Swallow-belly Mangalitsa sow.
There's a pig gallery that shows the Swallow-Bellied, Red and Blonde Mangalitsa pigs. They are different breeds, created by upgrading.
People care a lot about how pigs look, not just how they taste. It isn't enough for them to produce the right sort of pork. Pigs have been heavily selected for looks, just like dogs. It isn't too hard to see how that would happen: pig breeders are good at producing the kinds of pigs that people want.
One breeder told me that a few years ago, one could get a big premium for a pig so lean and muscular that it had a visible groove down its back. This year, pretty much every kid at the county fair had such a pig. There's no premium for them anymore.
In this way, the livestock business is like fashion. Historically, scientific farmers (aka "eggheads") have been responsible for starting and promoting destructive fads and crazes in farming.