MARTINSBURG, W.Va. — Law enforcement in the Eastern Panhandle had to temporarily become cow wranglers on Wednesday when a brown cow wandered onto busy I-81 in the northbound lanes just before exit 12. As a precaution, all lanes were shut down just before 10 a.m. The roadway was reopened a short time later as the cow had already left the interstate and walked into the tree line just off the roadway. Berkeley County Sheriff Rob Blair says despite…