Hi PaulthePhoenix, hope that I can help.
Tell me if I am wrong, Isn't it the question is asking whether or not keeping the animals in zoo instead of the role of maintaining the zoo? I just get little confused by reading the first sentence of the first paragraph...
And I believe if you can put some "Cohesive Devices" to your essay will help a lot for the reader to follow your points and ideas.
Predators raised in the zoo [...] The dependant on human ...
Maybe you can think about on changing the order for the above statement, so that reader will be easier to follow the correlation in between. E.g. animals are locked, well feed by humans so they lost their instincts. Since they lost those traits which is essential for them to survive when released to the wild, they are in danger...