That's more the color of intestinal shed than blood, which would normally appear more ruby red.
However, that amount and the frequency of it appearing are concerning and may indicate bacterial infection. An oral antibiotic would be a good idea if you know which individual it's coming from. Is it always one pile of poop or multiple piles?
I had a hen regularly produce such amounts of intestinal shed. I treated her with amoxicillin, and it cleared up.