Our supplier says: “These marrow bones are sliced to a 6″ – 7″ length from a USA beef shank bone, with some marrow in the center. Our marrow bones are slow roasted with trace amounts of liquid smoke for additional flavor. Marrow is an excellent source of healthy fats such as monounsaturated fatty acids, which is good for heart health (when consumed in moderation). This is a weight bearing bone, so it should not splinter. This extremely dense bone is not recommended for dogs who have underlying dental problems. Always observe your dog while they are chewing on any bone!” We recommend this long-lasting chew for large breeds!