CATALOGED
P 3 I 1 "I/ AUG 29 955


1S. K-A.A.M. .. 171 Issued September 1952
Reprinted, with amendment, July 1955

OFFICIAL UNITED STATES STANDARDS FOR GRADES OF
PORK CARCASSES (BARROW AND GILT)

(Title 7, Ch. I, Pt. 53, Seogi so the Code of Federal Regulations)


United States Department of Agriculture
AGRICULTURAL MARKETING SERVICE

SERVICE AND REGULATORY ANNOUNCEMENTS NO. 171


The following is a reprint of the official United States standards for the
grades of barrow and gilt carcasses promulgated by the Secretary of Agriculture
under the Agricultural Marketing Act of 1946 (60 Stat. 1087; 7 U. S. C. 1621
et seq.) and other authority. The standards are reprinted as amended effective
July 5, 1955.
DEVELOPMENT OF THE STANDARDS
Tentative standards for grades of pork carcasses and fresh pork cuts were
issued by the United States Department of Agriculture in 1931. These tentative
standards were slightly revised in 1933 and published in Circular No. 288.
New standards for grades of barrow and gilt carcasses were proposed by the
United States Department of Agriculture in 1949. These standards represented
the first application of objective measurements as guides to grades for pork
carcasses. Slight revisions were made in the proposed standards prior to
promulgation, by the Secretary of Agriculture, as the official United States
standards for grades of barrow and gilt carcasses, effective September 12,
1952.
The official standards were amended in July, 1955, by changing the grade des-
ignations Choice No. 1, Choice No. 2, and Choice No. 3 to U. S. No. 1, U. S. No.
2, and U. S. No. 3, respectively. In addition, the back fat thickness require-
ments were reduced for each grade and the descriptive specifications were re-
worded slightly to reflect the reduced fat thickness requirements and to allow
more uniform interpretation of the standards.
BASES FOR PORK CARCASS STANDARDS
The standards for pork carcasses developed by the United States Department
of Agriculture provide for segregation according to (a) class, as determined by
the apparent sex condition of the animal at the time of slaughter, and (b)
grade, which reflects quality of pork and the relative proportion of lean cuts to
fat cuts in the carcass.
PORK CARCASS CLASSES
The five classes of pork carcasses, comparable to the same five classes of
slaughter hogs, are barrow, gilt, sow, stag, and boar carcasses.
APPLICATION OF STANDARDS FOR GRADES OF BARROW ANDjIDGILT
CARCASSES
Differences in barrow and gilt carcasses due to sex condition ar uninor, and the '
grade standards are equally applicable for grading both classes.
Barrow and gilt carcasses are graded primarily on the basis of (1) differ-
ences in yields of lean cuts and of fat cuts, and (2) differences in quality of cuts.


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These factors vary rather uniformly and consistently from one grade to a1 ltm.
The U. S. No. 1 grade combines an optimum ratio of lean to fat with quality
characteristics indicative of acceptable palatability. U. S. No. 2 and U. 8. No. $
grades have higher degrees of finish with resulting lower yields oftI a etAu a
higher yields of fat cuts than U. S. No. 1 grade. In addition, the cuts from
U. S. No. 2 and U. S. No. 8 grades have more internal fat remaning-after trim-
ming of external fat than do the cuts from U. S. No. 1 grade carcasses. Medium
gradb carcasses have a lower degree of finish and a resulting higher ratio ot leaa
to fat than U. S. No. 1, U. S. No. 2, and U. S. No. 3 grades; however, Medium
grade carcasses are underfinished and lack the quality characteristics associated
with acceptable palatability as evidenced by a lack of firmness and indications
of little or no marbling in the lean. Cull grade carcasses are dcidelly under-
finished and the pork is soft and watery with no visible marbling. Only carcasses
with the firmness appropriate to their degree of finish are included under the
standards described in this part. However, carcasses which are typically soft or
oily as a result of feeds producing soft or oily fat may be graded in accordance
with these standards provided they are specially identified as soft or oily along
with the grade.
Measurements of average back fat thickness in relation to carcass weight or
length are closely related to yields of cuts and the quality of the cuts. The fol-
lowing table of measurements provides an objective guide in determining the
barrow and gilt carcass grades. ,

Weight and Measurement Guides to Grades for Barrow and
Gilt Carcasses


Average back fat thickness (inches)' by grade
Carcass weight or carcass ___________________
length I
U. S. No. 1 U. 8. No. 2 U. S. No. 3 Medium Cull *

Under 120 pounds or under 27 1.2 to 1.5.... 1.5 to 1.8.... 1.8 or more.. 0.9 to 1.2.... Less than 0.9.
inches.
120 to 164 pounds or 27 to 29.9 1.3 to 1.6.... 1.6 to 1.9.... 1.9 or more.. 1.0 to 3.... Less than 1.0.
inches.
165 to 209 pounds or 30 to 32.9 1.4 to 1.7.... 1.7 to 2.0.... 2.0 or more.. 1.1 to 1.4.... Less tha* 1.1.
inches.
210 or more pounds or 33 or 1.5 to 1.8.... 1.8 to 2.1.... 2.1 or more.. 1.2 to 1.5.... LeAs than LiL
more Inches.

I Either carcass weight or length may be used with back fat thickness as a reliable guide to.ade. The
table shows the normal length range for given weights. In extreme cases where the use of length with back
fat thickness Indicates a different grade than by using weight, final grade is determined subjectively as
provided in the standards. Carcass weight is based on a chilled, packer style cars arcass atoeOgt
measured from the forward point of the aitch bone to the forward edge of the first rib.
Average of measurements made opposite the first and last ribs and last lumbar vertebra.

The standards for grades of barrow and gilt carcasses include carcass measure-
ments and descriptions of carcass characteristics which indicate the lean and
fat yields and imply the quality of meat typical of the minimum degree of finish
of each grade. Visual estimates of fat thickness normally alleviate the neces-
sity for measuring carcasses in the grading operation. In addition to the
measurement guides to grade differences, the standards also provide the bass
for consideration of other characteristics. While carcass measurements furnish
a reliable general guide to grade, the final grade of borderline carcasses may
vary from that indicated by measurements due to consideration of other charac-
teristics such as visual evidences of quality; meatiness; conformation of hams,
loins, bellies, and shoulders; and fat distribution. However, application of
tlhese/additional factors is limited to borderline carcasses, and in no case may
the ofl tradee be more than one-half of the width of a grade different than that
indicated carcass measurements. The standards describe carcasses typical of
each grade and no attempt is made to describe the nearly limitless number of
combinations bf characteristics that may qualify a carcass for a particular
grade.
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SPECIFICATIONS FOR OFFICIAL UNITED STATES STANDARDS FOR
GRADES OF BARROW AND GILT CARCASSES
S.* U. S. NO. 1
e Carcasses in this grade have near the minimum degree of finish required for
tae production of acceptable quality cuts. Meatiness based on yield of lean cuts
Iirelation to carcass weight is slightly high; yield of fat cuts is slightly low.
lbe ratio of total lean and fat to bone is slightly high. Carcasses possessing the
minimum finish for U. S. No. 1 grade are slightly wide and moderately long
I- relation to weight. The back and loins are moderately full and thick with
.i .l-rounded appearance. Hams are usually moderately thick, plump, and
oth iand are slightly full in the lower part toward the hocks. Bellies are
aqd lately long and smooth, slightly thick, and moderately uniform in thickness;
the belly pocket is slightly thick. Shoulders are slightly thick and full but
Muupily blend smoothly into the sides. The carcass is moderately well-balanced
a. P smooth with moderately uniform development of the various parts. There
sWo moderate quantities of interior fat in the region of the pelvis, a slightly
Salbun t fairly extensive layer of fat lining the inside surface of the ribs, and a
ghty small quantity of feathering. The flesh is firm. Both exterior and
L T ntsor fats are firm, white, and of excellent quality. Carcasses with fat
|lcbess typical of the thinner one-half of the U. S. No. 1 grade but with the
irmness, quantity and distribution of interior fats, and belly thickness typical
tthe Medium grade shall be graded Medium. Carcasses with fat thickness
S typical of the fatter one-half of the U. S. No. 1 grade but with the fat distribu-
lons, meatiness, and thickness and fullness of hams, loins, shoulders, and bellies
typical of the U. S. No. 2 grade shall be graded U. S. No. 2.
U. S. NO. 2
Carcasses in this grade have a higher degree of finish than the minimum
r required for the production of acceptable quality cuts. Meatiness based on yield
or lean cuts in relation to carcass weight is slightly low; yield of fat cuts is
f gJlIfiy high. The ratio of total lean and fat to bone is moderately high. Car-
.. eases with the minimum finish for U. S. No. 2 grade are moderately wide and
Slightly short in relation to weight. The back and loins are full and thick and
appear fuller near the edges than at the center. Hams are usually thick, plump,
a.d smooth and are moderately full in the lower part toward the hocks. Bellies
a e moderately thick, smooth, slightly short, and rather uniform in thickness;
the belly pocket is moderately thick. Shoulders are moderately thick and full
bit usually blend smoothly into the sides. The carcass is well-balanced and
smooth with rather uniform development of the various parts. There are slightly
large quantities of interior fat in the region of the pelvis, a slightly thick and
moderately extensive layer of fat lining the inside surface of the ribs, and
moderate feathering. The flesh is firm. Both exterior and interior fats are firm,
I white, and of excellent quality. Carcasses with fat thickness typical of the
S thinne one-half of the U. S. No. 2 grade but with the fat distribution, meatiness,
and thickness and fullness of hams, loins, shoulders, and bellies typical of the
UI, No. 1 grade shall be graded U. S. No. 1. Carcasses with fat thickness
typical of the fatter one-half of the U. S. No. 2 grade but with the fat distribution,
Imetiness, and thickness and fullness of hams, loins, shoulders, and bellies typical
aothe U. B. No. 3 grade shall be graded U. S. No. 3.
U. NO. 8
Carcasses in this grade have a decidedly higher degree of finish than the mini-
mum required for the production of acceptable quality cuts. Meatiness based on
yield of lean cuts in relation to carcass weight is low; yield of fat cuts is high.
The ratio of total lean and fat to bone is high. Carcasses with the minimum
finish for U. S. No. 3 are wide and short in relation to weight. The back and loins
are very full and thick and appear especially full near the edges. Hams are
usually thick, very plump, and smooth and are full in the lower part toward the
hocks. Bellies are short, thick, smooth, and uniform in thickness; the belly





DIVERSITY OF ORIDA


pocket is thick. Shoulders are thick and fult but usually blend ms.$t"ty, Wt
the sides. The carcass is well-balanced and smooth with uniform development
of the various parts. There are large quantities of Interior fat la the region
of the pelvis, a moderately thick and extensive layer of fat lining the inside
surface of the ribs, and slightly abundant feathering. The flesh is Irm. Both
exterior and interior fats are firm, white, and of excellent quality. 'Careasses
with nearly minimum fat thickness for the U. S. No. 8 grade but with the fit
distribution, meatiness, and thickness and fullness of hams, lot e, J holder, and
bellies typical of the U. S. No. 2 grade shall be graded U. S. No. .
MEDIUM
Carcasses in this grade have a lower degree of finish thia the minimum
required for the production of acceptable quality cuts.' YTeld of lean cuts t
relation to carcass weight is moderately high; yield of fat eteit moderately
low. The ratio of total lean and fat to bone is moderately low. usaes with
the minimum finish for Medium grade are rather narrow and I elation to
weight. The back and loins are rather thin and deficient In and slop6
away from the center toward the sides. Hams are usually 81 thiSt aind
lacking in plumpness and taper slightly toward the hocks. wa1Jre aimod-
erately thin, long, slightly wrinkled, and moderately uneven l lem; the
belly pocket is moderately thin. Shoulders tend to be thin ah t bit often
show prominence at the junction with the sides. The carcass tetisf Abe utevwa
and rough with slightly irregular development of the various jrt '!Fher ae
slightly small quantities of interior fat in the region of the peW~t ty hid
incomplete layer of fat lining the inside surface of the rfbs, aal a small
quantity of feathering. Both exterior and interior fats are :m. ltly ,bft,
white to creamy white, and of low quality. The flesh is moderatel'tf and hai
little evidence of marbling. Carcasses with the fat thickness typical of the
fatter one-half of the Medium grade but with the firmness, quantity and distri-
bution of interior fats, and belly thickness typical of the U. S. No Iwgra phall
be graded U. S. No. 1. Carcasses with the fat thickness, typical W~ (tf1tfl
one-half of the Medium grade but with the firmness, quantity and 4~p tiqq
of interior fats, and belly thickness typical of the Cull grade shall be ail 0
CULL
Carcasses in this grade have a considerably lower degree of flntsh thatl
minimum required for the production of acceptable quality cuts, anMd a GB-ta
are suitable only for processing. Yield of lean cuts in relative 1:b cansm
weight is high; yield of fat cuts is low. The ratio of total lean and' ft to 1boneis
low. Carcasses with the degree of finish typical of the Cull grab ie Bw*W
and long in relation to weight. The back and loins are thin aS di4Slye.I....
lacking in fullness and have a definite slope away from the scene ow
sides. Hams are usually thin, flat, and wrinkled, and show a de Ate taper
toward the hocks. Bellies are very long, thin, wrinkled, and Men ia hi4-
ness; the belly pocket is very thin. Shoulders are thin and1 Sattblt,hflte
prominent at the junction with the sides. The carcass is unp&:S i"m"A
with irregular development of the various parts. There are oalym:Ein t.4l0 Um
tities of interior fat in the region of the pelvis and little or nO f-eUft as.a d
the inside surface of the ribs or as feathering between the rilb. Lsth 4eatUr$
and interior fats are soft, creamy white to white, and of low OaldAR .Tkhe eash
is soft and watery and has no evidence of marbling. Ca-relsses ~AWtWi TsAte
maximum fat thickness for the Cull grade but with the firmness, quantity aqd
distribution of interior fats, and belly thickness typical of the Medium grade
shall be graded Medium.


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