Personal experience with stray voltage! My brother-in-law had a small (30 head) dairy operation for several years. One day he called and told me his herd was acting very strange. "They won't come to the milk barn on their own anymore!", he said. "When they are hooked up to the milkers, they kick me and they won't stand still; often causing the milkers to fall off their udders." Next, he told me that he had walked past the milk storage tank and got shocked. He wanted me to come look at his equipment to see if I could determine why he got shocked. He was pretty upset because his milk production had fallen drastically and it was putting him in financial turmoil. I took a meter and started testing for stray voltage. I immediately discovered approx. 30 volts AC between his storage tank and his evacuation pump when the pump was running. So I asked him if he had done any work to the system recently. He explained that the evacuation pump motor had failed two weeks previous and that he had it rebuilt at a local motor shop (this shop has an excellent reputation for quality work). So I made a visual inspection of the motor and discovered the case ground was not installed properly. My brother-in-law had done the motor removal and re-installation himself and had mistakenly connected the ground wire improperly. He had been shocking the cattle through the milking equipment plumbing. I corrected the problem and all stray voltages were gone! Within a week, the cattle were once again gathering at the milk house as usual and milk production was back to normal!