i have 23 layers age 1 year to 15 months. egg production dropped about 5 weeks ago when i added 10 new 1 year old birds to the flock . i went from a dozen a day to half a dozen a day. the past week its gotten a little better getting 6-9 eggs a day. i have 1, 15 month old that is molting. dont know what up with the rest. i treated them for lice and mites. they have feed available 24/7 i feed layer mash . plenty of clean water. any suggestions.