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Oklahoma Cooperative Extension
Fact Sheet # 3855 |
Electric Fencing for Sheep |
Gerald Fitch
Extension Sheep Specialist
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The use of electric fencing
for sheep is relatively new in the United States.
Several other countries have used electric encing
with great success for several decades now. Electric
fencing is more economical than standard barbed wire
or hog wire fencing. Electric fencing also allows
for temporary fencing to subdivide pastures, which
can increase the stocking rate and forage utilization
and decrease parasite problems through rotational
grazing. |
Why has electric fencing
not caught on in the United States? The main reason
is the past failures producers have experienced due
to utilizing poor quality fence chargers and not understanding
the basics of electric fencing. The basic principles
of fence construction, grounding, and current flow
must be understood to ensure correct fence design
with minimal maintenance and maximum current flow.
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Fence Chargers and Grounding |
The major mistake that
is made in electric fencing is the use of poor quality,
“cheaper” fence chargers and the improper
grounding of the fence. The fence charger is the most
important purchase in construction of the electric
fence. Electric fence chargers have become much more
sophisticated than the older type low powered fence
energizers. Electric fence for sheep can be maintained
even in remote areas with the new solar powered chargers. |
Voltage must be maintained
at all times if an electric fence is to be effective.
The new high voltage energizers produce a very short,
.003 second, high-energy pulse. The high-energy pulse
charges even a long length of heavily weeded fence
with a shock that livestock respect. The short pulse
limits the overall energy, so posts are not burned
and the wires are safe, though painful to touch. The
short pulse also removes the chances of fire when
grass contacts the wire. |
The most important component
of electric fence construction is the proper grounding
or earthing of the system. With a poor ground, the
electric pulse could not complete its circuit, and
the fence would be completely ineffective. Improper
grounding is the number one reason for electric fence
failure and the main reason for producer’s in
the United States reluctance to use electric fencing.
More than 80 percent of the electric fence systems
in the U.S. are inadequately grounded. Three or four
ground rods, six feel long, should be used for proper
grounding. These rods should be placed in parallel
approximately six feet apart. Most fences are constructed
with only one ground rod (this is adequate only when
the ground is extremely wet) and will not be sufficient
to ensure proper current flow. |
Permanent Electric Fencing |
Permanent electric fencing
with five to eight properly spaced strands is excellent
for holding sheep. This fencing can be constructed
with high-tensile wire and various types of creosote
pressure treated posts or fiberglass posts for about
one-half of the material and labor cost of an equivalent
woven wire fence. |
Experience has shown
that a seven or eight wire fence that is approximately
48 inches high is ideal for sheep and cattle. This
fence will not only keep sheep in, but will also work
well for keeping predators out. Spacing will depend
on the number of wires used. A good fence design for
a seven-wire fence would begin with the bottom wire
charged 6 inches above the ground. The next two wires
would be spaced at 5 inch intervals and would be a
ground wire, followed by a charged wire. The next
wire would be a ground wire spaced 6 inches up, followed
by a charged wire and a ground wire at 8 inch intervals.
The top wire would then be 10 inches up and would
be a charged wire. This fence would be 48 inches high
and should do a good job of livestock control. |
The wires used in these
fences should be smooth 12 ½ gauge or 14 gauge
wires. If building a permanent fence, the 12 ½
gauge would be a much better choice. The 12 ½
gauge wire is much stronger and will carry the necessary
voltage better than the lighter 14 gauge wire. In
any case, when this fence is built from smooth wires
it is important to put a “wire strainer”
on each wire to take up the slack and keep the wires
tight. The principal idea of the wire is to give an
electrical shock to the livestock, and the actual
strength of the wire does not prevent animals from
going through. Consequently, all that is needed is
to space the wires properly and keep them tight. This
makes it possible on level ground to put fence posts
40 to 50 feet apart. By doing this and using high-tensile
smooth wire, it is possible to build a fence for much
less than the cost of a woven wire fence, and the
fence is a much better deterrent to the movement of
dogs and coyotes than a woven wire fence. |
Temporary Electric Fencing |
Recent interest in pasture
management involving intensive or controlled grazing
systems has created a need for semi—permanent
or temporary sub-division fence systems. These allow
forage growth, quick grazing, internal parasite reduction,
and regrowth of forage for future grazing. |
There are many different
types of temporary fencing, which includes lightweight,
high-tensile smooth wire, polywire, polytape, or flexible
netting. The lightweight ,high-tensile wire would
be best utilized when the fence is semi-permanent,
such as around a wheat field for the winter and spring.
This wire is not well utilized when constant moving
is necessary. The polywire and polytape is best utilized
in a rotational or controlled grazing environment
when the fence must be moved more often. |
A two or three wire temporary
fence around a wheat pasture or for controlled grazing
in any kind of pasture will normally be sufficient.
Most producers using temporary fencing feel that all
wires should be charged and no ground wires are necessary.
If a two wire system is used the bottom wire should
be 10 to 12 inches above the ground with the second
wire 10 to 12 inches above the bottom wire. If a three
wire system is used, the three wires spaced at 10
inch intervals works very well. |
| The new polywire or
polytape system has made temporary fencing for controlled
and intensive grazing a very feasible alternative.
With the use of portable reels and quick setup features,
the temporary fences can be moved quickly and are
also very efficient in keeping livestock in. |
Rejuvenating Existing Fences
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| Old fences, which have
deteriorated to the extent that they need complete
replacement, can be rejuvenated to last for many more
years by attaching offset brackets and an electrified
wire on one or both sides of the old fence. All single
offset wires should be attached at two thirds the
height of the animals to be controlled. The old fence
can be used as the “ground” wire and will
work well to complete the circuit necessary for good
sheep control. Charging barbed wire is not a good
practice for two reasons: 1) livestock caught in charged
barbed wire can literally be shocked to death; 2)
barbed wire is not as conductive as the smooth-high-tensile
wire and will not carry an adequate current for sheep. |
Training Sheep to Electric Fences
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It is necessary that
sheep become adjusted to and learn to respect electric
fences. All animals need time and space to quietly
discover that electrified fences are “hot.”
If they can be first exposed shortly after they are
shorn, they will have less wool for insulation. |
Sheep should be turned
into an area that is controlled by electric fence
and allowed to discover the fence in their own time.
Sheep that are crowded near electric fences frequently
get spooked through the fence. Rambouillet ewes brought
off the range of southwest Texas are easily spooked
and will require more time to get adjusted to the
electric fencing. The minimum time required is 12
hours and most animals will be fully trained in 48
hours. It is also true that a multi-wire fence will
teach sheep to respect electric fencing much quicker
than a one or two wire fence. |
The high levels of forage
production in Oklahoma make sheep production a very
viable enterprise. Problems associated with sheep
production in Oklahoma include predation and internal
parasite problems. With the correct use of electric
fencing those problem can be kept to a minimum. Electric
fencing is another alternative, which may prove a
valuable asset to your operation. For more information
on electric fencing, contact the local county Extension
office or the state sheep specialists. |
Oklahoma State University,
in compliance with Title VI and VII of the Civil Rights
Act of 1964, Executive Order 11246 as amended, Title
IX of the Education Amendments of 1972, Americans
with Disabilities Act of 1990, and other federal laws
and regulations, does not discriminate on the basis
of race, color, national origin, sex, age, religion,
disability, or status as a veteran in any of its policies,
practices or procedures. This includes but is not
limited to admissions, employment, financial aid,
and educational services.
Issued in furtherance of Cooperative
Extension work, acts of May 8 and June 30, 1914, in
cooperation with the U.S. Department of Agriculture,
Sam E. Curl, Director of Oklahoma Cooperative Extension
Service, Oklahoma State University, Stillwater, Oklahoma.
This publication is printed and issued by Oklahoma
State University as authorized by the Dean of the
Division of Agricultural Sciences and Natural Resources
and has been prepared and distributed at a cost of
20 cents per copy.
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http://osuextra.okstate.edu/pdfs/F-3855web.pdf
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