I'm interested in this too - I've got the flock of 6 hens listed below, the BO is broody and spending a few days in an elevated cage to break her but yesterday was the first day I've had a good set of eggs from the rest of the gang in quite a while!
They're all about a year old and get a good organic layer mix of grains with a couple of hours free ranging in the late afternoon daily. They averaged about 5 a day through the winter (with a light in the coop) and have really dropped off now that its spring.
My wife thinks that having a dozen 10 week old FR cockerels close by may be doing something to the hens' hormones but that seems like the equivalent of introducing a bunch of 8th grade boys to the Swedish Bikini team....
On the advice of my 80 yr old Aunt I fed mine red peppers and it helped pick up the egg production on some that were barely laying. It doesn't hurt to try it; my others used to eat my thia peppers like candy. Good luck! I used crushed red peppers which includes the seeds.