By Gail Ellis  STILLWATER, Okla. – Many cattle ranchers are turning bulls in with their cows and heifers this time of year, and Mark Johnson, beef cattle breeding specialist for Oklahoma State University Extension, has some tips for a successful breeding season. “It’s always a good idea to do breeding soundness evaluations on bulls prior to breeding season,” Johnson said. “BSEs are a general rule of thumb and good management practice.” Once bulls are determined sound,…