Dairy cows in intensive systems are typically culled at 3-5 years of age, far below their natural lifespan - improving longevity reflects better welfare and is economically beneficial.
Low longevity in dairy herds is both a welfare signal and a symptom. Cows that are repeatedly ill, lame, or reproductively compromised have poorer welfare throughout their lives. Herds with good welfare management - low lameness, low mastitis, good transition management - typically achieve better longevity. Improving longevity through better health management is a win-win: better welfare for individual animals and better economics for producers.