It would be a nice feature if you can pay guests or have it be free to feed the animals and have there picture taken with the animal like the Giraffe Encounter at the Phoenix Zoo.
Here's a site for more ideas!
https://www.phoenixzoo.org/plan-your-visit/daily-activities/
Here's a site for more ideas!
https://www.phoenixzoo.org/plan-your-visit/daily-activities/