Noel Lynch is running a successful and well-known fencing contracting business out of his Callan base in Co Kilkenny. While Lynch Fencing also complete domestic and civil fencing, agricultural fencing is still the bread and butter of the company’s projects. In this area of the country, dairy dominates on the livestock scene.

“What we sometimes find with farmers is that we complete the fencing and they themselves set up the electric fencer wrong in some way, which results in a weak pulsation if not set up correctly.

“Cows then scratch off the fence and loosen it.’’

Noel’s key tips for successful fencing:

Earth rods

“I see a lot of farms where the milking block has been extended and additional fencing installed. The farmer then sees that the current in the fence is down and either gets their fencing unit checked for faults or replaces it with a larger unit. In many cases, it’s an insufficient amount of earth rods that are the cause of the low voltage.’’

Looping of wire when connecting two lines will result in current traveling better through slowing it down.

Earth rods should be 1.5m in length and of galvanised steel. They should be driven down to their full depth in a damp area. Between three and five earth rods should be driven for a mains fencing unit, with the earth rods spread 3m apart from each other.

Noel recommends heavy duty (2.5m) galvanised insulated wire for earthing. Copper wire should not be used as it leads to corrosion which weakens the pulse. The wire should be firmly attached to each rod with a clamp. Simply wrapping the wire around the clamp is insufficient. Each rod should then be connected to the next rod with the same type of wire.

Terminating fences

For an electric fence to be properly installed it should not be a closed loop. When an animal touches the electric fence, this should be the missing link in the loop for the animal to get the shock. A closed loop system will see the current meeting in the middle of the fence and banging off itself.

2.5mm galvanised wire should be used for earthing of fences. Copper wire should never be used as it corrodes.

Where earthing occurs due to a tree falling on top of the line or a broken insulator, the wire that runs before the earthing point will generally carry much the same current. In a closed loop system, all of the wire is affected once the wire has been earthed by an object.

Keeping fences free from growth

“One of the worst things farmers can do is knock off a fence because it isn’t in use. I often see a farmer knocking off a particular section of the farm when it is closed up for silage.

The fence should be kept on at all times to allow it to control any new growth’’.

For hedge cutting and mowing, Noel has left straining posts two sward widths out from the hedge on his own dairy farm.

Should two or three paddocks together have to be mown out, then the contractor can treat the paddocks together as one regarding mowing, raking and baling headlands. Keeping the straining post out from the hedgerow and leaving a gap there also allows for full access with a hedge cutter for maintenance, as dead ends in a field can be difficult to cut properly.

Slowing down current

Slowing down the current when connecting rows of wires together or connecting two separate wires at a straining post is something very few farmers do.

“It’s like trying to send a car around a bend; if you try doing it at 100 miles an hour it’s going to be tricky, but if you slow down the car you’ll get around the corner’’ explained Noel.

Noel recommends looping to help slow down the current and allow it to travel better between two wires.

Quality insulators

Only high-quality egg insulators should be used when setting up an electric fence. Cheaper eggs can be prone to UV damage over time and can “pull’’ in the centre due to the strain from tensioned wire. A good test on the quality of an insulator is to snip it with a wire cutters. High quality egg insulators will be made of hard plastic and difficult to cut, while cheaper insulators will be softer and easier cut.

The same goes for insulating at posts or strainers. Hydrodare (water) piping should not be used as it is too brittle and soft.

Driving stakes to full depth

Noel recommends using 6ft (1.8m) stakes for all paddock fencing, driven down close to the height of the top line of electric fence (driven 2-2.5ft) in to the ground. Strainers should be 8ft long and driven 4ft in to the ground. Having posts or strainers significantly higher than the wire will encourage scratching from animals and loosening of the fence in Noel’s opinion.

  • Use three to five earth rods driven to their full depth in damp area.
  • Use galvanised heavy duty wire for earthing.
  • Terminate the fence. Do not have a closed loop system.
  • Drive stakes to full depth (strainers 4ft in ground, stakes 2-2.5ft).
  • Slow down the current of the fence when connecting rows of wires or at a strainer.