The important part is that cats need taurine, an amino acid that only comes in nature from animal protein (the taur- is from the latin word for bull). Cats can

The important part is that cats need taurine, an amino acid that only comes in nature from animal protein (the taur- is from the latin word for bull). Cats can not synthesize taurine in their bodies -- if you do not include taurine in your cat's diet, IT WILL DIE. This food explicitly includes synthetic taurine, which appears to be lab-synthesized so that it does not have to come from animal sources.