Dairy cows need to lie down for 10-14 hours daily, and restrictions on lying time cause significant welfare harm through increased lameness and physiological stress.
Dairy cow lying time welfare is directly measured and directly meaningful - a cow not lying enough is almost certainly experiencing welfare compromise. The motivation to lie is strong enough that cows will stand in wet or uncomfortable conditions for shorter periods than is healthy, choosing a limited poor-quality lying opportunity over standing. Lying time deprivation causes increased hoof loading, lameness progression, elevated cortisol, and reduced rumination. Cubicle design, stocking density, and bedding quality are the primary management factors controlling lying time, and all are modifiable with investment and commitment.