There is some debate on whether or not cats, dogs and ferrets needs variety in their diet. On the one hand our companions only had access to very limited sources of food in the wild, sometimes going days without eating. On the other hand, with human intervention we can provide so much more than our companions ever would have in the wild. Besides who wants to eat the same thing day in and day out for 15-20 years?
Variety prevents boredom, allergies and intolerances. Various proteins also have differing levels of amino acids and nutrients so when given in variety your companion will have a balanced diet. This also is essential to prevent having to use artificial and potentially harmful vitamin and mineral supplements.
You can provide variety by changing up protein sources of meat, organ and bone. Other forms of variety also can come in the form of chunk sizes, whole prey and ground meat, organs and bone. Variety can differ from meal to meal or from batch to batch.
Although variety is important, it isn’t necessary to be obsessive about it. Having chicken four days a week and a different protein the rest is perfectly fine! That being said a rotation of at least four proteins is ideal. As mentioned above our companion’s ancestors weren’t provided with the variety they have access to today so obviously they can survive on limited protein sources.