Electric fencing is an essential element of grassland management, for controlled grazing and utilisation of grass.
The type of livestock you want to control is the most important consideration when erecting a fence. A permanent fence will require different design than a temporary one.
Boundary fences may be designed differently than internal divisions.
Many farmers will be able to erect a good fence however a reliable contractor is usually the best long term option.
A good earth is 99% of the electric fence. Check instruction manual with fencer, and ensure fence is connected to an earth safely.
When erecting a fence, use quality materials. These may not always be the cheapest but will be more reliable and require less maintenance in future years.
These form the backbone of any fence. For most fences, the strainer or corner post should be 20 – 25cm diameter (8-10ins) and 2.1 – 2.5m (7 – 8ft) long.
This will allow approximately 1.2m (4ft) of the post to be driven into the ground. These posts may be softwoods or hard woods provided they are treated.
The distance between straining posts may be up to 200m depending on type and topography of the land.
The ideal post for most fencers would be round posts 10 – 12cm (4ins) diameter, 1.7m (5ft 6 ins) long.
The distance between intermediate posts can vary depending on the levels of the land but usually 15m is adequate.
A 2.5 (12 gauge) high tensile wire is most suitable for electric fencing.
Proper galvanised wire will have a life of 20 – 25 years, poor quality wire decays after seven to eight years.
1. Single strand electrified fence
This is cheap, easy to erect and very effective against cows and adult cattle.
It is most suitable for internal divisions such as paddocks. The height of wire for cows in 90cm (36 ins.).
2. Double strand electrified fence
This is suitable for cows, cattle and calves.
The height of top strand would be 90cm with the second strand 37.5cm (15ins) lower.This is very suitable near roadways.
3. Four/Five strand electrified fence
Cattle, sheep and lambs will be controlled. This fence requires annual maintenance.
Grass and weeds underneath the fence must be continually cut or sprayed. The five-strand fence is particularly effective against dogs and foxes.
The spacing for the five strands from the ground up is 12.5cm (5ins), 15cm (6ins), 17.5cm (7ins), 20cm (8ins) and 22.5cm (9ins).
Intermediate posts are spaced at 10m apart.
4. Sheep mesh with a single electrified strand
Cattle, calves, sheep and lambs are controlled. It is easy to maintain, stock proof and not dependent on power.
This type of fence is most suited to farm boundaries. It may also be used around farmyards, internal roadways and paddock for young calves.
An 80cm (32ins) sheep mesh is commonly used, topped with a single strand of electrified wire. Barbed wire could also be used. Intermediate posts are spread at 7-8m apart.
5. Temporary fencing
The temporary fencing of paddocks is now widely practised for strip grazing or block grazing.
Geared reels with wire and white electrified tape are most suitable. These are flexible, light and easily moved.
by Anthony O’ Connor, Teagasc Adviser, Galway/Clare Regional Unit.