The aecond method reviewed by Professor Wilford was that which i s recommended by t h e National Livestock and Meat Board.

Transcription

1 81 F I F T H AffNUAL RECIPROCAL MEATS h CONFERENCE - Uniform Slaughtering and Cutting Methods f o r Lamb: Last y e a r ' s conference r e p o r t by t h e Lamb Carcass Evaluation Committee pointed up t h e two most generally acceptable methods o f c u t t i n g lamb carcasses. The f i r s t method, a s presented i n Professor blilford's paper, concerned itself with t h e breakdown of t h e lamb carcass a s practiced a t t h e Beltsville, Md., Agricultural Research Center of t h e Bureau of Animal Industry, U.S.D.A. The aecond method reviewed by Professor Wilford was that which i s recommended by t h e National Livestock and Meat Board. The discussion which followed t h a t paper i s t h e b a s i s f o r t h e mater i a l which your committee is now about t o present. I - Pre-slaughter- A l l sheep t o be slaughtered f o r t h e purpose of c o l l e c t i n g carcass measurements and d a t a should be f a s t e d f o r a standard period of t h i r t y -six hours--the l a t t e r t e n hours of this period should have-the sheep r e s t r i c t e d from water as well as feed. A t l e a s t twelve hours p r i o r t o slaughter, the sheep should be shorn i n accordance with good shearing p r a c t i c e s and allowed t o rest, so that t h e carcass q u a l i t y and shrinkage due t o unnecessary excitement and handling may be avoided. Actual slaughter should be patterned a f t e r the usual comrnerical lamb slaughtering practices, where t h e head i s removed a t t h e a t l a s j o i n t, o r t h e union of t h e o c c i p i t a l bone and the f i r s t c e r v i c a l vertebra, t h e f o r e f e e t r e moved a t t h e "break joint" and hindfeet removed a t t h e pastern j o i n t. The shorn p e l t i s removed, and t h e contents of both t h e t h o r a s i c and abdominal c a v i t i e s removed v i t h t h e exception of t h e kidneys and kidney f a t a s w e l l as t h e l e a n portion of t h e s k i r t muscle and t h e hanging tender muscle. Weight of t h e shorn f l e e c e should be secured a s well as t h e weight O f t h e shorn sheep immediately p r i o r t o slaughter. Dressing percentage should be computed on t h e b a s i s of the shorn weight and hot carcass weight--not t h e l i v e weight of t h e unshorn sheep o r t h e c h i l l e d weight. Carcasses should be retained u n s p l i t and unshrouded i n a cooler having an average maximum temperature of 34?F for a period of f o r t y - e i g h t t o severity-twc hours. Weights of t h e unshrouded hot carcass should be obtained immediately following slaughter, and c h i l l e d carcass weight should be secured p r i o r t o c u t t i n g t h e carcass. A l l weights of t h e l i v e sheep and t h e carcasses should be obtained t o t h e one half pound.

2 82. For purposes of uniformity and a d a p t a b i l i t y t o r e t a i l sales of the products, t h e following method of carcass breakdown should always be followed when c u t t i n g 80 as t o obtain data from sheep carcasses. S t a r t i n g i n t h e c r o t c h and c u t t i n g out t o t h e flank so as t o pass through between t h e l e a n of the flank muscle and t h e f a t a t the upper forward edge of the leg, continue a s t r a i g h t l i n e cut t o the lower end of the t h i r t e e n t h r i b and continue forward across t h e r i b s t o i n t e r s e c t t h e humerus of t h e upper forearm a t t h e middle. The portion removed, which includes the forearm, b r e a s t and flank, may be separated a t t h e n a t u r a l separation between forearm and b r e a s t and a l s o by a c u t made perpendicular t o t h e already c u t surface and behind t h e c a r t i l a g e of the breast thus y i e l d i n g three separate pieces. - The corresponding c u t s may be made on the other s i d e of the sheep carcass in exactly t h e same manner. A c u t which is made perpendicular t o the l i n e of t h e back and touches t h e p o s t e r i o r edge of t h e f i f t h r i b end w i l l remove a four r i b shoulder and t h e neck. The neck may be removed by a c u t which is f l u s h w i t h t h e t o p of the shoulder. The two halves of the shoulder may be s p l i t with a saw down the m i d d l e of t h e backbone. A cut made perpendicular t o t h e l i n e of t h e back and touching t h e p o s t e r i o r edge of t h e twelfth r i b end w i l l remove a seven r i b rack which may a l s o be s p l i t along t h e center axis of the backbone. The loin i s best removed a t the a n t e r i o r edge of t h e p o s t e r i o r lumbar vertebrae i n a l i n e which c u t s a t right angles t o the t o p lfne of the carcass. This cut i s made p a r a l l e l t o that which separated t h e loin from the rack between t h e twelfth and t h i r t e e n t h r i b s. Again, t h e l o i n and l e g c u t s may be s p l i t on the m i d - a i s. Further breakdown of the carcass should include the remwal of t h e s a c r a l vertebrae (including such f a t and lean a s i s p r e s e n t ) rounding of the flank edge of the leg, trimming of a l l excess fat in t h e c r o t c h area, and removal of the lower l e g a t the hock Joint. Finally, t h e kidneys and kidney f a t should be trimmed from the loin. I A l l measurements secured e h a l l b e in the metric system, and a l l weights taken t o t h e second decimal. o r a t least t o the nearest t e n t h of a pound The outstanding changes in t h i s method as compared t o t h e methods put f o r t h i n U.S.D.A. Technical B u l l e t i n Ho. 944 and the second method as presented by Profeesor Wilford last year are as follows: 1. The sheep a r e shorn p r i o r to slaughtering and measuring as recommended by Professor Loeffel. This w i l l allow a more accurate determination of y i e l d s, and the wool value may be added t o the data when d i f ferences In animal values a r e determined. 2. A recommendation is herewith made concerning a standard f o r fasting, shearing, weighing and cooling.

3 3. The matter of starting the cut which is to remove the breast, shank, and flank at the crotch eliminates doubt concerning the quantity of tail on the flank. Removal of the shank at the midpoint of the humerus allows the use of the breast and shank as a rolled roast. 4. Separating shoulder and rack between fifth and sixth rib is a method which will allow a heavtep shoulder which more nearly fits the eastern trade practices as per Mr. Edtr@r's recommendation last year. 5. Cutting the rack from the loin perpendicular to the back and to touch the posterior edge of the twelfth rib gives a mcre definite point and angle of cutting than has here-to-fore been specified. 6. Removal of the leg of lamb so as to allow the last lumbar vertebrae to remain OD the leg will permit for greater uniformity of leg size and compensate or actually remove the possibility of variations in leg of lamb data due to varying ilium position. Should you members and participants in this conference so desire, I believe it is most appropriate for us to discuss these recommendations and adopt, reject, or modify them in order to standardize our methods of securing data from the slaughter and cutting of sheep carcasses.

4 U.S.D.A. Method of Cutting as Per Technical Bulletin No. 944 Closely Patterned after the National Livestock and Meat Board Method

5 85. A. MEASuREMEloTs AS INDICES OF THE AMOUNT OF MUSCLE (1) External Measurement6 Although these are essentially more indicative of skeletal. size than of muscle or fat development, several highly-significant correlations have been SKETCH A. -Carcass measurement oatained between various external measurements and the total weight of muscle t h e 0d-y 5~ the carcass. Since the carcasses had been telescoped for expprt, external measurement6 avsilable were G, F, and T.

6 86. MR. VANDER NOOT: Thank you very much. I believe, due t o t h e f a c t t h a t t h i s is t h e paper that we have f i l l e d i n and cut out on t h e b a s i s of l a s t y e a r ' s conference and have t r i e d t o give you a uniform method of c u t t i n g lamb carcasses, a t t h i s t i m e it would be appropriate t o have discussion on Professor Margerm's paper and then follow through with w h a t you think i s b e s t. Is t h e r e any discussion a t t h i s time? MR. A. M. PF,ARSC,N: I am not doing t h i s t o f i n d f a u l t with t h e paper t h a t has been presented, but I merely wish t o r a i s e t h e question o f t h e procedure. I believe t h e reason t h i s has been s e t up i s primarily t o avoid f i l l and t o make our standard conditions. On t h e other hand, I t h i n k Dr. Hall has had some experience with beef and I think he has c a r r i e d it over i n t o pork now, r a t h e r qukstioning some of our f a s t i n g procedures. He may wish t o comment on t h i s. DR. HAIL: A period between c u t t i n g o f f t h e wool and slaughter makes a very decided difference i n the keeping q u a l i t y of t h e meat that i s t o be obtained from t h e carcass, because of t h e l o s s o r t h e dissipation of t h e glycogen i n t h e t i s s u e s i n f a s t i n g ; p a r t i c u l a r l y if t h e animal i s hectorcized or excited o r shipped before slaughter t h e r e i s not enough carbohydrate l e f t in t h e t i s s u e t o generate enough l a c t i c acid i n t h e postmortem changes i n t h e carcass t o set t h e tissue up i n a f a i r l y s o l i d condition that you feel i s d e s i r a b l e and that again makes t h e t i s s u e subject t o spoilage more r e a d i l y and i n t h e case of curing prevents adequate penetration of t h e b r i n e i n t o t h e t i s s u e s. T h a t i s a s much as I know about it. MR. VANDER NOOT: what a r e you recommending? On t h e b a s i s of what you have j u s t t o l d US DR. HALL: Davey and t h e rest of us down t h e r e s t a r t e d some p r o j e c t s on pigs. We had varying periods of holdover on shipping, some e have had so f a r t h r e e experiments with feed and some without feed. W and one which was conducted i n t h e winter during t h e cold weather. It d i d not happen t o be a p a r t i c u l a r l y cold day e i t h e r, but it was d i f f e r e n t f'rom w h a t we a r e having now d e f i n i t e l y, and a t t h a t time t h e r e was a very r a d i c a l difference i n t h e amount o f glycogen present i n t h e livers of t h e animals, t h e generation of l a c t i c acid present i n t h e t i s s u e s and i n t h e a b i l i t y of t h e hams t o t a k e t h e b r i n e cure. The maximum period of recovery we allowed t h e r e was 16 hours f o r t h e pigs with feed, They had feed available a l l that time, up t o t h e t i m e they were slaughtered. I s n ' t t h a t r i g h t, Davey? MR. MACKINTOSH: Yes. DR. HALL: So t h a t is, of course, an extreme v a r i a t i o n from t h e usual p r a c t i c e. We wanted t o f i n d out how much difference it makes, and I am satisfied that a long period of slaughter, 36 hours, a s you recommend, is running p r e t t y c l o s e t o t h e danger point i n allowing t h e animal t o r e t a i n an adequate amount of carbohydrate. It i s generation of l a c t i c a c i d i n t h e t i s s u e which w i l l allow it t o come out a firm type of carcass which you want.

7 87. MR. BULL: Chairman, a s I remember, we came t o t h e conclusion that long f a s t i n g, p a r t i c u l a r l y under cold weather conditions is w h a t causes dark c u t t e r s due t o t h e absence of glycogen sugar. I am wondering i f t h a t might not e f f e c t tihe color of t h e lamb. MR. VANTIER HOOT: Professor Bull, our recommendations were probably given on t h e b a s i s of w h a t has been done more o r l e e s in the p a s t In our committee discussions nothing was s a i d about w h a t Dr. Hall has just brought t o our a t t e n t i o n. I am sure t h e committee w i l l take it under a d visement. Is t h e r e any other comment on Professor Margerum's paper? MR, BUTLER: Why not j u s t empty it after slaughter? You won't g e t any emptying of t h e omasum anyway. A t l e a s t our experience has been t h a t even after holding steers off feed for nine days t h e omasumwas just about a s fill as it was after t h e f i r s t day, and the content of the abomasum won't be very much. The only real v a r i a t i o n would be i n t h e rumen, I think, and it would be a simple proposition Just t o empty it. I feel that the point that Dr. Hall raised, on the basis of w h a t we checked with s t e e r s, i s an important point. While it i s t r u e that we a r e t r y i n g t o get uniform data on this, I think t h e r e w i l l be some v a r i a b i l i t y and I believe you w i l l l o s e more than you gain. MR. BULL: I might add also, Mr. Chairman, that i n some of our older work we cleaned out t h e contents of the digestive t r a c t and based t h e data on w h s t we c a l l e d t h e empty l i v e weight. I think some of t h e people a r e doing that with hogs a t t h e present t i m e. MR. VANDER NOOK: In our c o r n i t t e e we had a l i t t l e disagreement and we thought perhaps t h e b e s t way t o s e t t l e t h e argument once and f o r a l l was t o bring it up on t h e f l o o r for discussion. Kemp and Wgerum do not q u i t e agree on t h e t o t a l cutting. On the general plan, yes, but not on the f i n e r points, although I cannot present his ideas. MR. KEMP: The method that I suggest is a l i t t l e d i f f e r e n t from him. We s t i l l use t h e f i v e r i b shoulder, The l e g is removed a t the a n t e r i o r end of the p o s t e r i o r lumbar vertebrae. But t h e method of removing the b r e a s t and flank that I have suggested is a l i t t l e d i f f e r e n t, and from my own personal viewpoint I t h i n k it gives u8 Just a l i t t l e more uniform r i b rack and loin cut. I have a p i c t u r e here t h a t you probably can see a l i t t l e. Whereas his c u t goes t h r a i g h t across here, when I g e t down t o c u t t i n g thsd l o i n and rack, I t u r n t h e h a l f carcass these were s l i t before c u t t i n g s k i n s i d e down and I made measurements on the i n s i d e of the l o i n and r i b o r rack. A t the rear end I measured four inches from t h e s p l i t vertebrae down t o the flank that is on t h e inside it does not show on t h i s picture and t h e f r o n t end I measured 24 inches, which would be with the curve s t r a i g h t from t h e backbone down t o t h e s i x t h r i b. And that gave me w h a t I consider a f a i r l y uniform rack and l o i n c u t. The v a r i a b i l i t y w i l l be i n t h e b r e a s t and flank, b u t as that is a l e s s important cut than the l o i n o r rack, t h i s gives a l i t t l e more uniformly priced c u t, I j u s t wonder w h a t you think about that

8 88. MR. MARGERUM: Might I ask just where t h e cut comes out on the f r o n t end of t h e carcass there. In other words, t h e r e i s a d e f i n i t e s t e p down on t h e f i f t h r i b area. MR. KEMP: This i s j u s t above t h e elbow j o i n t, where the breast i s removed from t h e shoulder, whereas yours went up a l i t t l e higher, a t the middle of t h e humerus. Is t h a t r i g h t? MR. MARGERulvI: Yes, mine cut through. MR. KEMP: This gives a l i t t l e longer shoulder and a l i t t l e bigger b r e a s t o f flank than yours. MR. OLNER: It would be l e s s because he has half the shoulder. MR. KEMP: It i s deeper i n t h i s area, but not as deep i n t h e shoulder area. T h a t i s Just a suggestion and I should like t o hear what you have t o say about it. MR, VANDER NOW: Are t h e r e any comments? MR. JOHNSON: Do you think t h e idea of measuring t h e distance from t h e center of t h e backbone I s a good idea when you might have some v a r i a b i l i t y i n raize, e s p e c i a l l y if you go from t h e south down t o a western lamb MR. VAMDER NOW: WeU, a r e y o u r e f e r r i n g t o t h e measurements? MR. JOHNSON: Yes, f o w inches from t h e center r a t h e r t h a n j u s t making an anatomical separation. NR, VAKDER N m : measurement. I believe you w U 1 have t o use the anatomical MR. JOHNSON: He is suggesting a d e f i n i t e measurement two inches from t h e center o f the backbone r a t h e r than t h e anatomical. MR. KEMP: The lambs t h a t I used t h i s on were approximately t h e same s i z e, so it worked out a l l r i g h t. If you a r e going from 60 pound lambs t o o r 130 pound lambs t h e r e w i l l be more v a r i a t i o n. These v a r i e d somewhat i n weight but the body s t r u c t u r e s were s i m i l a r. So that is just a point of discussion and I should l i k e t o hear any more comenf on it that you have. MR. MARGERUM: To have it on a proportionate basis, r a t h e r than t o have an arbitrary 4 inches on the r e a r and Z'* inches i n front, would it not be better t o have it worked out i n proportions of some sort? MR. KEMP: It might be b e t t e r t o do that. s c r i p t i o n of just the way I d i d t h i s. I have here a de-