Former UFC lightweight title challenger and welterweight fan favorite  Donald “Cowboy” Cerrone was rushed into surgery earlier this week after suffering an injury while practicing riding a bull.   Cerrone was schedule to attempt to ride Dana White’s bull “Twisted Steel” at Professional Bull Riders (PBR) “Unleash The Beast” event on May 18 at AT&T Stadium in Arlington, Texas.  Instead, Cerrone will be recovering from surgery.   “As y’all know I was set to ride Dana White’s ‘Twisted Steel’ at the PBR World Finals on May 18,” Cerrone wrote on Instagram . “I was just rushed into surgery with 100-percent biceps tear off the bone! Guess you mess with the bull you sometimes get the horns. This is not the end