I read the lamb post first so didn't understand the pork comment until I saw this post.
I agree with the stress comments. Many years ago I was taking my pigs for the chop and as I was pulling out of the junction, some idiot jumped the lights so I had to slam my brakes on, I heard a thud in the trailer! I was at the abattoir a few minutes later and there wasn't any one ahead of me in the queue, I happened to mention it to them and rather than push them straight through, they put them in the pens, telling me it's for best! Apparent they killed them last as the meat was perfect.
Corn/Nuts, whatever you want to call it, CAN be an issue! I've had pigs REFUSE food as the mill have changed ingredients due to shortages (they came out and swapped it after taking samples!). Also, dad told me once, that when he and his parents were raising pigs and turkeys in the 1960's, they had contracts to fulfil, like folk now, but the butchers came back and passed on complaints to them from customers, grizzly, boar taint, tough, you name it they said it. Dad said the only thing they had done different was change feed supplier due to costs (dad is a tightwad, my Grandad was worse!)
Saying that, it's curious that ALL is bad! Too much of a coincidence for the whole lot to be bad, so for me, feed or abbatoir! If it were just the pork or just the lamb, then maybe you (my first pig had so much fat on him it was shocking, but then Sausage liked milk and me being me bought him milk and mixed it in with his nuts ....... But it was bloody good meat!)
Also agree with the person who asked are you sure it's your meat? 2010, My first beef home kill reared by me Swissy, (we'd eaten 2 previously but they had been reared by the cow to start with and then left here at 29months) When I booked him in with the haulier, he said "you're not taking him to *******, sure you'll get him back?" ( I wasnt) because there was a local abattoir that HAD in the past, seen a good carcass and sold it through the shop rather than give the owner their own meat back!