2 The fat on grain-fed steers and heifers is firm, brittle, and
creamy white; that of grass-fed animals is soft, plastic, and yellow. Certain breeds of
dairy cattle and most scrub cattle have yellow fat, and, as the cattle get older, there is a
marked increase in the amount of yellow pigment (carotene) present. The distribution of
the fat is called the finish on a carcass. A newborn calf has practically no finish.
a With good feeding in excess of body requirements, fat is
deposited on the external surface of the animal as it matures, first on the loin and ribs
on each side of the back, then progressively backward over the round, forward over the
chuck, and downward over the brisket, short plate, and flank.
b On the internal surface, fat is first deposited around the
kidneys and in the lumbar region. This fat finally extends over the internal surfaces of
the flank and the ribs. A completely finished carcass also has small rolls of fat on the
inner surface of the ribs (festooning) and a feathering of fat in the lean meat between
(b) Age is also a factor in determining quality, and can be judged by
the color, character, and size of the cut surfaces of the chine bones (vertebrae) and the
sacrum after the carcass is split.
1 Bone characteristics change as the animal ages. All bones in
newborn calves are soft and red, and the spines of the vertebrae are tipped with white,
glistening cartilage called buttons. As the animal grows older, the bones gradually
become white and hard, and the cartilage gradually turns to bone; by the time it is 6
years old, the change is complete. The 10th, 11th, and 12th chine bones are used to
make an estimation of age. Steers and heifers, which are usually slaughtered at less
than 2 years of age, show a considerable amount of redness of bone and white
2 The environment influences the rate of ossification. Plains
cattle from the Southwest have harder, whiter bones than cattle of the same age raised
in the Corn Belt.
3 The breed of the animal is a factor in grading. The size of the
bony framework varies among breeds. Animals bred for consumption have a high
percentage of meat to bone. Those animals of non-descript breeding usually have a
large, angular bony framework, with a much lower percentage of meat to bone.