I give our pigs shredded beet flakes ..
the feed store didn't stock it over the summer, saying they couldn't get it wholesale??
I like to "keep it in" for after farrowing & goat-kidding, as its full of energy, and if an animal is "off" then the juice ie molassed water makes a good lucozade!!
and its British grown, GM free
I find it doesn't seem to fill the pigs up though - they need pig meal or flakes too.