With the prey model, you really have to know what you're doing to balance it correctly. Most people consider balance and complete measured by AAFCO definition.
This is a really good chart, Tikka from Dogster put together. I saved it off so I didn't lose it. Tikka must of put a lot of time into developing it and deserves a ton of recognition.
http://www.lukesallnatural.com/downl...edingGuide.xls