Hi, I'm new to the forum, I have 6 white rock hens, all 8 months old, they are free range, they stopped laying about 2 weeks ago after I started feeding them oyster shell and DuMor chicken layer crumbles from tractor supply, I used to feed them Purina layena sunfresh recipe crumbles, they didn't completely stop laying I get about 2 eggs a day. When they where fed Purina they didn't get any oyster shell or grit. They have been fed crumbles for their whole life. These are my first chickens so I don't have much experience, just from viewing this forum. What can be the problem and how can I help.