I have some chicks that are about 4 weeks old. I hatched from my eggs and my flock has been tested and is clean. I was watching them in their brooder and noticed that one of them poohed and it has a distinct purplish-red color to it...almost like cranberry. Doesn't look like frank blood. No other signs of anything else. No other purple-colored pooh from anybody else at all. Only different thing they've had to eat was a few small bits of whole grain bread. Any ideas?