Hello, I recently ordered some chicks from a breeder. The hatch didn't go that well. So to make it up to me the breeder shipped me chicks that were between 4-5 weeks old. They were chicks that she was holding onto for herself. I had a bag of medicated mash ready to go for day old chicks. Instead of wasting the bag (it's already opened) can I feed the 4-5 week old chicks the medicated mash till its gone? Or should I go to the feed store tomorrow and get something different and unmedicated? Thanks for your help.