Yes, we need more "techniques" such as those that lead to an infection of spinach with some bacteria that is later traced to a gut of a wild boar used as a fertilizer.
I don't think you are remembering that case correctly. The animals are not being used as fertilizer. Instead, they are breaking through fences and contaminating the fields through defecation: http://www.capitalpress.info/main.asp?SectionID=94&SubSe...