Kindly have your birds on anti-stress agent e.g poultricin chick or egocin* chick. For the nasal discharge you have to administer a combination of tylosin and doxycline( tylodoxy). Caution omena if not properly properly stored can be major source of infection to your poultry. Don't take risk. Use certified poultry feed and if you have to make your own buy ingredients from reputable suppliers. Remember poultry are very sensitive to any slight food poisoning ( aflatoxin etc)