Stray voltage on Michigan dairy farms.

Stray voltage investigations were performed on 59 Michigan dairy farms at the request of dairymen, veterinarians, and county extension agents. On 32 farms, sources of stray voltage were detected. When the voltage exceeded 1 volt alternating current, there were increased numbers of dairy cows that had abnormal behavior in the milking facility and increased prevalence of clinical mastitis. Recovery from the stray voltage-induced abnormalities was related to the type of abnormality and the magnitude of the exposure voltage.