How do we stop these egg problems from happening...mine have been laying shell less eggs since last fall, not that they lay many, maybe two or three a month. They get calcium, roosters booster and I give them nutri-drench twice a week in a bowl of veggies. I only have five ducks right now and would like to get some chickens but want to wait until I know what I’m doing wrong with theses girls first. I’m positive they don’t have parasites or worms too.