Spamee34 Have they atarted laying yet?
Have you tried giving them some oats or oatmeal cooked or not?
Do your pullets have yard time or free range at all? For grasses and bugs.
I don't remember if you said, but you do have oyster shell and/or finely broken up egg shell out for them to munch on? Mine start munching on them about a week before they start laying, if given the chance, up to that time oyster shell is just ignored. I don't think they put enough Calcium in the layer foods.
Not having been on hen pellets before, they may need some time to build up their nutrition/metabolisms. By the way I give my breeding Ducks the Hen pellets to. The Ducklings and Chicks the chick Grower food. The grower food for the ducks and mother Ducks(broodies) from day one, Chicks from 6-8 weeks (I start them on Chick Starter). Having said all this, this spring I'm going to try Purina's Flock Raiser, we'll see how that goes as it will be simpler and a little cheaper in this area.
I mention this because you could have the same problem coming up with your ducks.