Sounds like they need to be in a cage and not general population?
After a certain age, yes they need to be separate, mostly because the quail are so much smaller than chickens.
I don't think that I was clear in my 'how I house my quail' answer.
The quail are in their own cage, the 'under the poop tray' area. So, they are breathing the same air... and I guess maybe a chicken poo could get into the quail cage... but probably not.
I too, would like to know how many quail breasts for instance, would it take to equal a chicken breast. I would imagine they are so small you wouldn't bother eating legs or wings.
Well, I have one son that loves to chew on bones, and eat bones.... but the kids loved the tiny legs and wings, super funny. I carved it like you would a giant turkey... since we had only the one quail, for the entire family. I was laughing so hard that I could only barely carve it. I accidentally broke the end of the drumstick off in my hand when I was holding it to carve it off... SO funny!
Quail do have very nice breasts... think a supermarket cornish cross chicken, but the entire quail is so tiny!
uhm... I think 6 quail eggs are supposed to equal one chicken egg......
maybe 9 quail breasts would equal one chicken breast? or twice that?

look at this photo:

from http://www.gamefarm.com.au/retail/quail/
that looks like a normal sized pan.... and those tiny quail have to be surrounded by veggies to fill in all of that space!