S.T.
julie and sunshine are both correct. yes, pigs do best and taste best when they're raised naturally and allowed to graze and root. but yes, if their last day is spent in terror, it will also taint the meat. it's why hunters try to drop an animal on the first shot. if they have to pursue it for miles to finish it off, the stress hormones affect the quality of the meat. (well, and hopefully because they're ethical hunters who don't want to cause needless suffering.)
it does sound as if your processor got backlogged and couldn't get to your pigs in a timely fashion. i'm sorry, i'm sure your intent was to have them swiftly and humanely dispatched and rendered. i know our local abbatoir makes a huge effort to have the animals downed and butchered as swiftly as possible. i guess sometimes it just doesn't work.
i'm so sorry your pork isn't good. the couple of times i've bought pig shares from local farmers and had them locally processed it's been AMAZING, and having raised your own heritage pigs, it must be especially bumming to have tough meat.
i'd talk to the butcher, and if you don't get a satisfactory answer, look for another. i would have thought that your local mobile butcher would be by far the best bet, and maybe he is and just had an off day.
i did have one cow i purchased locally come out poorly. i still don't know if it was the cow itself or the processing, but i sure was disappointed to spend all that money for meh.
don't give up on raising your own!
khairete
S.