The average dairy cow in intensive systems is culled after 2–3 lactation cycles — far short of her natural lifespan. Low longevity reflects cumulative welfare failure and represents a tractable target for system improvement.
Dairy cow longevity is a composite welfare indicator: short productive lives reflect accumulated welfare compromise from lameness, mastitis, metabolic disease, and reproductive disorders. A cow culled at age 4 for lameness has spent her productive life in pain — the culling is the end point of a welfare failure that began with housing design, hoof care, nutrition, or genetic selection for extreme milk yield at the expense of constitution. Farms with high longevity demonstrate that long productive lives are achievable — they typically have better hoof care programmes, lower clinical disease rates, and housing that allows cows to express normal behaviours including lying times above 12 hours per day. Breeding organisations are increasingly including productive life as a selection trait alongside milk yield, acknowledging the commercial and welfare value of longer-lived cows. Consumer labels and welfare certification should include longevity metrics as indicators of systemic welfare quality.