I'm hoping to find some quantitative info comparing pastured pork to conventional pork nutritionally. If you've ever seen such info, I'd be really interested to see it. If not, educated speculation is welcome. :-) Specifically, I'm wondering about the fat content and whether omnivorous animals is as adversely affected as that of ruminants when they pretty much just eat grain/soy, seeing as omnivores will not get as sick as cattle do on grain-based diets.
My husband and I bought Frederick, the 4-H pig recently at the county fair (having given up on finding pastured pork in our area). The girl who raised Frederick said he mostly ate grain and some soy and that he got to forage some. Frederick is certainly the best pork I've ever tasted. He was a healthy, handsome pig raised individually by a girl who really seemed to care a lot about the whole process, so I think Frederick is a far sight better than conventional, but he's still not up the level of a pastured pig. I'm just curious how great that divide is between conventional and pastured pork...
I've looked at the issue with respect to omega 6. I don't view pastured pork and industrial pork as that much different with respect to omega 6 because almost all pastured pork is fed corn. There are some old articles which can be found by google scholar which deal with the fatty acid composition of pigs based on what is fed to them. The more omega 6 their diet contains, the higher the omega 6 in their tissues. Feeding pigs less than .5% of their diet as omega 6 calories can get the omega 6 tissue content down to about 3% of fats. The other extreme, giving them lots of calories as omega 6 can get their tissue up to 47%. Modern research says that industrial pork is 15-27% omega 6 of fats. Nutrition Data says that pork has about 10% omega 6 is probably wrong.
Pigs aren't meant to eat grains such as corn nor soybeans. Their natural behavior indicates that they prefer digging for their food. Their natural diet is roots and tubers supplemented by whatever small animals they run across and maybe some green leafy matter. Corn is 4% omega 6 by calories. Various roots and tubers are .5%-1.5% omega 6 by calories and are balanced in omega 6/3.
Pigs can be raised on sweet potatoes as an energy source. This has been done in Vietnam, China, and Japan, although lately they started to also add corn to the diet. Pigs benefit from protein supplements because the protein in sweet potatoes is low and not very bioavailable. (Soybean meal, which is soybeans crushed to remove their soybean oil, is a common protein supplement.) Pigs in Europe are sometimes raised in a dairy operation and are fed dairy waste. I don't know what the best paleo protein supplement for pigs would be; just that omega 6 calories need to be low.
The local farm where I am about to start getting my pork says they feed them:
Our pigs live off clover, grasses, and woodlands. We also supplement their diet with fresh ground alphalfa, corn, oats, barley, and wheat. We will feed alfalfa hay in the winter. Our pasture pork will be finished with apples, pears, acorns, and dairy products (really).
Even though they do consume some corn and other grains I'm still guessing the Omega profile will still be greatly improved over conventionally raised pork.
I'm going to take a tour of the farm next weekend and I'll see if they have any knowledge of the nutritional differences since they seem to have that up on their site for the grass fed cows, just not for the pigs.
Edit: I just noticed this really thorough post which pretty much covers it: http://paleohacks.com/questions/4444/what-should-pigs-be-eating/8962#8962
I know pigs like to hang out around hazelnut trees, thus the requirement of feeding them hazelnut before made into prosciutto de parma, they also dig truffle (or at least are made to) which is normally grown under hazelnut tree. I also heard chestnut is part of their natural diet and it increases omega-3.
I can tell you the wild pigs will eat anything they find, above or below ground. They will destroy a soy bean field quickly, eating the beans that have just been planted and started to germinate, then eating the bean pods, plants and roots after the plants grow. They are equally happy to destroy a wheat field. Shoot their family member, and they will eat him too. They dig holes in the cattle pastures that cattle step in and get hurt. Wild hogs are a horrible problem for the farmers in our area. If you really wanna be hardcore paleo, come out to Oklahoma and I'll hook you up with a place to shoot more wild pig than in your wildest dreams.
I've had truly pastured pork (forage, vegetable and fruit scraps, plus a modest amount of non-GMO corn), and the taste is otherworldly. I could use a whole bunch of words, like rich, slightly gamey, and making my whole body happy, but you have to experience it to judge it.
ah, no kidding. Pastured pork has an extra gear when it comes to taste. They will be excellent, so long as they can be outside and have a reasonably varied diet. The difference with supermarket pork is incredible.