carcass. The positions and names of these Bones are important to you, as a veterinary
food inspection specialist, because they are the unchangeable landmarks used for
further breakdown of the carcass into smaller, more manageable pieces.
a. Chine Bones. The chine bones are the split bodies of the vertebrae,
resulting from the longitudinal division of the carcass into sides.
b. Featherbones. The featherbones are the split dorsal processes of the
thoracic vertebrae in each side of the carcass. They resemble the feathers in an
c. Buttons. At the dorsal end of the featherbones are small islands of cartilage.
These are called buttons. As the animal ages, these buttons of cartilage gradually
calcify, or transform, into bone. Thus, the amount of uncalcified cartilage present is a
rough estimation of the animal's age at the time of slaughter. To make this estimation of
age, the 10th, 11th, and 12th thoracic chine bones are used. For example: a steer at
approximately 18 months of age, will usually have only a few, small, scattered, red
pinpoints of bone embedded in the white cartilage of the buttons. These red, pinpoint
areas of bone are also termed blood islands.
d. Sternum. On the internal ventral aspect of the side is a group of seven
bones collectively termed the sternum or breastbone. These bones form the ventral
attachment of the rib bones.
e. Cartilage. A specialized fibrous, elastic, or hyaline connective tissue found in
the carcass. It is normally found on the ends of bones and more frequently in carcasses
of young animals. Cartilage ossifies as animals mature, thereby making it an important
consideration when determining a carcass' skeletal maturity.
f. Ossification. The formation of bone or a bony substance; the conversion of
fibrous tissue or cartilage into bone by the deposition of hard mineral material,
especially calcium and phosphorus.
a. In the Forequarter/Anterior Section. On the outside of the
forequarter/anterior section and under the shoulder muscles, is the scapula or blade
bone. Distal to the scapula is the humerus or arm bone, and distal to the humerus is
the radius and ulna or foreshank bones.
b. In the Hindquarter/Posterior Section. On the distal end of the hindquarter
posterior section are the tibia and fibula or hind shank bones. Proximal to this is the
femur or round bone.
c. In the Pelvis. The femur attaches to the pelvis or os coxae, which is
composed of three fused bones: the ilium or pin bone; the ischium or hookbone; and