So, my 7 month hen has black super runny poop, she is outside all day eating stuff. all of her sisters are laying, but not her. i think it started when i had the ducks in with the chickens. she's on corid, but it doesn't seem to do anything. all of her sisters are fine and laying but not her...
some chickens slow their production with age. if you are getting soft shelled eggs, you might need to feed them a little more calcium- oyster shells, or egg shells.