Is Stray Voltage a Problem for Beef Cattle?

Could power lines cause stray voltage at water troughs? Can stray voltage inhibit animals from drinking? If so, how much can their production be affected?
Several studies have been conducted to determine the effects of stray voltage from numerous sources (including over head power lines) on cattle behaviour and production. However, many of the findings are ambiguous or contradictory when it came to its effects on production.

There is no doubt that stray voltage can affect short term water consumption in cattle. Cattle can detect and perceive electrical currents (initially as a negative experience). Not all animals are affected in the same way by the same amount of current. This means that there may be big differences in the water consumption of individual animals exposed to the same current. The effects of a specific voltage on an animal are determined by the following 1) the magnitude of the contact voltage 2) the impedance of the animal between the contact points 3) any impedance associated with the conductors that connect the voltage to the animal and finally 4) the animal's sensitivity to alternating current.

In one study it was found that the time required for a cow to drink one gallon of water after the application of a specific voltage ( between 1 and 7 ) increased as the AC voltage at the water bowl increased.

Four out of the 30 test animals also refused to drink when volt readings were greater than 5. However, all the cattle were seen drinking within 36 hours of exposure to 3 and 4 volts at the water bowls.

Many studies conclude that there is no long term effect from stray voltage on the behaviour or performance of a herd. However, individual animals may suffer from the acute effects of stray voltage and that should not be ignored. One recent study on the effects of 500 kV DC transmission lines on beef cattle found no observable differences in the cows and calves exposed to the power lines. However, the researchers did report that a small portion of cattle (5-11 %) were sensitive to the electrical environment. It may be that the behaviour of the majority masked their discomfort.

To determine if this is a problem within your herd you can take voltage readings from suspect waterers on a regular basis. Readings should be taken at several locations (4-5) on the waterers as well as the ground around the waterers to get a representative voltage value that will help to pinpoint where the problem is. Based on previous data, any voltage reading greater than 4 is considered high and may be problematic for sensitive individuals. Good production and health records will also help in tracking any deleterious affects. Just watch for an unusually large number of sick animals, signs of dehydration or any other behaviour that is different from the norm when the cattle approach the water. You should always make sure that any changes in your animals water consumption or production is not due to other factors such as water quality, changes in feed, weather or herd composition.

If you do have a problem you can contact an electrician to come and take readings around the waterer and to determine the source of the problem.

Dr. Karen Schwartzkopf-Genswein
Alberta Agriculture, Food and Rural Development,
Agriculture Centre Lethbridge

Southern Alberta Beef Review - August, 1999. Volume 1, Issue 3

For more information about the content of this document, contact Barry Yaremcio.
This document is maintained by Kathy Andersen.
This information published to the web on September 11, 1999.
Last Reviewed/Revised on January 28, 2013.