Hi, welcome to BYC!Ok, so my question isn't about feeding but about eggs. It seems that out of 21 chickens, we have one that broods all day and have one that will lay an egg that has no shell! We have found an egg with what looks like just the membrane sac and no hard shell. My husband found another one today (which makes the fourth one we've found) and he said it looked like it had an umbilical cord attached to it, and sometimes when we gather the eggs, we notice that they are sticky like maybe an egg broke and they ate it....not sure what's going on, as we get appx 13-17 eggs a day out of 21 chickens. the most we've ever gotten is 20 and that's only been once. I have no idea what hens are laying eggs and every now and then we get an egg that's about as small as a pigeon egg. My main concern is the egg being laid with no shell.
Does anyone have any idea why we have a hen who lays an egg with no shell and why she would lay one like that. Is she sick?

I'm going to agree with Lazy Gardener... in that when I have soft shells like that it is usually a girl who is either just coming into or out of lay. I have OS available all the time, free range, and 20% protein feed available, and don't feed many treats... nutrition is NOT an issue for us. But it still happens sometimes.
And sometimes glitches just happen. That pigeon egg might not have a yolk, or it could be only yolk.
Though of course the other things mentioned are possibilities.