Sadly the traditional way of feeding pigs is now illegal - swill. When I was a small girl, many decades ago, my uncle had pigs which were fed on all the kitchen and garden waste, plus the left over, unpasteurised milk from his two hand milked cows. Everything went in, meat, bread, veg, fishbones, gravy, christmas pudding. All this was collected in an old bath outside, and the pig man came and collected buckets of it every day. The pigs loved it and probably got all the protein they needed which is nowadays provided by pig nuts instead. They also got left over fodder crops and grass as well. So, like it or not, nuts are the only way to adequately feed them their protein and vitamins as the law stands now.