Boars are intact (not castrated) male pigs used for mating.
It is common practice throughout North America to castrate market pigs. This painful and completely unnecessary mutilation is done without anaesthesia.
In North America, a limited number of mature boars are kept in large industrial operations to inseminate female breeding pigs (sows). Natural mating between boars and sows is a thing of the past on today's factory farms. Instead, sows are artificially inseminated with semen from boars purchased from pig genetics companies. Boars either mount a sow while she's in estrus or mount a "dummy" sow and the semen is collected for artificial insemination. The latter is most common.
When Canadian boars are no longer wanted for breeding, most are shipped long distances to the United States for slaughter where their bodies become cooked products such as pepperoni or sausage.
At the end of their productivity, boars, like cull sows, are often lame as they too have had lives of intense confinement. They are only allowed out of their barren metal crates during short periods for semen collection and are quickly returned to their crates afterward.
Boars typically do not get along well with other boars. Because of this, transport regulations require boars to be housed in separate compartments to avoid fighting. However, dividers take up precious space and there is more profit to be made when boars are crammed onto a truck. Instead, many haulers perform what's called "boar bashing," "tooth breaking" and/or "snout-tearing."
"Boar bashing" involves smashing the boars' snouts with crowbars. The aim is to break the boar's nose his most sensitive body part. Tooth/tusk breaking is done by way of rusty bolt-cutters which indiscriminately snap off the tusk, shearing through the innervated pulp canal and shattering the tooth into the gum line. Snout-tearing is also practiced where the same rusty bolt-cutters are used to tear off a chunk of the boar's snout. All of these horrendously cruel acts prevent boars from fighting because they are in intense pain.
Although the practices of boar bashing and snout-tearing are illegal, they are quietly ignored by government officials. The Canadian Food Inspection Agency (CFIA) was provided with evidence of the practice and a shocking Canadian Broadcasting Corporation documentary called Bêtes à Bord which aired in 2008 also exposed it, yet the CFIA did nothing to stop it.
In Western Europe where comparable regulations are actually enforced, the practice has all but ended.