My chickens (Production Red, Buff Orpington, Bard Rock, and various sex links) have not been laying well all year and it is getting annoying. When the year first started off we had so many eggs we didn't know what to do with them all. I have 70 hens and they would easily give me 3-4 dozen a day. So i was a little aggravated that about 20 of my hens were not laying but wasn't that concerned. They layed like that for about 2-3 months than they started dropping progressively until today were I only get 3 eggs a day. (Out of 70 hens) This has been going on for about 2 months. I have tried every food under the sun including layer pellet, cat food (high protein), and have been giving them a lot. Frankly I'm tired of going to the feed store. Also they are free range and they free range all over my farm. They are fat chickens. My chickens are 1-2 maybee 3 years old. Any suggestions?