You amuse me, how are You going to handle a cow?, who's cow are You going to kill?, and do You know how to butcher/preserve meat?. You couldn't live on a steady diet of jerked beef, and feed corn. There is a big hole in the vitamins and the need for extra water would be a problem because the salts would buildup in Your blood stream. You were closer with the 10lb jug of peanut butter and waiting 2wks for the major chaos to settle down. Beef jerky is OK but needs to be mixed with other foods after a while, feed corn is just fine, but You wont develop any cravings for it after a week, and You can go only so far on tortillas and gruel. Wouldn't it make more sense to prepare a bolt hole, and set aside something worth living for rather than attempting to be a maggot living off the carcass of civilization?