What is stray voltage?

Stray voltage is a small amount of voltage between two points that, when contacted simultaneously by an animal, form a complete electrical circuit. All farms with electric power have some degree of stray voltage. It is commonly caused by damaged grounding devices that elevate neutral-to-earth voltage, faulty wiring and electrical equipment such as electric fences and cow trainers, or by improper grounding.

If the stray voltage is high enough, you may notice some of the following changes in your cows' behavior:

  • Nervousness or excessive movement during milking
  • Hesitation to enter the milking parlor or stall
  • Reduced feed or water intake
  • Slow milk let down

Where is stray voltage found?

Stray voltage occurs when livestock touch two points. Some common sites are:

  • Water bowl to floor
  • Water bowl to stall
  • Stall or parlor steel to floor
  • Heated waterer to floor
  • Feed bunk to floor

WPS offers free stray voltage testing

At no cost to you, WPS will conduct comprehensive stray voltage testing at your farm. Our agriculture consultants know where stray voltage is likely to be found and have the proper equipment for accurate testing. They'll review a printout of voltmeter readings and test results with you.

There is something you can do about stray voltage. Call 877-444-0888 and arrange to have a WPS agricultural consultant conduct thorough testing at your farm for free.


WEC Energy Group