There is going to be a lot of information in this post and if anyone has questions please leave them in the comments below.
Taint is caused mainly by two compounds, androstenone which is produced by the testes and skatole which is produced in the gut -- skatole is the reason why gilts and barrows (castrated males) can also have taint. A boar's androstenone levels has shown to be linked to the animals genetics, with some lines having lower or higher levels than others. (Source)The majority of heritage breed pigs have low enough levels that taint cannot be detected. Duroc and Duroc crosses have the highest levels of androstenone and boar taint. (Source) Add to that, that only some people are sensitive to androstenone, boar taint is not normally an issue for those raising heritage breed pigs.
Diet and management practices can reduce the level of the skatole compound in pigs. Overcrowded pigs have higher levels of the compound than those given more space. (Source) A varied diet can also help to reduce skatole levels. This is significant, because studies have shown that when skatole levels are very low, meat with high androstenone levels are deemed acceptable by even androstenone sensitive consumers. (Source)
There is also an all natural way in which to prevent boar taint and that's chicory (and a few other feeds as will) -- which incidentally also makes a pretty good salad. Multiple studies have been done and it appears dried chicory root can almost completely eliminate taint in non-castrated pigs by bringing skatole levels down to nearly zero. (Source) There are even some that say it reduces androstenone levels as well, but that's still being disputed (it doesn't help that every study uses a different % of chicory in the pig's feed). (Source) Sniff tests performed by those sensitive to taint seemed to point out, that even if it doesn't bring down the androstenone levels it doesn't seem to matter, because chicory fed boars just don't have taint. (Source)
So what does all this mean? It means that while boar taint is real, it's very very rare in heritage breed pigs raised on pasture and given a varied diet, and can be possibly eliminated with the use of chicory. It can also be traced genetically and bred away from.
Does my herd carry boar taint genetics? I know Niles doesn't, but I'm not certain about my sows. Am I worried about boar taint? No, not with us planning to feed them chicory before sending them off to slaughter.
Some may wonder why don't you just castrate them anyways? Even if the risk is small, do you want to risk throwing all that money down the drain on an inedible pig? (Yes, I've actually been asked this)
Firstly, my whole reason for getting into farming was because I wanted to raise animals humanely and there is nothing humane about performing surgery on an animal without anesthetic. I could call the vet, but that's hardly economical. If you've never seen a piglet castration head on over to YouTube, there are a ton of how to videos. It's not like with a goat or cow where you can put a band around their testicles and just wait for them to fall off, it's actual surgery. You have to cut them open and pull the testes out. It's painful and very stressful for the piglet. Even pig farmers who defend the practice don't try to call it humane, they just call it necessary.
Secondly, I want to raise boars, because they are cheaper to raise. They are more feed efficient, grow faster (10% faster than barrows and 20% than gilts), and produce a leaner, juicier meat. (Source) With butchering the boars at 6 months of age the risk of taint is almost zero.
I understand if others don't want to take a risk raising boar piglets, which is why I do castrate some piglets, but personally I prefer to raise boars.
Update 9/5/2014: We sent 4 boars to market and not a one had taint. The meat from these guys is delicious. The butcher said it was some of the nicest, leanest pork he's ever handled. After searching for months we were unable to find a source for chicory, but thankfully sugar beet pulp is easier to come by and works just as well. Next year we will be holding back a few more piglets to raise as meat, and some cut males or females may be available if someone doesn't want to eat boar meat.