Master Butcher Marcel KropfOne Austrian expert I know swears by the addition of rye or triticale to a barley-based ration. He is a custom butcher, so he's killed countless pigs, finished different ways on different farms. He's been able, over the years, to learn what feed makes fat that is hard, white and without off flavors.
One American Mangalitsa producer asked why wheat, rye and triticale improve fat quality in pigs over a barley-based diet. He wanted a scientific justification for our advice.
I couldn't find any information in English (to be expected). I did find a German-language PDF that explains why rye is such a great thing to feed pigs. In a nutshell:
Rye is low in PUFA, so the resulting fat keeps and doesn't taste off.
Rye is low fat, so the pigs have to synthesize the fat. That gives the fat a neutral taste.
Wooly Pigs and other Mangalitsa producers take fat quality very seriously. If you read reports from Mangalitsa consumers, they often bring up the incredible fat:
Fat in desserts - The Magic of Mangalitsa Porkand so on.
"But the other night my final tablespoon of mangalitsa fat transformed an ordinary ..."
"Porcine Foie Gras"
"But even the fat is special..."
"Creamy and intensely flavored this is beyond any bacon you’ve ever tasted."
Of course, some people also bring up the incredible meaty flavor of Mangalitsa - but it is the fat that usually impresses them so much.
After writing this, I ate a bit of my own Mangalitsa lard and was struck by how light and clean-tasting it was.