La. R.S. 38:2251.1

Every person acting as a purchasing agent for any agency, board, commission, department, or other instrumentality of the state or of a parish, municipality, or other unit of local government, including a levee board, drainage district, school board, or special district, shall purchase milk and dairy products produced or processed in this state which are equal in quality to milk and dairy products produced or processed outside the state, provided the cost of the milk or dairy products produced or processed in this state does not exceed by more than ten percent the cost of milk or dairy products of equal quality which are produced or processed outside the state.