I just found a comparison of Anglo-American butchery versus seam butchery (as practiced by an Italian butcher):
The two butchers watched each other with keen interest. Andy Winterburn, the butcher from Berwick-upon-Tweed who works at Peelham and was taking care of Spidey, sniffed as Renato from Friuli made incisions to take out the spare ribs from the Italian pig's belly.Wooly Pigs (and other Mangalitsa producers) promote seam butchery because it allows the consumers of Mangalitsa to lower their costs. Mangalitsa is expensive enough that it pays to butcher the pigs with minimal waste.
'No butcher in Britain would do that,' he said. And when Renato started stripping down the pig's head for meat, Andy muttered: 'I could have done two pigs in the time this has taken. This is just not cost-effective.'
But, as Renato pointed out, there was 2kg of good meat on the head, including the cheeks - a delicacy once sold in Britain as Bath chaps...
Nowadays, in most British butchers, the head goes straight in the bin. When we'd finished, we totted up the proceeds. Spidey had started out at 75kg - and yielded 42kg of usable meat. The Italian pig weighed in at 62kg and produced 52kg.
The disparity shocked even Andy, who spent his career working in a busy butcher's shop.
To my knowledge, the next seam butchery class taught in the USA (by European experts) will be this one.