Most dairy cows are culled at 5-6 years old despite a natural lifespan of 20 years. High culling rates reflect welfare problems — lameness, mastitis, reproductive failure — that could often be prevented.
Premature culling is simultaneously a welfare indicator and a welfare outcome. A cow culled at 5 due to chronic lameness has typically suffered months of pain before the decision is made. Improving longevity requires addressing the root causes — better genetics for health rather than yield alone, improved housing, and proactive lameness management — but the welfare gains are substantial.