When an electric fence doesn't work the way it should, the energizer generally gets the blame. In actuality, the fault most frequently lies with the ground system, a fencing expert told about a dozen livestock producers at Star and Thistle Farm on May 1.
Kenny Fixmer, Minnesota and Wisconsin representative for Gallagher, spoke at the Southeast Wisconsin Grazing Network's pasture walk and fencing clinic at Star and Thistle Farm. Gallagher pioneered New Zealand's first electric fencing system in 1938 and now operates in 130 countries.
An electric fence consists of three equal parts: the energizer, the fence system and the ground system, Fixmer explained.
"If any one part doesn't work, you don't have an effective fence," he said.
For a well-grounded system, producers need a minimum of three 6-foot galvanized ground rods, he explained, and there needs to be a minimum of 10 feet between the ground rods to increase the probability of having contact with moist soil. One continuous galvanized 12.5-gauge wire should link the ground rods.
Fixmer said the best grounding systems are those where the ground rods are in a damp site since soil moisture facilitates the energy going to the ground. Electric fences should be at least 33 feet away from any power supply ground rod, underground telephone lines or power cable, he added. He also recommends using galvanized clamps for ground connections to avoid the oxidation that some metals can experience.
A bulletin from the Natural Resources Conservation Service provides additional grounding recommendations. Use the same type of metal throughout the fencing system, it says. Use galvanized ground rods when using galvanized wire and clamps for the grounding system.
If using stainless steel connectors on the energizing, copper can be used. NRCS says a good rule of thumb is to drive at least three feet of grounding rod into the ground per joule of output. To lessen the possibility of stray voltage at dairy operations, it recommends keeping the energizers and grounding systems as far away as possible from milking barns.
Producers also should be aware of the locations of underground utilities and fuel-storage tanks and avoid grounding the fencing system near these by the greatest practical distance.
Fixmer noted producers can select from 110/220-volt energizers or energizers that operate on solar power or by battery. He encouraged producers to buy their energizer based on the amount of fencing they might someday have, not just what they have today. Purchase a larger energizer than needed because graziers frequently expand their pastures, he added.
In selecting the energizer, producers need to consider both what they want to keep in a pasture and what they want to keep out. The hollow hoof structure of goats and elk, for example, make them more difficult to shock than other livestock species, Fixmer said.
Fixmer stressed the need to consider the safety of electric fences. Never electrify barbed wire, he said. If an animal gets caught in an electrified barbed-wire fence, the barbs can severely cut the animal as it tries to get away from the electric shocks.
Producers should never have more than one energizer per fence, he added. Do not use utility poles to support an electric fence or lead-out wires. To avoid stray voltage, avoid placing electric fences parallel to overhead power lines, telephone lines and cables; if fencing must be in the same vicinity, crossing under overhead and buried cables at a 90-degree angle is a better option.
An electric fence tester is a necessary piece of equipment for producers. It allows producers to periodically test the current running through their fences, helping to locate non-working fences before animals do; plus, it will help figure out where the problem lies in fences that are not operating properly.
Producers can utilize different types of electric fencing to suit their needs. Permanent electric fencing can be used for pasture perimeters or to subdivide pastures. Portable fencing is used for rotational grazing and to keep animals away from specific areas, like a newly-seeded area or haystacks. Offset fencing, which combines electric fencing and non-electrified fencing, is designed to increase the life span and effectiveness of conventional fences.
NRCS notes electric fences have two major advantages over other types of fencing. According to 2005 figures, NRCS says the cost to install a four-stand barbed-wire fence is about three times more expensive than a typical single-wire electric fence, and additional wires can be added to an electric fence at a relatively low cost. A second advantage of electric fencing is the relative ease of construction and, depending on how it is used, to improve forage management, said NRCS.
To build electric fences generally requires 50 percent less labor and 35 to 70 percent fewer materials, Fixmer said.
Fixmer noted electric fencing is not foolproof in keeping animals either in or out of certain areas or pastures. Animals must learn what happens when they touch an electric fence. If a fence is well constructed and maintained, animals will learn to stay away from it.
"You have to remember that it's a psychological barrier, not a physical barrier," Fixmer said of electric fencing. "...A lot of it is conditioning."
Pasture-walk hosts Vanessa Herald and Nikki Lennart moved to their Star & Thistle Farm on Stuart Road near Beloit in July 2013. Their operation includes a baking company, pasture-raised meats — chickens, heritage-breed pigs and goats — and laying hens.
The pasture walk and fencing demonstration was sponsored by Gallagher, Frank Organic Feed & Supply, Star & Thistle Farm and Town & Country RC&D, with funds from the Grazing Lands Conservation Initiative Program, which is administered through the Wisconsin Department of Agriculture, Trade and Consumer Protection.
For more information, download the 35-page NRCS Publication #80305 entitled "Electric Fencing for Serious Graziers" found at www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs144p2_010636.pdf.