Wouldn't we be doing the snakes and their live or dead prey a favour if we just left them all in the wild to do the natural thing?
Once more, humans have the boorish need to trap and capture and confine wild creatures in cages, so they can proudly display their spoils to other unevolved humans. That leaves the rest of us to have to decide whether it is better to kill said dinners in advance, or feed them live.
Wish I could make up a huge neon sign to blast a message to the entire planet: NATURE IS NOT OURS TO OWN OR MESS WITH! Sure would make life easier for all the rescuers, wouldn't it?