Briarwood Safari - This is an animal reserve located in Morristown, TN. Link to prices. You can drive through in your own personal vehicle and feed the animals from your car OR you can take a group and ride a wagon and feed the animals.
I had the pleasure of going to the Global Wildlife Reserve in Folsum, LA. I have yet to attend the local one here in TN, but I have heard great things about it. This would be a great homeschooling trip for interested parties.