Tail docking of dairy cattle — removing part of the tail — was widely practiced to improve milker comfort, but welfare science shows it causes harm with no production benefit.
Tail docking of dairy cattle is a welfare harm without compensating benefit — a rare case where the science is unusually clear. The tail is not a vestigial structure; it is actively used for fly control, balance, and social signaling. Removing it causes acute pain, potential neuroma formation, and reduces the cow's ability to manage insect harassment throughout her life. The original rationale — that it improved milker working conditions — has not been supported by production data. Voluntary and regulatory elimination of the practice represents straightforward welfare improvement.