Bangs is the common name for Brucelosis. Other then dairy cattle it isn;t required everywhere. Best to discuss it with your vet to see if it is required or at least advised for your area.
Bangs was a significant problem here 20 or 30 years ago, but there was an aggressive testing, culling, and vaccination program by the state. I'm pretty sure Texas is now brucellosis free. The state no longer pays for it, but I still have my heifers vaccinated.