Giving greens to adult hens that don't get then consistently could cause loose poops.and so can clippings that have been treated with chemical fertilizers, pesticides or herbicides. Either situation would likely be worse for chicks.My chicks are less than 2 months old and in a coop with a small run. Twice I've given them a little freshly picked clover, which they devoured, and both times they got terrible diarrhea. I won't give it to them again, I'll tell you that.