On first look i thought its a broad niche forum(anyone can post anything about anything),later by looking at the ads and some treads i figured it is a Veterinary Medicine Electronic Library.You should design your logo and site to make it as a veterinary forum. The cont is great.I think you should start link building and having discussions in related forums to bring some related traffic.
the banner Advertising 160*600 is mess up in the sidebar. but your forum is quite busy so your doing good. i'dprobably take out that tag cloud there as most users don't actually find it useful..