To prevent ketosis adequate feeding of energy supplements are required. An energy supplement will improve production and reproductive performance, and decrease the risk of ketosis. Supplements should be fed at least until the peak of lactation is reached or longer depending on the quality and quantity of available pasture. Very high-producing cows will be susceptible to ketosis every year. In these cases a preventive feeding program of Glucose Precursor immediately after calving may avert ketosis in individual problem cows.