The Farmer's around me that have "finishing" operations (where you feed animals to fatten for slaughter) use a lot of it from the local sawmills. There are always animals that are culled from the batch, rather than do anything useful with them, they cover them in sawdust (in dedicated shed) and let the animal decay into the dust. The sawdust is then scattered on the fields with the manure spreading operations. I'm told when you do this, nothing of the animal remains, except maybe for the larger cattle, then you may have a hip bone left. Anyway, the farmers pay a fairly steep price for the stuff, and it's become quite lucrative for the sawmills. I have noticed the price of lumber has not decreased due to this new revenue stream.