Hello, I think I've seen you are raising jumbo coturnix. They are still growing out to 10 to 12 weeks, so I still feed 28% out to at least the 10 weeks. I don't use layer feed anymore for any different types of birds I raise poultry/game birds/quail/turkeys/ducks. I always offer oyster shell/eggshells on the side 24/7. Layer feed usually has just the bare minimum of protein %, I like to feed my birds in the upper protein %. Have always had less health issues better egg production and better hatch rates with less issues with hatchlings since doing so. I raise/breed/ hatch and sell a lot of birds/hatchlings and like to give customers best bird I can. And I have seen better results in feeding upper protein %, but there are limits to how high without causing health issues most bird types have different acceptable % levels. Health/stress/molting/illness is all benefitted by upper protein% and not the bare minimums that most layer feeds have. Yes, you can, and a lot of folks do feed layer feed not saying it's a bad thing. But I have had and seen better results all around in my birds since feeding this way. Don't get me wrong some benefits can be small but I have always been one that if I raise something its done to the best of my ability and can in the long run end up being cheaper without loss of my time treating illness, loss of birds/meds/ loss of customers ext. Most info that I researched for jumbo quail recommend protein% of starter between 25%-32% and for mature or layers between 17%-23%. Hope this helps. How's that for a sell to CHANGE YOUR MIND