A little lardy pig helps with winter. I keep Yorkshire, Berkshire, Large Black, Tamworth which are not high lard pigs. I have selected them for more ability to put on weight on pasture - to deal with scant calories. People who buy our feeder weaner pigs and put them on a grain diet see them explode as a result. On a high calorie diet they get very lardy. On our diet we get about 1/2" to 1" of back fat depending on season and sex. I would think the Mangalitsa and AGH would do well with this but from what I have heard they have a slower growth rate.
Walter, they DO explode on grain. The Blond Mangalitsa on grain can get to 5" backfat. The Manga grain fed is about a 12-13mo grow out, and no grain could be 18mo, however the management used on some of my breeding stock is growing them slower on much less grain input 4 7 generations, and that slower carcass helps the marbling. They are long and lean, not the typical bubble with 4 little legs poking out. My goal is to keep it under 2" and my chefs are happy with that. I tried to calculate from eggs alone and the Lysine per egg that it would take something like 47 eggs per KG of pig growth (if 100% egg diet, which of course makes no sense). The 80% hay, and the rest in various other forage/feedstuff is our current next stage. I have hope that with generations we will see more adaptation to zero grain, and are culling heavily. I think a clamp is in order for future winter root crop feeding for sure. What you have done with the pastures as you describe certainly is our goal, and our poultry and sheep have been helping the pasture improvement for sure.
Have you had experience with any other silages like french mammoth sunchoke or comfrey as a perennial forage source for winter feeding? I would think a 1-2 acre intensely managed crop like this with an old timey forage chopper could provide a lot of winter feed (I think/hope) without having to intensely manage a garden seeding annually.
Do you worry much about winter fat sources, as the whey and hay and stored vegetables would be pretty low (other than their own reserves)?
Thanks Walter! Kerri