We have two RIR's and awhile back one got egg bound and the egg broke inside her. We got it all cleaned up and she's fine now. A few days ago I found another egg with no shell. So now our other RIR is once again not laying, and just sitting on the floor in the hay in their brooder box again. These two girls keep getting egg bound even though we have oyster shell free feed, in their feed, and crushed egg shells free feed. None of the other girls get egg bound just thesse two. ? so is there anything we can do to help them, keep them from getting egg bound?