Some people consider feeding, pigeon, racehorse, whatever, to be a science. Quantities, ratios, percentages etc determine what and how they feed.
Some of the most successful trainers work on those lines.
Others look at it as a craft, a skill learned over time. I have seen some truly great racehorse trainers. Men who could take a horse in poor form, and with nothing more than their eyes sense what was wrong. Then armed with a 2 pint dipper start feeding that horse back into condition.
Same with the pigeons. I knew a bloke who was formidable with both young birds and old birds. I have sat at his table and talked about his pigeons for hours. He knew each one intimately, what it was, what it liked, whether it was better in a head wind or a tail wind, oh, he was an encyclopedia.

Feeding, they were fed a mixture made up for him at a local grain store. It wasn't a secret, he gave me some to try. A nice mix but simple.
He fed them as much as he felt they needed. No scales. And he was near top of the sheet every year in the big money National races.
An artist.
I will never be as good as him, but his methods have stayed with me through the years. What I feed is based on his feed. The pigeons do okay on it.