crumble mash

I have always fed the mash/crumble feed but recently noticed that pellets are also an option. Which do you prefer and why? The pellets look like there would potentially be less waste(?)

Hello my duck friends.:frow I have a little muscovy that is 6 days old. CUTENESS ALERT: His neck does not look like the wry neck that I have read about. In fact the trouble only comes when he eats or drinks and then that isn't all the time. The little one will hold his head back touching it...