Stress and meat quality is a very important topic. Although it has been studied in depth, e.g. here is an in-depth treatment of the topic, many Americans don't understand the importance of stress on meat quality.
Essentially, stress results in chemical changes that prevent meat from "ripening" properly as it otherwise would. There's two recognized problems - meat from an that's been so exhausted that the meat doesn't have enough glycogen to ripen properly. That meat is called DFD - dark, firm, dry. The other problem is meat from a stressed animal, whose meat's pH drops too quickly, damaging the meat. The meat loses fluid, texture and water, so it is called PSE (pale, soft, exudative).
Please note that stress immediately before slaughter has the biggest impact. There's all sorts of stress that could conceivably ruin meat (e.g. transport stress, weaning stress or the mental trauma of an unhappy piglethood) - but stress just before slaughter seems to be most important.
One technique Austrians recommend is to feed animals sugar water 12 hours before slaughter. The purpose is to increase the glycogen in the muscle, so that it will ripen better. Some runners do similar things, in an attempt to fill their muscles with glycogen before a race.
Regardless of the actual mechanism or science, it is interesting to see how companies or individuals behave when they pay the price of stress:
- Austrian Mangalitsa breeders, like Mr. Gasser keep pigs, raise their young, slaughter them, then make and sell products from their meat. He is an integrated pork processor, in miniature. People like him are particularly careful to eliminate slaughter stress - they'll tell you that stress ruins months of work.
- Large meat packing companies spend millions of dollars to reduce preslaughter stress. Employees who stress animals, resulting in losses for the company, lose their jobs.
Finally, small slaughter plants are often bad at controlling preslaughter stress. This does not fit the typical paradigm that local, small and family-owned is necessarily good.
The small USDA plants - the kind that a small farmer uses - can't afford to spend the money that big companies do controlling stress, and they have little incentive to do anything better: small plants are paid by the head, not according to the quality of the slaughter. Most of their customers don't care; they are just happy to get USDA slaughter so that they can sell their meat to people.
I talked with a guy who works as a custom butcher, but who used to work in small, family-owned slaughter plants. He confirmed that the small USDA plants are the worst. E.g. there are employees working there who delight in making hogs squeal. Who do you think works in these plants, anyway? It gets pretty irritating to handle big, squealing, stressed pigs all day long.
Also, it isn't possible to pay the smaller plant more money in return for better service - that's like expecting to walk into McDonald's, pay a bit more, and get a waiter and table service.
E.g. I took in a few animals for slaughter. The big pigs (pictured at the very top) were put in their own area, but my Mangalitsa piglets were put into a feces and urine-filled pen with a bunch of bigger pink piglets that started to pick on them.
The root of the problem was that our slaughterhouse doesn't have enough pens for small pigs. There was no place to stick them but with the other small pigs (from another farm). If they hadn't been stuck in that pen, they might have escaped and ran down the road. Taking them home was not an option - they might bring home a disease. I needed to get my pigs slaughtered, and I wasn't going to stand outside the stalls for four hours, watching to see if they were trying to squeeze out - so my piglets had to go in with someone else's pink piglets.
The slaughterhouse folks had told us to bring the animals in at 8AM and we figured they'd be slaughtered soon after - but after we arrived we found out they'd be slaughtered in the afternoon. It was all a real letdown. Everything we did to try to mitigate slaughter stress was probably overshadowed by what happened to the pigs after they went into the pen at the slaughterhouse. I'd wanted to see them get slaughtered, but we weren't able to witness it. I'm just hoping they got those hogs slaughtered with a minimum of stress and coercion.
Please don't get too upset by the photo: when pigs live outside and it rains, they sometimes wind up in muck. And big piglets always seem to pick on smaller piglets and take the better spots. A pig's life is not an easy one.
Mangalitsa piglets are very stress resistant; they still taste good even after stress. E.g. I ate one that jumped out of a trailer and mortally wounded itself. It was in pain for quite a while, until they decided to butcher it and keep the meat. When roasted, it tasted absolutely fantastic. So I'm hoping my three sorry looking piglets will very good. Hopefully their lives weren't wasted.
I was actually glad to get these hogs done USDA. I need to get them done that way to sell them. Hence, raising a big stink about the piglets wouldn't have helped anything; I need to get my restaurant hogs done there, and I need to get along with the staff. Their place is probably the best USDA plant in our area. My big hogs looked like they were set up just fine. One could even argue it was my fault for bringing in such small piglets.
Also, I understand the economic constraints of that slaughterhouse: they don't have enough secure pens, and $50 per slaughtered animal doesn't give them a lot of money to spend on improvements. Nor would their existing customers want to pay a penny more for marginally better slaughter - because they aren't as focused as Wooly Pigs on low-stress slaughter. As I might be the only customer who cares about this; I can't expect it to go my way.
As I mentioned previously, custom meat is the way to go for the highest quality and animal welfare. I find it interesting that supporting small farmers may mean supporting small slaughterhouses, whose animal welfare policies might shock people if they knew more about them.
If you want to buy custom pork from me, I will sell you a good hog and arrange for humane on-farm butchering.