I had purchased new chickens to go in with the old last September. The older ones stopped laying eggs because they where moulting. I Haven't had a single egg since. I assumed they would lay after winter but no. What should I do!
It really helps us to help you if you include your general location in your profile. We don't need or want your street adress. For example my profile just days northern Colorado.
Mites are a real problem in some areas this year. They drain the birds resources and cause stress.
How old are the older ones?
Have you checked them over really well for mites or lice?
What do you feed them including treats?
How much of their diet is treats?
How many older birds are we talking about?