I believe oats have less protein than wheat......well i got both the young layers and meat chickens as chicks in May and i've been waiting for them to get to full grown. I live in southwest Manitoba, Canada. Dad probably has some oats somewhere that i could start feeding them and it looks like those are a bit higher in protein but, if i buy grower feed every day, I'm not going to have any profit left.
....but they're missing the (vitamins minerals, amino acids) of a premix or formulated feed that is necessary to assimilate any of the nutrients.
You can save money buy feeding less nutritious foods, but you will pay for it in slower development and lower production.....your choice.