Ironically, you can't straightforwardly get to the USDA contingency plans. The whitehouse.gov link on the page points to an index of all the contingency plans (across the federal government). Unfortunately, the entries for the USDA plans are just links pointing back to usda.gov...

I'd imagine you might get somewhere at archive.org (and there may well be other ways to get them from a .gov source), but still...