Absent big equipment (which creates problems of its own), and lots of space, its basically impossible for a modern person to support any number of productive modern breeds at anything like peak condition as a matter of self sufficiency. You can't feed chickens a single crop and expect anything but dietary imbalance - and most of us can't grow and store multiple crops in the amounts needed to overwinter and replant come spring.
What we can do, depending on space, climate, soil conditions, is "bend the curve" by planting a biodiverse polyculture. The key is that there is a mix of greens and grasses coming into season at any given time.
Here's mine (last year), I'm getting back to work on it this year, after I meet with some people about my house build early in the week.
The short form is that I have multiple grasses, multiple grains, multiple legumes, and even some fruits and veggies and "leafies" always going - but no single crop they can gorge on at any given time. Even then, all I can do is reduce my commercial feed needs. With better soil, more water, something heavier than hand tools and a (much) smaller flock, I could probably get the feed bill down to nothing for about half the year, by also providing meat scraps - but note that I am beginning to approach a "working farm", in that I have chickens, ducks, rabbits, goats, and ground. I'd like to add fish to the duck pond, as well - tilapia - but I need a way to aerate the water which is both cheap and not dependent on power. Solar cells aren't in the budget right now.