W. G. MJODY University of Kentucky

Transcription

1 QUANTITATIVE AND QUALITATIVE DIFFERENCES I N BEEF FROM VARIOUS ENERGY REGIMES* W G MJODY University of Kentucky Much a t t e n t i o n over t h e years has been given t o t h e s u b j e c t of devising t h e "best" system o r systems f o r feeding slaughter c a t t l e T r a d i t i o n a l l y, i n t h i s country, corn and other expensive grains have been used t o supply t h e needed energy f o r f i n i s h i n g c a t t l e t o t h e more d e s i r a b l e slaughter grades In m n y countries, and p a r t i c u l a r l y i n t h i s country during t h e last f e w years, increased a t t e n t i o n has been given t o feeding more roughage and l e s s g r a i n t o c a t t l e during t h e growing and e a r l y part of the f i n i s h i n g period The t o p i c of feeding beef c a t t l e on various energy regimes is a s u b j e c t t h a t is not e s p e c i a l l y new s i n c e it only takes a b r i e f scan of t h e l i t e r a t u r e t o see t h a t much of the work on forage and forage grain conibinations of feeding c a t t l e was i n i t i a t e d t h i r t y t o f o r t y years ago 1940; (Wilson, 1931; Trowbridge e t al, 1934; Bull, 1941; Black e t a-*,1 Foster and Miller, 1933; Barbelle e t al, 1941, 1942; Bray, 1938; Culbertson and Hamond, 1935) In f a c t, some of you in t h i s room were involved in portions of t h i s e a r l i e r work (Pearson, 1976) -- - Because of the vastness of t h e s u b j e c t matter on energy regimes i n beef c a t t l e feeding programs, it i s not my i n t e n t i o n t o present a comprehensive review of t h e literature I hope t o h i g h l i g h t some of the recent work that more s p e c i f i c a l l y relates t o t h e q u a n t i t a t i v e and q u a l i t a t i v e d i f f e r e n c e s in beef comparing forage fed, p a r t i a l g r a i n fed and f u l l g r a i n f e d c a t t l e Those of us who attended t h e 1975 R E heard D r D G Fox present a very i n t e r e s t i n g and provocative paper dealing with feeding systems as r e l a t e d t o t h e energy and economic e f f i c i e n c y of e d i b l e beef This paper, along with two very timely 1975 up-date t o p i c s presented by Drs F B Shorland and T D Bidner f u r n i s h t h e background information f o r my paper I'm sure many of you 'are a l s o aware that within t h e p a s t two years t h e s u b j e c t of grass o r forage feeding of c a t t l e has been and s t i l l i s a very important s u b j e c t within beef c a t t l e c i r c l e s I'm personally awaxe of a t l e a s t t h r e e partial reviews on t h i s general s u b j e c t within t h i s time period (Kelly, 1975; Cross, 1975; Carpenter, 1975) and t o show you that h i s t o r y has a way of repeating i t s e l f, W L Brown a t t h e 1954 R E presented a s h o r t paper e n t i t l e d "Beef Carcass C h a r a c t e r i s t i c s as Also, L D Mslphrus a t t h e Influenced by Grass and Other Roughages 1961MlRC presented a paper on "Consumer Preference f o r Beef Fattened on Grass and Grain" " * Presented a t the 29th Annual Reciprocal Meat Conference of t h e American Meat Science Association, 1976

2 In all due respect to this year's committee on Growth and Development, it does seem appropriate that results of current work be summarized under one title and put in perspective for future reference Much of what I present in this paper covers portions of research complelted at several of the Experiment Stations around the country I'm indebted to many of you for furnishing me with your data to use in this presentation, therefore, appropriate acknowledgements have been made throughout the paper I would hasten to add that this report could best be described as a progress report since much of the research in this area has not been completed and is, therefore, not available for publication Also, some very important work along these lines is just getting underway For example, a five year Southern Regional project proposal which has incorporated in it a good blend of basic and applied approaches to a nmiber of problem areas has been written and is awaiting approval by the Committee of Nine It, therefore, seems reasonable to assume that upon completion of this research we should be in a much better position to answer the many questions being asked relative to shelf life, color stability, tenderness and consumer acceptance of grass or forage-grain fed beef In presenting this pper I realize that some of you may view this research as lacking relevance since as mentioned earlier, a lot of work on altering energy regimes in beef programs was done several decades ago It seems to me that even though we have returned to some of the same concepts in feeding cattle we are doing so under an entirely different set of circumstances For example, today more than ever before we are being forced to develop alternative systems for feeding cattle that conserve expensive grains that covld be used more efficiently to feed the hmn population Secondly, the public's outcry against fat for health and/or esthetic reasons has far reaching implications which demands immediate attention by researchers if beef is to maintain the prestige and image it has enjoyed over the years Iast, but certainly not least, the meat industry has at its fingertips the technology and knowledge today to transform the so-called "less desirable'' carcasses and cuts into desirable and usable products This can either be accanplished through complete transformation such as flaked and formed or mechanically deboned products or by altering the carcass to bring about an improved tenderness Certainly this latter aspect has proved an incentive for more experimentation with anirnal types and feeding programs as well as providing more flexibility in the total program from point of production to point of consumption Energy Regimes Quantitative Aspects Brown, in his 1954 R E report stated that packers discriminate against cattle which have had access to pasture as a part of their fattening ration He went on to say that this discrimination was due to the lower dressing percentages, higher cooler shrink and lower quality of pasture fed cattle

3 Although t h i s r e p o r t was published more than two decades ago, I ' m s u r e if you would ask many of our packers today t h e same question, they would respond very s i m i l a r l y One should be cautious about condemning grass-fed c a t t l e before a l l t h e f a c t s are considered It should be remembered t h a t even though some of t h e above c r i t i c i s m s of pasturefed beef may be j u s t i f i e d t h e s e c r i t i c i s m s f o r t h e most p a r t represent t h e packers i n t e r e s t and may or may not represent t h e views of t h e e n t i r e industry Lofgreen (1968)published data where t h e body composition of c a t t l e was studied following a constant feeding period on varying planes of n u t r i t i o n in both feeder calves and yearling steers In t h i s study it was shown t h a t increasing l e v e l s of concentrates r e s u l t e d i n carcasses having Larger amounts of body and subcutaneous f a t ( t a b l e 1) The v a r i a t i o n in carcass weight was due t o t h e d i f f e r e n c e i n r a t e of gain with increased l e v e l s of concentrate i n t h e r a t i o n Table 1 Influence of Plane of Nutrition on Carcass Composition Treatment Final wt lb LLL LLK LMH HML HHL HHH ' Carcass c h a r a c t e r i s t i c s ( y e a r l i n g s ) Carcass Fat Marbling Yield wt cover score *3 = modest; 7 = moderate; Lorgreen, 1968 lb in *go F ina 1 body f a t * *3 7* o = s l i g h t l y abundant LLL = Low energy r a t i o n (2076 concentrate) f o r 273 days LLH = Low energy f o r 182 days and high energy (9@ concentrate) f o r 91 days LMH = Low energy f o r 91 days, medium energy (55$ concentrate) f o r 91 days and high energy f o r 91 days HML = High energy f o r 91 days, medium energy f o r 91 days and law energy f o r 91 days HHL = H i g h energy f o r 182 days and low energy 91 days HHH = High energy f o r 273 days

4 Preston (1971), i n a l a t e r r e p o r t, concluded that w i t h i n t h e p r a c t i c a l realm of r a t i o n s, plane of n u t r i t i o n does not a f f e c t t h e gross composition of c a t t l e carcasses He f u r t h e r s t a t e d that v a r i a t i o n i n c a t t l e carcass composition m y b e s t be achieved by varying slaughter and nature weight r a t h e r than by varying planes of n u t r i t i o n He q u a l i f i e d t h i s statement by adding t h a t he did not mean from t h i s t h a t t h e r e were no h i s t o l o g i c a l changes or changes i n t h e d i s t r i b u t i o n of f a t o r proteins i n animals fed d i f f e r e n t r a t i o n s In f a c t, a r a t i o n causing a negative energy balance could permanently a f f e c t carcass et a -l (1976) i n some composition according t o Preston Broadbent recent work i n Scotland, suggest using a conventional all-concentrate d i e t f o r Ayrshire c a s t r a t e s only during t h e growth phase up t o 250 kg l i v e weight Thereafter a d i e t of lower energy concentrate using cheaper feed sources, which do not r e q u i r e processing, can be s u b s t i t u t e d and t h i s w i l l allow t h e animls t o be taken t o slaughter a t higher l i v e weights without a f f e c t i n g carcass composition -- Beeson e t a l (1967) reported that c a t t l e slaughtered a f t e r l 9 l days on good pasture saved about 500 pounds of TDN per s t e e r compred t o d r y l o t fed c a t t l e These workers a l s o concluded that f u l l feeding of grain t o c a t t l e on good permanent or i r r i g a t e d pasture produced c a t t l e that were canparable t o c a t t l e f i n i s h e d in d r y l o t on a high concentrate r a t i o n Research a t t h e University of Tennessee (Duncan, 1958) demonstrated that unsupplemented c a t t l e grazed on pasture through t h e summer and f i n i s h e d in d r y l o t f o r 56 days returned more d o l l a r s per head above feed c o s t than c a t t l e supplemented a t various l e v e l s while on pasture Bradley and Boling (1972) a t Kentucky proposed a 4-phase program whereby it i s possible f o r t h e producer t o synchronize beef production plans and management with feed and forage production i n order t o minimize c a p i t a l outlay and labor Some of t h e e a r l i e r work with c a t t l e on grass and grain r a t i o n s concludkd that grass fed c a t t l e of equal f a t n e s s have t h e same value s o far a s carcass c h a r a c t e r i s t i c s are concerned (Barbella e t al, 1941) Dressing Percent and Grades I n a 1953 b u l l e t i n published a t t h e Virginia Polytechnic I n s t i t u t e e n t i t l e d "Grain or Grass-Fattened C a t t l e l " It w a s pointed out that t h e shrink i n t r a n s i t w a s g r e a t e r f o r grass-fattened c a t t l e than f o r those f a t t e n e d on grain Over a t h r e e year period ( ) t h e average d i f f e r e n c e was about t h e same each year, amounting f o r t h r e e years t o 23 l b s or 17 percent g r e a t e r shrink f o r t h e grass fed group Also t h e pasture c a t t l e showed a somewhat higher d r e s s i n g percentage on t h e basis of rnarket weights than d i d t h e grain fed c a t t l e (602% compared with 594%) The higher shrink i n t r a n s i t f o r t h e grass fed c a t t l e was mentioned a s t h e probable cause f o r t h i s d i f f e r e n c e

5 Table 2 Average Home, Market and Carcass Weights, Shrink and Dressing Percentages 1938 Home w e i g h t Market weight Shrink i n t r a n s i t : Pounds Percentage Carcass weight Dress ing percentage : Home w e i g h t Market weight Pasture Dry lot Pasture D r y lot Pasture Dry l o t Average Pasture l o *8 i o * * I201 3 years Dry l o t 1295 I * =o 6s '3 594 Taken from B u l l e t i n 458--Agricultural Experiment Station, Virginia Polytechnic I n s t i t u t e 1953

6 Carpenter e t a l (1968) f e d c a t t l e g r a i n on pasture a t 1 percent of body weight f o r 312 days A t t i m e of slaughter (18 months) 45 percent of t h e carcasses graded choice According t o these workers, t h i s system was superior t o grazing grass alone f o r 215 t o 225 days and feeding g r a i n a t 1 5 percent of l i v e weight f o r 90 t o 130 days Furthermore, it was superior t o grazing f o r 330 t o 340 days and then f i n i s h i n g i n d r y l o t f o r 112 days Another study (Baxter, 1974) compared English x Brahman and B r a m Swiss x English Crossbred s t e e r s grazed f o r 230 days on high q u a l i t y permanent pasture and slaughtered a t an average age of 20 months The dressing percentages of t h e s e c a t t l e were s l i g h t l y l o w but t h e y i e l d grades were almost a l l i n t h e two range indicating a high percentage of trimmed lean c u t s Approximately 75 percent of t h e s e c a t t l e graded Good b u t none reached Choice Conversely, research a t Auburn (Huffman, 1975) using Angus-Hereford crosses and s t r a i g h t b r e d Herefords allowed about 25 percent of s t e e r s t o Choice grade, on a pasture only regime In a Kansas experiment, Kropf e t a l (1975) compared grass fed, s h o r t fed and long-fed c a t t l e The carcasses from t h e long-fed c a t t l e were heavier, f a t t e r, had more marbling, a higher q u a l i t y grade and a lower c u t a b i l i t y grade than grass fed s t e e r s ( t a b l e 3 ) - 0 Similar r e s u l t s were revealed by Shinn e t a l (1976) a t the University of Missouri comparing t h r e e treatments, consisting of grass only, grass plus 56 days and grass plus 112 days of feeding a h i concentrate r a t i o n following t h e grazing period Hammes e t a l $964) and Moody e t a l (1970) shared that c a t t l e fed high corn s i l a g e r a t i o n s produced carcasses grading High Good t o Low Choice These grades were not s i g n i f i c a n t l y d i f f e r e n t f r o m t h o s e of t h e carcasses from c a t t l e fed a conventional high g r a i n f a t t e n i n g r a t i o n f o r a constant time, -- Carcass Cut -Out Stringer e t al (1968)reported t h a t s t e e r s f u l l - f e d on a f i n i s h i n g r a t i o n beyond average t o High Good had a disadvantage in t o t a l percent r e t a i l c u t s and in percents of r e t a i l cuts from t h e high priced primal (1967) studied t h e e f f e c t s of s e v e r a l feeding c u t s Garrigus et regimes on carcass t r a i t s a t d i f f e r e n t stages of growth Combinations of hay, corn s i l a g e and corn concentrates were fed t o 104 Angus s t e e r s slaughtered a t 475, 625, 850, 900 and 1,000 pounds l i v e w e i g h t Those c a t t l e fed hay had a lower percent f a t and a higher percent edible y i e l d whereas those fed corn s i l a g e were approximately intermediate i n t h e s e t r a i t s t o t h e hay and corn concentrate fed s t e e r s e A recent b u l l e t i n e n t i t l e d "Finishing Steers on Ryegrass -Clover Pasture with Supplemental Grain" by the Mississippi S t a t i o n (1976) presents t y p i c a l results ( t a b l e 4 ) of pasture vs g r a i n feeding t o s t e e r s In general, t h e steers f e d g r a i n tended t o be heavier a t slqughter and possessed more marbling while dressing percentage, c o n f o r m t i o n and r i b eye a r e a d i d not d i f f e r appreciably among groups

7 Table 3 Comparative Data from Carcasses of Short-fed, Grass-Fed and Long-Fed Beef, lbs Carcass w t Average Range Conformation scored h t u r itye Marb lingf Carcass q u a l i t y grade Av choice Choice Good+ Av good GoodStandard+ Av standard F a t thickness, in Rib eye area Rib eye/cwt Yield grade - Short fed Grass fed *3b b 501o *3c b 10 p a Variance ratio Least s ig: diff c J-Qng fed y 95 1go 22a 053c 116" ~ w 975H 031 P < 1% a,b,c Means in same row with same s u p e r s c r i p t l e t t e r s do not d i f f e r (p < 5 H * d Conformation score: Avg standard = 5, avg good = 8, avg choice = 11, avg prime = 14 e h t u r i t y : A- = 1, A = 2, A+ = 3 b r b l i n g : Prac devoid = 5, t r a c e s = 8, s l i g h t = 11, s m l l = 14 Kropf e t a l, 1975 F a t thickness and y i e l d grade were higher f o r s t e e r s that received grain f o r t h e duration of t h e t r i a l - d i f f e r e n c e s that r e f l e c t e d t h e i r g r e a t e r slaughter weight and higher t o t a l f a t content Other workers e t a1 -*, (Black, Warner and Wilson, 1931; Dorne e t a l, 1957; Meyer 1960; and Allen e t al, 1976) spanning over f o r t y years of research have reported similar r e s u l t s i n q u a n t i t a t i v e t r a i t s -- The percent composition of 9-lo-11th r i b from a Texas A & M (Bowling, 1975) study i s shown i n t a b l e 5 This study involved t h e evaluation of carcasses from s e v e r a l d i f f e r e n t management systems The grass f e d steers i n t h e long yearling group had s i g n i f i c a n t l y more

8 135 Table 4 Carcass C h a r a c t e r i s t i c s of Steers Grazing Ryegrass-crimson Clover Pasture with Different Levels of Supplemental Grain Ryegrass-crimson clover pasture Grain fed Grain fed throughout f o r last 64 No days of t r i a l * grain trial* Item Shrunk w t (lbs )w Carcass w t ( l b ) Dressing '$ c onf ormat ionc Marb lingd Fat thickness ( i n ) Yield grade Rib eye a r e a (sq i n ) Q u a l i t y gradec Fat color e Muscle colorf Armour tenderometer ( l b s ) a 246a oo 1 a 14 O 937 *3 569 * o 5 *75b 0 57b O ~ 2-33" *33 13 *7 * Grain fed d a i l y a t one percent of body weight Weight taken following a 24-hour withdrawal from feed and a l2-hour withdrawal from water a, b Means on t h e same l i n e with d i f f e r e n t s u p e r s c r i p t s d i f f e r s i g n i f i c a n t l y ( P < 05) C 10 = Good; 1 1 = Good+; I 2 = Choice-; e t c 5 = S l i g h t ; 6 = Slight+; 7 = Small-; e t c e 1 = White; 2 = Creamy white; 3 = S l i g h t l y yel1ow;etc 1 = Normal; 2 = Shady; 3 = Dark c u t t e r Bullet in 839, Mississippi A g r i c u l t u r a l Experiment S t a t i o n, 1976 bone, were higher i n percentage lean t i s s u e and had l e s s f a t than s t e e r s f i n i s h e d on g r a i n or fed g r a i n on g r a s s The percentages of bone and f a t varied inversely i n management groups, with a high percentage of bone i n d i c a t i n g a d e f i c i t of f a t not an excess of bone nor a deficiency of lean t i s s u e Q u a l i t a t i v e Aspects Color and Shelf Life The Kansas group (Kropf e t al, 1975) compared d i s p l a y color and p a l a t a b i l i t y c h a r a c t e r i s t i c s of beef c u t s from the t h r e e treatment groups r e f e r r e d t o i n t a b l e 3 (long fed on concentrates f o r 150 days, s h o r t fed f o r 70 days and grass fed on pasture without supplement u n t i l slaughter) The r e s u l t s of t h e f a t and muscle color scores are presented i n t a b l e 6

9 136 Table 5 Carcass C h a r a c t e r i s t i c s o f S t e e r s from Nine Management Systems Age group b,nagement system Lean" Fata Bonea 8-11 mo Slaughter calves Drylot, 125 days Drylot, 255 days Grass only Grain on grass Drylot 130 days after grass Grass only Grain on grass Drylot 9 days after grass : f 268e e 140g 576e 25 8f ~ 262f 565e 309' 150e Yearling Long yearling 2-yearo Id % 700; ,3f $ % 15ke 151e e 18gf 164f Ribeye area sq cm Fat thickness' f 671; 574, *3e 9 '3, e ~ 64 5f 684f 141e 77 4e m 15g 5 3f 18 5e 13 05: ' a Estimation of percentage f a t, l e a n and bone from t h e r i b cut by t h e procedure of Hankins e t a l (1946) Ribeye area i n sq cm of a cross-section of t h e longissimus a t t h e r i b juncture Average f a t thickness i n MIU over the longissimus a t t h e r i b juncture e, f, g Within t h e same age group, means i n t h e same column bearing d i f f e r e n t s u p e r s c r i p t s d i f f e r s i g n i f i c a n t l y ( P < 05) Bowling e t al, Texas A & M Although t h e grass f e d c a t t l e produced steaks that had a s l i g h t l y more yellow color of f a t than t h e fed c a t t l e, it was not considered a serious marketing problem The muscle color of f r e s h l y packaged beef steaks was most d e s i r a b l e from long-fed c a t t l e and least d e s i r a b l e from grass-fed c a t t l e It appeared t h a t grass-fed c a t t l e were more s e n s i t i v e t o pre-slaughter feed withdrawal, s o s h o r t e r f a s t i n g periods may be appropriate f o r them In a follow up study comparing e f f e c t s of vacuum s t o r a g e on color s t a b i l i t y of grass f e d beef, Allen e t a l (1976) concluded that channeling grass f i n i s h e d beef i n t o boxed beef s a l e s improved i t s d i s p l a y color, tenderness and t a s t e The e f f e c t s of vacuum storage and d i s p l a y on beef q u a l i t y a r e presented i n t a b l e -- 7

10 137 Table 6 F a t and Muscle Colors from Short-Fed, Grass-Fed and Long-Fed Beef F a t and muscle color Grass Long Short fed fed fed F a t color Muscle color Long i s s imus Day 0 Day 3 Psoas major Day 0 Day 3 Gluteus Day 0 Day 3 -%-E Variance rat i o Least Sig diff 135" 2 2Ob 120a 18 %** Jb 2 96b 3 ooc 3 8iC ," 8861~ 17174* 0 lo4 2 44b 274; 2,26& 1948~ 0 l b 2 72c 19ga 84 oi** I23 3 *55b 3 45b 3w 358 2gP 3 49b 612** 2686** o 117 P < 01 a,b,c Means i n same row w i t h same s u p e r s c r i p t l e t t e r do n3t d i f f e r (P < OS) F a t color: 1 = white, 2 = s l i g h t l y yellow, 3 = m d e r a t e l y yellow e Muscle color: 1 = very b r i g h t red, 2 = b r i g h t red, 3 = s l i g h t l y dark red or brown, 4 = dark red o r brown, 5 = extremely dark red o r brown Kropf e t a l, 1975 Jennings e t a l (1975)a t t h e Colorado s t a t i o n, i n i t i a t e d a study t o determine i f the l e v e l of concentrate o r length of time concentrate i s f e d has an e f f e c t on beef carcass q u a l i t y and shelf' l i f e c h a r a c t e r i s t i c s Steaks from c a t t l e reaching 70 t o 9@ concentrate l e v e l s i n 6 weeks displayed lighter muscle color scores than steaks from c a t t l e reaching 70 t o 9076 concentrate l e v e l s i n 14 weeks However, a f t e r 48 hours of storage simihr muscle color scores were apparent between concentrate feeding l e v e l s A t the completion of the two day storage t i m e, t h e treatments reaching 70 t o 90% l e v e l s of concentrate i n 14 weeks had l e s s l e a n s u r f a c e d i s c o l o r a t i o n than treatments reaching 70 and 90 percent concentrate l e v e l s i n 6 weeks (table 8 ) Some workers have not observed any apparent d i f f e r e n c e i n f a t color between grass and g r a i n fed beef (McCampbell e t al, 1972; and B u r r i s e t a l, 1975) Craig e t a l (1959) reported that beef from d r y l o t c a t t l e was b r i g h t e r i n color than pasture beef b u t t h e y pointed out that pasture per s e did not a f f e c t pigment concentration of t h e mat

11 Table 7 Mean Taste Panel Scores' for longissimus (Loin Eye) Muscle and Fat Samples Derived from 55F Conditioned and 36~ Chilled Carcass Halves Fabricated Before and After Vacuum Storage and Display (Grass Finished Cattle 18 Months Old) Treatment Fat Muscle Over -all flavor flavor Juiciness Tenderness acceptance 36~ Pre-vacuum, pre-display 36F Pre -vacuum, post -display 36F Vacuum, pre -display 36F Vacuum, post-display 55F Pre-vacuum, pre-display 55F Pre -vacuum, post -display 55F Vacuum, pre-display 55F Vacuum, post -display Variance ratio (treatment ) Least s ignif icant difference (p < os> a a ib 5 *73 5 *73a 5 6 ogab 6gb 5 *77& 157 NS 352** a 5 14a =35b 5 84bcd b 6 3ide b 572bc a 5 4Pb b 6 iocde b 648e ib 587bcd 113 NS 8 9 ~ 47w ** (P < Ol); NS = non significant abde Means within same column with same or no letter superscript are not different (P < 05) Z Flavor, juiciness, tenderness and over-all acceptability evaluated using 9-point scale (9 = most desirable, 6 = slightly desirable, juicy, tender, flavorful or acceptable) Allen et al, Kansas State, 1976

12 139 Table 8 Shelf Life and B a c t e r i a l Character i s t i c s of Steaks Derived from Cattle Fed 70 o r 9% Concentrate Levels f o r Varying Periods of Time Level and t i m e required t o reach concentrate l e v e l 14 wk @ 9& Surface Muscle color discoloration day day day day day day wk 6 wk 6 wk TPca day 2 day PSP 0 2 day day a TPC = T o t a l p l a t e counts, PSY = psychrotrophic counts Jennings e t a l, Colorado S t a t i o n, 1975 Muscle surface d i s c o l o r a t i o n scores ( t a b l e 9 ) compiled by Wheeling (1975) tend t o support t h e observations of r e t a i l e r s concerning forage -fed beef et al Table 9 Muscle Surface Discoloration Scores on Grain-Fed and Forage-Fed Beef Rib Steaks H i g h quality 5 Low q u a l i t y 5 7Zb Forage -f ed 442' a Mean values based on a scoring system where 4 = surface e d i s c o l o r a t i o n, 5 = surface d i s c o l o r a t i o n and 6 = < l surface d i s c o l o r a t i o n bc Means on t h e same line bearing t h e sam s u p e r s c r i p t s are not s i g n i f i c a n t l y d i f f e r e n t (P < 05) Wheeling e t al, Colorado S t a t e, 1975

13 14 0 After three day retail shelf display, forage fed beef was discolored to a higher degree than the two-grain-fed beef categories Forage fed beef which initially exhibited very bright and light lean color, discolmed very rapidly once initial discoloration started Thus retailers must sell forage fed beef very quickly in order to prevent this rapid visual deterioration One early report (Shenk _- et al, 1934) suggested that grass or grass plus grain increased the myoglobin content of beef beyond that in meat from animals fed only grain Also Jacobson and Fenton (1955) reported an increase in redness or hue for the semimembranous due to level of nutrition Longwell (1936), however, stated that grass feeding had no effect upon the color of the lean meat Tender ne s s Bowling et al (1975) from Texas A & M compared the tenderness of grain fed and forage fed cattle having the same maturity and marbling They found that the beef from the grain fed cattle were significantly more tender as measured by a sensory panel and the Warner Bratzler shear The differences in tenderness were attributed in part to differences in sarcomere length which were affected by carcass cooling due to variations in fat cover between groups Smith -- et al (1974) indicated that external fat acts as an insulator which inhibits the effects of cold shortening during chilling Several other stations have reported simihr findings The Missouri group (Shinn et al, 1976) observed a significant increase in flavor and tenderness when cattle were fed either 56 or 112 days compared to those slaughtered immediately off pasture No difference in tenderness, however, was noted between the 56 and 112 day fed cattle (table lo) Table 10 Effects of Pasture and Length of Grain Feeding on Beef Tenderness Grass Grass + Grass + only 56 days 112 days Sensory panel score Warner -Bratzler Shear, lbs 24 $ 17 I = tender 4 = slightly tender Shin et al, University of Missouri, 1976

14 141 In c o n t r a s t t o t h e Texas work, Huffmn and Griffey (1975) a t Auburn reported higher (non-signif i c a n t ) sensory r a t i n g s and s l i g h t l y lower shear values f o r forage f e d beef as opposed t o c a t t l e fed g r a i n f o r 90 days It should be noted that these c a t t l e were provided a very high q u a l i t y forage in t h e form of highly f e r t i l i z e d ryegrass and arrowleaf clover pasture during t h e e n t i r e experiment This, plus t h e f a c t that t h e carcasses were f a t t e r and c h i l l e d slower combined t o contribute t o t h e s l i g h t increase i n tenderness of t h e grass fed group Bayne e t a l (1969) showed t h a t n e i t h e r tenderness scores nor shear values of beef were s i g n i f i c a n t l y a f f e c t e d by f i n i s h i n g c a t t l e on a corn s i l a g e v s a high energy corn r a t i o n -- Workers a t t h e Colorado S t a t i o n (Wheeling, Berry and Carpenter, 1975) a l s o found that shear f o r c e values were lowest and tenderness r a t i n g s were t h e highest f o r steaks from forage-fed c a t t l e with t h e toughest meat coming from t h e low q u a l i t y ( t r a c e s t o s l i g h t marbling) grain fed group ( t a b l e 11) Table 11 P a l a t a b i l i t y of Grain-Fed and Forage-Fed Beef Rib Steaks Factor High q u a l i t? Shear f o r c e, kg Tenderness Flavor' J u i c ines s Overall s a t i s f a c t ionc Cooking loss, d/o 2 36de 5 5Zd 5e d 5 54d 1960de Low q u a l i t y 2 a4d 49d 5 *25d 5 m e 5 *IFe 2 1h o d Forage-fed 19ke 6 58e 4 50e 502e 4 86e 18 age a Steaks s e l e c t e d from carcasses possess ing modest, moderate marbling Steaks s e l e c t e d from carcasses possessing t r a c e s, slight marbling Based on an eight-point hedonic scale where 6 = l i k e moderately, 5 = l i k e s l i g h t l y, 4 = d i s l i k e s l i g h t l y, and 3 = d i s l i k e moderately de Means on t h e same l i n e bearing t h e same s u p e r s c r i p t a r e n o t s i g n i f i c a n t l y d i f f e r e n t (P < O5) b Wheellng e t a l, Colorado, 1975 These d a t a would suggest t h a t physiological maturity m y have influenced tenderness more than type of r a t i o n s i n c e t h e forage fed animals were observed t o be younger i n terms of t h e i r meat and bone characteristics Johnston (1976) a t t h e University of Keiltucky compared muscle f i b e r types and diameter from t h e longissimus muscle of g r a i n v s g r a i n on grass f e d c a t t l e Although t h e r e was a s i g n i f i c a n t increase in percent

15 142 cdi and a decrease i n aw f i b e r s f o r g r a i n on grass c a t t l e, t h e r e was no s i g n i f i c a n t d i f f e r e n c e i n t h e diameters of these two f i b e r types between groups The s i m i l a r i t y i n muscle f i b e r diameter between groups was accompanied by a non-significant d i f f e r e n c e i n tenderness scores f o r t h e two groups (table l2) Table 12 E f f e c t of Grain Feeding vs Grain o r Grass on LD Muscle Fiber C h a r a c t e r i s t i c s Grp GGain fed Grain or grass ma ma BRa diam diam diam * cdi % $ a&j * ~ 474*** $ BR Tendernessb a D i a m e t e r i n fl Sensory scores, 7 = very tender *P < *P < Johnston, Kentuclry, 1976 The c o n f l i c t i n g r e s u l t s from t h e s e s t u d i e s on tenderness make it apparent that the c a u s e ( s ) f o r post-mortem d i f f e r e n c e in meat tenderness a r e numerous h c h a t t e n t i o n has been given t o t h i s s u b j e c t over t h e years It seems f a i r t o say that we now know that marbling per se has l i t t l e e f f e c t on tenderness w h i l e the r o l e of muscle proteins, carcass suspension and e l e c t r i c a l shock seem t o be s o m e w h a t more involved While the above mentioned f a c t o r s are not t o be overlooked, by f a r t h e most overiding f a c t o r s which a f f e c t meat tenderness a r e method and/or rate of c h i l l i n g and method of cooking It would a l s o appear that, within limits, t h e n u t r i t i o n a l regime of c a t t l e would have l i t t l e e f f e c t on tenderness except as it a f f e c t s t h e cooling r a t e s of t h e carcass and the ultimate choice of cookery J u i c i n e s s and Flavor The l i t e r a t u r e abounds with results showing comparisons of j u i c i n e s s and f l a v o r scores between n u t r i t i o n experiments In general, t h e highest values f o r j u i c i n e s s and f l a v o r u s u a l l y come from g r a i n fed c a t t l e This i s because j u i c i n e s s and f l a v o r are more highly associated with t h e intramuscuhr f a t usually found i n g r e a t e r amounts i n g r a i n fed c a t t l e as opposed t o grass fed animals

16 Dube e t al (1971)conducted an experiment whereby s t e e r s were fed on s i l a g e alone t o 409 kg or on hay t o 340 kg and then s i l a g e t o 409 kg This work showed t h a t corn s i l a g e as compared t o hay during t h e e a r l y feeding period r e s u l t e d in more d e s i r a b l e broth and s t e a k f l a v o r as w e l l as g r e a t e r i n t e n s i t y of broth f l a v o r i n t h e longissimus Purchas and Davis (1974)moreover reported that t h e f l a v o r of topside r m s t from c e r e a l fed animals was more acceptable than pasture f e d c a t t l e No d i f f e r e n c e i n j u i c i n e s s, f l a v o r or o v e r a l l s a t i s f a c t i o n were noted by Burris e t a l (1975)and Bidner e t a l (1975)who compared t h e carcass c h a r a c t e r i s t i c s of s t e e r s grazed on pasture with d i f f e r e n t l e v e l s of supplemental grain Wheeling e t a l (1975), however, found t h a t f l a v o r of forage fed beef w a s r a t e d s i g n i f i c a n t l y lower than g r a i n fed beef -- Consumer Acceptance A very d e t a i l e d marketing study involving consumer acceptance of forage f i n i s h e d and limited g r a i n f i n i s h e d beef has r e c e n t l y been Tenderness, j u i c i n e s s, f l a v o r completed by t h e Louisiana Group (1975) and o v e r a l l a c c e p t a b i l i t y i n t h i s study were evaluated by two consumer type groups, a laboratory panel and t h e Warner B r a t z l e r Shear Although t h e r e s u l t s f o r tenderness d i d not agree, it was concluded that of t h e four methods used two showed no d i f f e r e n c e due t o animal feeding t r e a t ments while t h e other two methods revealed s m l l d i f f e r e n c e s i n tenderness among treatment groups ( t a b l e 13) This led t o t h e o v e r a l l conclusion t h a t d i f f e r e n c e s i n r a t i o n had l i t t l e e f f e c t on beef tenderness when evaluated by s e v e r a l types of panels These r e s u l t s agree with those of Malphrus (1961) The r e t a i l purchaser group found a s i g n i f i c a n t d i f f e r e n c e f o r j u i c i n e s s with t h e 108 day f e e d l o t c a t t l e having t h e highest score and t h e grain on grass c a t t l e t h e lowest s c o r e Only t h e r e t a i l purchaser group found a s i g n i f i c a n t d i f f e r e n c e among feeding treatments f o r f l a v o r Household and laboratory panel menibers could not d i s t i n g u i s h d i f f e r e n c e s i n f l a v o r among t h e grass f i n i s h e d and g r a i n f i n i s h e d c a t t l e Overall a c c e p t a b i l i t y was not found t o d i f f e r s i g n i f i c a n t l y by t h e r e t a i l purchaser group, household panel o r laboratory panel From t h e Louisiana Study it was shown t h a t heavy forage finished and limited grain f i n i s h e d s t e e r s of predominately English breeding produced beef which can be marketed successfully i n competition with Choice grain fed beef i f priced advantageously Another study of s i m i l a r nature w a s conducted by t h e Mississippi workers Fn 1975 These researchers selected the T-bone, ribeye and round steaks together with t h e bone-in blade chuck roast as r e p r e s e n t a t i v e f o r t h e i r consumer acceptance study Test c u t s t h a t graded USDA G o d were compared t o USDA Choice grade c o n t r o l c u t s Also, some of t h e USDA t e s t Choice c u t s were compared t o c o n t r o l c u t s of t h e same grade

17 144 Table 13 Treatment Grass Grain on grass 63 days d r y l o t 78 days d r y l o t 108 days d r y l o t Tenderness Evaluated by Different Methods Tenderness Pa Laba WBb RRC a 1-7 Hedonic s c a l e, 1 = highest r a t i n g lbs 1-3 Hedonic s c a l e, 1 = highest r a t i n g Code HP = Household Panel Iab = Laboratory Panel WB = Warner B r a t z l e r Shear RR = Retail Rating Adapted from I S U Beef k r k e t i n g Study, 1975 The p r i c i n g s t r u c t u r e used i n t h e s t o r e s was as follows: Store 1--the s t o r e ' s "normal" p r i c e of USDA Good r e l a t i v e t o t h a t of USDA Choice; Store 2--ten cents below t h e s t o r e ' s n o r m 1 p r i c e of USDA Good r e l a t i v e t o USDA Choice and Store 3--ten cents above t h e s t o r e ' s "normal1' p r i c e of USDA Good r e l a t i v e t o USDA Choice Realizing c e r t a i n l i m i t a t i o n s of the study, it was concluded from t h i s work that s a l e s of r e t a i l c u t s of beef from t h e t e s t animals that graded USDA Good disclosed no reluctance of consumers t o purchase beef from c a t t l e f i n i s h e d on pasture, e i t h e r with or without g r a i n supplementation (table 1 4 ) In f a c t, consumers favored s e l e c t e d c u t s from t e s t a n i m l s grading USDA Good a t a l l t h r e e p r i c e d i f f e r e n t i a l s It w a s f u r t h e r concluded that s e l e c t e d c u t s from pasture-finished beef grading USDA Good would be competitive with t h e same cuts of USDA Choice from regular sources of supply even a t more narrow p r i c e d i f f e r e n t i a l s than those used i n t h e s e t e s t s C oncl u s ions Certainly q u a n t i t a t i v e and q u a l i t a t i v e d i f f e r e n c e s in beef have been observed from c a t t l e fed various energy regimes In general, f i n i s h i n g c a t t l e on a high forage (low energy) r a t i o n r e s u l t s i n lower rates of gain, longer feeding periods, reduced feed c o s t s, improved c u t a b i l i t y (less f a t ) grades and a s l i g h t l y lower but acceptable q u a l i t y grade The p a l a t a b i l i t y t r a i t s of tenderness, f l a v o r

18 145 Table 14 Sales of Selected Cuts of Beef, USDA Choice from Regular Sources of Supply and USDA Good from Test Animals, Priced a t t h e S t o r e ' s tfnormal" D i f f e r e n t i a l Between Choice and Good, i n One Jackson, Mississippi, Store, May 23 and h y 30, 1975 USDA Choice beef from regular sources of supply Cut and date AV Price Displayed $/lb Number 2 og Round May 23 b y 30 Total io Ribeye May 23 b y 30 Total T -bone b y 23 May 30 Total Bone-in-blade Chwk r o a s t May 23 b y 30 Total 99 89a Sold USDA Good beef from t e s t animals wt Price Displayed lbs $/ l b Number Sold AV wt lbs a Price was reduced by t h e s t o r e manager Bulletin 839, Mississippi Agricultural Experiment Station, 1976 and o v e r a l l acceptance of beef appear t o be affected l i t t l e by a l t e r i n g t h e energy intake of c a t t l e within reasonable limits However, color of f a t and j u i c i n e s s appear t o be a f f e c t e d adversely by prolonged forage feeding without some supplemental g r a i n The marketability of forage fed beef has been enhanced by advances in technology which have improved tenderness, color s t a b i l i t y and shelf l i f e Currently, cohsumer acceptance of t h i s young, lean, s l i g h t l y mild flavored, forage fed beef is g o d and appears t o be improved with increasing b a r l e d g e and understanding on part of consumers, r e l a t i v e t o proper methods of preparation and cookery

19 146 L i t e r a t u r e Cited Allen, D M, M C Hunt, C L Kastner, D H Kropf, V Chen, A Harrison, 0 Corte, C Kimtapanit, M E Smith and J Thomas 1976 Methods of improving q u a l i t y of grass-fed beef In 63rd Annual Cattlemen's Day Report Kansas "Buffalo t o Beef ' I S t a t e University p 79 Barbella, N G, B Tannor, 0 G Hankins and R E Hunt 1942 Comparative ripening of beef from grass -fattened and g r a s s -fattened s t e e r s J Anim S c i 64:517 Barbella, N G, Bernard Tannor, 0 G Hankins and R E Hunt 1941 Quality of beef from grass f e d and g r a i n fed c a t t l e of equal f a t ness J Agr Res 64:517 Baxter, A 1974 Our experience with forage-fed beef Proc of Beef Cattle Short Course Texas Anim Agr Conf College S t a t i o n, Texas p IE Bayne, Barbara, H Bernadine, H Meyer and J W Cole 1969 Response of beef roasts d i f f e r i n g in f i n i s h, location and s i z e t o two r a t e s of h e a t a p p l i c a t i o n J Anim S c i Beeson, W M, T 14 Perry and M T Mohler 1967 Self-feeding s t e e r s i n W s t u r e with d i f f e r e n t l e v e l s of energy and supplement A v s Purdue 64 Purdue University Agr Exp S t a Res Progress Rpt 301 Bidner, T D 1975 A comparison of forage -finished and grain-f inished b e e f Proc 29th Annual Recip Meat Conf p 301, W i l l i a m Mcfiight, Alvin Schupp and Bidner, Thorns, John Carpenter, Jr David Smith 1976 Consumer acceptance of forage f i n i s h e d and l i m i t e d grain f i n i s h e d b e e f D A E Research Report Louisiana S t a t e University and A g r i c u l t u r a l and b c h a n i c a l College Black, WH, K R Warner and C V Wilson 1931 Beef production and q u a l i t y as a f f e c t e d by grade of s t e e r and feeding g r a i n supplement on g r a s s USDA Tech Bul 217 Black, W H, R L Hiner, L B Burk, Lucy M Alexander and C V Wilson, 1940 Beef production and q u a l i t y as a f f e c t e d by method of feeding supplements t o s t e e r s on grass in Apphchian Region USDA Tech Bul 717 Bowling, R A, J K Riggs, Z L Carpenter, R L Reddish, G C S m i t h and 0 D B u t l e r 1975 Production, carcass and sensory characteri s t i c s of s t e e r s produced by d i f f e r e n t management systems Unpublished paper from Texas Agr Exp S t a

20 Bowling, R A, T R Dutson, Z L Carpenter and G C Smith 1975 Sensory evaluation of beef of i d e n t i c a l physiological maturity and marbling-finished on forage or g r a i n J Food S c i (Submitted) Bradley, N V and J A Boling 1972 Four-phase pasture b e e f Cattle Day Reports University of Kentucky p 17 Beef Bray, G I 1938 Fattening of s t e e r s of d i f f e r e n t ages i n pasture with and without g r a i n and influence of feeding method i n q u a l i t y of meat Louisiana Agr Exp S t a Bul 296 Broaclbent, P J, C B a l l and T L Dodsmith, 1976 Effect of using r a t i o n s of reduced energy concentration f o r intensively reared beef c a t t l e from 250 kg l i v e weight t o slaughter B r i t i s h SOCAnim Prod 22 :207 Brown, W L 1954 Beef carcass c h a r a c t e r i s t i c s a s influenced by grass and other roughages 7th Annual Recip Meat Conf p 199 Bull, S, R R Snapp and H P Rush 1941 Effect of pasture on grade of b e e f I l l i n o i s Agr Exp S t a Bul 475 B u r r i s, bl Ray, W Edmond Brown, Robert W Rogers, W C Couvillion and Fred H m e r 1976 Finishing s t e e r s on ryegrass-clover pasture with supplemental grain Mississippi A g r i c u l t u r a l and Forestry Exp S t a B u l 839 Carpenter, Z L 1975 Consumer acceptance of forage-fed beef presented a t 67th Annual Meeting Am SOC A n i m S c i Paper Carpenter, J C Jr, R H K l e t t, P B Brown and G L Robertson 1968 Producing q u a l i t y beef with grass and g r a i n Louisiana S t a t e University, Agr Exp S t a Bul 627 Craig, H B, T N Blumer and E R Barrick 1959 Effect of s e v e r a l combinations of grass and g r a i n i n t h e r a t i o n of beef s t e e r s on t h e color c h a r a c t e r i s t i c s of lean and f a t J Anim S c i 18:241 Cross, H Russell and Gary C Smith 1975 The New Beef: Review of handling and processing techniques t o enhance consumer acceptance Paper presented a t Forage-Fed Beef Workshop New Orleans, Louisiana Culbertson, C C and W E Hamond 1935 Finishing y e a r l i n g s t e e r s i n pasture and i n d r y l o t Iowa Agr Exp S t a Leaflet 148 Dome, T W, J Iktsushima and V H Arthaud 1957 Full feeding vs limited feeding f o r beef production i n d r y l o t and on pasture Univ of Nebraska Agr Exp S t a SB440 Dube, G, V D Braniblett, R D Howard, B E Hamler, H R Johnson, R B Harrington and M D Judge 1971 Dietary e f f e c t s on beef composition J Food S c i 36:147

21 143 Duncan, H R 19% Producing beef on g r a s s from y e a r l i n g and twoyear-old s t e e r s w i t h and without supplemental feeds University of Tennessee Agr Ekp S t a B u l l e t i n 283 Foster and Miller 1933 The e f f e c t s of management and sex i n carcasses of y e a r l i n g c a t t l e University of Missouri Research Bul 186 Garrigus, R R, H R Johnson, N W Thomas, ' v i L F i r t h and M D Judge 1967 Effect of feeding regime on bovine body composition I Quantitative and q u a l i t a t i v e carcass t r a i t s Report t o NC-58 Tech Comm Furdue University I a f a y e t t e, Indiana H a m s, R C Jr, J P Fontenot, H T Bryant, R 2 Blaser and R W Engel 1964 Value of high-silage r a t i m s f o r f a t t e n i n g beef c a t t l e J Anim S c i 23:795 Huffman, D L and Id Griffey 1975 C a t t l e f i n i s h e d on winter pasture r a t e high i n carcass q u a l i t y Highlights of Agr R e s Alabama Agr Exp S t a 2 2 ~ 3 Hunt, R E, C 14 Kincaid and R C C a r t e r 1953 Grain or-grassvirginia Polytechnic I n s t i t u t e f a t t e n e d c a t t l e? Agr ~ x p S t a 458 Jacobsen, Marion and F a i t h Fenton 1955 Effects of t h r e e l e v e l s of n u t r i t i v e and age of animal on t h e q u a l i t y of b e e f 11 Color, t o t a l iron content and ph Food Res 21:427 Jennings, T G, B W Berry and J K lktsushima 1975 Beef carcass and s h e l f l i f e c h a r a c t e r i s t i c s as a f f e c t e d by time on varying l e v e l s of concentrate Progress Report f o r Regional P r o j e c t W-145 "Alternative Beef Production Systems I ' Johnst on, David Ph D Thesis Unpublished d a t a Kelly, Robert F 1975 Carcass c h a r a c t e r i s t i c s, meat q u a l i t y and consumer acceptance Q u a l i t a t i v e aspects : tenderness, f l a v o r, j u i c i n e s s, color of lean and f a t Forage-Fed Beef Research Workshop New Orleans, Louisiana Kropf, D H, D M Allen and G J Thounevelle 1975 Short-fed, grain-fed and long-fed beef compared I n 62nd Cattleman's Day Report Kansas S t a t e University p 78 Lofgreen, G P 1968 The e f f e c t of n u t r i t i o n on carcass c h a r a c t e r i s t i c s 4 t h Annual Arizona Feeds--Elanco Seminar p 7 Longwell, J H 1936 Color of lean meat as a f f e c t e d by grass and grain feeding W Virginia Agr Bkp S t a Bul 274 bhlphrus, L D 1961 Consumer preference f o r beef f a t t e n e d on grass and g r a i n Proc 13th Res Conf Am Meat Inst Foundation Chicago, Illinois

22 14 9 Meyer, B, J Thomas, R Buckley and J W Cole 1960 The quality of grain-finished beef as affected by ripening food Technol 1:4 McCampbell, H C, B E Greene and R S Lowrey 1972 Cooking and palatability of beef from Winter pasture with and without grain and dry lot fed cattle J Anim Sei 35:200 (Abstr) Moody, W G, J E Little Jr, F A Thrift, L V Cundiff and James D Kemp 1970 Influence of length of feeding a high roughage ration on quantitative and qualitative characteristics of beef J Anim Sci 31:866 Pearson, A M 1976 Personal cormmication Preston, R L 1971 Effects of nutrition on the body composition of cattle and sheep Proc Georgia Feed Mfg Conf p 26 Purchas, R W and H Llqd Davis 1974 Carcass and meat quality of Friesian steers fed on either pasture or barley Aust J Agric Res 25:183 Shenk, J B, J L Hall and H H King 1934 Spectrophotometric characteristics of hemoglobin I Beef blood and muscle hemoglobins J Biol Chem 105:741 Shinn, Jerry, Charles Walsten, J L Clark, G B Thompson, H B Hedrick and W C Stringer 1976 Effect of pasture and length of grin feeding on characteristics of beef J Anim Sci (Abstr Midwestern Section) Smith, G C, T R Dutson, R Hostetler and Z L Carpenter 1974 Subcutaneous fat thickness and tenderness of lanib J Anim Sei 39:174 (Abstr) Stringer, I! C, H B Hedrick, C L Cramer, R J Conley, A J Dyer, G F Krause and R H White 1968 Effect of full-feeding for various periods and sire influence on quantitative and qualitative beef carcass characteristics J Anim Sei 27:1547 Trmbridge, P E,, T H Hopper, Dorothy Berrigan and J T Sarvis Range pasturing and dry lot feeding experiments with steers 1934 Conf on Cooperative Meat Inv North Dakota Exp Sta Wheeling, M R, B N Berry and J A Carpenter, Jr 1975 Effect of breed and forage vs grain feeding on beef palatability and shelf life Proc Western Sec J Anim Sci 26:98 Wilson, Charles V 1931 Fattening two-year old steers on grass with and without a grain supplement Mimeographed Report West Virginia Agricultural Experiment Station Conf on Coop Meat Invest

23 Dave Anderson: If t h e speakers would come forward and be seated, w e ' l l begin our discussion period We'll take twenty minutes f o r our discussion of t h e four papers Are t h e r e any questions? Zerle Carpenter, Texas A & M: Are t h e r e c e r t a i n l i m i t a t i o n s, as you see it, on working with d i f f e r e n t types of c a t t l e r e l a t i v e t o t h e net energy table? Earle Klosterman: The bigger type c a t t l e, f o r some reason, do r e q u i r e more feed t o put on a pound of gain I covered it r a t h e r quickly, but I t h i n k t h i s is r e l a t e d, perhaps, t o physiological age of a d i f f e r e n c e i n composition In other words, a l a r g e r type a n i m a l of a given w e i g h t is probably physiologically younger and perhaps has a l a r g e r maintenance need than another animal that is nearly t h e same age, but physiologically more m t u r e It may be due t o t h e f a c t t h a t t h e r e ' s r e a l l y a d i f f e r e n c e i n maintenance r a t h e r than a d i f f e r e n c e i n t h e energy required f o r gain A 1 Pearson, Michigan S t a t e : This i s not a question I just t h i n k it ought t o go on record Back a t the second Reciprocal Meat Conference, those of you who were t h e r e m y not remember it, but a t that t i m e S l e e t e r Bull was t a l k i n g about "those grass-fed c a t t l e " and he kept repeating, "those grass-fed c a t t l e " So f i n a l l y, 0 D Butler, a t the back of t h e room got up, he is from Texas you know, and said, "down where I come from ' g r a s s ' i s not an obscene word" Robert A Merkel: I have a question f o r D r Keesey You alluded t o hormonal involvement i n t h e weight e f f e c t s of your hypothalamic lesions but d i d not e l a b o r a t e I w a s wondering i f i n s u l i n is involved? R E Keesey: Most of our wsrk t o d a t e has focused upon t h e gonadal hormones Cur r e s u l t s indicate that t h e weight reduction following In l a t e r a l hypothalamic lesions is independent of gonadal influences both males and females t h e changes i n body weight r e s u l t i n g from gonadectomy and l a t e r a l hypothalamic lesions a r e simply a d d i t i v e The p i c t u r e is somewhat d i f f e r e n t i n animals w i t h ventromedial hypothalamic lesions Gonadectoqy modestly augments t h e weight gain normally seen following ventromedial hypothalamic l e s i o n s in females Castrated m l e s, however, gain n e a r l y twice as much as gonadally-intact males following VMH l e s i o n s The gonadal hormones do, t h e r e f o r e, play an important r o l e i n determining t h e l e v e l of o b e s i t y i n ventro-medial hy-pothalamically les ioned animals Robert A Merkel: Do you how i f t h e r e a r e i n s u l i n changes associated w i t h t h e s e hypothalamic lesions? g E Keesey: Hyperinsulinemia i s a c o n s i s t e n t component of t h e obese syndrome i n ventromedial hypothalamically lesioned animals Unfortunately, t h e a v a i l a b l e d a t a do not answer t h e question of whether t h i s hyperinsulinemia i s primary o r whether it i s instead a secondary consequence of t h e hyperphagia and increased a d i p o s i t y It may be worth noting i n t h i s respect t h a t vagotomy has r e c e n t l y been reported t o reverse ventromedial hypothalamic obesity Since t h e c e n t r a l nervous influence over pancreatic b e t a c e l l s e c r e t i o n is exerted v i a t h e Yagus, t h i s observation would t e n d t o favor t h e view that t h e i n s u l i n r o l e i s a primary one

24 Little is known about the insulin levels in lateral hypothalamically lesimed animals One might, for various reasons, expect the insulin levels to be lowered in such animals Basal levels of insulin in rats are already low, however, and I doubt we will see significant differences in this measure The insulin response curve of the lateral hypothalamically lesioned animal seems a more likely place to look for meaningful deviations from the normal pattern Allen, Minnesota: Howard, this is in regard to your statement about growth of the Longissimus muscle Two questions: one, when you fast an animal, do you have a shortening of the fasciculi accompanied by a decrease in their diameter; secondly, what are your thoughts concerning the possible limits to fascicular length in animals that never get any depth developing in their eye muscle? H J Swatland: Regarding the first question, I mentioned in the talk the work of Joubert (J Agr Sci, Camb 47:59, 1956) who found this change in the depth of the eye muscle in lambs on a low plane of nutrition A possible explanation is that when the low plane of nutrition was imposed while animals were growing, it slowed down muscle growth while the skeleton might have continued normally What I think is so special about the longissimus dorsi muscle is that, in contrast to most muscles which extend from a tendon to a bone, the longissimus muscle has greater architectural freedom for fiber arrangement to change If you strip off the fat from the back of a pig, as you're going down toward the longissimus dorsi muscle, you come across a glistening aponeurosis of connective tissue which the muscle fasciculi connect onto dorsally So, this muscle may have a unique opportunity to change the length of its fasciculi without interferring with its mechanical function to any great extent I think this is why there is such tremendous versatility in the eye muscle depth Thus, the longissimus dorsi muscle is also an odd one when it comes to growth patterns I think as well as being extremely important commercially, it's possibly the most sensitive muscle on the carcass to change Which, I guess, is why everybody in the industry uses eye muscle areas so much to evaluate the carcass, becmse it may be the most sensitive, changeable muscle which reflects total muscularity I think it is changeable because its area is largely determined by the length of its fasciculi and I think fascicular length may be a major direction of growth as animals reach s laughter weight Allen, Minnesota: But in your model, the diameter of muscle fibers also has a bearing on the cross-sectional areas -- H J Swatland: Certainly But in the pig, according to Chrystall et al (Growth 33:361, 1969) there's very little radial myofiber growth after 150 days However, if you keep them longer than 150 days they'll certainly keep putting on muscle I did a simple correlation between the length of the fasciculi, carcass weight and longissimus depth right up to a very heavy weight There's a god correlation all the way So, in other words, muscle growth continues after cessation of radial myofi'cer growth If you were to plot the diameters, they would flatten off at about 150 days If you plot fascicular length, they just keep

25 152 growing So, i n other words, t h i s i s t h e explanation f o r where t h e e x t r a muscle mass is coming from i n a heavier pig I t h i n k t h i s is t h e r e a l importance of f a s c i c u l a r length--it keeps going when other t h i n g s have stopped Allen, Minnesota: Did t h e f a s c i c u l a r length decrease during f a s t i n g i n t h e study t h a t you made? H J Swatland: I haven't y e t studied t h e e f f e c t s of f a s t i n g on f a s c i c u l a r length In t h e f a s t i n g study I d i d on t h e p i g s a r t o r i u s, I took a simple muscle and expected t o f i n d t h a t, according t o t h e literature, t h e number of fibers a t t h e mid-length of t h e muscle would be constant It wasn't During growth t h e number j u s t kept increasing So, as an experiment t o check whether t h i s was a r e a l observation, I examined starved a n i m a l s and found t h a t t h e numbers stopped increasing, even though t h e animals were g e t t i n g o l d e r So, f i b e r number was a function of growth and was not n e c e s s a r i l y a function of age I t ' s q u i t e important t o separate t h e s e two b i o l o g i c a l l y R A Merkel, Michigan State: I have a question f o r Howard I a m curious as t o the contribution made by r a d i a l growth of t h e f i b e r s r e l a t i v e t o t h e contribution made by longitudinal growth H J Swatland: I see I don't know t h e a n s w e r t o t h i s question i n terms of percentage of muscle weight I guess it could be c a l c u l a t e d I hadn't thought t o do t h a t But i n terms of t h e o r e t i c a l importance, I t h i n k e a r l y growth ( p r e n a t a l ) occurs by an increase i n t h e r e a l f i b e r number Muscle growth of t h e younger animal occurs by increases i n lqyofiber diameter and length Muscle growth in the older a n i m a l is j u s t by f i b e r length alone In terms of diameter, t h e r e a l l y important t h i n g t o r e a l i z e is that d i f f e r e n t f i b e r types show growth a t d i f f e r e n t times w i t h t h e r e d f i b e r s growing simply i n response t o body weight There is l i t t l e opportunity t o change red f i b e r growth s e p a r a t e l y from body w e i g h t To increase muscularity would be t o increase t h e growth of white f i b e r s W h a t r e a l l y i n t e r e s t s me is t h e d i f f e r e n c e between red and white f i b e r growth I t ' s t h e white f i b e r s whose growth may be f r e e t o be manipulated R A Merkel, Michigan S t a t e : So, w e have t o be concerned w i t h what f i b e r types w e are measurlng when w e study animals a t d i f f e r e n t ages H J Swatland: Absolutely, yes J i m P r i c e, Michigan: W h a t accounts f o r t h e d i f f e r e n c e i n e f f i c i e n c y that you can see? Is t h a t a d i f f e r e n c e of absorption of energy o r of other things? R E Keesey: O u r lateral-hypothalamically l e s ioned a n i m a l s absorb t h e same percentage of t h e i r ingested food as normals Since t h e i r d a i l y intake l e v e l s a r e a l s o normal, it appears t h a t they a r e i n some way l e s s e f f i c i e n t a t u t i l i z i n g absorbed energy

26 Question: Do you see a c t i v i t y differences which might account f o r your observation t h a t l a t e r a l hypothalamically l e s ioned rats take normal amounts of food even though maintaining a reduced body weight? R E Keesey: There are no obvious differences i n t h e a c t i v i t y l e v e l s of l a t e r a l hypothalamically lesioned and c o n t r o l a n i m a l s, though we s t i l l have not looked i n t o t h e matter very thoroughly I should l i k e t o point out, however, that it would probably be necessary t o reduce a normal animal's d a i l y c a l o r i c intake by as much as half in order t o lower i t s s t a b l e l e v e l of body weight t o that maintained by a n i m l s with l a t e r a l hypothalamic l e s i o n s Thus, I doubt that d i f f e r e n c e s i n a c t i v i t y, unless very large, w i l l provide an adequate account Gene Allen, Minnesota: D r Klosterman, i s t h e r e any d a t a that you have which show an e f f e c t of body type on t h e b i o l o g i c a l v a r i a t i o n i n converting feed t o body weight? That is, do you f e e l that differences i n feed conversion have a s i g n i f i c a n t genetic component which i s r e l a t e d t o body type? Earl- Klos terman : Variation i n maintenance requirement, or v a r i a t i o n i n e f f i c i e n c y of e n e r a use above maintenance has approxirnately a six o r seven percent c o e f f i c i e n t of v a r i a t i o n The absolute r a t e of gain among d i f f e r e n t types of c a t t l e, however, has approximately a 15% c o e f f i c i e n t of v a r i a t i o n The v a r i a t i o n i n e f f i c i e n c y then is about half t h a t of the v a r i a t i o n in rate of gain among c a t t l e of d i f f e r e n t sizes Michael Dikeman, Kansas S t a t e : I have a question f o r D r Klosterman I n your opinion, would t h e o v e r a l l p i c t u r e have changed if t h e l a r g e r type c a t t l e had given above average milk? k r l e Klosterman: There's no question that i f t h e l a r g e r types gave more milk t h e i r calves would gain a t a g r e a t e r rate However, it takes feed t o produce milk as w e l l as f o r maintenance and body weight gain and thus would not l i k e l y change t o t a l e f f i c i e n c y Harold Herring, Armour: Do you t h i n k t h e r e i s anything i n grassf e d beef that serves as a pro-oxidant on myoglobin and, t h e r e f o r e, causes d i s c o l o r a t i o n a t a more rapid rate than i n grain-fed beef? B i l l Moody: It would seem that an increase in unsaturation of f a t could possibly cause a n excess of free r a d i c a l s which m i g h t have a pro-oxidant e f f e c t on t h e myoglobin and, t h e r e f o r e, r e s u l t in a darker color of t h e forage-fed beef However, t h i s i s only speculation J D Kemp: May I have your a t t e n t i o n, please Here r e s u l t s of the e l e c t i o n : O u r new President-elect i s Larry our new R E Chairman i s Don Kinsman; and t h e new Directors Cahill, Jim Stouf'fer and Lowell Walters Congratulations, * * * are the Borchert; a r e : Vern gentlemen

27 B i l l S t r i n g e r : I t ' s 8:io k t ' s get s t a r t e d on t i m e I t ' s my pleasure now t o introduce the program f o r today and welcome you t o t h e Tuesday Session Our f i r s t committee t o r e p o r t is t h e By-products U t i l i z a t i o n Commitee Dr Tony Kotula w a s t h e coordinator of t h i s group Harold Herring w i l l be presiding Harold HerrinK: I ' d l i k e t o thank t h e members of the committee f o r t h e i r suggestions and D r Tony Kotula, who acted a6 coordinator f o r t h e committee and d i d most of t h e work on t h i s program I n keeping with yesterday's session on t h e h i s t o r y of meat as a food, I t h i n k it is e s p e c i a l l y f i t t i n g t h a t t h i s year's conference includes a review on by-products u t i l i z a t i o n It i s t h i s aspect of by-product u t i l i z a t i o n t h a t has been e s p e c i a l l y important in t h e development of t h e meat industry since C i v i l War days I n 1935 t h e following anonymous passage was w r i t t e n : 11 I n no l i n e of industry has science worked a more wonderful transformation during t h e last s i x t y years than i n t h e u t i l i z a t i o n of t h e by-products of meat packing To go on, "Today, packinghouse by-products are inseparably linked up w i t h modern c i v i l i z a t i o n, since in one form or another, they are used by almost everyone every minute of t h e day; they 'enter i n t o t h e manufacture of a v a s t number of things t h a t go t o make l i f e more pleasant, that go t o r e l i e v e the s u f f e r i n g of the s i c k and that go t o improve t h e education of humanity" U n t i l about 1870, t h e by-products of meat packing were of no value-were wasted and considered a nuisance In f a c t, they were offered f r e e t o anyone who would c a l l f o r them a t t h e plants, or disposed of i n dumps, trenches, or on p r a i r i e s I n 1875, a t about t h e same time as the developfent of t h e r e f r i g e r a t i o n c a r s, as w e l l as oleomargarine, and t h e use of meat canning, things began t o change Uses were found for edible and inedible by-products Through t h e unceasing r e s e a r c h b y t h e packing industry, t h e number of u s e f u l products derived from l i v e s t o c k has l i t e r a l l y multiplied by t h e hundreds if not thousands Whole new industries were s t a r t e d from some of t h e by-product areas These include companies engaged i n t h e manufacture of soaps, others i n pharmaceuticals and v e t e r i n a r y products, a g r i c u l t u r a l chemicals and f e r t i l i z e r s, i n d u s t r i a l chemicals, leather, adhesives and abras ives, cas ings, rendering and g e l a t i n By-Products have been and s t i l l a r e being used t o support countless other i n d u s t r i e s For example, h a i r is used i n s e a t s, rugs and cushions and animal feed, bones and l o i n s i n novelty f i e l d s, meat scraps and tankage i n animal feeds, inedible o i l s i n l u b r i c a t i o n, wool i n wearing apparel, l a n o l i n In ointments and more r e c e n t l y collagen i s being studied as a base f o r immobilized enzymes Contrary t o opinion, by-product operations a r e not fabulously profitable--in f a c t, mny are q u i t e costly--but they are continued f o r t h e good of t h e public

28 Today we have five excellent speakers for this session on byproducts We're going to cover by-product value, blood and plasm, pharmaceuticals, rendering and international marketing The first topic will be Value of By-Products to be presented by Mr Donald Ferguson of Swift and Company He was born and reared in DeKalb, Illinois, on a farm He obtained hi6 BS from the University of Illinois and received his PhD from Cornell University in Agricultural Economics He served four years in Agricultural Economics Extension at Cornell and then joined Swift and Company, where he's presently Director of Business Research Dr Ferguson Donald Ferguson: Thank you, Dr Herring Good morning