I have four chickens in my flock, my first four that I started with, that are over two years old now. They have almost completely quit laying eggs. I have four others that are only about 6 months younger, and really I don't know whose laying but I know that I'm only getting about 3 eggs, at most, a day out of 8 hens! Now it is January, and I've been told by some that they're molting. I know it's normal for them to slack off for all of those reasons. But at what point do I need to cull (eat) them so that I can add to my flock young ones that will produce eggs for me? Also, after two are they still good to eat, or are they too tough? I have RIR, Buff, Barr Rocks and Americanas.