Decker Weaner Prevents Sucking - Calf

A Decker weaner is a type of anti-suckling device, usually a plastic nose flap or ring, that is applied to a calf's nose to prevent it from nursing. The device works by causing discomfort to the mother cow when the calf attempts to suckle, causing her to reject the calf's attempts to nurse without preventing the calf from grazing or drinking water.

The device typically has blunt plastic "thorns" or a solid flap that irritate the mother's udder or nose when the calf tries to suckle. This teaches the calf to stop attempting to nurse over a short period, typically 4 to 7 days, before it is permanently separated from the mother. This method is a form of "two-stage" or "quiet" weaning designed to reduce stress for both the cow and calf, as they can remain in physical and social contact during the initial period.