It sounds like you are doing everything correct in regards to diet. The advice that was given in the other responses are from folks much more experienced than I, and it is all spot on. weather and light (length of day) can certainly cause drops in production. The rubbery/abnormal shape/brittle shell are all signs of young layers, as is double yolks. I think that sometimes we can become easily startled when we see these kinds of things. In my brief experience as a chicken flock owner, patience and time end up solving most of these issues.
Something that you want to be doing is monitoring their behaviors...are they doing all the "chicken things" that they ought to be doing at their age? Do they move well? do they roost together? Feed them some delicious fruit and see if they go nuts over it. Pick them up, check them over, make sure they look well?, check for parasites. If you can, let them free range in your yard a bit and see if they are scratching and forraging....if they look/feel o.k., are acting normal, and are being fed the right diet (which it seems they are)....just waiting them out might be the answer.
Something that you want to be doing is monitoring their behaviors...are they doing all the "chicken things" that they ought to be doing at their age? Do they move well? do they roost together? Feed them some delicious fruit and see if they go nuts over it. Pick them up, check them over, make sure they look well?, check for parasites. If you can, let them free range in your yard a bit and see if they are scratching and forraging....if they look/feel o.k., are acting normal, and are being fed the right diet (which it seems they are)....just waiting them out might be the answer.
they do all chicken things scratch around ect and go nuts for treats, I haven't really worried about parasites but do handle them a lot and never noticed any, I will have a good look, would they be on the skin or in the feathers? What am I looking for? Little black dots or something scarier?! Lol
