"Your stamina indicates how much longer your character is able to gain experience. You can hunt for 42 hours until you no longer gain experience from killing creatures, however, the last 14 hours of hunting will only yield half the experience you would normally receive, and if you are the one to deal the highest amount of damage to the monster the loot will be destroyed"
After 14 hours of Hunting you only get half the experience and no loot.
About reaching stamina 00:00 you stop getting both experience and loot, here's the proof: Youtube Video Stamina 00:00