Our view is that fences must do two things - - - keep the sheep in and keep the predators out. This may seem to be two versions of the same thing, but we disagree. Predators are constantly on patrol looking for their next meal. They come in many forms and we have very little control over when they will challenge our facilities for a lamb dinner. Sheep, especially Shetland sheep, are trainable and, unless very hungry, will stay within the confines to which they have become accustomed. In fact, because of the Shetlands exceptionally long and thick wool, which is great insulation from electricity, a great predator control fence may be only marginally successful as a Shetland control fence if the grass is perceived to be greener on the other side of the fence.
Our first priority is to keep the predators out and the second priority is to keep the Shetlands in. To accomplish the first priority, we felt we had to build a great perimeter fence. Our major predator in Vermont is the Eastern Coyote, followed by neighbors house dogs. Coyotes relentlessly patrol, day and night, looking for their next meal. Although they are cowards, they are thorough and never give up. They will find a dead electric fence, a slight hole under or a lamb wandering outside. Dogs usually want to chase sheep for fun or kill them for fun. Fortunately, dogs have a good memory for electric fences and will not come back after getting a good zap. Dogs have a most interesting reaction to getting zapped by an electric fence; we cant explain it, you have to see it! Black bears, moose and catamounts are around the area but, with the exception of moose, are smart enough to stay away from a good perimeter fence. Usually, once they have determined that the fence is well put together, they will stay away, concentrating their efforts where they have better chances for success. Moose are too stupid to understand fences. They punch a hole in a fence (a real big hole) then cant figure how they got in, so they punch another hole in the fence to get out. We have found no defense against moose, but fortunately they dont want to get into our pastures very often. It will take us the better part of a day to patch up the fence after a moose visit. White tail deer are in and out of the pastures all the time, over the fence. The only problem is, because of marginal eye sight, they dont always make it over the top wire of the fence, getting tangled and breaking a wire.
There are basically two types of perimeter fences - - - non electric and electric. There are many types of wooden fences, but we have never seen one that a coyote would respect. The usual non electric fence used is called galvanized "woven wire". Barbed wire has zero effect in keeping the more serious predators out, and very little chance of keeping Shetlands in; however sheep can very easily get caught on barbed wire, get torn up and die from the stress. Woven wire sheep fence has a long history and is very effective at keeping everyone where they should be. If your pasture is relatively level, the soil relatively deep, and you have a philosophical problem with electric fence, woven wire may work great for you. Posts must go into the ground to a depth at least below the frost line. Pressure treated posts will last a long time, and the woven wire can be held to the posts with galvanized staples. The bottom wire must be close to the ground to discourage coyotes from digging under, which unfortunately increases the rate of fence corrosion. The weight of winter snow load can stretch a woven wire fence big time, and it may have to be retensioned every spring. Problems with sheep ear tags getting caught in the fence, ripping the tag out and shredding the ear are common. Sometimes sheep stick their heads through to get the grass on the other side. Frequently they can't figure out how to pull their heads back through and, unless we regularly patrol the fence and help them, the sheep will die of stress. Horns can easily get caught in the woven wire fence. We have shallow soil so the woven wire fence will not work for long because the posts will move or push out with frost heaves. Our pasture undulates a great deal, we tried woven wire fence and did not enjoy installing it either!
Although our experience with electric fence has been positive, it is not for everyone. It is easy to screw up the installation so the fence will be ineffective at controlling who stays where. For electricity to flow, it must have a complete circuit. In your house, electricity flows in through one wire, into your light bulb and out through the other wire (it is a bit more complicated than that but for our purposes, let's keep it simple). If you put a switch in the circuit and you open the switch, electricity cant flow and the light is out. Close the switch, electricity flows and the light is on.
Electric fence works the same way. The fencer (sometimes called a charger or energizer) supplies electricity to the system. It has two wires, one to the fence and one to ground. The one to ground means dirt, earth, pasture, soil, etc. You must be sure that the connection to earth is outstanding or the fence wont be effective. Fencer installation instructions make a big deal about how important the ground connection is and explain how many coated bars should be pounded into the pasture to assure a good ground. Most folks installing a fencer for the first time, us included, think this is overkill and provide much less ground connection. We found out that we are wrong somewhere along the way when the soil dried out or conditions changed. A fencer can never be grounded too well; always follow the manufacturers instructions.
The other wire goes to the fence. The only time electricity flows is when the predator becomes the "switch" and connects the fence to the dirt by standing on the dirt and touching the fence with its nose. The fencer makes the voltage very high, the current very low and the timed pulse very short. The goal is not to electrocute the predator but to encourage it to stay away. Of course, we don't want to electrocute our sheep, our dog, our child or our self so the fencer is designed to get our attention without doing any real harm. It works!! Everyone finds out sooner or later. We have a choke, a super lightening diverted and a surge protector. Fencers are no match for a lightening bolt. The fence and power lines to our house are right out there as great targets for lightening. The more protection we install up front, the less repair work we will have to pay for later. Also, we won't have an electrified fence while the damaged fencer is being repaired.
There are two types of fencers: the conventional weed burners used for horses and cows and the New Zealand style used for smaller animals and predator control. Weed burners are relatively inexpensive and work well for keeping large animals contained. They pump out a fairly large current to discourage large animals, and to burn off weeds that grow onto the wire. Because weed burners put out a lot of power, they can be fatal to small animals that get tangled in the fence, and can melt the plastic in portable fence. The New Zealand type fencers are quite sophisticated and much more expensive. They put out a somewhat higher voltage in order to reduce the impact of weed growth but a much lower current to reduce the danger to small animals and an extremely short (in the neighborhood of 3/10000 of a second) pulse. These three characteristics are regulated very closely and sometimes are automatically changed by the fencer to compensate for weed load.
The most perfectly installed system wont help at all if it isnt hot ALL the time. We are very near the end of our power companys distribution line with the worst service record. It seems that every time the wind blows, we are out of power for a few hours. We built an UPS (Uninterrupted Power Supply - similar to those used for computers) system for our fencer, so when the power goes out the fencer is switched to an inverter running off a truck battery. It is a simple thing anyone can build; let us know if you need more information. The other thing that happens is a tree falls on our fence or a deer breaks a fence wire. When this happens, the fence shorts out and is dead. We have a monitor at the far end of our 3/4 mile long perimeter fence, that sends a signal back to a receiver in our house when the voltage at the far end drops below 1500 volts. It alerts us to get out there and find the trouble before the coyotes or the sheep find the fence dead.
Our perimeter fence has 8 aluminum wires running through stainless steel clips on fiberglass poles. This may be more fence than you think you need but it works well for us. The following is an explanation of why we chose what we did for each component of the fence.
8 wires - We may not need 8 wires (one stainless steel and seven aluminum); local dairy farmers kid us saying the fence will keep mosquitoes out. Each wire performs a specific task.
#1 wire is 3 1/2" above the ground. It is connected to the ground terminal on the fencer and to the dirt at many places along the fence. Grass touches it and increases the connection with ground. This wire assures that we have a very good earth ground for the fencer and anything else. We use a stainless steel wire here to avoid oxidation of the aluminum wire that happens because of contact with our very acidic soil.
#2 wire is 8" above the ground. It is connected to the hot terminal of the fencer with a voltage regulator. Sometimes the weed load gets too great and it is necessary for the regulator to reduce the conductivity to this wire from the system to keep the system voltage up on the remaining six wires. It is best to weedwack the fence to reduce the weed load but sometimes it takes a while to get around to do that. It is good to keep this wire hot because it discourages varmints like woodchucks and skunks from entering and we feel that most coyotes would check it out. An animal wanting to sneak under #2 wire to enter the pasture, would have to go between #1 & #2 where they would be assured of receiving the maximum effect of the fencer.
#3 wire is 13 1/2 above the ground. It is connected directly to the fencer and must be hot all the time. Most coyotes and dogs will check this one.
#4 wire is 20 above the ground. It isnt connected to anything; nothing at either end and nothing anywhere along its length. By induction (look that one up in your Funk & Wagnalls) the #4 wire will have about half the voltage of the #3 wire. That means that the voltage between the #4 wire and ground is about half the voltage of the #3 wire, and the voltage between #4 & #3 is about half the voltage of the #3 wire. This assures that we get the reaction we want if a predator is grounded well and touches the fence with its nose, or if it is not grounded well (dry soil during a drought) it will get a zap if it tries to go between #3 and #4. Our 3/4 mile long perimeter fence gives us this result; youll have to check your own fence, and may want to make this wire either hot or ground.
#5 wire is 27 1/2 above the ground. It is not connected to anything, just like #4 wire. It picks up some voltage from #3 wire and #6 wire by inductance.
#6 wire is 36 above the ground. It is connected directly to the fencer and must be hot all the time. We use this wire as a feeder for all of our 33 high internal portable net fence. We also connect the fence alarm to it at the far end to detect voltage in this worst case scenario.
#7 wire is 45 1/2 above the ground. It is not connected to anything, just like #4 wire. It picks up some voltage from #6 wire by inductance. It may not be necessary but it discourages people from stepping over our fence and wandering around among our sheep. It seems weird to us that anyone would do this but it has happened, and a stranger entering the pasture this way spooks the sheep.
#8 wire is 56" above the ground. It is connected directly to the fencer and must be hot all the time. We use this wire as a feeder for another section of the farm.
Aluminum wire - We use a 15 gauge aluminum wire sold by most agricultural supply stores. This is a soft and pliable wire and is readily available in 1/4 mile and 1/2 mile spools. We like aluminum because it is a fantastic conductor of electricity, doesn't rust or corrode (as long as we don't let it touch acidic soil, or connect it to a very dissimilar metal causing galvanic action which will destroy the wire), is easy to repair (there is a special knot suggested by fence suppliers, similar to a square knot; we use a square knot) and easy to break so when a deer gets tangled, it can break itself free.
Stainless steel clips - Galvanized clips to hold wires to posts are available, but we have found that they rust quite fast and the stainless doesnt. The aluminum wires dont slide through the stainless clips very well which is a draw back but it works. There are some plastic clips available for some sizes of rods. The wire slides through the plastic clips easier but we havent found clips we think will withstand years of weather and tension, available for the size posts we use.
Stainless steel wire - We have used some 19 gauge stainless steel wire with good success. On the down side, we have found the stainless wire is more brittle, fails at knots and kinks more frequently, so more care must be taken during installation. It is also harder for the wildlife to see. But, we use it quite successfully for the bottom wire where snow load is not a factor and where corrosion resistance is important.
Fiberglass fence posts - Fiberglass posts are readily available in lots of diameters and lengths, are nonconductors and easy to install. All fiberglass posts may look equal but they aren't. Unless they have a very good coating, they will start to deteriorate after a year or two in the weather. They get all fuzzy with fiberglass and every time you touch them, a cloud of tiny fibers comes off. A very unpleasant experience for you and not good for fleeces.
Steel fence posts - The winter of 2000/2001 was especially snowy here in Vermont. Our 8-strand perimeter fence was in shambles after the snow melted. We had 3-4 feet of snow on the ground for most of the winter with much higher wind driven drifts. The official total snowfall for the winter was somewhere around twelve feet. Now, I'm not complaining, we love winter, but I want to give you an idea of what a real snowfall can do to a low tensile wire fence. Most of the snow melts from the bottom so new snow and gravity push the snow from the previous storm toward the ground trying to take everything else along with it.
We had to replace three dozen 3/8 fiberglass posts that broke during the winter. They broke in an unusual way. The posts failed at ground level with shards of fiberglass surrounding the posts. Apparently the weight of the snow load on the post and wires was so great that the posts failed in compression with what looked like a small explosion. We have had this happen before but never at this magnitude. We have tried something different, over the past few years, for replacement posts. We bought western style insulators for each wire on each post. They have a hole large enough to accept a 9/16 rod, with a plastic nut to hold the insulator in place on the rod. This design isnt anything new, they have been used for decades, but it is new to me. We used 3/8 diameter hot rolled steel for posts. Hot rolled steel is readily available from my local steel supplier and isnt very expensive. It comes in 20 lengths so I asked the supplier to cut them in thirds. 6+ feet of post gives me enough length to get down into some meaningful dirt. Being steel, I can really beat on the top end to get it to go where I want it to go.
How did the steel posts hold up during the great snow, you might ask? They did fine! We probably had ten in service. One bent a little because the fence apparently started to lean over with the snow load. The only real problem is that most of the western insulators slid down the post to the bottom. It was a simple task to adjust them to their proper height but it was one more thing to do. I plan to try steel reinforcing rod in the future. It has a surface texture to help it grip to concrete. #3 Rebar is 3/8 in diameter and I plan to use it instead of the 3/8 fiberglass posts. #4 Rebar is 1/2 in diameter and I plan to use it instead of the 5/8 fiberglass posts.
Some quick pricing indicated that both methods cost about the same. I haven't seen any difference in performance, but the "western" insulators may not be made to handle the high voltages of the new style fencers. I'll have to keep a close watch on them, especially when it is raining. It sure beats dealing with the fiberglass fuzz of the older fiberglass posts in the spring.
Fast forward a decade! Neither the 3/8" diameter hot rolled steel posts or the "western" style insulators worked well for our Vermont, mountaintop winters. The "western" style insulators failed two ways. The snow load forced most of them to slide down the smooth hot rolled steel posts. We tried using #3 & #4 rebars but the insulators still slide down. Further, water that got into the spaces between the rebars and insulators or between the parts of the insulators then froze which cracked the insulators and they fell off the rebars. This concept is quite easy to install and might work well in less harsh climates. I thought 3/8" diameter hot rolled steel for posts would work great. It takes a large load to push a 3/8" bar into the ground. Wherever the bars did not go down to ledge or solid rock, the snow pushed them down. Some were pushed down almost a foot more than they had been during the grazing season, breaking wires and destroying insulators as they went. Where the 3/8" bars were pounded in far enough to hit good solid ledge, they bent into weird shapes, something like Greek letters. They were so bent and misshapen that they could not be salvaged for fence posts. Again, these posts might work well in less harsh climates. All experiments don't always work as well as one would like but, some do so we keep trying to be innovative.
We try to put up fence in 700' sections. If the line is longer, we make two sections; if shorter, we will extend a section around a corner. We start by pounding 1 1/4" posts into the ground at each end of a section and at every corner. The post should go into the ground to below the frost line or until it hits solid rock. Choosing where to pound the post into the ground is critical and we must be sure to have a cap on top or the end will mushroom and we will never be able to install clips. Next we slide on the stainless clips and position them with the proper spacing. We put guy wires on every 1 1/4" post in a direction exactly opposite to the direction of the fence. We use 16 gauge stainless wire (aluminum wire will fail after a few years in the soil because it oxidizes) through a #68 Duckbill pounded a few feet into the ground. Duckbills are cast zinc devices with wire fastened to them that are driven into the ground with a special tool. Once in place, the tool is pulled out and tension is put on the wire to turn the duckbill and anchor it in the soil. They are widely available and used by many nurseries to anchor ropes used to stabilize newly planted trees. They are also available from fence suppliers. The duckbills are available with stainless cables already installed, but the cables are never long enough for our application. We double the stainless wire through the loop on the duckbill, to avoid tying a knot that will be under ground. We put a stainless hose clamp on the 1 1/4" post, several inches above the top wire clip. We then tie or clamp both ends of the stainless wire around the 1 1/4" post, just above or through the hose clamp so that the wire won't slide down the post.
Next we stretch a nylon string very tightly between the bottom clips (for the whole 700' section length). Everywhere the string touches the ground, we pound in a 5/8" post. We must be sure to use a soft faced mallet or a protective cap when pounding in the smaller posts also. It should go into the dirt until it hits something solid like ledge, or until it is below the frost line. Then we install clips at the proper heights and run the string through the bottom clip. Once all the high points have 5/8" posts, we go to the worst dip between posts. At this point, we pound in a #40 duckbill with a 16 gauge stainless wire through its loop, remove the installation tool and pull the wires to "set" the duck bill. We pound in a 3/8" fiberglass pole at that same spot, until it is in a reasonable depth. It doesn't have to go below the frost line but the deeper the better. We slide the stainless clips onto the 3/8" pole to the proper spacing and tie the 16 gauge wires to the bottom clip. We run the string through the bottom clip and move on to the next space between 5/8" posts to repeat the operation. Continue this alternating from 5/8" posts and clips at the high points and 3/8" posts with duckbills and clips at the low points until the string is following the contour of the ground nicely and you are confident that no varmint or sheep will be able to sneak under. Sometimes the posts will end up being 1' apart in very undulating soil, and sometimes 50' apart. We feel that posts should never be farther apart than 5', so we add enough 3/8" posts and clips where necessary to achieve that goal.
We remove the string and unwind one strand of 19 gauge stainless steel, laying it on the ground along side the row of posts. Fasten the first end of the wire through the bottom clip and to itself using some clamping device, leaving a foot or so of wire extra. We prefer 1/4" stainless hex screws, nuts and washers, but splices or split bolts work fine also. Walking along the fence line, we carefully lay the wire into bottom clip of each post. We then fasten the last end of the wire through the clip, around the post and to itself as we did the first end; leave generous slack in the wire and cut the wire from the spool. Repeat this operation for all the remaining clips using 15 or 17 gauge aluminum wires. Next we put about forty pounds tension in each wire, starting at the bottom wire, with a tightener located about halfway between each 1 1/4" post, and work our way up to the top wire. We prefer aluminum or plastic tighteners to avoid galvanic action between the aluminum wire and steel tighteners. Sometimes it is necessary to repeat tensioning a second time. We can tell when we have forty pounds tension because the wires make a sound like Chinese music when we strike them with a stick. We continue this around the perimeter, electrically joining the 1' long pigtails of wires at the ends of each section. Sometimes posts bend a little and have to be straightened, and guy wires at corner posts have to be adjusted.
We use 33" portable electric net fencing for our internal pasture divisions. They are electrically connected to the #6 wire on our perimeter fence. They are sold in 75' and 150' lengths and we have customized some to special lengths for specific locations. Individually or in series, they are set up in a general "L" shaped pattern next to the pervious net to form a small pasture and entrance way. We have made 8' long gates from what we can buy at the lumber yard as "strapping" or "furring" which is 3/4"x2 1/2"x 8' inexpensive wood. Every fall, we remove the net fencing and store it in the barn. This leaves the pasture wide open to allow for any kind of maintenance, and easily permits us to make modifications in our layout from year to year. We have well over 100 net fences. It takes us about three days to set them all up in the spring and two days to take them down and store them in the fall.
As with many farms, the parcel we graze is an odd shape. Our farm is sort of "L" shaped with the house off to one side of the middle. The fencer is at the house and an aluminum wire fence runs between the house and the perimeter fence. We have a road that runs in a "C" shape about half way between the house and the perimeter fence. The layout is such that almost all of the pastures open onto the roadway. Moving sheep becomes relatively easy. Open the destination pasture and block the road just past the open gate. Walk the fence line of the new pasture to be sure it is secure and check for poisonous plants. Go to the pasture where the sheep are waiting and block the road just past the gate there also. Open the gate and get out of the way, the sheep will figure out where to go. We check the pasture after the sheep leave to be sure no one "missed the bus" while asleep or is in some kind of trouble.
There are many suppliers of quality fence materials and most are very anxious to be sure customers get the right fence for their farm. With United Parcel Service and other carriers being so good these days, the help and service provided by the vendor are more important than close geographic proximity. We buy all of our fence supplies from two suppliers. They carry some different and some similar products:
Wellscroft Farm Fence Systems
46 Sunset Hill - Chesham
Marlborough, NH 03455
Phone: (603) 827-3464
Fax: (603) 827-3666
Don & Charles Kendall
Kencove Farm Fence
111 Kendall Lane
Blairsville, PA 15717-9685
Phone: 1-800-KENCOVE = 1-800-536-2683
Using our sample flock of 2 rams, 12 ewes and 6 lambs at a stocking rate of 10 per acre, we will need to fence two acres. If we subdivide the area into nine pastures with a perimeter fence and a U shaped road (easier to get equipment around than a dead end) to move sheep, the cost for materials comes to just under $3000 or $150 per sheep. The cost is very close to the same for all woven wire or an 8 aluminum wire perimeter fence subdivided with electric net fence. Installation of the electric fence should take around eight person days to set up the perimeter fence, the subdivisions and gates plus and annual maintenance of one person day to set up and knock down the subdivisions each year. There are a lot of posts for the woven wire fence which will probably take eleven person days to install and the annual maintenance will be around half a person day. These are VERY rough estimates that will be influenced by the topography, geography and geology of another farm.