E. ZOBRISKY STATUS OF METHODOLOGY IN PORN CARCASS V A L U A T I O N

266 STATUS OF METHODOLOGY IN PORN CARCASS V A L U A T I O N S E ZOBRISKY The i n t e r e s t of t h e Reciprocal Meat Conference (WC) Associates i n pork carcass evaluation, i n i t s broad sense, dates back t o June, 1948, P r i o r t o t h i s time members of t h e Cooperative Meat Investigation group were keen on t h i s subject Gne ste f u r t h e r back, before t h e t u r n of t h e century men of t h e c a l i b e r of Armsbyzog, SanbornZOS, Waters206, SchweitzerBo7, e t c, were working i n closely r e l a t e d areas Many of the early investigators v i s i t e d and/or corresponded with European researchers; noted t h e v a l i d i t y of t h e i r e f f o r t s and s t a r t e d similar investigations i n t h i s country It was t h e i r foresight and i n t e r e s t that led t h e way i n t h i s Important endeavour of l i v e animal and carcass evaluation i n t h e U S That t h i s i n t e r e s t has continued i s v e r i f i e d by one or more reports covering various aspects of t h i s subject i n each of t h e M C Annual Proceedings I am sure a l l of us a r e g r a t e f u l t o our predecessors (present or absent) f o r t h e time and e f f o r t given in assembling a l l of t h i s information The purpose of t h i s report i s t o continue t h i s t r a d i t i o n by gathering under one cover many methodologies t h a t have been used t o evaluate "composition of value'' of pork carcasses Occasionally methods may be referred t o t h a t have not been tested with pork but may warrant c r i t i c a l validation toward t h i s end Live Hog A t t h i s time it i s appropriate t o look back f o r about 15 minutes t o review where we have been, presently a r e and possibly w i l l go i n t h e future i n the area of pork evaluation Accurate selection and ranking of t h e carcass from the v i s u a l appraisal, or scores of l i v e hogs i s of limited value 1 through 4,7,8,193, Experienced l i v e stock men ap arently can "adequately" place groups of hogs on an average value basis193,y98* It has been i l l u s t r a t e d t h a t experienced people can increase t h e i r accuracy i n placing l i v e hogs and carcasses through c r i t i c a l t r a i n i n g 193,198 Live hog tape measurements appear t o be guides t o shape, s i z e and weight but not necessarily lean-fat -bone ratiosl94 The r u l e r probe a s an a i d i n evaluating the carcass from t h e l i v e lean meter9 has not been hog has been generally a ~ c e p t e d 5, ~, 2 3, 1 9 ~The graced by t h i s wide acceptance The differences i n cost of equipment, s k i l l required and possibly degree of precision between these two methods accounts f o r t h e difference in general acceptance Biopsy techniqueslo through %ave been developed through which muscle, f a t, bone and organ t i s s u e samples can be obtained from t h e l i v e animal Quantitative a s well a s q u a l i t a t i v e values of these t i s s u e s can be studied Biopsy methodologies provide a means of evaluating t i s s u e changes, with t i m e, a s influenced by various treatments without s a c r i f i c i n g t h e animal

267 High frequency sound (HFS) 17 through 43,47352 techniques a r e being used i n Europe, t h e U S and elsewhere t o determine muscle and f a t (area, thickness and r a t i o respectively) of hogs, c a t t l e and sheep These measurements a r e associated with t h e lean-fat r a t i o Some investigators a r e a l s o studying t h e association of t h e thickness of individual backfat deposits t o other f a t deposits& A t the present time most of the HFS measurements a r e taken over t h e back of t h e animal However, several Our investigators have studied other sites on t h e l i v e anima145,46,*7 present HFS techniques a r e not applicable t o the c h i l l e d carcass The r a t e of sound penetration through d i f f e r e n t media has been checked by s e v e r a l workers48 through 51,53,54 HFS techniques have t h e advantage Of being non-destructive, painless, acceptably accurate and can provide a prof i l e of t h e lean and f a t t i s s u e of t h e l i v e animal, X-ray observations by d i r e c t Gcreening and photographs have been used t o evaluat t h e develo ent of bone and f a t i n the l i v e hog and i n One investigator reported t h a t f a t shadow other animals radiography and ultrasonic measurements produced nearly i d e n t i c a l r e s u l t s Proper positioning and r e s t r a i n i n g of t h e animal plus correction f o r nonp a r a l l e l X-ray beams appear t o be the chief drawbacks t o t h i s method other than t h e cost of equipment However, a small portable X-ray apparatus for measuring backfat thickness i s a ~ a i l a b l e l 2 ~ ' '' Various attempts hav been made t o measure t h e s p e c i f i c gravity of whole dead and l i v e animals throqh 59,189 with varied success Inv e s t i g a t o r s recently6' reported very encouraging r e s u l t s between the s p e c i f i c gravity of l i v e hogs and body f a t and water Residual a i r volumes were considered' Gas displacement appears t o be a method of determining body s p e c i f i c gravity without corrections f o r residual or trapped a i r Several workers61r62,63,64, 65,189,199 have reported investigations employing t h i s technique Major c r i t i c i s m s of t h i s technique are: t h a t it i s time consuming, tedious and r a t h e r d i f f i c u l t t o control the e f f e c t s of temperature and humidity i n t h e enclosed environment Quantity of urinary creatinine appears t o be a reasonable index muscle in humans66,67,121 ; though s t u d i e s with hogs of t h i s non-protein nitrogen substance have not been shown t o be associated consistently or It appears t h a t t h e physiological strongly with muscle mass68,69,70 s t r e s s e s imposed during urine collection unpredictably a l t e r s t h e quantity of creatinine and urine excreted70 Of The potassium i s o t o e, K40, has been reported t o be associated t 7 3, body water7* and with t o t a l body potassium71,7f uantity of yo, sheep hogs*o and pork muscularit i n humans 75 thou& samples81 {hrough 84 The consistency of r e s u l t s between workers studying t h e relationship of K40 t o indices of muscle mass leaves much t o be desired T h i s f a c t in itself should not be discouraging since t h e f a c i l i t i e s involved in these evaluations were elaborate, complex, d i f f e r e n t and, f o r t h e most p a r t, t h e i r c a p a b i l i t i e s were l i t t l e understood Furthermore, t h e conditions under which the various studies were conducted were not a l i k e The r e l a t i o n ship of t o t a l potassium t o potassium-40 has been shown t o be r e l a t i v e l y constant in naturee5 Many unresolved problems remain in t h i s area 79~8f~t~2?'8,

268 Although regarded a s confusing and possibly not completely resolved, t h e use of blood volume and components of blood a s indices of l e a n - f a t r a t i o has received much a t t e n t i o n i n humans86r87,88 and animals 89,90,92, Since muscle tissue contains more blood per u n i t than f a t t y t i s s u e it i s l o g i c a l t o assume t h a t t o t a l blood volume o r volume of some blood cons t i t u e n t, ie, red c e l l volume, is associated with muscularity, body Water, etc Some early workers8' endeavored t o determine blood volume d i r e c t l y by attempting t o c o l l e c t a l l of the blood in t h e body by washing out t h e vascular system and leaching t h e macerated t i s s u e Volume was then determined by a cornparison of a given constituent i n the d i l u t e d and normal blbod from a given animal Later, various dyesa7 such a s B r i l l i a n t V i t a l Red, V i t a l Red, Congo Red, Trypan Red, Evans Blue, etc, were employed by d i l u t i o n methodologies t o depict volume Most recently, isotope d i l u t i o n procedures have become fashionable f o r determining quantity of blood or a blood constituent89,90,92,97,98 Blood or blood constituent volume methods can be used as an index t o the lean-fat r a t i o of hogs92,g3 However, due t o the nature of t h e materials employed a s markers t o quantify t h e blood or component, these procedures probably w i l l be used t o evaluate breeding stock or young animals t h a t w i l l not be used f o r food unless t h e t r systems a r e acceptably cleansed of the d i l u t a n t, Other d i l u t i o n techniques including antipyreneg4 N-acetyl-4 amino a n t i remg4, 1131 labeled 4-ido-antipyrbeg5, tritium 94,96 and deuterium285 have been used a s in vivo blood d i l u t a n t s t o determine t o t a l body water, which i s a r e f l e c t i o n of lean-fat r a t i o The reduction i n body water content with t h e increased fattening of animals has been observed by several investigators Procedural d e t a i l s of these methodologies a r e described i n t h e literature95,99,100 Methods which involve t h e separation of t o t a l body water from e x t r a c e l l u l a r water have a l s o been r e p 0 r t e d ~ ~ ~, 1 0 2, 1 0 3T h i s difference, t o t a l body water minus e x t r a c e l l u l a r water, equals i n t r a c e l l u l a r water which presumably forms a constant percentage of the weight of the c e l l mass Allowing a f a c t o r f o r bone, body f a t would be t h e difference between t o t a l body water and c e l l weight plus e x t r a c e l l u l a r water The continued advances i n detection instrumentation and t r a c e r methods will no doubt usher these techniques t o a more important position f o r evaluating l i v e animals i n terms of t h e i r carcasses, - _ I Photogrammetry rocedures a s determinants of body area were f i r s t recorded in Germanyf04 and France1o5, The rapid post World War I1 advances i n photomapping techniques suggested non-top0 r a h i c stereophotogrammetry a s a valid means of determining body volume186 through 109, Armour and Companyuo adapted t h e technique a s a beef c u t a b i l i t y determinant -- In vivo tissue temperature differenceslg0, gas absorptionlgz and t h e use of anesthetics technics a s means of determining body composition have not been extensively investigated It i s generally agreedu4 t h a t t h e l i v e animal i s more d i f f i c u l t t o evaluate than the carcass, Y e t, an acceptable evaluation of t h e carcass

269 is no simple task, The complexity, importance and continued interest in this endeavour is brought to the foreground when we realize that the early researchers investigating this problem could have celebrated their centennial better than a decade ago125 though 129, The weight and visual appraisal of the carcass apparently is adequate for some packing house carcass-lot evaluations Backfat measurements combined with complete cut-out data or the weight of a given cut from randomly selected carcasses serves the purpose of other packers136 Subjective quallty appraisal and carcass weight supplemented by backfat thicbpess, loin-eye area and carcass length satisfy some specific needsu0 Complete carcass cutout combined with carcass measurements and quality appraisals better serve the objectives of those interested in differences and relationships between the hysical characteristics under study on a large number of carcasses~lrq2,~3 A barometer of the producer's interest in carcass evaluation is registered by the &creased frequency and size of carcass contests This development coupled with a need for rapid, acc table evaluation methods has brought forth several indices of carcass value B4 through 142 These methodologies usually include subjective qualitative appraisal as well as some carcass measurements, cut-out and often other value determinants, None of these evaluations are "free of sin" to quote our Tennessee associatela Nevertheless, methods of evaluating the carcass that inch e the procedures of the Recommended Procedures for Quality Carcass Contests 644 will allow some -- degree of standardization which will further facilitate more useful utilization of the data for cmparative purposes The more dedicated individuals or those not completely satisfied wlth these evaluation results try to peer deeper into this complex problem One of the most direct classical methods of determining the quantity of skin, bone209, fatty and muscular tissue components of the camplet carcass is by p sical separation This method has b en used b several f27,145 though gzearly and present day investigators f253 throud 158 when meticulously carried out the separation technique can unquestionably yield valuable Information in terns of the ratio or Ucrease of the separated entities Since the procedure is quite costly in terms of time and tedious labor, much effort has been directed toward the selection of sample portions of the carcass which are representative or associated with the various carcass componentsl@+6 though 1% The carcass and sample separation methods have the common basic weakness of not evaluating the ve im ortant but elusive term "quality" Pre~edingU~~~~8, concurrent to U!657,f28 and since 165 through 168 the innovation about a century ago of the separation techniques carc88s and live animal "evaluators" were chemically analyzing samples from animals and carcasses Proximate and more detailed chemical analyses of carcass samples possibly are not necessary in maw carcass evaluations Hmver, in the more detailed investigations concerning the effects of treatment or the relationship between elemental entities, chemical analyses are essential for accurate description and identification purposeslg5 Archimedes' principle, when applied to carcasses or cmponents thereof, has been shown to be a reasonable index of the lean-fat ratio or percentage of moisture, protein and ether extractable materials

270 (fat) 173 As i s often t h e case, sev a 1 researchers have not been a b l e t o refine t h i s procedure t o s a t i s f a c t i o ny742 175 Specific gravity l i t e r a t u r e d a t i from 1757 t o 1958 have previously been comprehensively surveyed176, Two very i n t e r e s t i n g (1956) publications 175,178 c r i t i c a l l y discuss t h e adequacy of t h i s technique f o r accurate determinations and comparative purposes 37 Sane carcass measurelnents which include length, depth, width, circumference, plumpness of t h e carcass and ham a r e of l i t t l e p r a c t i c a l significance a s indices of carcass lean-fat r a t i o and possibly have been overly emphasized by v i r t u e of t h e i r frequent reference i n the l i t e r a t u r e These variables do serve as descriptive measurements of carcass conformat i o n and size and should be expected t o be associated i n t h e same general way t o t h e lean-fat-bone ccmpositionl93, The mean of t h e conventional backfat measurements remains a s one of t h e most racticalmeasurements of t o t a l separable o r extractable carcass f a t148,14, However backf'at measurements usually account f o r approximately 50$ or lessd3 of the variation i n carcass trim f a t This i s possibly due t o hwnan inconsistencies in trimming and a l s o t o quantitative differences i n where t h e f a t is deposited B6 influenced by managerial practices, sex, e t c, These differences fat deposition may account for t h e d i f f i c u l t y in establishing a strong r e l a t i o n ship between backfat and inter-intra-muscular f a t s There i s also evidence which suggests t h a t t h e three t r a d i t i o n a l backfat measurements a r e possibly not a s strongly associated with t o t a l carcass trim f a t a s a r e f a t measurements obtained a t other sitesla0 Preliminary data analyses suggest t h a t t h e thickness of t h e various f a t deposits that comprise the t o t a l backfat thickness may lead t o a reasonable index of inter-muscular and t o t a l carcass trim f a t and possibly marbling These f a t t y tissue deposits a r e e a s i measured i n vivo or from cross-sectional cuts of the untrimmed loinsl8 "Fat" f i g u r a t i v e l y speaking is probably t h e most a l t e r a b l e and variable cons t i t u e n t of flesh P Area of t h e cut surface of a s p e c i f i c muscle or muscles determined by photometricl82, 183,184,200 planimeter or cross -sectional measurements have been one of t h e more widely used indices of muscularity There i s reason t o believe that it may no longer be necessary t o cut l o i n s and t r a c e t h e Longissimus d o r s i i n t h e established manner Reports indicate t h a t there may be l i t t l e choice, i n terms of usefulness, between t h e 10th r i b and l a s t r i b Longissimus d o r s i area185, ham lean area 155,186,187 and tif these r e s u l t s are f u r t h e r confirmed, we s i r l o i n end t o t a l lean ar- may eventually stop c u t t i n g loins t o obtain t h i s measurement Conversely, several reports suggest t h a t the u t i l i t y of t h e Longissimus d o r s i area has been over rated Possibly t h i s inference i s we11 founded f o r the specific usage intended Loin-eye area correlated with r a t i o s based on large weight differences do, in extreme cases, r e s u l t i n correlation coefficients which a r e negative or which do not differ from zero It Is d i f f i c u l t t o explain, on a functional b a s i s reasons why t h e 10th rib, last r i b or other area O f t h e Longissimus dorsi202 should be any more strongly r e l a t e d t o t o t a l carcass l e a n than other similar area measurements of t h e carcass muscles a s long a s the area i s taken i d e n t i c a l l y each timel97, This same thought applies t o areas of fatl85,186,187 and area r a t i o s of lean t o fat155 - In conclusion t h e needs f o r p r a c t i c a l validated methods of evaluating t h e l i v e hog in terms of i t s carcass a r e obvious from t h e

, producers ' packers', and etc, viewpoint Similarly, it i s necessary t o re -evaluate some aspects of carcass methodologies More conclusive basic knowledge concerning growth and development i s needed t o augment more prec i s e approaches t o evaluation and selection from the l i v e and carcass point of view The two methods suggested a t the 10th RMCBo8 appear t o be the a ccept ed va l i d at ion procedures namely phy s ica 1 separation and/or chemica1 analysis It appears t h a t too l i t t l e consideration has been given t o the ultimate usefulness "on the plate" of many of the selection c r i t e r i a,, And, f i n a l l y, friendly differences of opinion should be encouraged and exchanged Differences of opinion should stimulate, and t h i s needs t o be emphasized, validation of results 1 Ferrin, E F 1939 A factual b a s i s f o r changing swine types Am SOC h i m Prod Proc 125-128 2 Bogart, R, Weaver, L A and Comfort, J E 1940 Carcass studies including scores, measurements and yields Reg Swine B r Lab Res I t e m No 1 7 (unpbaished) 2a Bogart, R, Weaver, L A, Ccmfort, J E 194Oa The r e l a t i o n of items i n l i v e hog and carcass scores t o the t o t a l carcass score in swine Reg Swine B r, Lab Item No 19 (unpublished) 3 Phillips, R W, Hetzer, H 0 and Hiner, R L 1939 Relation of scores of swine t o carcass yields and certain carcass measurements Reg Swine Br Lab Res Item No 15 (unpublished) 4 Hankins, 0 G 1940 A study of carcass characteristics in r e l a t i o n t o type of hog Am SOC An3m Prod, Proc 284-289 5 Hazel, L, N and Kline, E A 1952, Mechanical measurement of fatness and carcass value on l i v e hogs J Animal Sci 11:313 6 Pearson, A M, Price, J F, Hoefer, J A, Bratzler, L J and Magee, W T 1957 A comparison of t h e l i v e probe and lean meter for predicting various carcass measurements of swine J Animal Sci 16: 481 7 Bratzler, L J and Margerum, E P 1953 The relationship between l i v e hog scores and carcass measurements J Animal Sci 12:856 8 Hetzer, H O, Hankins, 0 G, King, J X and Zeller, J H 1950 Relationship between certain body measurements and carcass characteristics i n swine J Animal Sci 9:37 9 Andrew, F N and Whaley, R M I 1954 A method for measurement of subcutaneous f a t and muscular t i s s u e s i n t h e l i v e hog Purdue Univ Lafayette, Indiana,

10 Ewbg, P V, Wright, L E and Burk, L e B 1918 Cooperative soft pork studies, IV Method of extracting f a t samples from l i v e hogs Bull, Tex Agric Sta NO 226:15-18 11 Erwing, E S, Dyer, I A, Meyer, T 0 and Scott, K* W, Uses of aspiration biopsy technique J Animal Sci 12 1956 15:428 Scott, E L and Block, H W 1931 A method f o r removing f a t samples from l i v e hogs J Agric Res 42:47-13 Scott, J M, 1920, Soft pork studies Fla Agric Sta, No 157:67 14 Merkel, R A, Sorensea, D K, Kowalczyk, T and Bray, R W 1954, A technique f o r securing t i s s u e s t o study intramuscular f a t deposition i n swine Cornell Vet 44:3 15 preliminary report Bull Wilson, G D, Batterson, W E, Soremen, D K, Kowalczyk, T and Bray, R W 1955 A biopsy technique and i t s use in studying changes in muscle during fattening J Animal Sci 14:338 16 Bray, R W 17 K e U y, E (Edited by) 1957 Ultrasound i n biology and medicine Waverly Press, &IC Baltimore 15 papers include 243 pages tion 1963 Biopsy and core techniques f o r estimating composiconference on Body Composition, N Y Academy of Sciences 18 Dumont, B L,, 1957 Norvelles methods pour l'estimation de l a qualite des carcasses sur les porc vivants Paper read t o the j o i n t FAO/EAAP Meeting on Pig Progeny Testing, Copenhagen, July 19 Temple, R S,, Stonaker, H H, Howry, D, Paskong, G and Eazaleus, M H 1956 Ultrasonic and conductivity methods f o r estimating f a t thickness i n l i v e c a t t l e Am SOC Animal Prod West Sec, Proc 7:477 20 Claus, A 1957 The measurement of natural interfaces i n the pig's body w i t h ultrasound Fleischwirtschaft, 9:552 21 Lauprecht, E, Scheper, J and Schrijder, J 1957 Measuring the backfat thickness of l i v e pigs with echo-ranging techniques Mitt dtsch Landw Ges 72:881 22 Kliesch, J, Neuhaus, U Silber, Em and Kostzewske, H 1957 Studies of t h e measurement of f a t thickness of l i v e animals with the help of ultrasound 2 Tierz Zucht Biol 70:29 23 Hazel, L, N and Kline, E A 1953 Accuracy of eight sites for probing l i v e pigs t o memure fatness and leanness J Animal SCi 12~894 24 Hiner, Rm L 1958, Dec issue Sound waves measure f a t and lean '%eats"

25 Campbell, D, Stonaker, H H, and Esplen, A L 1959 The use of ultrasonics t o estimate the size of t h e Longissimils d o r s i muscle i n sheep J Animal Sci 18:1483 26 East, E, Taylor, J, Miller, I T and Widdowson, R W 1959 Measurements of back f a t thickness on l i v e pigs by ultrasonics J B r i t i s h SOC Animal Prod 1:129 27 Gaarder, R, 0 1959 Comparison of two methods of estimatiry: back f a t thickness of live hogs Agr Marketing Service 318:l-37 28 Stonaker, H He Somascope, 29 Stouffer, J, R, Wallentine, M V, Wellington, G H and Diekmann, A * 1961 Development and application of ultrasonic methods f o r measuring f a t thickness and r i b area i n c a t t l e and hogs J AnW1 SCi 2O:759 30 Stouffer, J R 1959 Status of t h e application of ultrasonics i n meat animal evaluation Proc Rec Meat Conf, 12:161 31 Stouffer, J R and Wellington, G H 1960 Ultrasonics f o r evaluation of l i v e animal and carcass composition Proc Am Meat Inst Foundation Res Conf l3:81 32 Price, J F, Pearson, A, M and Emerson, J A 1960a Measurement of t h e cross-sectional area of t h e loin-eye muscle i n l i v e swine by ultrasonic reflections J, Animal Sci 19: 786 33 Price, J F,, Pearson, A M, Pfost, H B and Deans, R J, 1960b Application of ultrasonic r e f l e c t i o n techniques i n evaluating fatness and leanness in pigs J Animal Sci 19:381 34 1956 New way t o measure feeder c a t t l e f i n i s h, Successful Farmer, October Price,SomeJ Fobservations, Pfost, H Pearson, Mm and Hall, on t h e use of ultrasonics measurements f o r B, A C W determining fatness and leanness in l i v e animals 1 7 : 1S6 1958 J Animal Sci 35 Urban, W E and Hazel, L N 1960, Ultrasonic measurement of fatness i n swine during the growing fattening period J Animal Sci, 19: 1228 36 Alexander, M A 1961 A study of beef carcass composition Thesis Univ of Mo 37 Howry, D H and Bliss, E R 1952, Ultrasonic visualization of s o f t tissue structure of t h e body J Lab and Clinical Medicine 40: 579 38 Panier, C 1957, Ultrasonics in t h e determination of t h e s t a t e of fatness of hogs Revue de l ' a g r i c u l t u r e 10:482 M S

274, 39 40 41 42 Zobrisky, S E, Moody, Win G, Day, Wm and Naumann, H D 1960 The estimation of loin-eye area by high-frequency sound J Animal SCi 19: 1244 Zobrisky, S E, Moody, W G, Day, B IU and Naumann, H D 1961 High-frequency sound estimates of meatiness i n swine 3 Animal SCi 20:922 Zobrisky, S E, Moody, W G, Ross, C VI, Naumann, H D and Hedrick, H B 1961 Live animal and carcass indices of lamb composition J A m 1 Sei 20:922 Hedrick, H B, Meyer, W E, Alexander, M A, Zobrislry, S E, Naumann, B D 1962 Estimation of rib-eye area and f a t thickness of beef c a t t l e with ultrasonics J Animal Sci 21:362 43 Meyer, W E 1962 M S Thesis i n beef c a t t l e Univ of Mo 44 Moody, W M and Zobrisky, S E 45 m e r, R L 46 1963 Stouffer, J R A s t u d y of meatiness and quality (unpublished) Univ of Moo (personal communication) 1962 (personal communication) 47 Devis, J K,, and Long, R A 1962 Ultrasonic and other methods of estimating muscling i n beef c a t t l e J Animal S c i c 21:970 48 Goldman, D E and Hueter, T F 1956 Tabular data of the velocity and absorption of high frequency sound i n mamalian tissue J AcOUS SOC Of Am 28~35 49 50 51 Hutchison, T S 1960 Ultrasonic absorption in solid Sept 9, V 132, No 3428 Science, Ludwig, G D 1950 The velocity of sound through t i s s u e s and the acoustic impedence of tissues J ACOUS SOC Am 22:862 Ipm, J G, Luvener, R L, Chick, R J, and Miller, A E, 1943 A new method f o r t h e generation and use of focused ultrasound i n experimental biology J Gen Physiol 26:179 52 Shrewsbury, C, L, Gunkel, W and Widerman, D 1960 Results in determining fleshing i n livestock, Nat Prov Sept 24 53 W i l d, J J 1950 The use of ultrasonic pulses f o r t h e measurement of biological tissues and the detection of t i s s u e density changes 54 Surgery 27:183 Wild, J J and Neal, I) 1951 Use of high frequency ultrasonic waves f o r detecting change of texture in l i v i n g tissue Lancet 260(1) :655

55 56 57 58 59 60 275 Pace, N and Tathbun, E N 1945 Studies on body composition 111 The body water and chemically combined nitrogen i n r e l a t i o n t o f a t content J Biol Chem 158:685 Kraybill, H F, Bitter, H a L and Hankins, 0, G 1952 Body composit i o n of c a t t l e 11 Determination of f a t and water content from measurement of body specific gravity J Applm Physiolm 6:27, Kraybill, H F, Goode, E R, Robertson, R m S B and Sloane, H S 1953 In vivo measurements of body f a t and body water in swine, J Appl PhySiOl 6~27 Behnke, A R 1942, Physiologic studies pertaining t o deep sea divin6 and aviation, especially in r e l a t i o n t o t h e f a t content and composition of the body Harvey Lect 37:198 Behnke, A R, Feen, B, G and Welham, W C 1942 of healthy man J Am, Med Assn ll8:495 Specific gravity Liynch,composition G Pa and Wellington, H 1963 Predicting the whole body of l i v i n g hogs from specific gravity determinations G Conf on Body Composition t o Feb 2, 61 62 N Y Academy of Sciences Jan, 28 - Kohlrausch, W 1930 Methods of estimating the body composition in vivo Arbeit pbysiologie, 2:23 Ger Kohlrausch, W 1930 2:46 Ger The degree of fitness, Arbeit - pbysiologie 63 Liuzzo, Jm A *, Reineke, E P and Pearson, A M 1956 An a i r displacement method f o r determining specific gravity J Animal Sci 15:1270 64 Blaxter, K L, 1955 A note on the estimation of body composition of pigs (unpublished) Agric, Res Council No ARC 491/55, 65 S i r i, Wm E, 1956 The gross composition of the body Biol Med 4:239 66 Shaffer, P A 1908 Diminished muscular a c t i v i t y and protein metabolism Am J, Physiol 22:445 Advances 67 Miller Jr, A, T and Blyth, C S 1951 Estimation of lean body from basal oxygen consumption and creatinine excretion J Appl Physiol 5: 73 68 Saffle, L E, Orme, L E, Sutton, D D, Ullrey, D E and Pearson, A M 1958 A comparison of urinary and blood serum creatinine with l i v e probe a s measures of leanness J Animal Sci, 17:480 69 Mullins, A M 0 1957 (unpublished) Univ Of Mo

276 70 Swisher, Win L 1959 The relationship of urinary creatinine t o the lean mass of swine M S Thesis Univ of MO 71 Vinogradov, A P, 1957 Riokbimiya 22:14 72 73 74 75 The isotope K-40 and i t s r o l e in biology Anderson, E C 1959 Application of natural gamma a c t i v i t y measuremeats t o t h e meat industry Sci Lab, Univ of C a l i f, Los Alamos, N Mex Anderson, E C, and Langham, W H 1961 Estimation of t o t a l body f a t from potassium-40 content Sci 133:1917 No 3468 Woodward, K T, Trujillo, T T, Schuch, R, L and Anderson, E C 1956 Correlation of t o t a l body potassium with body water Nature 17:97 July 14 Sievert, R M and Hultquist, 3, 1957, Some Swedish investigations Of the radioactivity of the human body B r i t J Radiol suppl 7 1-12 76 Sievert, R M 1951 Measurements of gamma radiation from t h e human body Ark Fys 3:33? 77 Miller, C E and Marinelli, L D, 1956 temporary man Sci 124: 122 78 Miller, C E and Marinelli, L D, 1956 Progress Report: Measurement of t h e gamma ray a c t i v i t i e s from t h e hwan body Argonne Natl Lab, Lemont, XU, Doc ANL-5518 pp 52-56 79 Kirton, A H Pearson, A M, Nelson, R H,, Anderson, E C 1961 Use of naturally occurring potassium 40 t o determine t h e carcass composition of live sheep J, Animal Sci 20: 635 Zobrisky, S o E, Naumann, H D, Dyer, A J, Anderson, E C 1959 The relationship between pot&ssium isotope, I@ and meatiness of l i v e hogs J Animal Sci, 18:1480 80 81 82 Gamma ray a c t i v i t y of con- 83 84 Kulwich, R, Feinstein, L and Anderson, E C, 1958 Correlation o f potassium-40 concentration and f a t - f r e e lean content of hams SCi, 127~338, Golunbic, C, Hiner, R L, Seymaur, W R? and Kauffman, W R 1960, Relation of gama ray measurements t o the lean content of hams J Animal Sci, 9:1238, *, 1961 9 Relationship of gamma-ray emissions to t h e lean content of beef rounds, Food Tech 15:411 &ingle, D E and Kulwicb, R 1961 I@ g a m a give estimate of lean meat content Nucleonics 19: 74 No 2

277 85 Rodriguez, J and Mattingly, G E G 1960 Estimation of potassium i n s o i l s by determination of K-40 content, J Sci Food Agric pp* 717-721 86 Gregersen, M I 13:397: 4l2 87 Reeves, E B 1947 Methods of estimating plasma and t o t a l red c e l l volume, Nutrition Abstracts and Reviews 17:830 88 Erlanger, J 1921 Blood volume and i t s regulation Reviews 1:181 89 Doornenbal, H, Asdell, S A and Comar, C L 1962 Relationship between Cr51 determined t o t a l red c e l l volume and lean body mass in r a t s J Appl Physiol 17:737 90 91 1951 Blood volume, Annual Review of Physiology Physiol and Wellington, G H 1962 C h r o m i d l determined red ;ell volume a s an index of "Lean Body Mass" in pigs J Animal Sci 21:461 Judge, M Do, Stob, M, Kessler, W V and Christian, J E 1963 Lamb carcass and l i v e lamb evaluations by potassium-40 and carcass measurements J Animal Sci 22:418 92* Hansard, S L swine 93, 1956 Residual organ blood volume of c a t t l e, sheep and SOC Exp Biol Med 91:31 Hansard, S L 1963 (personal communication) 94 Reid, J T, Balch, C C a and Glascock, R F, 1958, The use of tritium, of antipyrine and of M-acetyl-4-amino-antipyrine i n t h e measurement of body water in living rabbits B r i t J Nuto l2:43* 95 Hansard, S L and Lyke, W A 1956, Measurement of t o t a l body water in sheep using 1131 labeled 4-iodo-antipyrine SOC Exp Biol Med 93:263 96 Langham, W I Eversol,, W J, Hayes, F N, and T r u j i l l o, T T 1956, Assay of tritium a c t i v i t y in body f l u i d s using a liquid s c i n t i l l a t i o n system J Lab Clin Med 47:819 97 Stahl, P R and Dale, H E 1957 Blood volume of dairy calves comparing C r 5 1 tagged red blood c e l l s and F1824 plasma d i l u t i o n methods J Dairy Sci 40:617a 98 Stahl, P R and Dale, H E 1958 Effect of constant environment, temperature and growth on blood volume of calves Federation Proc V 17, No 1, 990 Soberman, R, Brodie, B B, Levy, B, Bo, Axelrod, J, Hollander, V and Steele, J M 1949 The use of antipyrine i n the measurement of t o t a l body water i n man J Biol Chem 179:31

278 100, Hansard, S L 12:402 1953 Blood volume of farm animals J Animal Sci 101 McCance, R A, and Widdowson, E M 1951 A method of breaking down body weights of living persons i n t o terms of extracellular f l u i d, c e l l mass and f a t, and some applications of it t o p ~ s i o l o g yand medicine Proc Ray Soc B 138:lIS 102 Lavietes, P H, Bourdillon, J and Xlinghoffer, X A 1936 The volume of t h e extracellular f l u i d s of t h e body J Clin Invest 15:261 103 Bansard, S, L 1963 Radioisotopes procedures f o r estimating body composition i n animals N Y AcadenZy of science (in press) 104 Weidenfeld, S 1902 "Uber den Verbrennungstod" Arch, derm syph 61:33-56, 301-356 Ger 105 Roussey, B 1899 "Pelliplanemetrie, Essai de Determination de la Parte d' Erreur que Comparte c e t t e Nouvelle Methode" Comptes Rendus de l a Societe de Biologie, 51:653 c i t e d in Bogd E, 1935 The growth of the surface area of t h e human body, Minneapolis: U of Minn Press French 106 Geoghegan, B 1953, The determination of body measurements, surface area and body volume by photography, Amer J Phys Anthrop 11:97 W R 1957 Non-topographic photogranmetry a s a research technique, FIEP Bull 27:48; 1959, The v a l i d i t y of stereophotogrammetry i n volume determinations P O t O g r a m Eng 25:83* 1070 Pierson, 108 Pierson, W R 1961 Manophotogrammetric determination of body volume Ergonomics 4:213, No, 3 109 Pierson, W R 1962, The estimation of body surface area by monophotogrammetry h e r Jm Pbys Anthrop, 20:399 UO Armour and Company 1962 Photogranmetric system f o r evaluating l i v e c a t t l e Nat'l Provisioner, April 21, p 54 Henkels, P and Kliesch, J 1929 X-ray growth studies on the fore-part and thorax of young goats from b i r t h u n t i l one and a half years old 2 Tierz, Ziicht Biol 15:l Ger 111 monacher, C, 112 Kronacher, C and Hogreve, F 1936 Bvestigations on the causes of rump shape in different breeds of pigs from X-ray s t u d i e s 2 Zucht B 35:161 Ger 113 Schmidt, J and Hogreve, F 1939 Investigations on body conformat i o n in t h e pig with special reference t o t h e supporting framework I Method of investigation and investigations on t h e Edelschweb 2 Tierz Zucht Biol, U:1

279 114 115 Rees Evans, E T 1954 Investigations on t h e vertebral colwuz of t h e Welsh pig Proc B r i t SOC Animal Prod p 65 T u f f, P and Berge, S 1936 Inheritance of vertebral number and 2 Zucht Biol 35 :213e Ger body length i n pigs 116 Shaw, A M 1930 A method of determining t h e variation i n t h e v e r t e b r a l column of t h e l i v e pig, Sci Agric 10:690 117 Hogreve, F 1938 A new experimental method f o r determining f a t deposition and f a t production a t d i f f e r e n t stages of f a t t e n i n g I n l i v e pigs of various breeds 2 Zucht B 40:377 Ger Wussow,i n Wth eandpigweniger, J, H 1953 Determination of f a t deposition by means of X-ray measurements of backfat thickness 118 119 Tierzucht 7:221 Ger Fredeen, H T, Bowman, G H and Stothart, J G 1955 Appraisal of c e r t a i n methods f o r evaluation of ham quality Canad J Agric Sci 35:91 120 Kliesch, J and Bankwitz-Silber, E 1956 X-ray studies of the r e l a t i o n between body length, number and s i z e of vertebrae i n p i g l e t s of 7-10 days of age Zuchtuqskunde 26:208 121 Van Niekirk, B D H, Ried, J T, Bensadaun, A, and Paladines, 0 L 1963 Urinary creatinine as an index of body composition J Nutr 79:463, No 4 122 Urbana, I l l i n o i s, 1963 Atomic science f o r livestock selection National Hog Farmer, June, p 18, Whalley, Vet 123 J K Rec 1951 Use of X-rays f o r selection of breeding stock 63:628 Peterson, A W and Baird, F F 1952 A study of t h e dressed hog Prod Ser Livestock and Poultry Div Dept of Agric 0 Harva, 124 Canada Pub No 542 125 Leibig, C 1850 Cited by Leathes, J B and Raper, H S Monographs on Biochemistry, The Fats, p 105 126 Wolfberg 1876 Cited by Sherman, H C and Nutrition, 3rd Edit p 144 127 Lawes, J B and Gilbert, J E 1877 On t h e formation of f a t i n t h e animal boaj J of h a t, and Physiol 11:577 128 M u n k, I 1884 Zur Lehre van der Resorption, Bildug and Anlagerung de F e t t e im Tier korper Arch Path A n a t U Physiol Bd 95:407 Ger 129 Armsby, H P 1908 Feeding f o r meat production Bur An Ind B u l No 108 1925 1925 Chemistry of Food USDA

280 130 Certification Carcass Standards 131 Cummings, J N and Winters, L M 1951 A study of factors related t o carcass yields in swine Univ of Mim Agric E- Sta Tech B u l 195 132 North Central Reg Pub No 30 1952 Objective carcass grade standards for slaughter hogs Univ of Minn Agric Exp Sta B u l 414 133, Zobrisw, S E, Lesley, J F, Brady, D E, and Weaver, L A 1954 Pork carcass evaluation, Agric Exp Sta Univ of MO Res Bul 554 134 Judge, M D 1963 "Carcass scoring system developed a t Purdue" (personal communication) 135 Plager, C, 1962 Ham-loin index, Geo A Eormel and Co, Austin, Minn, Natl Pork Industry Conference Columbus, Ohio, dated 11-8-62 (personal communication 3-14-63) 136 Haase, W C 1963 Swift and Co (personal communication 4-ll-63) 137 Breidenstein, B C 1963 Univ of Ill '$concanic adjustment f o r percentages Ir (personal communication 5-10-63) 138 Kline, E A 1963 "Ham and l o i n calculation," (personal communication 4-9-63) Iowa State Univ 139 Cahill, V R and Bruner, W H 1962 "System of carcass evaluation," Ohio S t a t e Fair Nat'l Hog Farmer, 7:32, p 6, Dec 140 Gregory, K E and Dickerson, G E 1952 Influence of heterosis and plane of n u t r i t i o n on r a t e and economy of gains, digestion and carcass composition of pigs Univ of Mo Agr Exp Sta Res Bul 493 141 Zobrisky, S E, Brady, D E, Lasley, J F and Weaver, L A 1959 Significant relationships in pork carcass evaluation IV Loin equivalents as a c r i t e r i o n for l i v e hog value J Animal Sci 18:594 142 Zobrislzy, S E, b o d y, W e G a d,-n H D 1960 Ham equivalent as an index of carcass value J Animal Sci, 19:1244 143 Cole, J W 144 Reciprocal Meat Conference Recommended procedures f o r quality carcass contest Pub by National Live Stock and Meat Board, 36 So Wabash Ave Chicago 3, Ill Received May, 1963 1963 (personal coaxtunication 4-2-63)

281 145 Hammond, J 1921 On the relative growth and development of various breeds and crosses of sheep J Agr Sci ll:367 146 on sheep Oliver 1932 Grovth and the development of mutton q u a l i t i e s and Boyd London 147 Hirzel, R 1939 Factors asfecting quality i n mutton and beef with special reference to t h e proportion of muscle, fat and bone Onderstepoort J V e t Sci and An Ind 12:379, 148 McMeekan, C P 1940 Growth and development i n the pig with part i c u l a r reference to carcass quality J Agr Sci 30:276 149 Pdsson, H 1939 Meat q u a l i t i e s i n t h e sheep with special reference t o Scottish breeds and crosses J Agr Sci 29:544 EO Hankins, 0 G and E l l i s, N R 1934 Physical characteristics of hog carcasses a s measures of fatness J Agr Res 48:257 151 Aunan, W J and Winters, L M 1949 A s t u d y of the variations of muscle, f a t and bone of swine carcasses J Animal Sci 8:187 152 Loeffel, W, J, Derrick, I? W and Peters, M 1943 Weight of pigs as it a f f e c t s gains and carcass qualities Neb Agr Exp St8 B U l 351 153 Bowman, G H, IJhatley, J A and Weaver, L E 1962 Physical indices of leanness in swine J Animal Sci 21:955 154 Cook, C, F, Weckel, K G and Bray, R 11 1962 Physical and Chemical variation among three beef l i p i d e depots J Animal Sci 21:979 155 Zobrisky, S E, IJaUmann, 8 D, Lasley, J F, Brady, D E and Mullins, A 14 1958 Fhysical composition of swine during growth and fattening Univ of Mo &r Exp Sta Res E u l, 672 156 Sink, J D and Miller, R C 1962 J Animal Sei 21:985 Fat deposition in swine 157 Aunan, W J 1952 A method of measuring the proportion of f a t and lean tissue i n swine carcasses J Animal Sci 11:319 l58 Fourie, P D 1962 Growth and development of sheep dissection technique N Z J Agr Res 5:190 I A C&TCBSS 159 Joubert, D M 1954 On the post-natal growth md development of muscle i n r e l a t i o n to quality i n meat Proc BSAP pp 49-57 160 1956 A n analysis of f a c t o r s influencing postn a t a l growth and development of muscle fiber J Agr Sci 47:59

282 161 162 163 164 165 Butterfield, R M 1962 Prediction of muscle content of steer carcasses ITature 195, No 4837 Pearson, A M, Bratzler, L J and Magee, 17 T, 1958 Some simple cut indices f o r preaicting carcass traits of swine I Cut-out and l o i n lean area J Animal Sci 17:20 leanness ~, 1958 11 Supplementmy measures of J Animal Sci 17:27, Hoefer, J A, Price, J F, Magee, W T, and Deans, R J 1S6, The fat-lean r a t i o i n the rough loin as a t o o l i n evaluation of pork carcasses J Animal Sci 15:896 Callow, E H 1942 The nation's food, V Meat as food 3 The fat, protein and water contents of mat Chem and Ind Sept 12, p 381 166 Benne, E J, Van H a l l, N H and Pearson, A M fresh meat Journ AOAC Nov, p 937 167 Hogan, A G, Weaver, L A, 168 Lams, J B and Gilbert, J H 1959 Experimental inquiry i n t o t h e composition of animals fed and slaughtered as human food Phil Trans B 494:680 169 1956 h d y s i s of Edinger, A T and Trowbrldge, E A The r e l a t i o n of food consumed t o protein and energy retent i o n of food consumed t o protein and energy retention i n swine VQ Agr Exp Sta Res Bul No 73 1925, Brom, C J, Hillier, J C and Mhatley, J A 1951 Specific gravity as a measure of the f a t content of pork crncass J Animal Sci 10:97 170 Whiteman, J V, Vhatley, J A and Hellier, J C 1953 A f u r t h e r investigation of specific gravity as a measure of pork carcass value J Animal Scl 12:859 171 O m, L E, Pearson, A, M, Bratzler, L J and Magee, W T 1958 Specific gravity as an objective measure of marbling J Animal Sci 17:693 172 Price, J F, Pearson, A M snd Benne, E J 1957 Specific gravity and chemical composition of t h e untrimmed ham as r e l a t e d t o leanness of pork carcasses J AnimaL Sci 16:s 173 K r q b i l l, H F, Goode, E R, Robertson, R S B and Sloane, H S 1953 I n vivo measurement of body fat and body water i n swlne J Appl Physiol 6:27 -- 174 Osinska, Zofia 1963 (personal communication 5-6-63) Instytu Fizologii i zyrnenia Zwlerzat Pan, Bydgoscz Russian

283 175, Von d b e l n 1956 Human standard and maximr1 metabolic rate i n relat i o n to fatfree body mass Acta physiol, Scand 37 (supp 126) 176 Boyd, E 1933 The specific g r a d t y of t h e human body Biol 5:647 177 Cowgill, G R 1958 Red 19:l 178 Evaluating body composition, Human Rev Nutr Pitts, G C 1956 Body f a t accumulation i n the guinea pig Physiol, 185:41 Am J 179, Hankins, 0 G and Ellis, M R 1934 Physical c h a r a c t e r i s t i c s of hog carcasses as 8 aqeasure of fatness J Agr Res p 257-267 180 Hiner, R L 1963 (Personal communication 5-17-63) 181 Wody, Wrn, G and Zobrisky, S E 182 1963 Unpublished Univ, of No Deans, R J, Bratzler, L J and Price, D C 1959 The photometric measurement of carcass cross section& areas d i r e c t l y from projected Polaroid transparencies J Animal Sci 18:1485 183 Corbin, J E, Williamson, J 5 Geurin, H B and WilcIre, H L 1959 Photographic method of measuring loin eye mea J Animal Sci, 18rl485 184 Shrewsbury, C L and Ifideman, D 1961 A new photographic technique f o r determination of fat and lean areas i n meat carcass cuts J Animal Sci 20:274 185 Kline, E A and Hazel, L N, 1955 Loin area at tenth and l a s t r i b as r e l a t e d t o leanness of pork carcasses J Animal Sci 14:65 9 l86 187 Fredeen, H T, Bowman, G H, Stothart, J G, 1955 Appraisal of c e r t a i n methods for e v a h a t i o n of ham quality, C a n a d i a n J Agr Sci 35:91 1 S 5 Relationships between c e r t a i n measurements of' ham aud carcass quality C a n a d i a n J Agr Sci, 35:98 188 Nelson, E C, Dehority, B A, Teague, H S,, Sanger, V L, Punden, 'GI D 1960 Biochemical and physiological changes occurring wlth hypovitaminosis A i n pigs, J Animal Sci 19: 1278 189 Liuzzo, J A, Reineke, E P and Pearson, A, M 1958 Determinat i o n of specific gravity by air displacement J A n i m a l Sci 17:513

Adams, C H and Koch, R M 1959 Thermister thermometer f o r estimating fat thickness on l i v e beef c a t t l e J A n i m a 3 Sci 18:1469 190 TJarren, R B, Arthmd, V H, 191 Feinstein, L 1955 Body composition and sleep time induced through t h e use of anesthetics Froc Eighth Annual Reciprocal Meat Conf p 140 192 Kastelic, J 1953 Determination of body f a t by cyclopropane absorption Proc Sixth Annual Reciprocal Meat C o d p 105 * 193 Wiley, J R, Paarlberg, D, Jones, R C 1951 Objective carcass f a c t o r s r e l a t e d t o slaughter hog value, Pardue Univ Agr Exp Sta Bul 567 194 Iforris, W E and Zavoral, H G o 1950 Livestock weights from measurements Ext Folder 70 Agr Ext Ser, Univ of Minn 195 D a h l, O, 1958 The c h a r a c t e r i s t i c s of slaughter a n i m a l depot f a t s and t h e i r i n t e r r e l a t i o n s Acta Agric S c a d supp 3 196 DePape, J G and Ikatley, J A, 1956 Live hog probes at various sites, weights and ages as indicators o f carcass merit J Animal Sci 15: 1029 197 Kauffman, R G, Bray, R IJ, and Goll, D E 1959 The relationship of lumbar lean measurements t o pork carcass muscling J Anima3 SCi 18:1481 198 Harrington, G, Pearson, A $1 and Magee, I? T 1960 Subjective evaluation of c u t t i n g y i e l d s and l o i n eye area i n hogs and t h e i r carcasses J Anbd Sci 19:1220 199 Gnaedinger, R H, Pearson, A M and Reinelre, E P 1962 Estimat i o n of dens ty of live p i g s by air aisplacement and helium d i l u t i o n procedures J Animal Sci 21:981 200 Marcum, J B and Stouffer, J R 1961 Relationship of l o i n indices t o pork carcass meatlnessc J Animal- Sci 20:919 201 Shu Chien and GreGerson, 14 I 1962 Determination of body f l u i d volumes Physical Techniques i n Biologicd Research IV:1 202 PImcum, J B 1961 Fork loin indices as related t o lean cuts M S Thesis, Cornel1 Univ 203 Stouffer, J R 1963 Relationship of ultrasonic measurements and X-rays t o body composition Conf on Body Comp N Y Academy of Sci Jan 204 Armsby, H P 1908 Feeding f o r meat p r o b c t i o n, USDA Ind Bul No 108 Bur An

285 205 Sanborn, J W 206 Waters, H J 1909 The influence of n u t r i t i o n upon t h e animal form Proc 305h Annual Meeting Soc Prom &re Sei 1887 Feeding f o r flesh, Col of Agr Columbia, Mo 207 Schmitzer, P 18% An enquiry i n t o t h e composition of f l e s h of c a t t l e Col of Agr Columbia, fib 208 Pearson, A M 1957 Measures of muscling i n pork carcasses Tenth Annual Reciprocal Meat Conf p 139 209 Kropf, D H 1959 t i c s i n swine Proc The relationship of muscle and bone characterlsproc Twelfth Reciprocal Meat Conf p 139