So my girls started laying a couple of weeks ago! I'm so proud of them! I switched them to layer feed. I discovered a large bag of medicated chick feed in my shed today. Is it okay to use it even though they have started laying? I hate to waste it, but don't want to harm the girls by giving them the wrong food. I also have a bag of oyster shell, so I can supplement the calcium they wouldn't be getting from the chick feed... Any thoughts?