This report provides information regarding the five U.S.D.A. yield grades

Gee, Dan H.

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South Dakota State UniversityOpen PRAIRIE: Open Public Research Access InstitutionalRepository and Information ExchangeSouth Dakota Sheep Field Day Proceedings andResearch Reports, 1979 Animal Science Reports1979Lamb Yield Grades - Symbols of ValueDan H. GeeSouth Dakota State UniversityFollow this and additional works at: http://openprairie.sdstate.edu/sd_sheepday_1979This Report is brought to you for free and open access by the Animal Science Reports at Open PRAIRIE: Open Public Research Access InstitutionalRepository and Information Exchange. It has been accepted for inclusion in South Dakota Sheep Field Day Proceedings and Research Reports, 1979 byan authorized administrator of Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange. For moreinformation, please contact michael.biondo@sdstate.edu.Recommended CitationGee, Dan H., "Lamb Yield Grades - Symbols of Value" (1979). South Dakota Sheep Field Day Proceedings and Research Reports, 1979.Paper 7.http://openprairie.sdstate.edu/sd_sheepday_1979/7LAMB YIELD GRADES - SYMBOLS OF VALUE Depart m e n t  of A n i mal  Sc i ence Experi m e n t  Stat i o n  D a n  H .  G e e  U S D A  y 2 G I R E A L D D E So u t h  Dakota State U n i vers i ty A.S.  Seri es 79-15 U . S . D . A . yield  grades  p rovide an add i t ional marke t ing tool for use by a l l  who b uy o r  sell l ive lamb s and lamb carca s se s . They are a means of iden t i fy ing one o f  the import ant value- d e t e rmining charac t e ri s t i c s --the p roport i on of the carcass that can be sold as t r immed re t ai l  cuts . U . S . D . A . y i e ld grades for  lamb have been avai lab le for indus t ry use s inc e March 1 ,  1 9 6 9 . They p rovide a na t i onal ly un i fo rm me thod of iden t i fy ing carca s s e s  for  di f ferences in "cutab i l i t y , "  spec i f ically the y i e l ds of closely t r imme d , boneles s ,  r e t ai l cut s from the le g ,  lo in , rack and shoulder . The f ive U . S . D . A .  y ie ld grades are numbered 1 through 5 .  Yie ld grade 1 carcas ses  have the h i ghe s t  y i e ld s  of re t a i l  cu t s ; yield  grade 5 ,  the lowe s t . When used in conj unc t ion with q ua l i t y  grades , y ie ld grades can bene f i t  a l l  s e gment s o f  the sheep indus t ry .  For the p roducer - They p rovide a means t o  iden t i fy lamb s f o r  d i f ferences in yields o f  s alab l e  meat . For the p acker - They can help evalua t e  more p re c i s e ly d i f f erences in value among t he animals  he  b uys and the mea t  he s e l l s . For the r e t a i l e r  - They p rovide  a means for  purchas ing lamb w i t h  as surance as t o  its  y i e ld o f  ret a i l  cut s .  For the consume r  - They p rovide  an ind i r e c t  means for  re f le c t i ng consumer preference s  for  lamb - - th i ck mus c li n g  and a minimum of  exce s s  f at . Var iat i ons in y i e l d s  o f  r e t a i l  cut s  among carca s s e s  are accounted  for  chi e f ly by two cons i d e ra t ions : ( 1 )  the  amount of  fat  that mus t  b e  t rimmed from the carcass in making re t ai l  cut s  and ( 2 )  t he t h i ckness  and ful lne s s  Prepared f o r  Sheep Day , June 8 ,  1 9 7 9 . 3 2  - 2 -o f  mus c l ing . Y i e ld grades  are d e t e rmined by using the f o l lowing three fact ors ( 1 )  amount of external fat , ( 2 )  amount of kidney and p e lv i c  f at and ( 3 )  confo rma t i on grade o f  the le g .  The amoun t  o f  ext erna l fat i s  the mos t  import ant yield grade f a c t o r  s ince i t  i s  a good ind i c a t o r  o f  t h e  amount o f  fat  tha t i s  t rimmed i n  making re t a i l  cuts . The amount o f  ext ernal fat  i s  evaluated in t e rms o f  i t s  thicknes s  over t he cent er o f  the r i b  eye mus c le b e tween t he 1 2 th and 1 3 th ribs . I f  a l l  o the r factors are equal , each . 1 5 -inch change in fat  thicknes s  over the r ib eye makes a ful l yield grade change . The f o l lowing cha r t  shows the relat ionship between fat  thi cknes s  and p rel iminary yield grade . Ext e rnal Fat Thi ckne s s  . 05 inch . 1 0 . 1 5 . 20 . 2 5 . 30 . 3 5 . 40 Yield Grade 2 . 3 3 2 . 66 3 . 00 3 . 3 3 3 . 6 6 4 . 00 4 . 3 3 4 . 66 Fat on the ins ide  o f  the carcass  around the kidneys and in the pelvic area i s  norma l ly le f t  in the carcass at t ime o f  s l aughte r . However , s ince mos t  o f  this fat  i s  removed in making re t a i l  cut s , inc reases in the s e  fats  decrease t h e  yield  o f  cut s . The amount o f  kidney and p e lvic fat  i s  evaluat ed subj e c t ive ly and expres sed as a percent age o f  the carcass  we i ght . An ave rage l amb has about 3 to 3 . 5 % o f  carcass we i gh t  in ki dney and pelvi c f a t . All  othe r  factors  be ing equal , a change o f  4%  o f  the carcass we i gh t  in ki dney and pelvi c fat  makes a ful l y ield grade change . U . S . D . A .  s tud i e s  have shown that among lamb s  o f  the same degree o f  f a tnes s those tha t have higher l e g  conformat ion grade s have h i gher yie lds of  re t a i l  cu t s . The l e g  conformat i on is subj e c t ively evaluat ed on the b a s i s  o f  the thickne s s  o f  mus c l ing in relat i on t o  length o f  t he le g .  An average lamb has a Choice  l e g  conformat ion . A change o f  one ful l l e g  s core grade only alt ers  t h e  y i e l d  grad e b y  . 1 5 .  Evaluat ing s laugh t e r  l amb s in t erms o f  the i r  y i e l d  grade i s  ve ry use ful in app rai s ing the i r  value . Thes e  grades p rovide a b a s i s  for  p r i c ing bo th s laugh t e r  l amb s and carca sses  in relat i on t o  the i r  y i e ld o f  s alab le me a t  t o  the consume r . Lamb s having a h i gh y ie ld o f  re t a i l  cuts  are thi ckly mus c le d  w i t h  very l i t t le fat . Those that are ve ry f a t  and thinly mus c led have a low y i e l d  o f  ret a i l  cu t s . S ince fatne s s  and mus c l ing have opp o s i t e  e f f ec t s  on yie lds of cuts , evaluat ing l ive animals for y i e l d  grade requires an ab i l i t y  to make s ep arat e , accurate  eval ua t ions o f  those  two fac t o rs . The following t ab le shows a va lue per  hundredwei gh t  comp ar i s on for  Cho i ce q ua l i t y  grade l ambs of  d i f f erent yield ,grades . 3 3  w � Compar ison o f  Yields o f  Re t a i l  Cu t s  and Ret ai l  Sale  Values o f  Cho i ce Lamb Carc asses  CHO I CE LAMB Y i e ld Grades P r i ce Re t a i l  Cut p e r  pound Leg , sho r t  cut 2 . 3 9 S irloin 3 . 1 9  Shor t  l o in 3 . 9 0 Rack 3 . 59 Sho ulder 2 . 1 6 Neck 1 . 34 Breas t Fores hank Flank Kidney Fat Bone Tot a l  1 . 1 8 1 .  7 7  1 .  5 9  1 . 1 7 . 1 2 . 0 3 1 % o f  car- Value / cass cwt . 2 3 . 6  56 . 40 6 . 7 2 1 . 3 7 1 0 . 4  40 . 5 6 8 . 1 29 . 08 24 . 9  53 . 7 8 2 . 2 2 . 9 5 9 . 8 3 . 5  2 . 3 0 . 5 4 . 6  3 . 4  1 1 .  5 6  6 . 2 0 3 . 6 6 . 5 9 . 5 5 . 1 0 1 00 . 0  2 2 6 . 80 2 % o f  car- Va lue / cass cwt . 2 2 . 2  5 3 . 06 6 . 4  2 0 . 4 2 1 0 . 1 3 9 . 3 9  7 . 9  2 8 . 3 6 2 3 . 8  5 1 . 4 1 2 . 1 2 . 8 1 9 . 8  3 . 4  2 . 3  0 . 5 8 . 2  3 . 3  1 1 . 56 6 . 02 3 . 6 6 . 5 9 . 9 8 . 09 1 00 . 0 2 1 8 . 3 5 3 % o f  car- Value / cass cwt . 20 . 8  49 . 7 1  6 . 1  1 9 . 4 6 9 . 8  38 . 2 2 7 . 7  2 7 . 64 2 2 . 7  49 . 03 2 . 0  2 . 68 9 . 8  3 . 3 2 . 3  0 . 5  1 1 .  8 3 . 2  1 1 .  5 6  5 . 84 3 . 66 . 59 1 . 4 2 . 0 9 1 00 . 0 209 . 9 0 4 % o f  car- Value / cas s cwt . 1 9 . 4  4 6 . 3 7 5 . 8  1 8 . 5 0 9 . 5 3 7 . 05 7 . 5  2 6 . 9 2 2 1 . 6  4 6 . 66 1 .  9 2 .  55  9 . 8  3 . 2 2 . 3  0 . 5  1 5 . 4  3 . 1 1 1 . 5 6 5 . 66 3 . 66 . 59 1 . 8 5 . 09 1 00 . 0  2 0 1 . 4 6 5 % o f  c ar- Value / cass cwt . 1 8 . 0  4 3 . 02 5 . 5  1 7 . 54 9 . 2 35 . 88 7 . 3  2 6 . 2 1 20 . 5  44 . 28 1 . 8 2 . 4 1  9 . 8  3 . 1 2 . 3  0 . 5  1 9 . 0  3 . 0  1 1 . 5 6 5 . 49 3 . 66 . 59 2 . 28 . 09 1 00 . 0  1 9 3 . 0 1  D i f f erences in r e t a i l  va lue be tween y i e ld grades - - 8 . 4 5 per cwt . o f  c arcas s . The compari s ons re f le c t  average y i e ld s  of r e t a i l  cut s  f rom lamb carcas ses  typical  of the midpoint of each of the U . S . D . A .  y i e ld grades and average pr ices  for U . S . D . A .  Cho i c e  lamb during Ap ri l ,  1 9 7 9 . From U . S . D . A . L ives tock , Mea t , Woo l  Marke t News , Weekly Summary and S t a t i s t i cs , Ap r i l  1 0 , 1 9 7 9 . w - 4 -In summary , t he cha r t  shows t ha t  for  a l l  o f  the re t a i l  cut s  f rom the leg to the foreshank , the ind ividual r e t a i l  cut as a pe rcen tage of carcass we i ght decreases as you go from yield grade 1 to 5 .  The char t  also  shows the increase in t r immable fat  as a percent o f  carcas s wei gh t  as you move from yield grade 1 to 5 .  The increase is from 4 . 6  to 1 9 . 0 % .  Lamb yield  grades are a bene f i t  t o  a l l  segmen t s  o f  our l ives t o ck indus t ry . Used in conj unc t ion with  q ua l i ty grades , yie l d  grades enab le se l lers  and buye rs to arrive a t  p r ices  commensurate  w i th value . Thi s  resu l t s  i n  great e r  marke t ing e f f ic iency and as surance t h a t  consumer p r e f erences  are re layed back through t he marke t ing channels t o  the p roducer . 35  

Lamb Yield Grades - Symbols of Value

https://openprairie.sdstate.edu/cgi/viewcontent.cgi?article=1006&amp;context=sd_sheepday_1979

Lamb Yield Grades - Symbols of Value

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