There's an article here that mentions Cambodians importing pigs from England. The English have also exported pigs to China - including some with Meishan admixture.
As incomes rise, people in Asia want to eat more pork. More and more pigs are produced on modern farms that raise imported pigs with modern technology. The smallholders, who raise small numbers of pigs (generally traditional breeds) can't compete. The imported pigs eat concentrates, which are expensive (and compete with humans for food). The smallholders typically allow the pigs to scavenge or feed them cheap feed like rice bran; the pigs eat the stuff that humans don't want to eat, like in Egypt.
Traditional housing of pigs in Southeast Asia is worth checking out. E.g. pigs on water, more floating pigs, pigs in outdoor sties, etc. Hog manure going right into a body of water is really something.