Authors: Kristine Piccart & Diederik Van Damme (ILVO) - Date: February 20th, 2019

Nearly every dairy barn is equipped with electrical components and automated tools (e.g. in the milking parlour, concentrate feeders, manure scrapers, selection gates…). When the electrical system is not properly grounded or its insulating material is affected, unwanted stray voltage may occur in the barn. Unfortunately, the accurate diagnosis of stray voltage issues is still a bottleneck in practice: it can be a long, strenuous process for dairy farmers.

Cows are very sensitive to stray voltage. Possible symptoms include nervous behavior during milking, such as refusing to enter the parlour, kicking off the milking clusters and defecating more frequently. Their drinking and feeding behavior can also be affected, depending on the source of the issue. Cows will not be milked out properly, increasing the risk of elevated cell counts and mastitis.

Preventing stray voltage starts at the beginning, during the designing and building phase of the barn and milking parlour. All metal parts should be insulated and grounded, including the wire mesh in concrete walls. The electrical enclosure and equipment ought to be also installed properly. In case one suspects stray voltage might be at play, the help of a professional should be invoked to find the source of the problem.