AFAIK the Germans would take what they would need if it suited them, be it animal fodder or...labour.
(I have gotten to know quite a few farming folks from Denmark, and they shae the tales of the food they used for cows, i.e. old newspapers and such because crops had been taken by the army).
Anyway, moving from Denmark to the Atlantic wall in France, - that one was mostly build on slave labour.
I hope this img uploads. Not much for the eye, some of them...:
