I've been mulling this one over, since a couple months before you first posted it, because I also have some lamb trotters in the freezer, awaiting my decision on exactly this conundrum. I've taken a certification
course in raw, species-appropriate food nutrition for dogs & cats, so while I'm no expert, I do have *some* idea what I'm talking about, when I say that yes - offered as-is (maybe the manure and such washed off, lol) is the most nutritionally beneficial way to feed them to your dogs. But, I also happen to have both sheep and goats, and don't want my dogs to see them, and think, "ohhh, there's supper!!"
I also feed eggs, egg shells, chicken feet, raw bones, raw offal, etc. But, the one thing I always try to do is ensure that what I feed my dogs bears little to no resembled to my livestock. Eggs are not served whole, but raw or very lightly cooked, and the shells are dried, ground to powder, and blended into the rest of their food. Chicken feet, though are thoroughly scrubbed, then frozen or dried - and feed whole, but they don't look or smell at all like they do, attached to the life bird.
Deer legs & hooves are the only thing I've given directly from the prey to the dogs, without some prep, but I've no worries of my dogs taking down a deer, even though we live in though we live in the woods (one is a 16 - 20lb Cavalier, the other a 130lb or more Irish Wolfhound - neither leave the house off-lead), because only one small strip of
land lies between our property and a 65mph highway, with loads of blind curves.
So, with the idea of protecting my livestock, yet maximizing their nose-to-tail nutritional value to the dogs, maybe washing them thoroughly to remove the ick & lanolin, skinning them, then drying both the skins & the trotters, to give separately, would be sufficient.