A fence can act as two kinds of barriers: a physical barrier and a psychological barrier.
A physical barrier is a fence that does not have electricity running to it, but just serves are a divider between the inside and outside of the fence line. Fence types that would provide a physical barrier for the animal would include high tensile, rail-type fences, barbed wire, and board fences. These types of barriers have enough strength to prevent the animal from going through the fence or pushing the fence out of their way to go under, or through. Physical fences typically require more strands of fence than a psychological barrier.
In a pasture land setting, it is recommended to use 6-8 strands of wire depending on the height of the fence. This is using a 6 inch wire spacing system from the ground to the top of the post. When using a barbed wire for the barrier, it is only necessary to have 4 strands of fence due to the 2-ply construction of the barbed wire. Barbed wire is relying more on the spike of the barb rather than pure strength and tension. Barbed wire can only serve as a physical barrier because is not an electrified fence type.
Physical barriers can be labor intensive to construct, but decrease the concern of power outages. These barriers can present a hazard to the animal due to possible entanglement in the high tensile or a chance of getting cut by a spike on the barb. However, materials for physical barriers are built to last many years and require less maintenance.
A psychological barrier is an electrified fence that causes the animal to have a fear of the fence line once they have been shocked from touching the barrier. Electrified tape, twine, braid or wire are examples of fence types that serve as psychological barriers. These fence types do not have the strength alone to keep the animal from going through the fence, but inflict an electric shock to discourage the animal from escaping or entering.
Psychological barriers do not need as many strands of the high tension to be effective. These types can hang loosely on a pole, with only a few strands and prevent the animal from crossing the fence line as long as they are energized properly. After being shocked a few times, the animal will learn to fear the fence causing the barrier to exist more in their mind than physically in front of them.
When using psychological barriers there is less chance of an animal getting injured. Polytapes and rope fencing are two of the best barriers to use on horse fences, due to the sensitivity and injury risk associated with them. There is usually a lower cost with the fencing materials, but a fence energizer must also be purchased to complete this set up. The energizer price and size will depend on the length of the fence it will be servicing.
Some fences can be both physical and psychological. Coated wire is made with the same 200 KSI high-tensile wire as a physical barrier, but the increased size of the coating improves its visibility. Powercote combines the high visibility of coated wire while retaining its ability to carry a charge.
The type of fencing needed for an animal will vary depending on the following factors:
Also, many times this could depend on the individual animal. Fencing a bull will require more of a barrier than a horse. In the same breath, horses are often individualistic in their attempt to break through a fence to get where the grass is greener.
You can look at our blog Which Fence Type is Best for my Livestock Species? to determine which fencing type is best for you on your farm.