Sheep fat Filled cow hooves are basically an edible ‘Kong’ for your dog. 
The cow hoof is rich in Keratin & is very unlikely to splinter. It will grind down naturally as the dog chews, acting as a toothbrush.
The sheep fat filling aids and promotes digestion, supports a shiny, healthy coat and skin. It also aids digestion/food intake and is good for the heart and blood vessels. 
If you want to make the treat last even longer, once the original filling has been eaten you can actually re fill the hoof with something like Pate!