Winnie Lou Bison Marrow Bones are true to the Winnie Lou brand, utilizing even more local, Colorado Bison with hindshank and femur marrow bones. From the slow-roasted bison on the outside to the rich, delicious marrow on the inside. NO OTHER INGREDIENTS added. No spices, no salt, no rubs, no smoke, no charcoal, nothing harmful or toxic in the way our bones are slow-roasted. We roast them at a very low temperature, slowly over 40 hours ensuring the perfect amount moisture is maintained throughout the process, strengthening the bone, and preventing splintering and breakage as our furry friends