for some reason you are talking about formulating feed (mixing dozens of ingredients in correct proportions like feed companies do) and giving your birds no other choice but eating that feed.The most important thing a bird can get from us is a balanced feed, and the chances of a backyard owner having the knowledge, inclination, resources, time and testing to make a complete feed are near zero. Best they can usually do is copy the works of another in hopes of ending up with what is, on average, a decent, balanced feed - but for every person choosing to copy J Rhodes, there seems to be several copying "Garden Betty", whose website is slick with feel good words.
The original discussions was about giving the birds free choice access to fruits/veggies instead of considering them harmful and "in moderation as treats only"