Sorry, Blue Buffalo has NO credibility in my book. It is a company built on advertising and profit and claims about nutrition are just without merit.
If you check their web site, they list all their top executives, board of directors and nowhere is a veterinary nutritionist.
Do they ever do food trials that are based on anything other than palatability as do many reputable food companies including Purina, Mars/P&G (Iams, Eukanuba), Hill's, Royal Canin?
Their whole schtick is that they provide a natural, holostic diet with things you'd eat with no "objectionable" ingredients. Their premise that byproducts and meat meal is objectionable is just false. Quality byproducts and meal (and even grains) can provided needed nutrients and can be excellent sources of valuable nutrients.
They got caught.
Doug, DVM