For the 12th time this feed did not kill your birds... Unless it was full of mold. Please remember that you can send a dead bird overnight to your state lab to get an answer.
The feed tag that you have shown... Which is a 20% protein... Did not kill your birds unless it was full of mold.
Are you aware that you can send a dead bird's body to your state lab to have a necropsy perform to find out the exact reason it died?