grains like corn,soybean,wheat do not need to be crushed before pelleting,our animal feed pellet making machine can press them into pellets directly,but if you manufacturing other materials like straw,grass,alfalfa etc,you have to crush them into powder form and then pelleting them,when you manufacturing your own animal feed,single raw material do not also a mixer machine,but if you use several material,it is better to use a mixer machine,thus powder raw material can be mixed evenly.