Hi, I have three ex battery hybrid girls approx 18 months old. I feed Allen and page ex battery crumb and fresh veggies every day plus some pasta, bread, meal worms, porridge etc... as treats. They live in enclosed run and have access to another grassed enclosure few times a week as their run is now giant dust bath. I've wormed them and they have constant access to grit and oyster shell and I've been giving crushed cooked egg shells. Now... One hen is nice and fat but she is having constant problems with egg laying. Either not laying at all or laying thin shelled eggs which crack on landing. This only started about month ago. I think extra egg shells helped for a day but it says their special crumb should have all the calcium and vitamins they need? Sometimes she's tried to lay egg in nest box and it breaks or it comes out during the night while roosting/asleep and this morning I just found wet eggy patch where it had cOme out in night but she had eaten the shell/egg remnants. On top of that her poo seams runny and watery in day. The other two are laying normally and have access to same conditions but are skinnier than her. Why aren't other two putting weight on too? They all get access to food as I stay and watch. Only thing I can think of is giving them a vitamin/mineral tonic but why do they need it? How do I fatten up other two as winter is now here and I'm worried they won't be able to keep warm. Sorry for lots of questions. Thanks.