This cut of USDA select Beef Marrow Center Cut Femur Bones are farm fresh and provide a healthy source of natural collagen, glycine and many other essential nutrients. They are beneficial for bone health, teeth, skin, joints, immune system and so much more. No additives or hormones are ever used in our food sources. At My Paleo Pet, we flash freeze these bones for nutritional integrity and convenience in storage and shipping. Be sure to also check our select variety of other BioComplete raw frozen bones as well.