At what strength do you mix the milk powder? Will adding more water make it last all day or just make their pens wetter? Once outside are they fed a more concentrated milk or less of it so they can drink it in one sitting.The drums are from when we did used to have 20 plus calves on one drum so needed to fill it. Plus they have to suck harder which apparently is a good thing. Two drums means that a pen of 22-24 calves can all drink at once. Can’t get that many round one drum without bullying. Despite being ad-lib they all like their breakfast at the same time.