Hes got some gnarly antlers.

He is quite young still, so i believe this is his first pair.

Some of the weird growth could be attributed to being captive. Diet, fencing and other things can factor into it. Its common for captive deer to have different antlers.

As far as I'm aware he was born in captivity. So you might be right, I don't know a lot about deer. :p

Genetics will play a much larger role in antler form then will simply being captive. Diet does play an important role in antler development, but generally affects antler size more then form, and diet is usually something you watch pretty close when raising deer. The fencing may affect antler form if they happen to injure them on the fence which is quite possible as it is not uncommon for a deer to run into a fence if it is frightened. Another item that affects antler development and form are injuries to the deer's body, such as a broken leg, that occur while the antler is still developing. Of the things that affect antler form and development genetics is the most important which is why people who raise deer put extensive effort into breeding, and tracking blood lines.