Operation Vegetarian

Somewhat drastic, not without potential though, just needs tweaking, surely.

"Operation Vegetarian was a British military plan in 1942 to disseminate linseed cakes infected with anthrax onto the fields of Germany. These cakes would have been eaten by the cattle, which would then be consumed by the civilian population, causing the deaths of millions of German citizens."
http://en.wikipedia.org/wiki/Operation_Vegetarian