The average dairy cow is culled after three or four lactations at age six or seven, far short of her natural lifespan. Extending productive longevity improves welfare, reduces environmental impact, and often improves farm economics.
Early dairy cow culling represents a welfare failure of two kinds: the poor welfare conditions that cause cows to be culled prematurely, and the loss of the longer, richer life that well-managed cows are capable of living. A cow culled at age six from lameness she never had adequately treated has experienced preventable suffering ending in preventable early death. A cow managed to a healthy seventh or eighth lactation has had the welfare of a longer life alongside the welfare of better management. Longevity as a welfare indicator captures the cumulative quality of life in a way that snapshot welfare assessments cannot.