"Over 600,000 of these pigs are confined in factory farms, where they have no access to fresh air, sunlight or open space."Can't say I really agree with that.
"...the pigs are taken to a slaughterhouse, where they are shot with a electric bolt gun and then killed."LOL, why shoot them with a bolt gun if your just going to kill them "later"? I think the author is a little confused

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"After about 40 minutes of being locked to the truck..."
I wonder how hot it was inside for the pigs without any air movement?
Personally, I would have sat right in front of them with a fork in one hand and a plate in the other... drooling all over myself of course. Unless I had a camp stove, then I would have been frying bacon for the crowd with a sign that said "Keep Pork off your Fork... Eat it while it's HOT!"