Premix refers to the ingredients in advance is a component that is mixed with the food. That must be mixed well in advance because there are fewer, and the concentration of the substance is quite high.
Premix means the ingredients are pre-mixed with food components. The need for mixing prior to use small amounts and relatively high concentrations of muscle substance.
Premix mean mixture in advance as ingredients mixed with food. The need to mix in advance because the dribs and concentration of substance is relatively high.