Stray voltage is an unwanted electrical potential difference in the environment, often found around equipment or grounding systems in dairy farms. This phenomenon is dangerous for animals because even very small unintended electrical currents can pass through the ground, metal equipment, or water sources in a stable and be picked up by an animal’s body.
Livestock such as dairy cows are especially sensitive because they frequently stand on damp concrete floors and have large contact areas with milking machines, water bowls, or metal stalls, which can complete an electrical path. Cows are more sensitive that other animals due to their body mass. Because they are large animals, they often have greater total contact with conductive surfaces, which increases the likelihood that small voltage differences can drive current through their bodies.
When stray voltage is present, an animal may receive a mild but repeated electric shock when it drinks, eats, or is milked. This can cause pain, stress, and anxiety, leading to behavioral changes such as reduced feeding, avoidance of water, and reluctance to enter milking parlors. Over time, this stress can lower milk production, affect growth, and increase the risk of health problems.
