It's me and my poopie butted chick again. My 8 chicks will be 5 weeks old on Monday 7/18 and my one White Plymouth Rock is still in need of a bottom cleaning at least twice, usually three times a day. At the advice of various folks on this forum I've tried oatmeal (which they love) adding apple cider vinegar to their water (which they don't seem to mind). On one person's advice I tried a dab of olive oil on the vent (although stopped after a week at the advice of another person). Same thing with yogurt, tried it once but then was told not to and since they mostly walked in it anyway, didn't try again. The affected chick seems lively and energetic but is now about a third of the size of her age-mates and while she has a few pathetic looking tail feathers, her poor little backside is mostly bald. As her wing feathers are growing quite long and wrap around her backside, they are now getting soiled with poop as well. So here are my questions: 1) Have any of you had pasty butt go on this long? 2) Tell me more about this pro-biotics I've heard mentioned and do I have to give it to all the chicks or somehow isolate this one? 3) Do I continue to drop the temperature in the brooder? It gets pretty cool here at night in the Colorado mountains and while most of the girls are up on roosts at night on the far side of the brooder, my little poopie-butted one seems to stay under the heat lamp. 4) Along those lines, I'm hoping to move the girls outside to their coop next weekend...should I wait until the little one's tail is recovered with feathers? Any other words of advice or encouragement?