University of California
Fire in California

Grazing

Well managed grazing can be beneficial in reducing the risk of a catastrophic wildfire, maintaining and enhancing habitat for many native grassland plants and animals, and maintaining the open character of our iconic grasslands and oak savannas, also known as rangelands.  In the recent fires, grazed rangelands burned less severe than areas not previously grazed.  Grazing that is well managed, can proved positive outcomes including:

  • Reduce future fire fuels loads, keep your land open and productive
  • Provide a regular revenue stream
  • Grazing management standardized to meet your resource goals
  • Increase local food production
  • Opportunity to provide grazing land to a local rancher

Livestock grazing reduces fire fuels more effectively than most mechanical methods. Grassland not grazed creates high levels of fine fire fuels which can pose fire hazards.  In addition, the invasion of ungrazed lands by shrubs also creates long-term fire fuel issues.  Increased shrub cover from removal of grazing has caused “a general increase in fire hazard within the open spaces of the San Francisco Bay Area” and in the context of the landscape matrix as a whole, this increased hazard indicates a greater possibility of fire being spread into adjacent forested areas and residential communities3.

Using livestock to treat fuels has significant potential for managing combustible vegetation. While grazing as a tool is well established in California Rangelands, it is relatively underutilized in forested and urban systems. In recent years, niche fuels reduction with goats and other livestock have become more common in urban parks and other green spaces, but are typically limited to small areas (<10 acres).

It is important to understand the benefits and costs of using grazing when removing hazardous wildland fuels. Risk from predation, vegetation toxicity, and nutrition must all be considered when using livestock to reduce fuels. Additionally, managers need to understand that in most circumstances, a single entry of grazers will not eliminate undesirable species and fuels in the same way that herbicides and mechanical removal will, respectively.

Selecting Livestock Type

Selecting the right animal for the job is dependent on your management goals and what forages are available. Livestock class or type that is used as part of a grazing strategy has a significant impact on the resulting vegetation. Various livestock types have different preferences and utilization patterns depending on the vegetation present, the terrain, their experience with various plants, and their familiarity with the site. All livestock may eat whatever vegetation is available but they clearly have preferences (Table 1).  Forage can be utilized efficiently when more than one type of livestock utilize a site. Site goals may be more effectively achieved by using more than one type of livestock.

Cattle (cows with calves) tend to prefer grass species. Cows with calves tend to prefer feeding close to water, within ½ mile and on areas with gentle slopes, under 20%.

Cattle (yearlings) tend to feed long distances from water and readily utilize areas of steep terrain.

Sheep tend to eat forbs such as clovers, dandelions and other broad leaf plants.

Goats tend to eat shrubs and to a lesser extent forbs and grass.

While goats may be more effective at removing small (<1in) woody material, cattle are more effective at removing grassy fuel. In addition, animals do not consume all plants equally which can lead to a shift in plant species if overgrazed (good or bad depending upon aforementioned management goals).

Forage

Cattle

Sheep

Goats

Grass

78

53

50

Forbs

21

24

29

Browse

1

23

21

(Table 1) Percent of time spent by animals feeding on plant types: select the grazer that prefers your problem fuels/vegetation.

Controlling Effectiveness

Although livestock may have a mind of their own, here are some ways to direct their attention.

  • Strategically position feed supplementation areas, water sources, or mineral supplementation sites to encourage activity in a specific location where you want increased livestock impact.
  • Increase herd density to encourage consumption of less palatable species
    • Follow grazing with mechanical treatment of toxic or physically unavailable vegetation.
  • Select appropriate grazing species and breed to meet your needs.
    • Cull individuals that do not directly meet management goals.

Treatment Timing

Timing of use has been shown to impact plant species composition, as some plants tend to be more palatable and preferentially selected by livestock at different times of the year. Also most plants have certain times of the year when they are more susceptible or resistant to grazing.

Fall/winter grazing with cattle tends to reduce annual grasses and encourage forbs, including weed species.

Spring grazing tends to be a good time for livestock gain as grasses and forbs are highly nutritious. During late spring livestock will graze some forbs and perennial grasses that stay green longer than the annual grasses.

Summer grazing tends to be a period when forage values decrease and livestock may concentrate in riparian areas and utilize shrubs and oaks for forage.

Grazing impacts surface fuels by removing vegetation (existing fuels), but does not affect the plant roots. To have a successful fuel management program with livestock, a grazing routine should be applied every 1-2 years at the minimum to exhaust the root stock.

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