Based on the symptoms you describe it sounds like a toxin. First thought with a neighboring farm was glyphosphate, aka roundup. Typically it is safe for animals to go out and graze after about 3 days after spraying. I don't know if roundup ready seeds have a longer effect or if that leeches into surrounding soil. Anyone??Yes, they use chemicals. I try and always but the girls up when they are using them. So far the 2 larger girls have been fine. The chicks are in the garage so they aren’t affected.