There's really no reason other than custom that appropriate numbers of pigs couldn't be raised and slaughtered in any city. They can subsist entirely on table s

There's really no reason other than custom that appropriate numbers of pigs couldn't be raised and slaughtered in any city. They can subsist entirely on table scraps, the disposal of which is a regular burden for cities. They don't require lots of room to roam. They do produce effluent, but that is only a burden at mega-farm volumes. An individual hog will produce roughly what an individual human will produce, but only when it approaches the right size to butcher. Eventually this will seem normal, if only because chicken husbandry is growing more common all the time in many cities.