedlots, the confined areas of factory farms.
There are two different types of grazing, continuous and rotational, differentiated by how often the grazing animals are moved from one pasture to another. In rotational grazing there are three further subtypes of grazing that use different methods to time the movement of the animals between pastures.
In a continuous system of grazing, animals are let out onto one large field that is not divided into smaller sections. Continuous grazing requires little oversight. Ranchers don’t have to worry about moving animals from place to place, can use a single central water supply and the cost of building and maintaining the fencing for the pasture is low.
However, there are several downsides to continuous grazing. Perhaps the most significant of these are the impacts on the environment. Cattle tend to overgraze the areas where their favorite food grows. This can destroy the sensitive balance of an ecosystem, with only the unwanted grasses left by the grazing animals, which can in turn become overly mature and of less use for grazing, ultimately using the land less efficiently. It can also lead to an overabundance of manure in a particular area. The nutrients in the concentrated manure may make their way into waterways more easily, which can lead to eutrophication and algal blooms.
There are two major types of rotational grazing — in both animals are periodically moved from pasture to pasture. Each type of rotational grazing differs in how often animals are moved and what happens to the land while there are no animals living on it.
Deferred rotation grazing systems comprise several different pastures, with each pasture supporting grazing farmed animals once per season. This means that the length of time that the pastures are grazed is relatively short and the length of time between these grazing periods is also shorter than in some other systems. It is not abnormal for the order in which individual fields are grazed to be changed from year to year, to better support the restoration and preservation of natural systems and regrowth of plants.
In rest rotation grazing systems, there are several individually fenced pastures that are grazed in a cycle that allows them to recover for a year every few seasons. This method allows vegetation and wild animals to recover more fully from the heavy impacts of the grazing farmed animals.
The type of grazing system that requires the most oversight is the management-intensive system. In this system, farmed animals are rotated across much smaller areas of land called paddocks, but the length of time that they graze a particular piece of land is much shorter than in other rotational systems. This type of grazing system is sometimes referred to simply as “rotational grazing,” but it is a specific type of rotational grazing system.
Though most of the animals raised for food spend their lives on factory farms, cattle raised for beef are likely to spend much of their lives out on pasture grazing. On farms that sell animals for meat, virtually all cattle start their lives on pasture, where they stay until they are fully weaned at around 6 to 7 months old. Some bulls and heifers may be retained at this point to help continue the herd. Most, however, are likely to be sold and moved directly to a feedlot, where they will transition to a diet that includes grains to make them rapidly gain a lot of weight before slaughter. Alternatively, if pasture is available, cattle be maintained on pasture for another few months as they continue to gain weight without being fed grain, though ultimately these animals will also be sold on to spend their last months in a crowded feedlot.
There are many different types of animals that graze. Among farmed animals, cattle, sheep and goats are all grazing animals.
Many wild animals also graze as part of their natural behaviors, including bison, deer and elk. Like domestic grazers, these animals are all herbivores. However, unlike domestic animals, the grasslands that they have long used for grazing are not fenced off and maintained specifically for them. Instead, much of that land is also used as pasture for farmed animals, who compete for the same grasses as the native species.
Grazing offers certain benefits for both the animals grazing and the environment if managed correctly. However, grazing ruminants like cows and sheep also comes with many environmental downsides, and doesn’t necessarily eliminate animal suffering or labor abuses rife within the meat processing industry. In addition, grazing can increase pandemic risk just as much as factory farms do.
For animals, having access to a pasture in which they are able to spend their time grazing provides better welfare than feedlots. One study published in Animals in 2021 compared four different types of housing systems for cattle, ranging from open pasture grazing to a feedlot, and found that those which provided the animals with the opportunity to graze also housed animals that spent more time ruminating, less time lying or standing and more time walking. All of these behaviors indicate that the cattle housed on pasture had greater welfare than those housed on feedlots.
When managed properly, grazing can help reduce the amount of dead brush in an area, resulting in a healthier environment and lowering the chances of fires spreading. Grazing animals can also help clear old growth, which can make space for new, native plant species to take root, though in practice grazing often ends up wiping out native species and wildlife.
Grazing is perhaps one of the greatest threats to grasslands, but can also be one of the key components of a healthy grassland. Although overgrazing can have severe and even crippling consequences, grazing by indigenous wild animals can help maintain biodiversity in some environments by encouraging the growth of more diverse plants and preventing the overabundance of grasses. Grazing animals also play a key role in transitioning nutrients from a form that plants cannot easily absorb to one that they can by way of the animals’ digestive system. The manure produced by grazing animals is rich in nutrients that can easily be absorbed by plants.
When not appropriately managed, grazing can lead to the destruction of ecosystems. Overgrazing can be a culprit, as well as the destruction of forests in order to create pasture for raising farmed animals.
Overgrazing negatively impacts everything from soil health to plant life to wild animals. There are several ways in which overgrazing negatively impacts soil. More empty patches leave soil exposed to wind and rain, causing greater erosion. Fewer plants means fewer roots to keep soil in place and to help hold water in an area and maintain a healthy water system. When it comes to the plants themselves, animals are likely to consume the same few plants to exhaustion. Eventually, these plants are all gone and are replaced by less desirable species instead, including invasive plants. In addition to the loss of plant species due to overgrazing, wild animals are also impacted — with their native environments altered, they have to find new habitats.
Clearing land to create pasture for millions of cows is a major contributor to deforestation in the Amazon rainforest. In fact, of all deforested land in the Brazilian Amazon, about 80 percent was cleared to raise cattle.
Grazing is a complicated issue. Allowing cattle and other farmed animals to graze on open fields provides them with greater welfare than alternative industrial food production systems and can play a key role in maintaining healthy grasslands. However, overgrazing destroys natural ecosystems and can degrade soil. Plus, cattle ranching — whether feedlot or on pasture — emits methane emissions and contributes heavily to the deforestation of the Amazon. One way to be sure that you are not contributing to overgrazing, deforestation and other issues caused by farming is to simply avoid consuming products that were sourced from animals commonly raised on pasture, especially those produced by companies like JBS. For resources to help you adopt a plant-rich diet, see our Take Action guide.
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