You're not allowed to feed pigs on household scraps ('swill') since foot and mouth. This pretty much removed the traditional smallholder / home-reared pig diet at a stroke.
Bit of a shame in purely functional terms; a pig is superb at converting vegetable peelings and the like into meat.
The scrap food bin at schools used to go to pig feed too.
I reality composting is probably even more effective at creating more food ablietly it is not meat in its first incarnation.
I think the Foot'n'Mouth outbreak back in 2001
https://en.wikipedia.org/wiki/2001_United_Kingdom_foot-and-mouth_outbreak#Health_and_social_consequences
resulted in changes to freedom of livestock movement and feedstock restrictions,
making it much harder to keep a suburban pig fed on 'swill'.
Not a farmer/not a meat-eater, could easily be wrong.