In order to determine the value of culling information, the net returns to housing, labour and management were calculated analytically using three different replacement policies in the presence and absence of a milk quota. The conclusions were that in the absence of a milk quota there are considerable benefits from using a decision support system, but under a quota the benefits are negligible if compared to the very simple policy of only replacing cows which fail to conceive within 238 days. If a system based on calculations assuming no quota is used under a quota the dairy farmer will be directly misinformed. Decision support systems for culling should be specifically designed for the quota situation, where reductions of costs are the most important means for improving herd net returns. Emphasis should therefore be put on information that support reductions on average costs of keeping a cow.