The distance between the microingredient system scale and the mixer should be as short and direct as possible. Physical clean-out of the scale and conveying system should be possible and should be done on a routine basis. Many feed plants place drugs at the end closest to the mixer and place ingredients such as salt, limestone, or dicalciumphosphate at the end farthest from at the mixer so that these ingredients can act as a flush when material is conveyed to the mixer.