The cows and steers are not agressive. A range bull is a different story. If faced with a life endangering situation try popping a couple of .45 slugs into it's skull. That is usually enough to rectify the problem.
Seriously, the biggest danger those cows present is slipping after stepping in cow ****. The cattle lease is reviewed every year prior to issuing a permit to release them onto the allotment. Any documentation with date, time, location and a picture would be extremely helpful.