the only live food that's fed is crickets.

All the big cats get horsemeat daily, bones, and a rabbit once a week. all reptiles and birds of prey get pinky mice, chicks, or small rabbits that have just been killed.

I don't think it turns keepers off, animals having to eat is part of nature. although the reason is that while animals do need to eat, the Zoo doesn't want to put live prey under stress, and secondly, if live prey decides to defend itself it could be harmful to our animals.

If you ever see snakes with scars in a zoo you can assume they have lived in the wild in their past. Zoo bred snakes won't have scars, cause they eat dead prey on a stick.