I rotate the pigs fairly rapidly through my pasture, so after I moved them off the first paddock of the spring, I wanted to plant something. Because it was spring, and because it was a fairly small area, the pigs had rooted quite a few areas up. Here is a picture I took back in May that shows the general area.
I find it very difficult to evaluate the overall value of forage as compared to buying feed. With buckwheat especially, there's not a whole lot of data on it's nutritive value. I did find one study, but it is focused on ruminants. In general, my goal with pig forage is to increase the protein, starch, and sugar content of the forage over the typical naturalized grasses, minimize cellulose and lignin, and maintain or improve palatability. When you're harvesting grain, hay, or silage, it's easy to get a good count of the amount of feedstuffs you're harvesting, but when the pigs are doing the harvesting, it's much harder.
Nonetheless, I'm pleased at a basic level that the pigs are enthusiastically eating a forage I planted. I plan to do much more of this in the future.