This paper analyzes the effects of policy instruments used in the dairy sector. The analysis considers the supply of milk, the processing step characterized by joint production and the final demand for processed goods. A short term partial equilibrium model is defined. We use it to determine the effects of different policy scenarios on price, production, consumption and exports for the different products. Because the GATT agreements imply a decrease in the volume of subsidized exports, we particularly analyze the impact of policy instruments on the exports of different milk products.