The maximum line wire/batten spacing and minimum height of a plain wire [fence] for the control of sheep

Abstract

Throughout New Zealand there is a considerable divergence of opinion among farmers about the strucural requirements of a farm fence to control sheep and cattle. For example, in some areas of the North Island, fences consisting of 250 posts and 2000 battens to the kilometre and with five plain and two barbed wires, are commonplace, while in other parts of the country, fences containing far less material are being used to restrain the same type of stock. The question arises: what are the minimum structural requirements of a farm fence to restrain stock? If the rate of increase in fence material costs over the last three years is maintained, the cost of basic materials (posts, wire, battens) for a kilometre of the type of fencing given above will be well over $3000 by 1982. Of course much has been done by research to make lighter weight, cheaper, but none the less structurally adequate, fencing materials and systems available to the farmer. Lower cost, 2.5 mm, high tensile galvanised wire has been shown to be structurally superior to dearer 4.0 mm mild steel galvanised wire in a fence . Nevertheless, the single most expensive item of material in the fence mentioned in the first paragraph would be the 2000 battens - and these could well cost the farmer upwards of $1500 in 1982. Consequently, in an effort to determine if the number of battens and line wires in our fences could be reduced, the NZAEI undertook a series of trials aimed at answering the question: "For the control of sheep, what is the maximum line wire and batten spacing possible in a fence? Trials were also carried out to determine how high sheep could jump because any reduction in the height of fences could also lead to cost savings. And an attempt was made to wean lambs against the fences found capable of controlling adult sheep.