The differences between domestic and wild hogs is not nearly as drastic as most people think, especially in North America where hunters go on about searching for "Hogzilla" and wild boar hunting is a macho sport and considered extremely dangerous. Ninety-nine percent of your wild boars hunted today are just escaped domestic pigs!
But domestic swine are fat, smooth and docile while wild boars are large, scraggly with tusks sticking out the sides. The wild hogs "viciously attack" anything that moves and are more clever than most people, while domestic ones are calm and sedate, causing little trouble for anyone and then marching docilely in to the butchers to be slaughtered. It is not the wild hog breed that is different from the domestic animals, it is nutrition and environment that have created these differences!
A Domestic hog is nice and fat, often just rooting around or sitting in a mud puddle, but that is because of modern animal husbandry practices! The swine on the farm gets proper nutrition, both in the form of a well-balanced diet as well as large quantities. If it is a proper farm, the pigs are also getting veterinary health care through their entire life. No parasites and diseases are treated as soon as they show up. They are the civilized swine.
The wild animal is exposed to the elements and has to fight for survival, looking constantly for food and often not knowing when or where the next meal will come from, they are also exposed from an early age to parasites and disease. A wild hog lives a rough life and most die in a few weeks. The ones that survive end up tough, cagey and often mean!
Comparing domestic swine to wild hogs is similar to comparing a person raised in the cradle of culture to a homeless waif that has had to survive the back streets of a slum. They are both human beings, with the same genes and needs. The differences are in how they view the world and in how they survive.
The wild hog fights and struggles, developing a rough coat, large teeth and quick reflexes. The domestic hog learns security and trust, and how to relax! The difference are psychological more than physical, but the environment can result in physical changes! Both are the same species!