Based on what I've learned about pork (and beef), if some meat tastes consistently better than an alternative, it has to do with the following factors (listed roughly by importance):
3) age at slaughter
4) post-slaughter ripening
5) pre-slaughter stress
Heath Putnam Farms, the only farrow-to-finish Mangalitsa producer in the USA, started by optimizing factor #1, but also optimizes factors 2, 3, 4 and 5 (subject to economic constraints).
I was looking on the Elysian Fields website to try to find out what factors they control to make the lamb. I found the philosophy section:
Pure Bred’s Keith Martin and Thomas Keller here offer a new perspective on one segment of this industry, raising lamb, a method that puts the animal first and as a result makes what this farmer and this chef believe is the best possible lamb... Mr. Martin and Chef Keller believe that lamb raised according to its nature results in better lamb, and hope that those who buy Pure Bred, likewise share in and encourage these convictions about how livestock is raised in America...That got me thinking.
What does it mean to "put the animal first"? Does it mean to cater to whims of each pig? If we did that to the pigs, besides feeding them a steady diet of ice cream and hamburgers, we'd have to get each pig a personal belly-scratcher. The ice cream and hamburgers would ruin the quality of the pigs' fat, Heath Putnam Farms would fail, and the Mangalitsa breed might go extinct (in this hemisphere) as a result.
If you look at the front page of the Elysian Fields site, you'll see a link to the following ("Voice of the Lamb"), a personal message from the owner:
All of us at Elysian Fields have discovered one thing for certain, how insignificant and out of focus we all can be in relating to the natural order all around us. We live within a miracle that continues to reveal itself, the dynamics of which we can barely begin to grasp. We feel, for some reason, that we are the center of this natural process when in reality we are completely outside. We have been given a great gift, a gift of choice, which we have decidedly developed into authority over all things. Or so we think. We have moved away as a culture and a society from “real” values, which has in turn removed us from our true mother….earth. No longer are we connected to the soil as all other things are. No wonder our walks in the park rejuvenate us, why getting our hands dirty feels so good. Within the order of nature exist the relationships which are its very fabric. Within these relationships are inter-dependencies proving we are all one, not The One.That's doesn't explain why the lamb tastes so good either.
Keep looking and you'll find this page:
Once becoming part of the flock, Pure Bred Lambs are fed only natural grain without the presence of growth hormones or stimulants,which may interfere with the quality of the lamb in its commercial presentation. The feed (hay and grain) each lamb consumes is carefully monitored to avoid overeating. Thorough testing for content and nutrient levels is consistently conducted and monitored. Additionally, the water each lamb consumes is also tested continuously to ensure its purity by independent testing sources.
By feeding them grain, they set themselves apart from most lamb producers, who just have them forage. The bit about preventing overeating is necessary because unlike pigs, sheep will overeat. As explained on this sheep website:
Sheep "love" the taste of grain. It's like "candy" to them. They will overeat if grain consumption is not regulated. If grain is slowly introduced to the ruminant's diet, grain can be supplemented and in some cases replace some of the forage in the diet. Whole grain is better for sheep because it requires them to do their own grinding of the grain. Digestive upsets are less common with whole grain as compared to processed grains (ground, rolled, or cracked). Some forage should always be fed to ruminants to keep their rumens functioning properly and to keep them content.Pigs are a lot simpler (and smarter!). They don't overeat to the point of hurting themselves, so they are easier to raise.
The fact that they feed the sheep grain is probably a bit controversial. A lot of people seem to think that ruminants should just forage. But most people like marbled, juicy, flavorful meat. It is a lot easier to produce fatty meat by feeding the cows or sheep grain, because grain has so much more calories.
Here's a guy writing about the difference:
Grass-fed lamb sounds good. New Zealand lamb is grass fed. Loncito Cartwright’s succulent lamb from Dinero Texas is grass-fed. But the best lamb I have eaten in a long time is grain-fed... The meat is buttery tender and has a fresh vibrant lamb taste, but the flavor is not at all gamy... A grass-fed New Zealand lamb carcass weighs somewhere between 35 and 45 pounds. The lamb chop is small, you can eat the whole thing in a couple of bites. An Elysian Fields lamb carcass is almost twice as big–they weigh 65 pounds on average–and a lamb chop is a meal. Don’t get me wrong, I like the gamy flavor of grass-fed lamb, especially on the grill. But comparing a New Zealand lamb chop to a Elysian Fields lamb chop is like comparing fajitas to filet mignon. And as you might expect, the Elysian Fields lamb goes for a lot more. Racks of Elysian Fields lamb are selling for $26 a pound in New York.I wonder, what would happen if someone got the best-tasting sheep and optimized the diet and age at slaughter? How much better would their meat taste than the stuff from Elysian Fields?
I should mention, feeding pigs an optimal ration makes it possible to consistently produce high-quality pork. If the pigs are out foraging, depending on what forage is available and what the pigs like to eat, you'll get different pork - often worse than if you just fed the pigs the right grains.
When Hungarians switched from free-range pigs to pigs fattened in pens, they improved their quality, efficiency and consistency over the previous free-range system.