For two years David Veale was puzzled by the bizarre behavior of his 90 dairy cattle. The Okotoks, Alta., farmer’s cows were skittish, unpredictable and they often refused to drink from indoor troughs. Most disturbingly, they were producing far less milk than they should have been. Then, while milking a cow, Veale was literally shocked into discovery when he placed a recently cut hand against a metal stanchion. He discovered that his farm was a hotbed of “stray voltage.” Experts estimate that the Alberta farmer shares his problem with at least 20,000 other farmers in Canada and as many as 100,000 in the United States. And as the cause of decreased milk yields and possible disease among animals, stray farmyard volts are at the centre of a growing controversy between farmers and the electrical utilities they blame for upsetting their otherwise contented cows.
The technical name for the phenomenon is “neutral-to-earth” voltage, and it occurs as a matter of course in electrical systems that allow currents to escape through wires or grounding rods. As
well, old or faulty connections and the heavy electrical demands of farm automation can increase the amount of current that strays into the ground and charges nearby conductive surfaces, especially the metal housings of electrical appliances. People can detect only 30 volts or more unless they place an open
A few stray volts, undetectable by humans, can turn a barn into a maze of electricity for cows
wound on a charged surface, but some scientists estimate that dairy cows may be as much as 50 times more sensitive.
For unknown reasons, Ontario’s 13,000 dairy farmers seem most affected by stray voltage, and many of them are pressuring Ontario Hydro to modify its system to eliminate the problem. For their part, Hydro officials refuse to ac-
cept total responsibility for the problem and they claim that expensive changes to the system would benefit only a small number of customers. But they acknowledge that “three or four” Ontario farmers faced with losses from declining milk production and sick animals have launched lawsuits against the utility. Farmers in Indiana and Minnesota have recently won similar suits, setting a potentially important precedent, and another in Wisconsin is claiming $9 million in damages from his local utility. Said Murray Clarke, chairman of the Ontario Federation of Agriculture’s Hydro committee: “If Hydro loses one case, it will be flooded with lawsuits.”
In their defence, Hydro officials point out that the province’s system is designed to allow as much as 10 stray volts and that farmers who require better performance should pay for it themselves. To that end, the utility has helped to develop a “tingle voltage filter” which costs about $300 and is supposed to eliminate stray voltage when wired into farm electrical systems. But David Veale noted that a filter which he bought did not provide any relief to his agitated herd. Instead, last spring he embedded an expensive steel mesh in the floor of his barn to neutralize the stray volts. Said Veale: “In effect, the cows are now like birds sitting on a wire.” -PAUL BERTON
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