Tail docking in dairy cattle — removing part of the tail — has been widely practised but is increasingly banned as evidence shows it harms welfare without improving hygiene.
Tail docking is a textbook case of a welfare-negative practice justified by assumption rather than evidence. When systematic reviews examined whether docking improved udder hygiene or mastitis rates, the evidence for benefit was absent — while the welfare costs (amputation pain, loss of fly-swishing function, increased insect irritation) are well-documented. Countries and states that have banned the practice report no hygiene consequences, and docking rates in dairy production have declined substantially as evidence-informed policy has spread. The primary remaining welfare action is extending prohibition to jurisdictions where docking persists, and ensuring that producer education replaces outdated practice justifications with current evidence.