We purchased 12 laying hens. First eight are RIR /Red star. We got them last Sunday, 4 of the eight hens laid an egg later that afternoon. We then added 2 Buff & 2 Barred Rock later that day. Monday there was 2 eggs. Today only one egg. Does anyone know if the move to a new place or the fact that new hens were introduced is affecting their laying? How long should I give them before becoming concerned for their health?