Aspergillosis is caused by mold spores, and won't respond to antibiotics unless there is another secondary respiratory infection such as infectious bronchitis, MG, and others. Removing the mold, such as in wet pine shavings is the only treatment. Where did you get the chicks, and what are the brooder conditions? Could they be over-heated? Many chicks can be exposed to respiratory diseases on farms where they are raised by a carrier bird, and MG is one that can pass through the hatching egg to a chick. For bacterial respiratory infections, oxytetracycline, Tylan, and lincomycin/spectinomycin 50 are sometimes used to treat them, but the chickens will remain carriers.
I bought them from a feed store near home. They are 5 months old and I keep them in a large cage used to transport a dog. They are located in my garage now until I finish building their own coop.I am using grass as a bedding now though I was using pine shavings previously untill 3 weeks ago. Temperature in my town has been 88 degrees or less lately.