Exposure is spot on and the detail is fantastic especially on the face. With that being siad the composition of this picture is very troubling. Your giving your subject no room to breath whatsoever. Your framing is so tight that you have cut off not only his arms and tail but also his ear and the 2nd ear is disturbing close to the edge of the frame.
There is nothing wrong with cutting some of your subject off in the composition as its done all the time with both fashion and animal photography but in this case your simply neither here nor there. If you wanted a detail shot of the animal then you should have zoomed in more and if you were going for more of a full body shot then you should have zoomed out, giving your subject some room in the frame and not cutting off some of the features you have cut off, especially the ears. Again your simply neither here nor there and that is really not something you want to do.
I actually started out shooting pictures of animals in zoos and it is really a fantatsic exercise in composition because alot of the time your forced to compose very close shots to cut out all of the unwanted background crap most zoos have. If your going to cut off some features and do a detail shot then dont be afraid to cut to much. There are some photographers doing fantastic work with animals in this regard. They zoom in an shoot just thier eyes or just part of the face. It can turn what would have been a pretty ordinary shot into something very dynamic and interesting. On the other hand if your shooting the whole animal or even most of the animal then make sure you give it some room to breath. Again this is where the compositinon comes into play. Whatever you do you never want something touching the edge of the frame and this is where the neither here nor there comment comes into play. It not cut off and it doesnt have any room to breath, its nether here nor there and that is a sign of a bad composition.
Shooting in zoos is one of the more difficult places to get a great picture but again there are very few places that offer such a great oppotunity for learning especially in regards to composition.
A great tool for experimenting with composition is a 8x10 matt board. Cut out a hole that is identical to the aspect ratio of your camera. Then you simply use it to compose images.. Ansel Adams is one of many photographers who use this technique. I have been doing it for years and its an amazing tool for visualizing your shot.