For people interested in pigs and pig breeding, there's Animal genetic resources of the USSR. Soviet agricultural scientists constructed synthetic breeds in an attempt to meet their exact needs.
Just as the French constructed a breed for the Haitians, the Soviets constructed breeds to fit their climates. One of the breeds was based on the Mangalitsa. They called it a Mangalitskaya (it is near the bottom of the document).
The history of the Mangalitsa says that the various Mangalitsa breeds were created in the 1800s by crossing half-wild pigs with lardy ones, a process somewhat similar to the Soviet process. As the Hungarians switched from running hogs completely extensively (outside) on forage to fattening them in pens on grain, they needed fatter hogs.Quoting Dr. Radnóczi Lászlo:
In period of the development of the breed the main purpose of hog keeping was to utilize the wet, swampy pastures and forests. The typical breeds of the 18th century were the "reed-hog" from the Great Hungarian Plain and the "Bakonyi" from the woods of the Transdanubian hills, whereas the voluminous, red coloured "Szalontai" was found in the eastern border of the Great Hungarian Plain. Late maturity, slow growth, poor dressing percentage and tough meet, stingy, substandard bacon were characteristic of these breeds. Their advantage was the resistance to the rigours of weather and diseases., The so called "spiny" hogs, which did not differ much from the wild boar, as they were outstanding runners and ready to bite, were the most hardy breeds in the Carpathian Mountains.
The half-wild herds walked around the forests and grazing lands all the year round, the sows farrowed in self-made nests placed in reeds and shrub bottom . Piglets constantly following the sow, grew into skinny young pigs on the poor grazing lands, spent the winter outside and by digging up scraps left on agricultural lands or by acorn mast they put on some meat and bacon, thus became suitable for slaughtering at two years old...
As a result of the wider use of maize production and the ploughing of forests and grazing lands and forming to arable area, there was a radical change in the conditions of keeping and feeding from the second half of the 18th century. In the 19th century the regulation of the river-ways accelerated this process. Due to the change of market requirements, there was a greater demand for fat and bacon of good quality and less fibrous meat.
The extensive husbandry could not cope with these conditions. The old breeds, such as Bakonyi and Szalontai were taken to the farmyards of the domains and the small owners, fed with maize and crossed with the "Sumadia" breed of Serbian origin. The constitution of the animals have gradually changed and the "fat-type" hogs were developed. Sows of the
slow growing type were mated with the "new-type" boars...
The three varieties of Mangalitsa are genetically distinct, which the DNA shows, because the Hungarians first created the blonde Mangalitsa and then the red and swallow-bellied. People don't talk about it much, but the original breeds used to construct the Mangalitsa don't exist anymore, because it didn't pay to maintain them. Today's pork producers likewise abandon genetics that don't pay - explaining why besides Wooly Pig's recently imported Mangalitsa herd, there are no other commercially viable lard-type breeds in North America.
If you read about the Soviet synthetic breeds, you'll see that at times, they crossed wild boar with other existing breeds in order to produce tough, disease-resistant animals. That's not very different from the Hungarians crossing lardy hogs with their half-wild breeds, to produce tasty ones.
As a result of the crossbreeding, the red Mangalitsa have more snub noses, larger testes, larger penis sheaths and blockier bodies than the other Mangalitsa. Those details aren't just curiosities; researchers study things like testis size, because it is related to reproduction.
Some people don't like the Red Mangalitsa because of the introgression. Yet due to the Hungarians selecting them for meat and fat quality, they taste like the other Mangalitsa. They didn't select the crossbred animals for their looks, but rather their superior pork, because the customer just expects a Mangalitsa to be a curly-haired hog with Mangalitsa-quality meat and fat.
One would presume that had the Hungarian breeders had access to the resources the Soviets had, the various Mangalitsa varieties might have turned out differently. There's no reason to think they would have held back; the creation of the various Mangalitsa varieties and the disappearance of the Mangalitsa's founding stock makes it clear they were pragmatic.
My own thought on this is that it is very important to conserve biodiversity. It may not be necessary to conserve breeds (we can create them if we have enough biodiversity, money and time) - but without biodiversity, there's nothing to work with.