High Tensile Smooth Wire Fence For Pasture Subdivision And Predator Control
Livestock Update, July 1997
Steve Umberger, Animal and Poultry Sciences, Virginia Tech
When constructing new fence or modifying existing fence, the value of the fence for both improved pasture management and predator control should always be considered. Subdividing large grazing boundaries into smaller units provides more flexibility for altering grazing management and increasing hay production. The importance of properly constructed fence cannot be overstated as a tool for protecting livestock from dog and coyote predation. Highly effective, safe, and inexpensive electric fencing systems has made fencing for pasture subdivisions and predator control more practical. High tensile (HT) smooth wire electric fence is cheaper and easier to construct than most traditional types of fence. Electrified boundary fence is one of the most effective tools used for predator control, and provides the opportunity to tie in temporary electric fence to facilitate pasture subdivision for improved grazing management.
Boundary fence for sheep should consist of at least five strands of electrified HT wire. Internal fence for pasture subdivisions requires a minimum of three strands of wire. Internal fence may be permanent or temporary. Types of temporary electric fence include: 1) polywire; 2) polytape; and 3) electric netting. Some of the benefits for temporary fence are: 1) flexibility to subdivide pastures for certain times of the year rather than year-round; 2) the opportunity to experiment before settling on the best combination of temporary and permanent pasture subdivisions; and 3) the opportunity to fence in front of and behind sheep when strip grazing. Temporary fence will not carry a charge as far as HT fence, nor is it as effective in controlling predators.
Factors influencing the effectiveness of electrified HT fence include: 1) proper construction of fence; 2) sufficient grounding (noted as the most common error by fencing experts); 3) the amount of vegetative growth coming in contact with the fence; and 4) quality and power of the fence charger. All fence chargers are not built to the same specifications. Unfortunately, a uniform set of standards for comparison of various makes and models of chargers is not available. Only high energy, low impedance chargers should be used. When purchasing a charger, producers should be familiar with the reputation of the company, their product, their warranty, and their dealer's service record. The company representative should be willing and able to assist the producer in determining the charger that best meets their needs. In general, electric fence intended to control sheep and deter predators should average 4000 to 5000 volts and carry a minimum charge of 2000 volts at all times.