C&MS-SRA 189 ISSUED FEBRUARY 1966
United States Department of Agriculture
CONSUMER AND MARKETING SERVICE 4~ -
C&MS-SERVICE AND REGULATORY AN EMENT 189
OFFICIAL UNITED STATES STAND D FOR GRADES
OF FEEDER PIGS
(Title 7, Ch. 1, Pt. 53, Sections 53,150,53.151, 53.158 and 53.159 of the Code of
The following is a reprint of the Official United States Standards
for the Grades of Feeder Pigs promulgated by the Department of
Agriculture under the Agricultural Marketing Act of 1946 (60 Stat.
1087; 7 U.S.C. 1621 et seq.), as amended. The standards are
reprinted as adopted effective January 1, 1966.
DEVELOPMENT OF THE STANDARDS
In 1940, tentative standards for grades of feeder pigs were
developed and published by the Department of Agriculture in
Circular No. 569, "Market Classes and Grades of Swine." These
tentative standards were never revised nor were they promulgated
as official standards.
The tentative standards served as the basis for Federal and
Federal-State livestock market news reports on feeder pigs.
Official standards for grades of feeder pigs were proposed by
the United States Department of Agriculture in 1965. Slight revisions
were made in the proposed standards before they were promulgated
as the Official United States Standards for Grades of Feeder Pigs,
effective January 1, 1966.
APPLICATION OF STANDARDS
The official standards for swine developed by the U.S. Depart-
ment of Agriculture provide for segregation first according to
intended use--slaughter or feeder--then as to class, as determined
by sex condition, and then as to grade, which is determined by
the apparent relative excellence and desirability of the animal for
a particular use. Differentiation between slaughter and feeder swine
is based solely on their intended use rather than on specific identi-
fiable characteristics of the swine. Slaughter swine are those which
are intended for slaughter immediately or in the near future.
Feeder swine are those which are intended for slaughter after
a period of feeding.
i r ** H
There are five classes of slaughter andfeeder swine. Definitions
of the respective classes are as follows:
BARROW.--A barrow is a male swine castrated whenyoung and
before development of the secondary physical characteristics of
GILT.--A gilt is a young female swine that has not produced
young and has not reached an advanced stage of pregnancy.
SOW.--A sow is a mature female swine that usually shows
evidence of having reproduced or having reached anadvanced stage
BOAR.--A boar is an uncastrated male swine.
STAG.--A stag is a male swine castrated after development
or beginning of development of the secondary physical charac-
teristics of a boar. Typical stags are somewhat coarse and
lack balance--the head and shoulders are more fully developed
than the hindquarter parts, bones and joints are large, the skin is
thick and rough, and the hair is coarse.
The grade of a feeder pig is determined by evaluating two gen-
eral value-determining characteristics--its logical slaughter po-
tential and its thriftiness.
The logical slaughter potential of a thrifty feeder pig is its
expected slaughter grade at a market weight of 220 pounds after
a normal feeding period. In these feeder pig standards, logical
slaughter potential is determined by a composite appraisal of
the development of the muscular system and the skeletal system.
Both of these factors have an important effect on the development of
lean and fat as the animal grows and fattens, and therefore, on the
expected slaughter and carcass grade.
Thriftiness in a feeder pig is its apparent ability to gain weight
rapidly and efficiently. Size for age, health, and other general indi-
cations of thriftiness are considered in appraising the thriftiness of
The standards provide for five grades of feeder pigs-- U.S. No. 1,
U.S. No. 2, U.S. No. 3, Medium, and Cull--corresponding in name to
the five grades for slaughter swine and pork carcasses. The No. 1,
No. 2, and No. 3 grades include all pigs which are thrifty. Differ-
entiation between the No. 1, No. 2, and No. 3 grades is based
entirely on differences in logical slaughter potential. Feeder pigs
in the No. 1 grade have sufficient muscling and frame to reach
a market weight of 220 pounds with near the minimum degree of
finish required for the production of cuts with acceptable quality
characteristics. Feeder pigs in the No. 2 and No. 3 grades usually
have progressively less muscling and less frame and are expected
to have progressively more finish when marketed at 220 pounds.
The Medium and Cull grades include only pigs which lack thriftiness.
Differentiation between these grades is based entirely on differences
in degree of unthriftiness.
Most feeder pigs are marketed when relativelyyoung and before
reaching a weight of 125 pounds. At this age, sex condition exerts
little influence on the basic factors determining the feeder grade.
Therefore, these standards are equally applicable for grading
barrow, gilt, and boar pigs, although it is recognized that sex con-
dition may influence the market price in some instances. It is
assumed that boar pigs will be castrated prior to developing the
secondary physical characteristics of a boar. Sows, stags, and
mature boars are seldom used as feeder animals, and these
standards do not apply to those classes.
Only one combination of muscling and skeletal characteristics is
described in the standards for the No. 1, No. 2, and No. 3 grades.
However, it should be recognized that pigs with thicker muscling
and less frame or those with thinner muscling and greater frame
than described in each of these grades also may be eligible for
that grade. Since no attempt is made to describe the numerous
combinations of characteristics that may qualify a feeder pig for
a specific. grade, making appropriate compensations for varying
combinations of characteristics requires the use of sound judgment.
SPECIFICATIONS FOR OFFICIAL UNITED STATES STANDARDS
FOR GRADES OF FEEDER PIGS
U.S. NO. 1
Feeder pigs in this grade near the borderline of the U.S. No. 2
grade are slightly long in relation to width and have moderately
thick muscling throughout. Thickness of muscling is particularly
evident in moderately thick and full hams and shoulders. The back
usually appears slightly full and well-rounded. They usually
present a well-balanced, stylish appearance. Feeder pigs in
this grade are expected to produce U.S. No. 1 grade carcasses
when slaughtered at 220 pounds.
U.S. NO. 2
Feeder pigs in this grade near the borderline of the U.S. No. 3
grade are slightly short in relation to width and have only slightly
thick muscling throughout. The hams and shoulders are slightly
thick and full and the back usually appears moderately full and thick.
Feeder pigs in this grade are expected to produce U.S. No. 2 grade
carcasses when slaughtered at 220 pounds.
U.S. NO. 3
Feeder pigs typical of the No. 3 grade are short and have rather
thin muscling throughout. The hams are thin and rather flat,
particularly in the lower parts toward the shanks. The back usually
appears full and thick and the width at the topline usually is greater
than at the underline. Feeder pigs in this grade are expected to
produce U.S. No. 3 grade carcasses when slaughtered at 220 pounds.
Feeder pigs in this grade near the borderline of the Cull grade
usually are small for their age and appear unthrifty. They often
have a rough, unkempt appearance indicating the effects of disease
or poor care. The hams and shoulders usually are thin and flat -11--_
and taper toward the shanks. The back is thin and lacks fullness. ,-
Pigs in this grade near the borderline of the U.S. No. 1, U.S. No. 2, h)
and U.S. No. 3 grades are slightly small for their age and appear O~
slightly unthrifty. It is recognized that Medium grade feeder pigs 00-
will produce No. 1, No. 2, or No. 3 grade carcasses when slaugh- W9
tered at 220 pounds provided their unthrifty conditions corrected. Cw
Feeder pigs typical of this grade are very deficient in thriftiness _
and growthiness and often appear stunted or diseased. Hams and
shoulders usually are verythinandflatandtaper toward the shanks.
They are narrow over the top and the back is thin and often slopes
away from the center.
* GPO : 1966 O 208 054