Jerky, nuts, crackers, Twizzlers nibs (also comes in handy for low glucose, if you are hunting with a diabetic), etc...
Our primary source of venison is Pronghorn Antelope. Since you end up with a lot of burger (compared to other big game), we tend to turn quite a bit of it into jerky. On most hunts, you'll find 3-5 good sized pieces of Antelope jerky in my pocket ....right up until I start to smell like an Antelope. Then, I stop eating it for the rest of the hunt.
"Such is the strange way that man works -- first he virtually destroys a species and then does everything in his power to restore it."