I can't find anything on the Kansas Department of Animal Health's website to confirm this, but there are several news articles that seem to back up the following:
A new Department of Animal Health rule states that no person shall engage in, sponsor, instigate, assist, or profit from the release, killing, wounding or attempted killing or wounding of feral swine for the purpose of sport, pleasure, amusement, or production of a trophy. Owners or legal occupants of land, the employees of such owners or legal occupants or persons designated by such owners or legal occupants may kill any feral swine when found on their premises or when destroying property. Such designees shall have a permit issued by the livestock commissioner in their possession at the time of the killing of the feral swine.