First, I know birds don't have vocal cords, but they do have an apparatus for making sounds and that apparatus is unique to each species, therefore chickens will not sound like quail unless this part of them changes also. The article did not state he used embryos, not that I recall anyway, and certainly nothing was said about stem cells. If they are already brain cells then the odds of them being unformed stem cells seems remote. If stem cells were not used then it is highly likely no quail DNA was incorporated into the chicken, if it wasn't then there would be no growing of quail feathers and no sounding like a quail, no matter how much the chicken wanted to.
Don't be so quick to be an asshole, it is bad for your health. I stand by my statement, this could very well be false research and nothing but BS, witness the Korean scientist and his human stem cell "research" that was all faked. If you have any more smart assed, facetious or patronizing remarks please feel free to express them.
In your first post, you sounded like an ignoramous. So I guess you decided to google a few things to sound impressive. But then again, you have a solid anti-science streak so I doubt if you even have the capacity to understand the article.