I have a friend who has a bird sanctuary. They (very many years ago) consulted with several avian vets, a nutritionist, a chemist, a dietian, a pharmacist and some other people, I forget all now. They came up with a human grade (not human nutrition, just grade) pellet, no preservatives, no colouring and not hard like a little stone. It requires a freezer as the shelf life is only about 3-4 weeks. The pellets are like little logs, not balls, and are able to be broken between your fingers. Every bird I have had since these were developed has loved them, and turned their beaks up at all the other pellets. I do have other pellets as when getting a new breeder (years ago) some would only eat certain brands. Because of this, and to use up extra pellets not really being eaten, and having some birds who would not touch a pellet with a 10" branch, I keep a container of pellet dust in the freezer and sprinkle it on their 'chop' or whatever they're having that day. (I grind them up in a coffee grinder) Solves two problems, getting rid of unwanted, getting to end of 'best before date pellets, and assures that even picky-ish eaters get some decent nutrition. I mix a vitamin/mineral powder in with the pellet powder too. If I have a bird who is 'fluffy' I make a small container for it, and include extra suppliments as needed. Usually this just means some extra nutrients or sometimes it just means a phone call with the vet, cheaper, easier, as I'm housebound and don't drive, and I keep extras of stuff in the freezer. I get them in 50 lb bags, and rebag them to keep in the freezer.