Nature's weed eaters
Sheep and goats have long been used to control unwanted vegetation.
Their use has increased in recent years because of the desire
for biological control agents in environmentally sensitive areas.
Grazing is also a more economical alternative in many situations. Sheep mostly graze forbs (flowering plants) and grass while goats
prefer shrubs and other woody plant material.
Sheep are currently being used throughout the Great Plains and
Intermountain regions to control noxious and invasive weeds. Many
of these weeds could not be controlled by means of chemical, mechanical
or cultural practices due to the high cost associated with these
control methods or their relative ineffectiveness. One such weed
is leafy spurge (Euphorbia esula), a Eurasian weed which
has consumed millions of acres and is so competitive that it quickly
crowds out all other plants to form a monoculture.
Another weed, which has impacted many areas throughout the West,
is Spotted Knapweed (Centaureamaculosa). This weed invades
native ranges and threatens even pristine areas such as our national
parks. Sheep readily graze knapweed and are being looked at as
another tool to fight this aggressive invader.
Sheep will readily consume kudzu (Pueraria montana), a
vine that completely replaces all vegetation where it grows in
the Southeast. Larkspur (Delphinium sp.) is a weed that
is poisonous to cattle. Because sheep can tolerate up to 3 to
4 times more larkspur than cattle, they can be used to help control
the weed in cattle pastures.
Sheep will voluntarily graze and sustainably control sericea lespedeza (Lespedeza cuneata), a noxious weed in some states. An added benefit is that the condensed tannins found in lespedeza have an inhibitory effect on internal parasites (worms). In fact, in some states, sericea lespedeza is recommended as a safe, nutritious pasture for small ruminants.
Sheep are being used in many places to reduce the threat of wildfire
in areas where wildlands interface with urban communities. This
method of reducing wildfire is called creating a fuelbreak.
The goal is to reduce the amount of fuel, reduce vegetation height,
and create an effective firebreak.
Improving plant biodiversity
Numerous studies have shown how sheep and goats, used under prescribed
conditions, can help increase the plant biodiversity on western
ranges. Since sheep prefer to graze and bed on upland areas away
from wet lowlands, they are easier to manage in grazing areas
where critical riparian and watershed issues are a concern.
When sheep are grazed in the same areas for several years, the
level of perennial grasses within the plant community tends to
increase which has been shown to increase water infiltration and
Improving wildlife habitat
Prescribed sheep grazing has been shown to enhance wildlife habitat
in a variety of ways. By allowing sheep to graze different areas
at specific times of the year, the quality and quantity of certain
critical vegetation types can be enhanced.
Sheep producers in Canada are now being paid up to $35 per sheep
to graze newly planted tree plantations. This method of prescribed
grazing increases the viability of the new tree seedlings by reducing
the competition of grasses, forbs and weedy species for water,
soil nutrients and sunlight. "Trained" sheep have been
used to graze in vineyards.
Grazing under powerlines
Power companies are hiring sheep (and goat) herds
to keep areas under power lines in forested areas grazed, thus
reducing the chance that an errant spark from the lines might
start a wildfire and destroy the power line and surrounding forest.
Sheep and solar power
Many of the growing number of solar arrays utilize sheep for vegetation control. Combining the two activities provides both an economic and environmental benefit. Most of the vegetation under the solar panels is available for grazing. Without the sheep, the site would need to be mowed frequently and sprayed with herbicides. To allow grazing, the panels simply need to be positioned high enough off the ground to allow grazing.
The extensive grazing of hefted sheep on the commonland of Britain
is a unique phenomenon in Europe, enabling livestock to be kept
in unfenced areas without constant shepherding. Each hefted flock
has its own territory and is self-confining to that area, a heft.
Extended areas are divided into numerous hefts, with each flock
knowing its own area and returning to it after lambing, veterinary
treatment or other husbandry requirements.
Hefted sheep are integral to maintaining the unique and "wild"
or semi-natural environment of which they form part. Unfortunately,
the numbers of hefted sheep were reduced drastically by the British
government during the 2001 foot-and-mouth disease outbreak. Misquided politics continues to challenge this age-old practice.
<== What Sheep Eat