FUR BE F FOR EVALUATION* CARCASS AND MEASURING GRADING. i n commercial coolers where it i s impractical t o obtain cold carcass weights,

Transcription

1 108, A RECOMMEMDED GRADING By able whether ly, t h e Beef cedures such data. BE F PROCEDUfiE FOR FUR CARCASS MEASURING AND EVALUATION* t h e creation and use of standard methods data i s made more comparit be from t h e same source o r widely d i f f e r e n t sources. ConsequentCarcass Evaluation Committee i s confident t h a t the adoption G f proas those which follow w i l l a f f e c t greater u t i l i t y of beef carcass A paper and demonstration on beef carcass measurements were presented a t t h e l a s t Reciprocal Meats Conference. The discussion period that followed t h e presentation indicated t h a t c e r t a i n considerations needed c l a r i f i c a t i o n. Consequently, the necessary changes have been made t o s a t i s f y t h i s need. The question of a standard cooler shrink was r a i s e d l a s t year. A standard shrink of two and onehalf per c e n t of t h e hot carcass weight i s suggested. Since a l a r g e majority of t h e carcass measurement i s necessarily done i n commercial coolers where it i s impractical t o obtain cold carcass weights, hot weights must be used t o determine t h e shrunk weight. Weights obtained a t t h e home laboratory may e a s i l y be converted, i f necessary t o t h e standard shrink. The committee r e a l i z e s t h a t t h e recommended shrink does not exactly correspond to a l l circumstances since t h e r e i s v a r i a t i o n from p l a n t t o p l a n t a t t r i b u t i b l e t o r e f r i g e r a t i o n and other influences. It i s f i r t h e r recognized that v a r i a t i o n i s encountered from carcass t o carcass depending on f a t covering, size, compactness, e t c. It i s expected, though, that f a c t o r s such as these will not introduce a s much heterogeneity i n t o r e s u l t s, i n t h e aggregate, a s f a i l u r e t o use t h e standard shrink. The measurements t h a t follow and t h e o u t l i n e which has been handed t o you i n mimeograph form a r e those recommended. The mimeographed o u t l i n e has been p a r t i c u l a r l y designed t o serve as a guide f o r workers j u s t i n i t i a t i n g investigat i o n s of t h i s nature. Equipment Needed (1) Flexible s t e e l tape should be s i x f e e t long, have a white background with black numerals and be c a l i b r a t e d i n millimeters. * Large outside measuring c a l i p e r s adequate. twenty o r twentyfour inch s i z e i s A preliminary and more d e t a i l e d discussion may be found i n the Report of Proceedings, Fourth Annual Reciprocal Meat Conference, pp 89 93, (1951..

2 109. used i n conjunction with t h e c a l i p e r s and t o make measurements on t r a c i n g s. (3) Rigid transparent r u l e Compensating polar planimeter for area of r i b eye. (5) Incidentals a platform or stepladder, protractor, shroud pins, PTM t r a c i n g paper, and an 8 x 11 inch piece of heavy wax i m pregnated cardboard. Unribbed Carcass S i d e (1) Length of body Measure from t h e a n t e r i o r edge o f t h e 1st thoracic v e r t e b r a t o t h e a n t e r i o r edge (lowest p o i n t ) of t h e a i t c h b o n e. Length of hind l e g Measure from t h e a n t e r i o r edge (lowest p o i n t ) of t h e a i t c h bone t o t h e highest point on t h e t a r s a l bones i n the hock j o i n t. This point i s indicated on t h e accompanying diagram of t h e hock a r e a. I round is measured perpendicular t o the l e n g t h o f t h e hind l e g measurement s i x t y percent of tke distance from t h e hock t o t h e a n t e r i o r edge o f t h e a i t c h 'Done. The procedure is t o e s t a b l i s h a s t r a i g h t l i n e with skewers o r shroud plns between t h e t w o points used when determining t h e length of hind l e g s. Place one skewer ( a ) exactly s i x t h percent of t h e distance from t h e hock j o i n t t o the a n t e r i o r edge of t h e a i t c h bone on t h e previously established

3 110. l i n e. From t h i s point place a skewer (b) on t h e a n t e r i o r side o f t h e round along a l i n e perpendiculsr t o t t i e previously established l i n e and another ( c ) i n t h e same manner on the p o s t e r i o r side of the round. T h b An 8 x U inch e s t a b l i s h e s t h e three necessary guides (a, b, and c ) piece of wax impregnated cardboard may be used when placing skewers (b) and ( c ) perpendicular t o t h e length of l e g. Measure t h e circumf'erence by placing a steel t a p e below these t h r e e mentioned skewers and taking a reading a f t e r making sure t h e tape i s t a u t and touching a l l t h r e e skewers.. (5) Depth of body Measure from t h e dorsal s i d e of t h e s p i n a l canal a t t h e 5 t h thoracic vertebra t o the v e n t r a l s i d e of t h e sternum (breast bone) with the tape being held p a r a l l e l t o t h e f l o o r. Length of loin Measure from t h e a n t e r i o r edge of t h e a i t c h bone (lowest point) t o t h e middle of t h e 12th thoracic vertebra. Measure from i n s i d e t h e carcass a t t h e f i r s t thoracic vertebra t o t h e outside of t h e shoulder with 20 t o 24 inch outside measuring c a l i p e r s, Hold t h e a x i s of t h e c a l i p e r s i n a median plane t o t h e carcass and p a r a l l e l t o t h e f l o o r. The sum o f t h e measurements of t h e r i g h t and l e f t side i s used. ( 6 ) Width of shoulder (7) Width of round Measure with t h e c a l i p e r s t h e highest point of the a i t c h b o n e t o t h e t h e axis of t h e calipers i n a median plane t o t h e f l o o r. The sum of t h e measurements i s used. from inside t h e carcass a t outside of t h e round. Hold t o t h e carcass and p a r a l l e l of t h e r i g h t and l e f t aides Ribbed Carcass Side The measurements from the ribbed carcass s i d e a r e designed t o chara c t e r i z e t h e eye muscle (longissimus d o r s i ) and t h e adjacent e x t e r n a l f a t of t h e 12th r i b. The measurements a r e customarily taken from a t r a c i n g of t h i s portion o f t h e carcass because it is d i f f i c u l t t o take t h e measurements d i r e c t l y from t h e r i b c u t. The t r a c i n g should be made on a transparent nonabsorbent paper which has a s u i t a b l e surface f o r writing. PTM173 t r a c i n g paper meets these s p e c i f i c a t i o n s. A s h a r p pointed l e a d p e n c i l should be used when making t h e t r a c i n g. The eye muscle and t h e e x t e r n a l f a t covering a r e traced a s i n dicated i n t h e accompanying diagram. (1) Area of eye muscle Follow t h e o u t l i n e of t h e eye muscle with a compensating polar planimeter. Length of eye muscle eye muscle (AB). (3) Width of eye muscle This is t h e distance along t h e long a x i s of t h e 9hree measurements a r e averaged f o r t h e width Of eye muscle. The f i r s t (CD) is made perpendicular t o t h e l i n e used i n determining t h e length of t h e eye muscle a t a point onehalf t h e length of the eye. The second (GH i s p a r a l l e l t o t h e first a t a point anefourth t h e length of the eye muscle from t h e v e n t r a l edge of t h e eye muscle. The t h i r d (EF) i s p a r a l l e l t o t h e f i r s t a t a point onef o u r t h t h e length of t h e eye muscle from t h e d o r s a l edge of t h e eye muscle.

4 Width of f a t Measure from t h e outside o f t h e f a t where the surface of t h e f a t i s perpendicular t o t h e t h r e e points on t h e outside of t h e eye muscle t h a t were uaed t g determine t h e width of eye measurement. The t h r e e measurements may be averaged o r used independently. L The carcass should be ribbed between t h e t w e l f t h and t h i r t e e n t h r i b with t h e k n i f e held perpendicular t o t h e carcass and following t h e contour of t h e t w e l f t h r i b. The shape and s i z e o f the ribeye may be g r e a t l y a l t e r e d by t h e manner i n which t h e carcass i s ribbed. Every e f f o r t should be made, t h e r e fore, t o insure standardized ribbing. Scoring Subjective A l l carcasses should be graded t o t h e nearest onethird f e d e r a l grade and scored on a U.S.D.A. Beef Carcass Grading Chart. The grade should be d e t e r mined by a committee of government graders with t h e scoring done by a t l e a s t one member of t h i s committee. In such cases where it i s necessary or desirable t o have someone other than a government grader fill out t h e grading c h a r t t h i s person should a l s o serve as a member of t h e greding committee. M R. MACKINTOSH: Are there any recommendations f o r changes? I might say here that two o r t h r e e persons have mentioned t o me during t h e p a s t year o r c i t e d t h e measurements and some of the routine analyses recommended by t h e North Central C a t t l e Breeding group. I do not know whether t o l i k e that or n o t. There a r e a t l e a s t f i v e men i n t h i s room

5 112. here who were present when t h a t vas prepared. I do not know whether we should r e f e r t o those o r not because, a f t e r all, t h a t was condensed from o t h e r sources and put together t h e r e. I s t i l l think it i s a good source o f information because they hare it i n mimeographed form. Are t h e r e any suggestions? MR. MARGEHUM: In taking t h e measurement or t h e circumference of t h e round, I think it is r a t h e r d i f f i c u l t t o g e t t h e tape uniformly t a u t. I was wondering i f it would not be possible and advisable t o have a guide point on t h e outside of your round as well as t h e three points already indicated. MR, MACKINTOSH: We have done t h a t somewhat with ours. This p a s t week i n Kansas C i t y we did t h a t. We used a l i t t l e longer r u l e and t h e t h r e e scores were a l i t t l e f a r t h e r apart. It was kind of hard t o measure, but i n my opinion if you can do it, it i s desirable. Are t h e r e any other coments? A l l r i g h t, t h e committee i s asking f o r your approval of t h i s o u t l i n e of stzndard procedure f o r meameasuring beef carcasses. MR. KEMP: I move that it be approved. (The motion was seconded.) MR. MACKINTOSH: It i s moved and seconded t h a t t h i s be approved and added t o aur standard procedure. A l l those i n favor s i g n i f y by saying "aye" : opposed. (Carried) Our next paper is by Dr. Clifton, of Iowa S t a t e College. He i s going t o give us an i l l u s t r a t i o n o f what can be done with t h i s l a s t to01 that we have been discussing, carcass measurements. I think I can say a t t h i s time t h a t we hope you w i l l shoot it f u l l of holes or endorse it t o some degree. It i s t h e f i r s t material prepared f o r publication. I think it i s ready f o r publication, is it, Mr. C l i f t o n using measurements as and Nr. a means of acquiring information r e l a t e d t o Grades of beef C l i f t o n has consented t o t e l l u s about t h e work he has done during t h e p a s t two o r three years. It i s a s m p l e of what is being done a t two o r t h e e other i n s t i t u t i o n s, but t h i s is prepared. 1 am very happy t o introduce Dr. C l i f t o n t o t h i s group a t this time and I am glad t h a t he consented t o come down here.