We have seen a high number of milk fever cases possibly linked to the autumn grass. While grazing dry cows on plentiful autumn grass seems attractive, it interferes with efforts to reduce milk fever. Grass has a high calcium, high potassium and low magnesium content and the cow does not mobilise her body stores. Tight stocking, magnesium supplementation and provision of an alternate forage – for example, whole crop or straw – can help redress the mineral balance.