When are Coturnix quail are old enough to put on wire?

I believe you can put them on 1/2 in wire as soon as a week, they grow extremelly fast! At 1 week and half was when I put mine on wire and I didn't have any problems at all.

 

Mine go on wire once they go outside, about 3 weeks old this time of year, 6-8 weeks old in the colder months. But they can be raised on wire just like any other birds if the wire size is small enough so their legs don't get stuck.