If I were in the OP's shoes, I'd do as her grandaddy said. It'd save a heck of a lot of money and the birds will still get everything they need by eating bugs and such *and* the cracked/shelled corn. I had to do this one year after I'd become disabled because the money simply wasn't there for the $15/bag regular feed I used at the time. I went to the $8/bag of shelled corn and didn't change anything else (they always free ranged), and I never noticed any difference in them size-wise nor egg production-wise. Their poop is slightly runnier, not a whole lot, but a tiny bit noticeable, but none died and they stayed fat and happy.