This picture was taken by Hugo Jaeger, one of Hitler's personal photographer, and showing German Heer (Army) soldiers milking a rather docile Friesian cow during a break in the drive through Netherlands, summer 1940. Apart from the ordinary water, Wehrmacht soldiers may also fill their canteens with milk (or coffee), and drink it when it's still fresh. Especially when the water may be flavoured. There's also 'Klim', a German canned milk (dry powder? condensed? This seems to be "milk" spelled backwards, or 'milch' close enough likewise). Some photos show German troops using it, and others show it used by Allied POWs in Luftwaffen Stalag. The need for fresh milk sometimes unbearable. Rumour has it that during the war, a U-boat put to shore in New Zealand with one aim - to milk a cow. Having snuck ashore, they successfully milked several cows before returning to their U-Boat, leaving confused farmers the next morning wondering why their cows didn't need milking!