When you are just starting a rotational diet you need to take it slowly. Choose a food you like and slowly transition to it and then go choose the next food you want to try. When you get near the end of the first bag, start mixing in the new one. Start out with changing monthly, then as your dog gets used to rotating, you can decide to rotate more frequently or keep it at monthly. You can also add canned, fresh, freeze dried, or whatever as toppers and change those more often.
I rotate kibbles weekly and feed half raw, which I change daily, but everyone does it differently.
