November 24, 2013

Gallagher SmartPower MBX System Keeps Chimp Pen Secure

Wellington Zoo has installed a SmartPower MBX electric fence system to make sure there is no monkey business in the chimpanzee enclosure.

Known for their intelligence and almost human-like behaviour, chimpanzees are a popular attraction at the zoo.

Mammal curator Simon Eyre says the zoo’s twelve chimps spend much of their time in an outside enclosure which is about 800-900 square metres in size.

Electric fencing around the top of the enclosure acts as a gentle deterrent to any chimpanzee with plans to travel further a field.

This fencing is powered by Gallagher’s innovative SmartPower MBX system – a highly intelligent mains-powered energizer with a battery backup.

SmartPower monitors voltage levels and sends out an instant alert if voltage levels in the fence vary from the norm. Simon Eyre says the zoo’s system will soon be fitted with an auto-dialler that dials the cell phone numbers of on-duty staff the second any problem is detected.

He says the system gives staff peace of mind because they know the enclosure is protected from breach from both the inside and the outside.

Electric fencing is an important part of modern zoo security and Simon says Wellington Zoo has around a dozen separate electric fence systems - all incorporating Gallagher components.

 

November 23, 2013

Fencing Materials For Livestock Systems

Fencing Materials For Livestock Systems

Author: Susan Wood Gay, Extension Engineer and Rick D. Heidel, Extension Agent, Animal Science; Virginia Tech

Publication Number 442-131, Revised 2003


 

Good fencing protects and confines valuable livestock by presenting barriers to restrict animal movement. Barriers may be physical, psychological, or a combination of both. Physical barriers consist of enough materials of sufficient strength to prevent or discourage animals from going over, under, or through the fence. Psychological barriers depend upon inflicting pain to discourage animals from challenging a physical barrier of inferior strength.

Traditional livestock fencing materials have included barbed, woven, mesh, and electrified wire, and combinations of these materials. Board fences have also been popular. These conventional materials are still widely used and make excellent fences if properly constructed. However, new materials such as high tensile wire should also be considered when selecting fencing types.

The type of fencing needed for livestock confinement depends on several factors including animal species, age, breed, and production system. Beef cattle on a controlled grazing system have different fencing needs than horses on recreational pasture. Permanent boundary or division fences require different fencing materials than fences for temporary paddocks.

Fencing type and material influence the cost, lifespan, and function of the fencing system. This publication discusses the types of fencing and materials that are available for livestock systems and provides some guidelines on fencing material selection for various livestock types.

 

 

Fencing Types

Factors for selecting fencing type include affordability, maintenance, durability, and effectiveness of containing livestock. Fencing types vary from physical barriers such as woven wire and board fences to psychological barriers such as electrified poly wire or tape. High tensile electric fences are a combination of both barrier types.

Woven Wire Fences
Woven wire fences consist of smooth horizontal (line) wires held apart by vertical (stay) wires. Spacing between line wires may vary from 1 1/2 inches at the bottom for small animals to 9 inches at the top for large animals. Wire spacing generally increases with fence height.

Woven wire fences are available in numerous combinations of wire sizes and spacings, number of line wires, and heights. Most fences range in height from 26 to 48 inches. Stay wires should be spaced 6 inches apart for small animals and 12 inches apart for large animals.

The standard design numbers listed on the manufacturer's tag (attached to fence rolls) describe the fence (Figure 1). For example, a design number of "1047-12-11" indicates that the fence has ten line wires and is 47 inches high, has 12 inches of spacing between stay wires, and has 11-gauge filler wires (wires between the top and bottom line wires).

Barbed Wire Fences
Barbed wire consists of two or more strands of smooth, galvanized wire twisted together with two or four sharp barbs spaced every 4 to 5 inches. Standard barbed wire fences usually have three to five strands of barbed wire stretched between posts. Typical fence height is either 51 or 54 inches. Spacing between wires depends on the number of line wires and fence height (Figure 2). Line posts are usually spaced 12 to 20 feet apart.

Suspension barbed wire fences consist of four to six strands of 12 1/2-gauge barbed wire stretched taut so no more than 3 inches of sag exists between posts. The wire strands are held apart by twisted wire stays or plastic battens or droppers spaced 16 feet apart. Line posts are usually spaced 80 to 120 feet apart.

Cable Wire Fences
Cable wire fences are expensive and generally used for confinement areas. These fences consist of 3/8-inch steel wire cables stretched between anchor posts. Fence height varies from 60 inches for a 4-cable fence to 72 inches for a 6-cable fence.

A heavy-duty spring is fixed to one end of each cable and attached to an anchor post to absorb the shock on the wires caused by animal contact. The fence may consist of as many cables as desired, although a 6-cable fence is recommended for large animals. This fence has become less popular in recent years; 10-strand high tensile electric fence has taken its place.

Mesh Wire Fences
Mesh wire is made in 11, 12 1/2, 14, and 16 gauges and fences are available in diamond-mesh and square knot designs. Fence height generally varies from 50 to 72 inches. The square knot wire design is formed from single line wires spaced 4 inches apart and stay wires spaced 2 inches apart (Figure 3). The joints are held by a piece of short wire formed into a knot.

The diamond-mesh wire design uses two smooth wires spaced 4 inches apart and twisted together for all line wires (Figure 4). Stay wires consist of single smooth wires the same size as the line wires. These are wrapped around adjacent line wires to form a triangle with a 2-inch base. The diamond shape is formed when two of these triangle bases are fitted together.

Both mesh fence designs are strong and highly safe for animals. However, these fences are expensive and used primarily for confinement areas or small acreages. Mesh wire fence is priced similarly to woven wire fence on a per roll basis, although mesh wire rolls typically contain 1/3 of the fence length found in woven wire rolls.

Board Fences
Board fences are made from 1- to 2-inch thick, 4- to 6-inch wide boards nailed to flat-sided wooden posts (see Fencing Materials and Equipment section). Board fences can be built to any height, although 4 1/2 and 5 foot heights are most common.

Posts are typically spaced at 8 feet. However, board length should always be checked before deciding on spacing. For example, if 16 foot boards are purchased, the posts cannot be driven straight enough to attach the boards every 8 feet and post spacing must be decreased.

Board fences are strong, attractive, and safe for animals. However, these fences are often built incorrectly by placing the boards on the wrong side of the post to maintain aesthetics. Boards should always be attached to the side of the post facing the livestock. Otherwise, animals tend to push boards off the post when they lean or push themselves against the fence.

Board fences are expensive to build and maintain. Furthermore, the addition of one more board significantly increases the amount of materials needed or the labor required to build and maintain the fence. Labor is considerably higher for board fences than for most wire fences. Other disadvantages include splintering, breaking, and rotting of boards.

High Tensile Fences
High tensile fencing is easy to handle, requires little maintenance, and can be relatively low-cost. This type of fencing can withstand livestock contact and low temperature contraction without losing its elasticity. High tensile wire undergoes reduced stretch or sag, which is commonly associated with conventional fence wire. This type of fencing is not recommended for horses unless electrified versions are used and the owner is willing to accept some risk of injury. For more information on fencing systems for horses, see "Horse Fencing 101" available from Augusta County Cooperative Extension.

High tensile fencing is constructed with 11- to 14-gauge wire with a tensile strength of 170,000 to 200,000 pounds per square inch (psi) and breaking strengths of approximately 1,800 pounds. Wires are held in tension along posts spaced 16 to 90 feet apart. At installation, each wire is tightened with a permanent in-line strainer (Figures 5a and b) and is set at 200 to 250 pounds of tension. In-line strainers should be placed near the middle of the fence line to provide the same tension in both directions.

Tension indicator springs (Figure 6) are used to set and maintain the correct wire tension. Use one tension spring on one wire per fence and set it to the proper tension. The other wires can be tightened to the same tension by feel or sound (similar to tuning a guitar). The tension spring is generally set on the second wire. However, placing the tension spring on the top wire provides some additional "give" to minimize damage caused by falling tree limbs.

Electric Fences
Electric fences are a safe and effective means of providing permanent and temporary fencing for most livestock. Their purpose is to supply sufficient electrical shock to any animal, whether livestock or predator, that comes in contact with the wire. Livestock that are unfamiliar with electric fences must be trained to respect and stay away from the electric wire.

Temporary Fences
Temporary electric fences can be constructed from numerous products. One of the more popular products consists of fine aluminum or stainless steel wires woven together with polyethylene fibers to form what is known as poly tape. This product comes in various colors with black being the most difficult for animals and humans to see. Brighter colors such as white or orange are much easier to notice and are recommended where visibility is especially important. Poly tape is also available in various wire densities. The maximum length for poly tape with a low wire density is about 1200 feet. Poly tape with a high wire density can be used for longer runs.

Permanent Fences
Permanent electric fences generally consist of two or more strands of smooth wire. However, fences designed for small predator control may have as many as ten or twelve strands. Alternate wires are ³hot.² Other wires serve as grounded returns to the controller. The ground wire return design is recommended where the soil may be dry some of the time.

Permanent electric fences can be built from aluminum, stainless steel, and high tensile wire. These types of wire conduct electrical charges for longer distances than poly tape. However, they are more difficult for animals to see. Animals will not be effectively trained to avoid electric wire unless they can see the wire as they feel the shock. Attaching strips of brightly colored cloth or plastic to the wire creates contrast and movement for easier visibility.

Controllers
A controller, also called a charger or energizer, regulates the flow of energy in fence wire by supplying pulses of high voltage electricity in short duration. An animal that comes in contact with energized fence wire completes the circuit from the fence wire through its body, and then through the ground to the ground rod. The discomfort of the shock discourages the animal from further contact with the fence.

In Virginia, it is unlawful for any electric fence to be energized unless a controlling device regulates the charge on the fence wire. The controller must meet the safety standards of either the Underwriter's Laboratories, Inc. (UL) or the International Commission for Conformity Certification of Electrical Equipment (ICCC). Do not use homemade or inexpensive, high impedance controllers. They may cause serious injury or death to both humans and livestock. Furthermore, the use of poorly designed controllers may result in grass fires around the fence. Consult Section 55-298.2 of the Code of Virginia for precise specifications for lawful electric fences.

Return to Table of Contents

 

Fencing Materials and Equipment

Fence posts
Many types of fence posts are available including wood, steel, and fiber glass posts (Table 1). Fence post selection should be based on your specific fencing need. For example, treated wood posts are best for permanent boundary fences while steel or fiber glass posts are suitable for temporary paddock fences. Fence posts must be long enough to accommodate fence height, depth of setting, and an additional 6 inches. Recommended post spacings for various fences are in Table 2.

Table 1. Fence post characteristics.

Post TypeBending StrengthExpected Life (yrs)Maintenance
Wood
treated good 10 - 30 very low
untreated good 2 ­ 25 high
Steel
"T" fair 25 ­ 30 low
3/8-inch rod poor 15 ­ 20 medium
Fiberglass
heavy-duty "T" fair1 25 ­ 30 low
light-duty "T" poor1 15 ­ 20 medium
1Fiberglass posts are moderately flexible.

Table 2. Recommended post spacings for various fence types.1

FenceSpacing (feet)
Woven wire 14 - 16
Barbed wire (standard) 12 - 20
Barbed wire (suspension) 80 - 120
Temporary electric 20 - 40
Permanent electric 20 - 90
High tensile 16 - 90
Board2 7 - 8
Corrals 6
1Post spacing are approximate and need to be adjusted for topography, livestock pressure, post size, wire tension, and use of poly spacers, battens, or droppers (electric fence).
2Allowances must be made relative to board length and straightness of driven posts.

Wood
Wood posts are commonly used and can be less expensive than other materials if cut from the farm woodlot or if untreated posts are purchased. Post durability varies with species (Table 3). For example, osage orange and black locust posts have a lifespan of 20 to 25 years whereas southern pine and yellow-poplar rot in a few years if untreated.

Table 3. Life expectancy (in years) of treated and untreated wooden posts.

SpeciesUntreatedTreated
Black locust 20 - 25 N/A
Hickory 5 - 7 15 - 20
Honeylocust 3 - 7 10 - 20
Osage orange 20 - 25 N/A
Red cedar 15 - 20 20 - 25
Red oak 5 15
Southern pine 3 - 7 25 - 30
Sweetgum 3 - 6 20 - 30
White oak 10 15 - 20
Yellow-poplar (Tulip tree) 3 - 7 20 - 25

Wood posts are highly variable in size and shape. Strength of wood posts increases with top diameter. Post strength is especially important for corner and gate posts, which should have a top diameter of at least 8 inches. Brace posts should be 5 inches or more in top diameter. Line posts can be as small as 2 1/2-inches in top diameter, although larger diameter posts make fences stronger and more durable.

Flat-sided posts should be used for board fencing; the flat side provides a good surface for board attachment. There are three types of flat-sided posts: faced, square, and half-round posts (Figure 7). Faced posts are the strongest followed by square posts. Half-round posts are made by sawing through the center of the heartwood. These posts are inexpensive, but inferior in strength to faced and square posts.

Steel
Steel posts weigh less and are easier to drive into the ground than wood posts. Steel posts also ground the fence against lightning when the soil is wet. One main disadvantage of using steel posts is that they are likely to be bent or forced out of line by livestock. Using wood posts every 50 to 75 feet can help keep steel posts from bending and improve the strength of the fence.

Electric Fence Posts
Various kinds of posts are available for electric fences including fiber glass, plastic, steel, or low-conductivity wood. Wood and steel posts require insulators to prevent short-circuiting of the fence through the posts. Plastic step-in posts work well for temporary fencing, but should be treated with ultraviolet inhibitors (UV treatment) to minimize deterioration in sunlight.

Wire
Steel wire longevity depends on the type and thickness of protective coating around the wire. Zinc is commonly used to cover (galvanize) steel wire to protect it from rusting. There are several ways of applying zinc to steel wire and some are claimed to be superior to others. However, results of the American Society of Testing and Materials (ASTM) show no practical difference among galvanization methods.

Zinc coatings are measured in ounces of zinc per square foot of wire surface. The more zinc per square foot, the more years of wire use before rusting starts. The ASTM has established "classes" of zinc coatings for steel wire based on the number of years that galvanizing delays wire rusting under different climatic conditions (Table 4). Class 1 has the lightest zinc coating and Class 3 has the heaviest. Machinery, livestock, and fire may damage the zinc coating which results in wire that rusts sooner than undamaged wire. Steel wire may have less than a Class 1 coating. This is often referred to as "regular" galvanizing. Many local dealers stock steel wire with either regular or Class 1 coatings. Wire with a Class 3 coating may have to be special ordered from the manufacturer.

Table 4. Approximate protection given steel wire by Class 1 and Class 3 galvanizing.

Climatic Condition
Wire SizeDryHumid ClassCoastal and Industrial
131313
9 15 30 8 13 3 6
11 11 30 6 13 2 6
12 1/2 11 30 6 13 2 6
14 1/2 7 23 5 10 1 1/2 4 1/2

Steel wire will completely rust within one to three years once rust appears. Wire size is most critical at this point since rusting slowly reduces the diameter of the wire and subsequent wire strength. Small wires are at a disadvantage since the surface area per unit weight of wire is much greater than for larger wires.

Staples
Staples are used to fasten fence wire to wood posts. Selecting the appropriate staple is important to the overall strength and longevity of the fence. Staple withdrawal is a common fencing problem when using pressure-treated softwood posts. The lubricating action of the wood preservative, combined with the soft nature of the wood, causes staples to loosen and fall out of the post. To avoid staple withdrawal, use 1 1/2-inch or 2-inch long, 8- or 9-gauge, hot-dipped, galvanized staples with cut points and barbs. Shorter staples can be used with untreated hardwood posts. Do not select ³bright² staples as they will rust immediately. Aluminum staples should not be used since they bend while being driven into posts.

Nails and Screws
All fasteners should be galvanized with a Class 3 coating to minimize rusting. Nails with grooved shanks are less likely to withdraw from fence posts. Sixteen penny nails work well for fastening. Galvanized screws are another option for fastening boards to fence posts.

Table of Contents

 

Material and Fence Costs

Fencing material costs are highly variable depending upon material types, post spacings, size and terrain of pastures and associated paddocks, and the use of permanent versus portable or temporary fencing. Labor costs also vary depending upon fencing type and pasture terrain. General fencing costs are discussed in this section.

Labor Estimates
Labor requirements vary with specific farm conditions. Table 5 is a guideline for estimating labor to construct permanent fences on the farm. Multiply these estimates by the labor wage rate to approximate labor costs for building or installing a given length of fence. Labor costs are minimal for temporary or portable fencing. Therefore, these costs are often incorporated into management functions or assigned to the cost of checking animals or animal husbandry. Copies of the "Farm Custom Work Rates Guide" are available from your local Extension agent.

Table 5. Estimated labor requirements for permanent fence construction.

ItemLabor Requirement
Line posts
Hand tamp 20 min/post
Machine driven 6 min/post
Brace posts
Machine driven 8 min/post
Brace assemblies (construction)
Single span 45 min/unit
Double span 1.25 hrs/unit
Spacers or battens 2 min/spacer
Woven wire
Unwind and stretch 1/2 min/ft
Fasten 6 min/post
Barbed wire (per wire)
Unwind and stretch 1/5 min/ft
Fasten 1 min/post
High tensile wire (per wire)
Unwind 1/100 min/ft
Stretch 10 min/stretch point
Fasten 1 min/post (2 min/post for electric fence)
Electric fence controller 2 hrs/unit

Material Cost Estimates
Table 6 is a summary of relative costs for common fencing materials. Check with local fence suppliers to determine actual material costs.

Table 6. Approximate material costs for fencing materials.

Permanent Fence Cost Index1 (Materials Only)Expected Life2 (yrs)Maintenance
Barbed wire (2- or 4-point)
Standard fence
3 strands, 12 1/2 ga. 12 33 high
4 strands, 12 1/2 ga. 13 33 high
5 strands, 12 1/2 ga. 14 33 high
3 strands, 14 ga. 11 19 high
Suspension fence
4 strands, 12 1/2 ga. 8 33 medium
6 strands, 12 1/2 ga. 10 33 medium
Woven wireStay heightSpacing
Light weight (in) (in)
26 6 14 19 high
32 6 15 19 high
Medium weight 26 6 16 30 medium
32 6 17 30 medium
39 6 18 30 medium
47 6 20 30 medium
Heavy weight 26 6 19 40 low
32 6 21 40 low
39 6 23 40 low
47 6 25 40 low
High tensile
3 strands, 12 1/2-gauge 4 30 medium
4 strands, 12 1/2-gauge 5 30 medium
5 strands, 12 1/2-gauge 6 30 medium
8 strands, 12 1/2-gauge 10 30 medium
Temporary Fence
Barbed wire (2- or 4-point)
1 strand, 12 1/2 gauge 4 30 medium
2 strands, 12 1/2 gauge 5 30 medium
Aluminum wire
1 strand, 9-gauge 6 30 medium
1 strand, 13-gauge 5 30 medium
Poly wire (stainless steel wires)
1 strand, 6 wire 2 5 medium
2 strand, 6 wire 4 5 medium
1 strand, 9 wire 3 5 medium
2 strand, 9 wire 5 5 medium
Poly ribbon (7/8-inch)
1 ribbon, 6 wire 3 3 medium
2 ribbon, 6 wire 6 3 medium
1Cost index figures are to show relative cost, not actual cost. For example, fence with a cost index of 25 costs about twice as much per foot as fence with an index of 12.
2Fence life based on a combination of post and wire life expectancy in a humid climate.

Return to Table of Contents

 

Livestock Considerations

Special fencing requirements for various livestock types are discussed in this section. The most important criterion to consider during the fence selection process is that of the fence's effectiveness to contain livestock. This ability can be diminished if neighbors own the same livestock species or if extremely palatable forages are available on the other side of the fence. Woven wire fence with an electrified wire has been used successfully in this case. The strand of electrified wire should be placed at 2/3 of the height of the animals to be controlled. Selecting a stronger fencing type is also recommended for animal control when stocking rates and grazing pressure are high.

Cattle
Barbed and woven wire fences have traditionally been used for cattle. Four- or 5-strand barbed wire fences are adequate for cattle. The initial cost of materials for barbed wire fences is about 70 percent of that for woven wire fences of 1047-12-11 design. However, barbed wire fences require higher maintenance and have shorter lifespans than woven wire fences.

Heavy and extra heavyweight woven wire fences with one or more strands of barbed wire above the fence are excellent for cattle. Fence height should be at least 39 inches. The initial cost of woven wire fence is about 130 to 175 percent of the cost of a 5-strand barbed wire fence. However, woven wire fences require less maintenance and last longer that barbed wire fences.

High tensile electric fencing with four or more strands of wire also makes excellent cattle fence. Fence height for perimeter fences should be a minimum of 54 inches. The cost of a 4-strand high tensile electric fence is about 50 percent of the cost of a 4-strand barbed wire fence and 30 percent of the cost of a 1047-11-12 woven wire fence. A moderate amount of maintenance is necessary for high tensile electric fences.

Wood or heavy wire panel fences are highly recommended for cattle handling facilities. Fence height should be at least 60 inches to prevent escape. Fences should also be clearly visible to reduce stress on the animal and to enhance movement through the facilities.

Sheep and Goats
Barbed wire fences have typically been used for sheep and goats. However, these fences are not recommended for sheep since barbs pull the fleece. Furthermore, barbed wire fences do not effectively confine goats if moderate grazing pressure is applied to the fenced-in area.

Heavy or extra heavyweight woven wire fences are excellent for non-horned sheep and goats. Fence height should be at least 39 inches high to prevent animals from climbing over the fence. However, fence height depends upon the breed to be confined. Mesh wire fences also make excellent fences for non-horned sheep and goats. Temporary fencing is not recommended for sheep or goats since they can easily escape

Special consideration must be given to fencing for horned sheep and goats. Fencing should prevent horned sheep and goats from placing their heads on the other side of the fence or should have openings that are large enough to let animals slide their head through the fence and back. Permanent electric fences also make good fences for horned goats and sheep.

Predator control is another important consideration for sheep and goat fencing. Five-strand high tensile electric fence is particularly useful for discouraging predators such as dogs and coyotes. However, fences must be kept free of vegetation to maintain electric current on the fence.

Woven wire fencing is excellent for predator control. One strand of high tensile electric wire can be used at the bottom of a woven wire fence for predator control. If electric wire is not used, the fence bottom should be placed on the ground to allow for the use of snares where predators dig under the fence. At least one manufacturer makes woven wire fencing with stay wires attached to line wires with a fixed knot. This prevents predators from sliding apart the stay wires and entering the confined area.

Coyotes can pass through openings as small as 4 1/2 inches. Woven wire fences with stay wires spaced close together can prevent predators from entering fenced-in areas. Some manufacturers produce fencing with bottom openings of 6 inch by 3 inch for predator control and 3 inch by 3 inch for predator proofing.

Swine
Barbed (standard and suspension) wire and cable fences are not effective for swine confinement. Woven wire fences with one or more strands of barbed wire (placed along the ground to discourage rooting) provide good hog control. Medium and heavyweight woven wire fences with small openings are excellent for restraining swine. Maximum fence height should be 54 inches. Fences built close to the ground prevent hogs from escaping by rooting underneath the fence.

Horses
Visibility is the most important characteristic of horse fencing. Poorly visible fences such as high tensile and barbed wire fences should not be used with horses; the animals may incur severe injuries (e.g. deep lacerations and broken bones) if they become entangled in fence wires. Woven wire fence with openings of 4 inches or more should not be used since legs may become trapped in the openings.

Woven wire fencing with openings less than 4 inches are suitable for horses if a single 1 inch by 6 inch board is placed at the top of the fence to increase visibility. Diamond-mesh wire of 12?-gauge minimum makes good horse fencing. Electric fencing is also an option since it will discourage contact and decrease the incidence of fencing-related injuries. For more information on fencing systems for horses, see "Horse Fencing 101."

Return to Table of Contents

 

Conclusions

Producers have numerous fencing options for the confinement and protection of livestock. Many traditional materials such as barbed and woven wire fences are suitable for fencing. However, newer materials including high tensile wire should also be considered prior to selecting fencing type. Fencing type should be selected for maximum effectiveness of your fencing need. Fencing materials should provide the longest life and lowest maintenance to optimize the fencing system for livestock confinement and protection. Routine inspection and maintenance will be helpful in giving long and trouble-free service.

Return to Table of Contents

 

Acknowledgments

The authors would like to express their appreciation for the review and comments made by Lori S. Marsh, Associate Professor and Extension Engineer, Biological Systems Engineering, and Robert "Bobby" Grisso Professor and Extension Engineer, Biological Systems Engineering.

Return to Table of Contents

 

For Additional Information:

On Fence Construction
NRAES-11 "High Tensile Wire Fencing" ($4.00)

To order NRAES publications, contact your local Virginia Cooperative Extension office.

On Fencing For Horses
"Horse Fencing 101" available through the Augusta County Cooperative Extension.

On Planning Fences
VCE Publication 442-130 "Planning Fencing Systems for Controlled Grazing"

On Predator Damage to Livestock
VCE Publication 410-030 "Addressing the Consequences of Predator Damage to Livestock and Poultry"

Publication Modified from:
Turner, J. H. 1997. Planning Fences. American Association for Vocational Instructional Materials (AAVIM): Winterville, GA.

Bushermohle, M. J., J. B. Wills, W. W. Gill, and C. D. Lane. 1996. Planning & Building Fences on the Farm, University of Tennessee Agricultural Extension Service PB 1541.

Worley, J. W. 2000. Fences for the Farm. Circular 774, The University of Georgia Cooperative Extension Service, Athens, GA.


Please order online 24/7 or call VALLEY FARM SUPPLY at 717-786-0368

November 23, 2013

Birds Gets Most Out Of A Gallagher Electric Fence

 

The least tern is a small bird, an endangered species that causes some big problems because it likes to nest in hostile environments.  Protecting them from predators usually means taking some drastic steps.  About 10 years ago, the folks at Vandenberg Air Force base, located on a rugged stretch of the California coast about half way between Los Angeles and San Francisco, wanted to find a better way to protect the bird from marauding coyotes.

 

Vandenberg Air Force Base is headquarters for the 30th Space Wing and home to the Western Launch and Test Range. The Test Range begins at the coastal boundaries of Vandenberg and extends westward to the Marshall Islands, including sites in Hawaii on Oahu and Molokai.

 

The 30th Space Wing at Vandenberg Air Force Base, Calif., is responsible for all Department of Defense space and missile launch activities on the West Coast. All U.S. satellites destined for near polar orbit are launched from Vandenberg.The Wing supports West coast launch activities for the Air Force, Department of Defense, National Aeronautics and Space Administration, and various private industry contractors. The wing also supports Force Development and Evaluation of all intercontinental ballistic missiles.

 

Oh, yeah.  It’s also serious about protecting a little 3 ounce bird.Jon Francine, a biologist with SRS Technologies, a high tech engineering firm that does a lot of work for the Department of Defense, said coyotes love to attack these ground nesting birds and feast on their eggs and fledglings.  It only takes them a few days to wipe out an entire generation of terns. 

 

Francine polices one of California’s most rugged sections of coast line because the Air Force, facing growing pressure from environmentalists to protect endangered species on its bases, asked SRS Technologies to help solve the problem.

 

“One solution is to try to shoot the coyotes but you’d have to kill about 70% of them over a five year period to get rid of them,” Francine explained.  “A better solution is to find some way to keep them from getting to the nests.”

 

SRS built a power fence around the nesting site with design help from Gallagher.  It’s short, only about a half mile long, ending at the cliffs on the coast.  It’s a sturdy 10 wire fence built to withstand particularly harsh conditions.  “It’s cold, wet and foggy here most of the time,” said Francine.

 

“We tried powering the fence with solar powered energizers for years but fog can block the sun for 30 or 40 days sometime.  We finally convinced the military to run a line out to the fence so we could have a more reliable, hard-wired source of electricity,” said Francine as he described the difficulties he faced.

 

The fence has some unique maintenance problems.  Several times a year Francine has to wash down the wires to get rid of the salt that collects on them.  “Salt gets into the connections, causing a big voltage drop,” he said.  Even with that kind of care, corrosion still eats away at the wire and he has to “restring” the fence every two years.

 

The fence works, stopping coyotes from entering the nesting grounds without the need to take more drastic measures.  “Once we put it up, the predator problem was essentially over,” said Francine.

 

Please order online 24/7 or call VALLEY FARM SUPPLY at  717-786-0368 

November 22, 2013

Electric fencing basics that you should know.

Fencing

Fencing is usually the largest capital expenditure on a sheep farm. In many cases, existing fence can be modified for sheep-raising. Two types of fencing are required on sheep farms: perimeter and interior fencing. 

Perimeter fencing is usually installed around the boundary of the property (or grazing area) and is the first line of defense against predators. It is intended to last for a long period of time and should be constructed of high quality materials. Suitable perimeter fences for sheep are multi-strand, high-tensile, electric fences and woven wire fences with electric offset wires and barbed wires at the top and bottom of the fence.

Interior fences (or cross fences) are used to subdivide fields into smaller areas (paddocks) for grazing. Interior fences may be constructed from permanent, semi-permanent, or temporary fencing materials. 

While an interior fence does not need to deter predators, it does need to be good enough to keep weaned lambs away from their dams and/or rams away from ewes. Temporary fencing can be used to enclosed areas for temporary grazing (e.g. a corn or wheat field). 



Perimeter Fencing

High-tensile, electric

High-tensile electric fences last for a long time, are relatively easy to construct, and cost less than other types of fencing. Whereas cattle can often be controlled with 1 or 2 strands of electric wire, sheep require multiple strands, not so much to keep them in, but to keep potential predators out. 

Five, six or seven strands of 12 ½ gauge high-tensile wire is common for sheep fences. The bottom wires of the fence are more closely spaced than the top wires. Wire spacings of approximately 6, 5, 5, 8 and 10 inches are typical. In areas where there is relatively even rainfall and some green vegetation most of the year, it is recommended that all wires be hot. 

Ground return wires are recommended where there is low rainfall, stony and dry soil conditions, or where the ground is frequently frozen or snow covered. Switches can be installed so that wires can be turned off if the situation warrants. For example, it is useful to put a switch on the wire closest to the ground, so that it can be turned off if there is too much vegetation on the fence line.

 

High-tensile fences are made with smooth wire that is pulled to an initial tension of 250 pounds. They require strong corners and end braces to achieve adequate tension. The wire is held on fence posts with staples. These staples are driven at a slight angle off of vertical so the slash cut points steer the staple into different grains of the wood. The staples are not driven tight against the wire, but instead allow freedom for the wire to move during tensioning, temperature changes, or livestock pressure.

Grounding
Poor grounding is the leading cause of electric fence failures. An electric fence must be properly grounded so that the pulse can complete its circuit and give the animal an effective shock. It is important to follow manufacturer's instructions for grounding electric fences. A minimum of three ground rods should be used for each energizer. It is estimated that 80% of electric fences in the U.S. are improperly grounded. A voltmeter is an inexpensive tool that measures the charge the fence delivers and can be used to trouble shoot electric fence problems.

The charger
The charger (or energizer) is the "heart" of the electric fence system. It converts main or battery power into a high voltage pulse or "shock" as felt by the animal when it touches the fence. In the past, electric fence chargers shorted out easily. Today's chargers are low impedance, meaning they are designed to effectively shock though vegetation and other foreign materials touching the fence.

A 4,000 volt charger is usually sufficient for sheep. The number of joules needed depends on the length of the fence, the number of electrified wires and the severity of conditions. A joule is the amount of energy released per pulse. As a general rule, 1 joule will power 6 miles of single fence wire; 4.5 joules is usually adequate for 20 to 50 acres. Lightning strikes can damage energizers. Surge protectors and lightening arrestors are recommended to minimize energizer damage.

High tensile electric fencing requires periodic upkeep. Fence wires should be kept properly tensioned. Weeds and brush should be cleared from the fence line by spraying or mowing.

It is important to note that an electric fence much more of a psychological barrier rather than a physical one. Sheep and lambs must be trained to respect electric fence. Once trained, they will usually respect the fence even if it is off for any reason. 



Woven Wire (American Wire, Page Wire)

Woven wire is the traditional type of fencing for sheep. It consists of horizontal lines of smooth wire held apart by vertical wires called "stays." The distance or spacing between horizontal line wires may vary from as close as 1 1/2 inches at the bottom for small animals, to as wide as 9 inches at the top for large animals. In general, the spacing between wires gets wider as the fence gets taller. Stay wires should be spaced 6 inches apart for small animals and 12 inches for large animals.

A four-foot high woven wire fence, with one to two strands of barbed or electric wire along the top of the fence makes an excellent perimeter fence for sheep. A strand of barbed wire along the bottom of the fence will serve as a "rust" wire and extend the life of the fence. 

An electric "offset" wire at shoulder height will keep sheep from poking their heads through the fence. Another offset wire, approximately 7 inches up from the ground will help to deter predators that try to go under fences.

High tensile woven wire fences are more expensive but will not sag or stretch as readily as standard woven wire. They are more resistant to rust and are considerably lighter in weight. Less fence posts are needed with high tensile woven wire.

The advantage to woven wire fences is their effectiveness as a visual barrier. Their biggest disadvantage is their cost. 



Mesh wire

Mesh wire fences have smaller openings than woven wire fences. Two types of mesh wire are the diamond mesh, which uses two wires twisted together in a diamond formation with 2-inch x 4-inch openings, and the square knot mesh, which has single horizontal lines with the wire spaced 2 to 4 inches apart. Because they are more expensive than woven wire, they tend to be used for confinement fencing, such as corrals and barnyards. 

Barbed Wire Fences
Barbed wire fences are generally not recommended for sheep because they may not effectively deter predators and they can cause injury to livestock. Sheep can get their wool snagged in the barbs. Barbed wires should not be charged due to their poor conductivity and safety for the animals. 

When barbed wire fences are used they should contain at least 5 to 6 wires, preferably 8 to 10 closely-spaced wires with several twisted vertical stays. The best use of barbed wire is to rejuvenate old fences or enhance woven wire fences. It is common to install 1 or 2 strands of barbed wire along the top of a woven wire fence and/or one wire along the bottom of the fence. 

Rail Fencing (wood or vinyl)
Rail fencing will generally not contain sheep or repel predators unless electric wires are placed between the boards or the entire fence is covered with woven or mesh wire. Rail fences are expensive to build and maintain. On the other hand, permanent, wooden fences are often used for corrals and barnyards. 

Other Types of Fencing
Fences made from hog wire or chain link, while effective are generally too expensive to enclose large parcels of land. They work well for corrals and barnyards and other high pressure areas. 

Rejuvenating Old Fences
Old fences can last many more years by attaching offset brackets and an electrified wire on each side of the old fence. Single off-set wires should be set at two-thirds of the height of the animals to be controlled. The old fence can serve as the ground wire and will work well to complete the circuit and control the sheep. 



Fence height
Fences can be built at different heights. Commercial fencing products come in different heights. Most predators climb, go through, or go under fences, as compared to over them.

Fence Posts
There are many types of fence posts. Fence post selection should be based on the specific fencing need. For example, treated wood posts are best for permanent boundary fences, while steel or fiberglass posts are suitable for temporary fences. Wood posts are highly variable in size and shape. Strength of wood posts increases with top diameter. Post strength is especially important for corner and gate posts, which should have a top diameter of at least 8 inches.

Brace posts should be 5 inches or more in top diameter. Line posts can be as small as 2 1/2-inches in top diameter, although larger diameter posts make fences stronger and more durable. T-posts and landscape timbers can also be used for line posts. 

Steel posts offer a number of advantages. They are lighter in weight, fireproof, extremely durable, and relatively easy to drive. They also ground fence against lightning when in contact with moist soil. Fence posts must be long enough to accommodate fence height, depth of setting, and an additional 6 inches. One of the advantages of high tensile fencing is that it requires less fence posts. 

Most fences use a post spacing of 8 ft. whereas the line spacing on high tensile fences varies from 16 to 90 feet. Post spacing needs to be adjusted for topography, livestock pressure, post size, wire tension, and use of poly spacers, battens, or droppers. 

Estimated construction costs for fencing (based on 1,320 feet, ¼mile)

Type
Total cost
Cost per foot
Woven wire, 1 barbed strand
$1,987.09
$1.51
Barbed wire, 5 strands
$1,613.65
$1.22
High tensile, non-electric, 8 strands
$1,483.75
$1.12
High tensile, electric, 5 strands
$927.13
$0.70
Electrified polywire, 3 strands
$309.69
$0.24

Source: Estimated Costs for Livestock Fencing, Iowa State University, updated 2005.



Wire
Wire may be galvanized steel, aluminum, or aluminum clad steel. Several gauges and breaking strengths of wire within the different wire types are available. Steel wire is covered with zinc, commonly called galvanizing, to protect it from rusting. More zinc means more years of service before rusting starts. 

High tensile wire typically carries three times as much zinc coating as barbed or woven wire, which accounts for its long expected life. Aluminum wire is lighter, more conductive, and never rusts; however, the breaking strength of aluminum wire is only about one third that of steel wire. A combination of these two materials is also available as aluminum clad hi-tensile steel. This is a hi-tensile steel wire with aluminum coating in place of galvanization. This wire has the high breaking strength of steel wire and the conductivity of aluminum.

12.5 gauge wire is usually the wire of choice for most permanent fences, while lighter gauges can be used for internal subdivision fences, both permanent and temporary.

Insulators
Insulators are a fundamental component of any electric fence. They are made from a non-conductive material, such as porcelain or plastic and form a barrier between the electrified wire and its support material to prevent current leakage to the ground. Plastic insulators are the most common type of insulator used on electric fences. They are cheap and easy to fit. 

Porcelain insulators have the best insulation properties, and if good quality, are the strongest. They are the most expensive. Plastic tube insulators are useful for taking a line wire around a post. Off-set insulators are used to attach a wire to a new fence or a non-electric fence. Cut-off switches are used to isolate parts of a fence without the need to turn off the energizer. 



Temporary fencing

Different materials can be used to construct temporary electric fences: high-tensile wire, polywire, polytape, and electric netting (or net fence). 

High-Tensile
Light weight, high-tensile wire (17 or 19 gauge) is most suitable for semi-permanent fences that will not be moved constantly. Two or three wires is usually sufficient to control sheep and lambs.

Polywire and Polytape
The most common materials used for temporary fencing are polywire and polytape. Both are combinations of metal and plastic filaments. Polywire has the appearance of heavy cord or plastic baler twine. It comes in several colors or combinations of colors. Several grades are available depending upon the number of filaments and gauge of the conductor. Most polywire sold is either 6 or 9 strand. 

Polytape similarly comes in several options and should be purchased on the basis of the number of filaments and the quality of the plastic weave. Compare to polywire, tape has the advantage of greater visibility, which leads to quicker animal recognition and training to the fence. Polywire is less expensive and lasts longer. Poly products come in reels with various capacities and with different locking systems. If you plan to move a fence, reels are an absolute necessity for polywire and polytape. 

Step-in posts

Plastic step-in posts are the most common line posts used with poly products. They are the easiest to use, especially if the fence will be moved frequently. The pre-molded loops provide plenty of flexibility for wire spacings. The metal re-bar posts are cheaper and last longer than plastic or fiberglass posts. They require insulators to hold the wires and can be difficult to get in the ground when the soil is hard. 

Fiberglass posts

Fiberglass posts are best suited to situations where the fence will not be moved frequently. Drive caps are usually used to hammer fiberglass posts into the ground. A spent shotgun shell also works well Wire clips or plastic insulators are used to hold the wire in place. All types of posts can be difficult to install during the winter. 

T posts

Metal “t” posts are stronger and last longer than the other temporary posts, but they cost more and require more labor to install and remove. 



Electric Netting

Electric netting combines traits of net-wire and electric fencing, providing a formidable mental and physical barrier in a portable format suitable for temporary or semi-permanent fencing of pastures. It is constructed of polywires and plastic twines. It is usually supplied in fixed lengths of 50 or 25 meters with support posts already installed. 

Netting is lightweight and easy to install. Compared to other temporary fences, electric netting provides greater protection from predators. However, with electric netting, there is some risk of animal entanglement, especially young lambs and animals with horns.

Comparison of fencing types

 

Type
Pros
Cons
Best use
Barbed wire
May already exist on property
Safety
Stock control
Predator control
In combination with woven wire
Woven wire
Visual barrier
Predator control
Cost
Installation
Entanglement
Permanent
Perimeter 
Holding areas
Stock panels
Visual barrier
Strength
Cost
Installation
Corrals
Holding areas
Mesh wire
Visual barrier
Cost
Installation
Perimeter
Holding areas
Board
Split-rail
Vinyl
Physical barrier
Aesthetics
Cost
Installation
High maintenance
Stock control
Predator control
Estates
Farm entrance
High tensile,
non-electric
Long life
Installation 
Cost
Predator control
Perimeter
Corrals
Holding areas
High tensile
electric
5 to 7 strands
Long life
Installation
Cost 
Predator control
Maintenance of fencelines
Permanent
Perimeter
Interior
Polywire
2 to 3 wires
Cost
Installation
Short life
Predator control
Interior 
Temporary
Polytape
2 to 3 strands
Cost
Installation
Short life
Predator control
Interior 
Temporary
Electric
2 to 3 wires
Cost
Installation
Predator control
Interior 
Temporary
Electric netting
Visual barrier
Installation
Cost 
Entanglement
Short life
Interior
Temporary
Small areas
Chain link
May have materials
Visual barrier
Predator proof
Cost
Installation
Corrals
Holding areas

November 22, 2013

Fencing Management

Introduction

Fencing is the key to pasture management. It allows a livestock producer to rotate pastures and control livestock and predators. Many types of fences are used in Ontario to provide a physical barrier. they include an assortment of cedar rail, stone, page wire, barb wire, suspension, hihg tensile, and board fences.

Livestock farms need at least an exterior or perimeter fence. Interior fences allow a farm to be subdivided and moveable fences add flexibility to grazing management. Electric fencing offers this versatility and is effective and inexpensive.

Electric Fencing

Electric fencing can replace worn out fences or be used as a new fence. It will support and extend the life of a page wire or rail fence. The high cost and labour involved in putting up and maintaining traditional fences has made electric fencing more attractive. When properly constructed, modern electric fencing is much more dependable than the older style battery-operated units used in the past.

Figure 5-1. One strand high tensile wire supporting a rail fence.

This image shows one strand of high tensile wire holding together a rail fence by being wrapped around the poles of the fence.

Training

Electric fencing is a psychological, rather than a physical, barrier. The success of electric fencing depends on training your livestock to respect the fence. Try the following:

  • keep your training area small
  • place a charged wire inside a permanent corral or barnyard fence, where there is little chance for escape
  • leave your livestock inside this area for a few days to familiarize themselves with this electric fencing before putting them out pasture.

Untrained, an animal may try to go through the fence. But many hours of time can be saved rounding up livestock and repairing fences if the animals are well trained.

How Does It Work?

A power source, either hydro or battery operated, is needed to operate the energizer. The energizer sends out a current in a pulse. Wire is used to carry the current along the fence. A ground completes the circuit. When an animal comes in contact with a live wire, it shorts the current to the ground and the animal receives a shock. An electric fence line with no vegetation touching it requires very little power to maintain high voltage levels. Normally the fence will have to handle some plant growth. This is called the fence load. Every plant in contact with a live wire draws a small amount of current to the ground. With miles of wire, this power drain can reduce your fence's effectiveness.

November 22, 2013

17 Mistakes To Avoid With Electric Fencing


By Wayne Burleson email: rutbuster1@mcn.net

With 30 years of experience building hundreds of miles of smooth-wire electric fence, I've seen just about every fencing mistake possible. And I continue to see folks make many of the same common mistakes. I still make mistakes myself, because I'm constantly challenging myself to make fencing easier, faster, stronger, and safer. 

High-tensile, smooth wire, electric fencing is the fastest and most affordable fence that I know about, and its technology has drastically improved over the past 10 years. But many folks are hesitant to use it because they remember old failures -- wires breaking, chargers starting fires, wet vegetation shorting out the fence and other troubles.

With a little commitment and a modest investment in time to learn how to use this new technology, you can save thousands of dollars and hours of maintenance time by making electric fencing work for you. So you won't have to learn the hard way, here are 17 common mistakes that you should avoid:

red ballPoor earth grounding. Lots of folks (including me) still think you can skimp when it comes to adequate earth grounding. What we must all learn to do, is install several ground rods -- at least three that are 6 to 8 feet long, galvanized, and attached with good ground clamps. The electricity must complete a full circle back to the charger through the ground. Poor grounding gives weak shocks. 

red ballUsing different types of metals. Don't do it. When you hook up steel wire to copper something call electrolysis happens and the metal becomes corroded, making a poor contact and weakening shocking power. 

red ballInadequate animal training. Each and every animal must learn that the fence hurts. So please build a handy training fence, preferably on heavy wet soil. Flag the fence for visibility, and force the animal to try and cross the fence. 

red ballFenceposts too close together. Well-intended government agencies recommend lots of fenceposts in their fencing specifications. Fifty-foot spacing on flat land is just too close. You want the fence to act like a rubber band. When something runs into the wire, you don't want to break all the insulators or knock posts out of the ground. If the posts are spread apart far enough -- say 80 to 100 feet -- the wire will just bend to the ground and pop back up. 

red ballToo many wire tie-offs. Again, fencing specifications may call for braces every quarter mile wire to tie the wire off. But I have found that even 5,000 feet is OK, and actually adds more elasticity in the fence wire. This reduces the chance of wires breaking.

red ballWires tied tight to each fencepost. To maintain elasticity (the rubber band effect), wires must float past each line fencepost. 

red ballBuilding new fences near old existing fences. Old fence wires seem to be always moving somewhere and coming in contact with the new electrified wires. This almost always causes a complete short in the fence, and away the animals go.

red ballBottom wire in contact with heavy, wet vegetation. Wet grass will suck lots of juice out of any fence charger. Hook up the lower wires separate from the other wires, and install a switch for the lower wires that you can turn them off when the grass is tall. 

red ballPoor-quality insulators. Be careful here. Sunlight deteriorates plastic. So buy good-quality, long-lasting insulators. Usually black ones are treated to resist degradation by ultraviolet light. I have found that poor quality insulators turn white or clear after a few years in direct sunlight. 

red ballStaples driven in all the way. When using plastic tubing as an insulator, don't staple it too tight. I once spent several hours trying to find a short in a gate. Finally, I discovered a staple had damaged the tubing next to a ground wire, causing a hidden short. 

red ballSolar panels not directly facing the sun. This seems almost too obvious to be a problem. But a solar panel won't function at its potential if not properly installed. Please read the instructions. Don't just guess if you have done it right. 

red ballKinks in high-tensile wire. A small kink in stiff wire will always break. Also avoid hitting this kind of wire with a hammer, as this will easily damage the wire causing a break. Always cut out a damaged section of high tensile wire and splice it. Incidentally, I have found that a hand-tied square knot makes the strongest splice.

red ballInstalling in-line strainers close together. Wires will flip together once in awhile. If in-line strainers are installed one above the other, they will sometimes hook up. Separate in-line strainers by a fencepost and they will never catch on each other. 

red ballWires too close to each other. Keep them at least 5 inch apart. 

red ballNo voltmeter. Without a voltage meter to check how hot a fence is, you're just guessing. 

red ballWire too small. The larger the wire, the more electricity it will carry. Don't skimp.

red ballInadequate charger. A wimpy fence charger gives you a wimpy fence. Don't skimp here because animals will think a smooth wire fence is a joke without a strong bite, and they'll walk right through it. 

Your fence charger should be low-impedance, come from a dependable supplier, and have a warranty and replaceable components. Please buy one that puts out lots of power. During a rainy year, you may have lots of plant growth touching the wires. That's when you will need extra power to shock through the heavy, wet vegetation. It's also handy to find folks with an extra charger they can loan to you while yours is being repaired. Expect some breakdowns, especially from lightning. Certain fence suppliers offer lightning protection with their warranties. 

Don't be afraid to try electric smooth wire fencing. Find a good fence suppler and learn some of the tricks of the trade. I know folks who hate electric fencing. But their pocketbook is not big enough to build a conventional fence, which may cost up to $1 per foot. 

The next time your bulls get in a fight with the neighbors bulls and tear down all the fence, remember that most animals will learn not to touch a wire with 5,000 volts running thorough it.

November 21, 2013

Electric fence installation guide

 

http://www.valleyfarmsupply.net/Articles/install%20guide.htm

November 21, 2013

The basics of electric fencing

Introduction

Whether you're trying to keep livestock from roaming off of your property or trying to keep pesky deer out, an electric fence is the ideal solution. When installed properly, an electric fence will generate a mild shock to discourage the animal from venturing through the fence. While installing an electric fence is not an overly difficult job, electricity is involved so extreme care must be taken. Before you attempt to install one on your own, please read this article and check the Tips and Warnings found at the end.

Instructions

Difficulty: Moderately Challenging

Things You'll Need

  • Electric Fence Controller
  • 10 to 14 Gauge Wire Insulated for 20,000 Volts
  • Grounding System (copper or galvanized rods and brass clamps)
  • Electric Fence Posts
  • Insulation Wrap
  • Post-Hole Digger
  • Hammer
  • Screwdrivers
  • Wire-strippers
  • Pliers

Steps

1

Step One

Find a weather-resistant location for your electric fence controller. This can be under an overhang or inside your basement or garage. Wherever you decide to place it, make sure that there is an available 120 Volt polarized outlet (an outlet where one blade slot is slightly larger than the other). Install the electric fence controller, but do not plug it in yet.
2

Step Two

One grounding rod will need to be installed within 20 feet of the electric fence controller. The grounding rod should be at least six feet long (all of it underground) and made from copper or galvanized. Run a grounding wire (10 to 14 Gauge, 600V to 20,000V) from the controller to the grounding rod and use the grounding clamp to secure the wire to the rod. Ensure that the clamp bites through both the wire and the rod.
3

Step Three

For the best grounding system, install two more grounding rods spaced 10 feet apart and reaching six feet underground. Daisy-chain these rods to the grounding wire as well. Check the Warnings Section below for more information about grounding rods.
4

Step Four

How you install your fence posts will be determined by how much land you are protecting. If you have a farm or other large parcel of land, then you will want to space your posts between 25 and 75 feet apart. Use the post-hole digger to make the installation quicker and easier. The distance between posts ensures that if something runs into the wire, there will be enough flexibility that it will not cause the connections to break.
5

Step Five

With the fence posts installed, it is time to install the wiring. Start your wiring with the farthest post from the electric fence controller. Make sure to use proper splices and tight connections throughout. Wrap your connections with insulation wrap to help reduce corrosion.

The common height for an electric fence for horses is 48 inches. With fences this high, it is best to run wires closer together (about six to eight inches apart) near the bottom of the fence to prohibit smaller animals from getting in. The wires from the middle to the top of the fence should be spaced about 10 inches apart. One wire should be set at shoulder height of the animal to be contained.
6

Step Six

When each post is wired, use an insulated length of 10 to 14 Gauge, 20,000 Volt wire as a jumper to connect each of the rows of wire. For instance, connect a jumper wire from the top wire to the second, from the second to the third and so on.
7

Step Seven

Now that the fence wires are connected, make your connection from the electric fence controller to the top wire of the electric fence. Once your connections are made, go back and re-check all of your connections along the fence. Do this before applying the power. When you are finished, insert the electric fence controller's plug into the available polarized outlet. There should be a light on the controller that will light up to notify you that the fence is working properly.
8

Step Eight

Once your installation is complete and the fence is electrified, use a voltmeter to check voltage along the length of the fence to ensure the electric is flowing the entire length.

Tips & Warnings

  • Place "Warning: Electric Fence" signs as often as you need, so from any vantage point one is easily seen
  • Educate family and friends how to safely disconnect the electric fence in the case of an emergency
  • Check your electric fence thoroughly every year for signs of damage, poor connections or poor insulation
  • Avoid installing your electric fence grounding system within 50 feet of any utility grounds, underground telephone lines or water pipes.
  • Do not use standard household electric wire. It is only rated for 600 Volts
  • Avoid using barbed wire
  • Do not add any other pieces of equipment to the circuit dedicated for the electric fence
  • Do not "tie in" any equipment to the electric fence field controller
  • Only fuses rated for 1 Amp/250 Volts should be used for the electric fence
  • Avoid adding a second fence controller on the same fence at the same time
  • Avoid standing near the electric fence during a lightning storm
  • If you are using metal fence posts, ensure that the wire DOES NOT come in contact with the post

Please order online 24/7 or call VALLEY FARM SUPPLY at 717-786-0368

November 21, 2013

How to Select, Install Electric Fence

How to Select, Install Electric Fence
Advice from an electric-fencing expert on selecting and installing it for maximum security and safety for your horse. Plus, a maintenance checklist for you.

When you need to build a new fence or replace an existing one, there's a major reason for using electric fence: Properly selected, installed and maintained, it's the most effective way to safely contain your horse. It's also economical and easy to install and maintain. Let's look at the basic components of an electric fence and how to avoid common problems.

 

Key Electric Fence Components
Charger. Sometimes also called an energizer or fencer, the charger needs to be powerful enough to deliver a definite jolt when your horse touches it, even when its current is reduced by vegetation touching the fence line or (as sometimes happens) by moist, dewy early-morning conditions.

Ignore chargers whose power is rated by miles; look instead for one rated by joules, a measure of the oomph with which the charger is pulsing its thousands of volts of current through the fence once every second. One joule is a minimum rating for fencing that encloses up to five acres, but I always recommend getting the most powerful charger you can afford. A higher joule rating doesn't mean the fence's jolt--which can't injure horses or other animals--will be harder or more painful, but that it will be more consistent.

The difference in cost will be insignificant compared to the value of your horses and your peace of mind; expect to pay $100 to $120 for a good one-joule charger that plugs into an outlet in the barn or elsewhere; six-joule chargers now sell for less than $200, a small premium for peace of mind. (Worried about your electric bill? Fence chargers use negligible amounts of power, whatever their rating.) I recommend solar-powered chargers--about three times as expensive as the plug-in type--only for paddocks where 110-volt power is unavailable; as well as delivering relatively low power for their cost, they're susceptible to failure.

It's possible to run insulated cable up to 1/4 mile from a charger to the fence without significant power loss. Install the charger under cover (except for solar-powered chargers, of course), where you can check it easily during each day's routine. Most chargers have a light that flashes with the electric pulse when they're plugged in and functioning.

Ground system. This is a series of three 6-foot-long, galvanized-steel rods pounded into the ground 10 feet apart and connected by insulated cable (see below) to the "ground" terminal on the fence charger. (In areas where soil is very dry, more than three rods may be needed.) Assuming that you have a good charger, the ground system is the key to your electric fence's effectiveness. If your horse touches the fence, he feels a jolt only when the brief pulse of electric current that goes through his body and into the ground is picked up by the ground system and returned to the fence charger, completing the circuit. Be sure to use a ground rod clamp to attach the ground wire as tightly as possible to the rod, rather than just wrapping it around.

Insulated cable. The cable that carries the electric pulse from the charger to the fence needs to be specifically for electric fence, with insulation rated for up to 20,000 volts (most fence chargers emit from 5000 to 10,000 volts)--the same degree of insulation as on automobile spark plugs. By using cable designed for electric fence, you avoid the electricity leakage that results when you connect the charger to the fence with heavy-duty household electric cable, whose insulation is rated for only 600 volts.

When attaching the cable to the fence itself, use a connector clamp rather than just wrapping the cable wire around the fence; cable connected by wrapping comes loose more easily or loses power due to oxidation or corrosion buildup. All fence manufacturers sell a connector clamp designed to work optimally with their product. You'll also need the cable to carry the electric fence current from one side of a gate to the other: Connect all strands of the fence to the cable on the side of the gate nearest the charger.

My preference is to then run the cable above the gate via an archway high enough to safely admit horses and paddock-maintenance equipment, but most people prefer to run the cable underground. That's fine as long as the cable is encased in waterproof plastic tubing, plugged at each end with silicone caulking and buried in an 18-inch-deep trench to protect it from damage by hooves and equipment. On the far side of the gate, use connector clamps to attach all strands of the fence to the cable.

Cut-off switch(es). Save lots of extra steps by installing a weatherproof knife-type cut-off switch (sold in the electric fence section of farm stores) between the insulated cable and its attachment to the fence, enabling you to turn the fence off without going back to the barn to unplug the charger. I also like to install cut-off switches on both sides of a gate--multiple cut-off switches allow you to isolate sections of the fence for easier trouble-shooting.

The fence itself. Visibility is key to an electric fence's effectiveness and safety. Materials such as 1.5- or 2-inch poly tape, braid, rope or coated HT wire make the fence easy for your horse to see and avoid. (Thinner fence materials such as poly wire or 1/2-inch poly tape are suitable for temporary installations or as a "hot wire" to keep horses away from solid fence; uncoated electrified wire--although dangerous when used as a fence material on its own--can also be used to protect solid fence.)

Choose a product with a long warranty (for instance, some fence materials have a guaranteed lifetime of 20 years) and follow the manufacturer's recommendations for number and spacing of strands. A good general rule of thumb is four to five strands of fence, 4 to 4.5 feet high, for perimeter fences and three to four strands for interior fences. Space the top two or three strands no more than 12 to 14 inches apart and the lower strands 18 inches apart, with the lowest strand 18 inches from the ground to minimize interference by grass and weeds.

Insulators. The type of insulator you need (to hold the fence material on the post that supports it, while preventing the fence from contacting any surface that will cause current to leak) is determined by your choice of electric fence; most manufacturers market insulators specifically suited to their fence products. In general, braid, rope, and coated wire are installed on insulators that allow the fence to slide through. To help prevent chafe and wear on a tape fence, however, insulators need to be the type that clamps and immobilizes the tape (especially important in windy areas), and to be installed vertically on the fence post. Avoid cheap "generic" insulators (often made of brittle plastic), which only last a few years.

Testing, Testing... Why It's Important
When your electric fence is built, monitoring its voltage regularly--I recommend daily--is a basic management practice, just like checking water buckets. Use a digital voltmeter that tells you exactly how many volts of current are on the fence. (How many volts are enough? Four thousand to 5,000--remember, there's no way this jolt of current can hurt your horse, but it needs to be definite enough for him to remember it and want to avoid it.)

Your first check of your new fence's voltage gives you a baseline so that future checks can alert you to voltage drops that signal problems. Depending on the strength of your charger, it will emit 6000 to 10,000 volts when nothing is connected to it. After you've hooked it to your fence, check the voltage at the furthest point from the charger. Some drop in voltage--1500 to 2000--is normal. A more than 2000-volt drop means either your charger is underpowered for the fence, vegetation or something else is "loading" the fence (touching it, causing voltage to leak away), there's a short-circuit somewhere in the system--or a combination of these.

If the base voltage on your newly built fence is 4000 or better and everything's working fine, watch on subsequent checks for an overall voltage drop of 1500 or more. (It's normal for voltage to be 500-1000 lower in the morning when moisture on the fence, posts, and nearby vegetation can cause temporary current leakage.) Such a significant decrease means it's time to check for problems and correct them before your horse discovers the fence no longer packs a punch; in fact, many horses can sense when the fence is or isn't functioning.

 

Electric Fence Maintenance Checklist
  • Look for and remove sources of "load." Mow or trim under bottom strand to prevent grass and weeds from touching the fence; watch for fallen limbs or other objects on the fence or caught in insulators. (Tips: Listen for the rhythmic snap that indicates a voltage leak; follow your ears to find the source. Drag a long stick on the ground beneath the bottom strand as you walk the fence-line; it may knock away an interfering object you don't even see.)
  • Check insulators. A broken insulator can allow the fence strand to touch the post--not an immediate problem with a nonconductive wood post, but if you're using steel T-posts a broken insulator can cause the fence to go dead when the strand touches the metal.
  • Check connections. Ground-rod wires can get knocked or kicked away. Wires attaching the cable to the fence may come loose.
  • Check the charger. A spider's web built between terminals can cause it to spark.
  • Check insulated cable. Look for places where the cable may be abraded, for instance where it passes through a hole cut in metal barn siding.
  • Check fence strands: Look for frayed spots in poly tape--if metal fibers in the weave become separated, tape can't conduct current.

Texas-based international fence authority Bob Kingsbery grew up on a family-owned horse-breeding farm; he has written widely on electric fencing and has conducted more than 300 seminars on fence technology and grazing management throughout the world. You can reach him with your electric-fence questions via email at bob@kingsbery.com.

 

This story originally appeared in the March 2004 issue of Practical Horseman magazine.


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November 21, 2013

How to Build High Tensile Fence

How to Build High Tensile Fence

Building your High Tensile fence

You have already decided what kind of fence you need, now the next step is to determine where you will put it. Be sure of your boundaries, check local laws and regulations pertaining to fencing and locate any potential hazards, both natural and man-made, such as underground utility lines and overhead electric wires. Make sure the fence path is clear of brush and debris. Once you're ready, install all end and corner posts. Next, run out a single guide wire to help assure a straight fence line. This wire will become the bottom wire of the fence and serves as a guide for setting the line post.

Attach the guide wire to both end posts. Use a chain grab wirepuller or an in-line strainer to pull the guide wire taut (about 100 pounds tension). For safety's sake, wear appropriate clothing, heavy leather gloves and eye protection when working with any wire fence and, when driving posts or operating other power equipment, wear hearing protection. If the terrain is hilly, drive the rise and dip post first and staple the guide wire to them before setting the line posts.

Setting the post(s)


Check the chart, which gives suggested post space distances for the type of fence that you are building. In most cases, the use of Kiwi Droppers® will allow you to reduce the cost by increasing the distance between posts.

Posts, small end down, can be mechanically driven with a hydraulic post driver or set using an auger-drilled pilot hole and rammed into place. Posts can be handset but driven posts have about five times the holding strength of handset posts.

If you hand set posts for brace assemblies, set the end post in concrete to keep it from uplifting. Dig the hole with a bell-bottom. Before you place the post, hammer a ring of staples, driven half way in, around the end of the post about 2 inches from the bottom. Place the post and tamp in tightly 8 inches of dry concrete mix. The soil moisture will cause it to set up. Fill the remaining hole with tightly tamped dirt to ground level. For gatepost, add an additional 8 inches of dry concrete mix 18 inches from the top of the hole. Fill the hole with dirt to ground level, tamping tightly.

To prevent overturning a post in soft soil and lifting of a post in a dip, increase the post length and drive deeper; again, check the chart.



Brace assemblies

The ASAE (American Society of Agricultural Engineers) recommends a double brace end assembly for American soil conditions. A double brace is rated at 9,000-lbs. pullover resistance and is more suitable for longer runs and larger livestock. Single brace assemblies can be used for fences of six wires or less. You can increase the holding ability of a brace assembly by increasing the length of the top horizontal post. Recently, a new double brace has become popular, which has the holding properties of a traditional double brace, but affords a cost savings in materials and labor. Drive a 6"x8' end/corner post but then use 4"x7' posts for the rest of the brace. The key is that the brace wire extends in a double wrap from the bottom of the end/corner post to the brace pin on the second brace post. To make the job neater, double figure 8 the brace wire.

 



Corners and changes in direction


A corner can be made using a common end post and building two brace assemblies at an angle from that end post. To reduce material costs, corners may be constructed using post leaning against the pull of the wire: For every 10-degree directional change, use a 4" x 8' post on a 4" lean, 4' deep; for every 20-degree change, use a 5" x 9' post on a 5" lean, 4 1/2' deep; for every 30-degree change, use a 6" x 9' post on a 6" lean, 5' deep. Drive the post by machine on a lean or to the bend. With either type of corner, string the wire to the outside of the bend, or any curve in the fence for that matter.


Stringing the wire

Once the line posts are set, mark them for the proper wire spacing, and string the remaining wires. A spinning jenny or multi-wire fencer will make handling the wire easier.

For electrification, slide on the required number and type of insulators. Staple the wire accurately to its mark at all corners, major dips and rises, and at the post next to where you will install the in-line strainers. These points will create some friction. The in-line strainers should be installed near the middle of these friction points.

To ease installation, attach a chain grab wire puller to the wire at least four feet from a post, pull out the slack, cut the wire and use crimping sleeves to secure the strainer. Thread the other end of the wire through the hole in the drum, cut off the surplus. With the handle turn the drum until no slack remains. Use one tension indicator spring for each set of in-line strainers.

Joining and tying off wire

You can join wire by manually tying a knot but a knot in the wire will reduce the wire strength by a minimum of 30%. It is better to join wire with a mechanical wire link or three crimping sleeves; both create a joint as strong as the wire. To anchor wire at the end, as in joining wire, you can knot the wire but you reduce its strength. The better way to anchor the wire is to use two crimping sleeves or drill holes into the end post and use a wire vise mechanism, which has a tapered barrel that firmly holds the wire.


Stapling

Before stapling the remaining line posts, tension the wire taut, about 100 pounds, using the in-line strainers. This will prevent crossed wires and aid in positioning the wire. To reduce pullout use 1 1/4 - to - 2 - inch long, 8 or 9 gauge slash cut, electro-coated galvanized staples with barbs. If you rotate the staple 30 to 45 degrees away from the flat face, you will prevent the post from splitting and the staple leg will spread, curving outward from the flat face for greater holding power. Drive staples at an upward angle into posts in dips and at a downward angle into posts on rises. The staple should allow the wires to move back and forth freely. Staple the wire to the livestock side but on the outside of corners and curves.


Tensioning the wire


One in-line strainer per wire can tension 4, 000 linear feet of high tensile wire on a straight-line fence over level terrain. To calculate the number of in-line strainers needed add 500 feet for each corner, severe dip, rise or curve to the total linear feet of your fencing project. Divide this total by 4,000, round the answer up to the nearest whole number (for example, 1.3 = 2) and multiply by the number of wires on your fence (2 x 6 wires = 12 strainers or two sets). Tensioning from the top wire down will provide clearance for turning the in-line handle. Use the wire with the tension indicator spring attached as a guide to tension the other wires. Pull the wire towards you and tighten until all the wires have the same "feel" (resistance). After a day or so the fence will set, check each wire and if necessary, correct the tension to the recommended 250-lb. pull.


Grounding non-electric fence

All fences utilizing steel wire on nonconductive posts must be grounded for safety from lightning. Drive a galvanized steel post, 3/4 - inch galvanized steel pipe or an approved ground rod at least 3 feet into the ground, not more than 300 feet apart (150 feet in dry, rocky soil). Attach 5 strands of galvanized wire to the rod and lace through each fence wire. Bend the top of the ground wire bundle into a loop and staple home to a post.

Electric fence

Your high tensile fence can be easily electrified using new high voltage, low impedance type energizers. The construction methods described for non-electric fences also apply to electric fences with one important exception. Energized wires must be insulated from the post; The need for insulation makes it necessary to plan for electrification before you begin construction. For specific help on energizer selection see Energizer guide.