Try a QTip soaked in olive oil or mineral oil, and moisten the vent opening just barely inside. What does the baby chick's crop feel like? Hard or soft? It is located in the chick's upper right chest. Is it alert and drinking water? What is the temperature on the floor of your brooder? Shipping stress and dehydration, or too hot of a brooder temperature can cause or prolong pasty butt. Try a few drops of molasses or Karo Syrup in a tsp of water held up to the chick's beak, which may act as a mild laxative. Keep dipping it's beak or offering fluids to get it drinking.