We plant a smallish patch, maybe tenth of an acre with fodder beet which is pretty similar each year for feeding to the pigs. We're just now coming to the end of last year's crop, the seeds are expensive as you have to buy by the acre but £60 for seeds saves us nearly £300 on pig food so its a good deal in the end. We feed about 1:9 ratio of fodder beet to pig nuts for the sows and about the same to the weaners once they are three months old. Chickens like them too. Pound for pound and taking minimal effort they are probably the best crop we grow!