It's not the biggest zoo in the world but the Baton Rouge Zoo is a wonderful place to take the family or enjoy a day. They've been growing in recent years so it's always getting better.
There are also a great number of special events. Summer camps for kids and special events on holidays. Their website is updated often so take a look at it to find out what's new.
My personal favorites are the elephants. I've been there multiple times in my life and always had a great time. I suggest you check it out during the Spring so you don't get worn out by that Louisiana heat too much.
Boo At The Zoo - A very popular Baton Rouge halloween event. Great for the whole family. Every October.