Inclusion of lb of calcium propionate in the prefresh and fresh ration, provides a extra daily dose of propionate which reduces both subclinical and clinical ketosis. Propionate is used as a glucose source to make milk lactose (or milk sugar). Propionate is also used at the liver to convert acetate (from mobilized fat) to energy. Some researchers believe that calcium propionate mainly spares dietary protein from being metabolized to glucose. Thus, with the addition of calcium propionate in the diet, more amino acids are available for conversion to milk protein and total milk production increases.