That's strange to find a hog that size that has never been bred, we shot one several years ago about 175 lbs that had never been bred either.
For some reason its not unusual in that area. We've trapped over 20 mature wild sows there this fall. Over half of them never had a litter and not one was pregnant: Three of those sows were nursing. Someone may be releasing neutered sows into the wild near there: We have found neutered boars there.