The ones that are TWO days old I would NOT tube feed they have the yolk to feed them right now. Are they holding there heads up? If so try soaking the food and see if they can eat that way.One is 4 or 5 days old now, the other is just two days old. The older one is the one that has what looks like wry neck. Both have had Nutri-Drench and Rooster Booster B12. I also have an injectable B, but have no idea how much I should give them.
FWIW, I have successfully tubed baby pigeons, peachicks, poults and chicks, just haven't done ducklings.
-Kathy