(b) Udder fat (dug fat) in young females is the smooth, thick covering of
fat in the groin area associated with the fat that is normally present in an immature
udder. Older females (cows) will also have a large amount of smooth fat located here
as well as some milk producing glandular material. This glandular material will be
trimmed away at a later time.
(4) Shape of the gracilis muscle. Lastly, the shape of the gracilis muscle
can be used to determine the sex of the carcass. In males, the shape of the muscle is
roughly triangular or round. In females, the muscle is oval to kidney bean-shaped.
The USDA's Agricultural Marketing Service (AMS) Meat Grading and
Certification Branch (MGCB) provide the service of grading carcasses; they are the only
ones that may apply the official grade marks. The USDA grades are based on
nationally uniform Federal standards of quality. The use of the system is entirely
voluntary and on a fee-for-service basis. The marks (legends and brand) are applied
directly to the carcass and are made from the same edible vegetable dye as the
wholesomeness brand. Grading is performed after the hot carcass has been cooled,
and ribbed down. Steers, heifers, cows, and bullock carcasses may be graded, for
quality only, yield only, a combination of quality and yield, or left ungraded as
established by the regulations and as suits the needs of slaughterers and their
customers. Steers and heifers are eligible for all designations. Bullocks may only be
graded Prime, Choice, Select, Standard, and Utility. Cows are eligible for all but the
Prime grade and bulls may not be quality graded.
a. Quality Grades. Quality grading is a process to estimate the tenderness,
juiciness, and flavor of the beef. Carcasses are not trimmed prior to a quality grade and
yield grade designation being assigned.
(1) Factors considered. There are two factors considered in determining the
grade of beef: quality and age. The quality grade of beef purchased must be as
specified in the inspection data packet and the product graded in accordance with the
US Standards for Grades of Carcass Beef.
(a) Quality is the more important of the two grading factors and the
primary indication of quality is the degree of marbling. Good quality beef has fat
streaks, known as marbling, interspersed with the lean meat. Good quality beef has a
fine texture and a velvety feel when the fingertips are rubbed lightly over it. The meat is
firm to the touch and cherry red. Final determination of grade is dependent upon factors
evaluated in the area of the rib eye muscle.
1 The color of beef is usually darkest just after slaughter, and
becomes lighter after chilling. When exposed to the air for an hour or more the surface
becomes even lighter in color. Extended exposure to air causes the tissue to darken;
this is due to drying and oxidation. If beef feels sticky or gummy, retards the passage of
the finger over a cut surface, or is dark or purplish in color, it is usually coarse in texture
and of inferior quality.