xt7qjq0ssh69 https://exploreuk.uky.edu/dips/xt7qjq0ssh69/data/mets.xml   Kentucky Agricultural Experiment Station.  journals kaes_circulars_004_614 English Lexington : The Service, 1913-1958. Contact the Special Collections Research Center for information regarding rights and use of this collection. Kentucky Agricultural Experiment Station Circular (Kentucky Agricultural Experiment Station) n. 614 text Circular (Kentucky Agricultural Experiment Station) n. 614  2014 true xt7qjq0ssh69 section xt7qjq0ssh69 PORK
  U CARCASS
EVALUATION
Circular 6I4
O _ “
ByW.Y.V¤rney
\ umvznsnv or Kmrucxv
COOPERATIVE EXTENSION SERVICE
AGRICULTURE AND HOME ECONOMICS

   \

 PORK CARCASS EVALUATION
By W. Y. VARNEY
As a pork producer you should know the merits of meat from
different grades and types of hogs to realize an effective program
in marketing the meaty, high-quality pork that consumers demand.
The marketing job is not finished when the packer buys hogs, but
rather when the consumer goes through the check-out lane at her
favorite market.
You don’t have to be an expert in all of the details of meat
evaluation. However, it is essential to have a working knowledge of
a few basic evaluation points.
_ Some factors to consider in arriving at the relative meatiness
‘ and quality of pork carcasses are discussed here. They are not
necessarily listed in the order of importance.
‘ C¤rc¤ss Yield or Dressing Percent
Carcass yield is an important consideration. Lot yields are more
accurately determined than single animal yields. In arriving at a
single animal yield, the live weight should be taken to the nearest
pound immediately before slaughter. This weight is divided into
\ the chilled carcass weight (packer style). Of course, excessive fill or
emptiness of the animal will alter the yield considerably. The
normal range is 68 to 72 percent.
C¤rc¤ss Length
Adequate length is necessary, but excessive length should not
be stressed at the expense of other meatiness factors. Always meet
the minimum certification requirement of 29 inches. Carcass length
is determined by measuring, to the nearest tenth of an inch, the
distance from the front of the first rib at the backbone to the bot-
tom of the aitch bone as the carcass hangs (Fig. 1 
Bcckfut Thickness
Baekfat thickness is a good indicator of meatiness and is easily
obtained. It is determined by averaging three measurements to the
nearest tenth of an inch: opposite the first rib, opposite the last
. rib, and opposite the last lumbar (straight) vertebrae (Fig. 1).
The maximum backfat thickness for U. S. No. 1 hogs of normal
market weight and for certification is 1.6 inches.
3

 ’ ,. N * ’ Bottom of ,
*~ i § Aitch Bone
Oppmaie ~ ~ tt? g O O
Lust Lumbor ·*·— _s °
Vertebrcue Mw
Je
 
Opposite   A "xg
. so-   V tt?
Lost Rub ‘~_éf_ will
1%;*%  
4 its ‘ X .
mi \
. ~ .·‘ri` *   V. ?l  
Opposite _.   if i A‘ Front Of _
First Rib ‘—""'     I First Rib
  O 'iai i. it
  g i, i I ,l .
  .I}·Vq V ` ~·,A___
i `黤a;i"5·'~t
  i  
Fig. '|.——Pork side showing length and backfat measurements.
4

 Hum Fat Thickness
Ham fat thickness is probably a better indicator of relative car-
cass meatiness than backfat thickness; however, it is often more
difticult or inconvenient to obtain. No definite maximum thickness
for a iven wei ht of carcass has been established- however, a
7
maximum of 1 inch for a 140- nound carcass 200 nounds live
l 1
weight) seems reasonable. This measurement is taken at the butt-
end of the ham, in line with the aitch bone, from the lean meat to
the outside of the skin (Fig. 2).
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Fig. 2.-Ham fat thickness measurement.
5

 Loin Eye Area
Loin eye area has long been considered one of the most im- .
portant meatiness factors. It is apparently not so highly correlated
with total carcass meatiness as once thought, but the loin remains
one of the most valuable cuts. In arriving at the loin eye area, cut
at a right angle to the run of the loin at the tenth rib before the
backfat is removed. (Fig.   A sheet of transparent tracing paper ·
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Yi  Ma,   if   `'`f
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Fig. 3.-Position of cut of loin for tracing.
G

 is then placed over the cut surface and the outline of the large
single muscle traced (Fig. 4). The area in square inches is deter-
mined by use of a compensating polar planimeter (Fig. 5). The
area in square inches may also be determined by placing a grid
directly over the cut surface of the loin and counting the squares
(Fig. 6) or by the “D0t” method (Fig. 7). Each square on the grid
' represents 0.1 square inch. Each dot represents 0.05 square inch.
This is probably not so accurate as thc planimeter but may be useful
4 in some cases.
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  .2 rr‘¤   · y   · ` ` A  
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Fig. 4.-—-Lcin eye tracing.
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 = \   *3
+x_`
"kah
Fig. S.·—-Compensating polar planimeter.
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Fig. 6.-—Loin eye being measured with grid.
S

 I I O O I I Q C O O O I I O I C O
• •   I-  °" .·__ W   _‘ • • • • •
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·   ···• ` - ‘’‘‘   at _       ·».;_    y
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Fig. 7.—Dot method of measuring loin eye.
Percent Lean and Primal Cuts
The four lean cuts (ham, loin, Boston-butt, and pienie—Fig. 8)
make up tw0—thirds to three—f0urths 0f the total value ef a pork
CZIYCZISS; l]CllC(i, tllé lfHpOI'tllIlCC of their p()I`CCDtElg(3 of live OI' CHI'-
eass weight is emphasized. Extremes for very poor (over—fat) hogs
and very meaty hogs are shown below along with those for the
primal cuts (the four previously mentioned plus the belly—Fig. 9):
Leap Cuts _ 7 Primal Cisits
Percent Percent Percent Percent
0t of 0f of
live carcass live carcass
wt. wt. wt. wt.
P00r (ever-fat) h0g 3l 44 4l 59
Very meaty hog 43 60 Sl 7l
9

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Fig. 8.——Four lean cuts.
Percent Hum and Loin
Thc hams and l0ins constitutc morc than 0ne—half 0f thc total
valuc of a pork carcass and arc currcntly bcing widely used as
thc solc mcatincss factor in carcass contcsts. For this purposc, thcy
lf)

 ` .. =‘*·    
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  .».V .. _ .~—· i  ¤¤%-? ¤~ >— 1 M ;  ‘ _vV- . ‘,.:<    {
  Q.]   = :~f_ · , Y { ja- Y, p. $14 , { q.`_
    . ·-» .<    P` P  it `· Q   pa ‘»—~    —·  
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e,"·~·L; _, .·’... · , . ··z~._r_   .· , 7 ·· V
Téiirlisc   r‘ l$· '    :"~_ _*· · . V *5* Z
bh!  A Z n., ·"{ ·:Y   _v l v  ~ v. { ·  ?rU     ww. · ,1
  ·,·. .· . ‘;_;_,¥r   rj    
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`i__·;i,c,};§‘},¢'{,   JAJ7 "     wr. I . n V V
Fig. 9.——Five primal cuts.
nrc trimmed into conventional wholesale cnts. weighed together,
and expressed as ex percentage ot live or carcass weight. Extremes
ot very poor and very good in this respect are shown here.
t-lam and Loin
Percent of 7 w#n wm Kr Pércgotrg
live wt. carcass wt.
Poor (over-fat) hog 22 32
Very meaty hog 32 44
Complete Cut-Out
It all possihle error is eliminated. complete cnt-out is probably
the most uecnrute wuy ot evaluating; u pork cureuss. llowever,
great chance for error exists heernise ol the many m;anipnlutions
und weights neeess:n·y in u complete cnt—ont. Precision in entting
and trimming is essential, and ull ents mnst he vvei5.(liei?$¤i§$i"i`SS.Z'dui.?
furtherance of the Acts at May 8 and June 30. 1914. mM__u_m