My first thought is, "Wow! How expensive would that be???"
I feed Harrison's to my parrot, also. I just ordered a fresh bag, that's why I was joking about the price. I feed a lot of other things, too, like a wide variety of fresh fruits & veggies, sprouts, cooked mixes with beans, birdy bread, lean meat, seeds, nuts, palm oil and whatever else I'm forgetting here. Shhh, don't tell anyone, but his favorite junk food is a bit of Avi-cake. I like to keep a bowl of pellets available all the time, though.
There's a pretty wide range in the Harrison diets. There wouldn't be nearly enough calcium in the Harrison's for a layer. There's more fat in the Harrison's, too. The protein is too low in many of them, like only 14% and the ones with a higher protein have 20% protein and a lot more fat in them, like 15% fat. A typical layer food has 16% protein and 2.5% fat, just as an example.
I'm sure you could pick the most suitable formula and add other things to it, to get a balanced diet. I think it would be a lot easier to find a good organic layer feed and just use that, though.
What kind of parrots do you have? I am down to just my African Grey, Kirby. He is still a handful!
