While I disagree with the DNR's sweeping action, in the comments section of the article the only person I noticed that was actually from MI said the following:
Melissa Johnson DeHaan · Muskegon, Michigan
Guys, these are not livestock, these are feral swine that have been a problem plagueing Michigan farmers for decades, destroying crops and forests. There has been open season on feral swine in Michigan for over 30 years, this story isn't even newsworthy. If someone decides to capture and raise these beasts, they still are not livestock any more than a captured squirrel or hawk.