QUANTITATIVE AND QUALITATIVE DIFFERENCES I N BEEF FROM VARIOUS ENERGY REGIMES*

W . G . MJODY University of Kentucky

Much a t t en t ion over the years has been given t o the subject of devising the "best" system o r systems f o r feeding slaughter c a t t l e . Tradi t ional ly , i n t h i s country, corn and other expensive grains have been used t o supply the needed energy f o r f in i sh ing c a t t l e t o t h e more desirable slaughter grades. In mny countries, and pa r t i cu la r ly in t h i s country during the last f e w years, increased a t t en t ion has been given t o feeding more roughage and l e s s gra in t o c a t t l e during the growing and e a r l y part of the f in i sh ing period.

The topic of feeding beef c a t t l e on various energy regimes is a subject t h a t is not especial ly new s ince 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. (Wilson, 1931; Trowbridge e t al., 1934; Bull, 1941; Black - e t a1 -*, 1940; 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 subject matter on energy regimes in

I hope t o highl ight some of beef c a t t l e feeding programs, it is not my intent ion t o present a comprehensive review of t he literature. the recent work that more spec i f i ca l ly relates t o t h e quant i ta t ive and qua l i t a t ive differences in beef comparing forage fed, partial grain fed and f u l l grain fed 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 in te res t ing and provocative paper dealing with feeding systems as re la ted t o the energy and economic eff ic iency of edible beef. This paper, along with two very t imely 1975 up-date topics presented by Drs. F. B . Shorland and T. D. Bidner furnish the background information f o r my paper. I'm sure many of you 'are a l s o aware that within the pas t two years t h e subject of grass or forage feeding of c a t t l e has been and s t i l l is a very important subject 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 th ree partial reviews on t h i s general subject within t h i s time period (Kelly, 1975; Cross, 1975; Carpenter, 1975) and t o show you that h is tory has a way of repeating i t se l f , W . L. Brown a t the 1954 R E presented a shor t paper e n t i t l e d "Beef Carcass Character is t ics as Influenced by Grass and Other Roughages ." 1961MlRC presented a paper on "Consumer Preference f o r Beef Fattened on Grass and Grain."

Also, L. D . Mslphrus a t t h e

* Presented a t the 29th Annual Reciprocal Meat Conference of the American Meat Science Association, 1976

In a l l due respect t o t h i s year 's committee on Growth and Development, it does seem appropriate t h a t results of current work be summarized under one t i t l e and put i n perspective f o r fu ture reference. Much of w h a t I present in t h i s paper covers portions of research complelted a t severa l of t he Experiment Stat ions around the country. you f o r furnishing me with your data t o use i n t h i s presentation, therefore , appropriate acknowledgements have been made throughout t he paper. as a progress report s ince much of t h e research i n t h i s area has not been completed and is, therefore , not avai lable f o r publication. Also, some very important work along these l i nes is just ge t t ing underway. For example, a f i v e year Southern Regional pro jec t proposal which has incorporated i n it a good blend of basic and applied approaches t o a nmiber of problem areas has been wr i t ten and is awaiting approval by the Committee of Nine. It, therefore, seems reasonable t o assume t h a t upon completion of t h i s research w e should be i n a much b e t t e r posi t ion t o answer the many questions being asked r e l a t i v e t o shelf l i f e , color s t a b i l i t y , tenderness and consumer acceptance of grass o r forage-grain fed beef.

I ' m indebted t o many of

I would hasten t o add that t h i s report could bes t be described

In presenting t h i s p p e r I real ize that some of you may view this research as lacking relevance s ince as mentioned e a r l i e r , a l o t of work on a l t e r i n g energy regimes i n beef programs was done severa l decades ago. same concepts i n feeding c a t t l e we a r e doing so under an en t i r e ly d i f f e ren t s e t of circumstances. For example, today more than ever before w e are being forced t o develop a l t e rna t ive systems f o r feeding c a t t l e t h a t conserve expensive grains t h a t covld be used more e f f i c i e n t l y t o feed the h m n population. Secondly, t he publ ic 's outcry against f a t f o r hea l th and/or e s the t i c reasons has far reaching implications which demands immediate a t t en t ion by researchers i f beef is t o maintain t h e pres t ige and image it has enjoyed over the years . Iast, but cer ta in ly not least, the meat industry has a t i t s f inge r t ip s t h e technology and knowledge today t o transform the so-called " less desirable' ' carcasses and cuts i n to desirable and usable products. This can e i the r be accanplished through complete transformation such as flaked and formed o r mechanically deboned products o r by a l t e r i n g the carcass t o br ing about an improved tenderness. la t ter aspect has proved an incentive f o r more experimentation with anirnal types and feeding programs as w e l l as providing more f l e x i b i l i t y in the t o t a l program from point of production t o point of consumption.

It seems t o me that even though w e have returned t o some of t h e

Certainly t h i s

Quant i ta t ive Aspects

Energy Regimes

Brown, i n h i s 1954 R E report s t a t ed that packers discriminate against c a t t l e which have had access t o pasture as a part of t h e i r fa t ten ing r a t ion . t o the lower dressing percentages, higher cooler shrink and lower qua l i ty of pasture fed c a t t l e .

He went on t o say t h a t t h i s discrimination was due

Although t h i s report was published more than two decades ago, I ' m sure if you would ask many of our packers today the same question, they would respond very s imilar ly . 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. remembered t h a t even though some of t he above cr i t i c i sms of pasture- fed beef may be j u s t i f i e d these c r i t i c i sms f o r t he most pa r t represent t he packers i n t e re s t and may or may not represent t h e views of t h e e n t i r e industry.

It should be

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 nu t r i t i on in both feeder calves and yearling steers. In t h i s study it was shown t h a t increasing levels of concentrates resul ted i n carcasses having Larger amounts of body and subcutaneous f a t ( t ab le 1). var ia t ion in carcass weight was due t o the difference in r a t e of gain with increased leve ls of concentrate i n t h e r a t ion .

The

Table 1. Influence of Plane of Nutri t ion on Carcass Composition

Carcass charac te r i s t ics (year l ings) F ina l Carcass Fat Marbling F ina 1

Treatment w t . Yield w t . cover score1 body fa t

l b . 4 l b . i n . 5 LLL 1036 59 -9 621 76 6.1 23.1

LMH 1223 64.1 784 089 6 *3 27.0 26.2 HML 1159 62.9 729 *go 7 03

HHL 113 7 62.7 713 .88 7 *3 27 .o HHH 12 58 65 *3 821 97 7 *2 29.4

LLK 1113 61.4 683 70 7-1- 24.9

' 6 = modest; 7 = moderate; 8 = s l i g h t l y abundant. Lorgreen, 1968.

LLL = Low energy r a t ion (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 for 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.

Preston (1971), i n a l a t e r report , concluded that w i t h i n the p r a c t i c a l realm of ra t ions , plane of nu t r i t ion does not a f f ec t the gross composition of c a t t l e carcasses. He fur ther s ta ted that var ia t ion i n c a t t l e carcass composition m y bes t be achieved by varying slaughter and nature weight ra ther than by varying planes of nu t r i t i on . He qual i f ied t h i s statement by adding t h a t he did not mean from t h i s t h a t there were no h is to logica l changes or changes in t h e d i s t r ibu t ion of f a t o r proteins i n animals fed d i f f e ren t r a t i o n s . In f a c t , a r a t ion causing a negative energy balance could permanently a f f e c t carcass composition according t o Preston. Broadbent -- e t a l . (1976) i n some recent work in Scotland, suggest using a conventional all-concentrate d i e t fo r Ayrshire cas t ra tes only during the growth phase up t o 250 kg l i v e weight. feed sources, which do not require processing, can be subst i tuted and t h i s w i l l allow the animls t o be taken t o slaughter a t higher l i ve weights without a f fec t ing carcass composition.

Thereafter a d i e t of lower energy concentrate using cheaper

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 dry lo 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 iga t ed pasture produced c a t t l e that were canparable t o c a t t l e f inished in dry lo t on a high concentrate r a t ion . 1958) demonstrated that unsupplemented c a t t l e grazed on pasture through the summer and f inished in d ry lo t for 56 days returned more dol la rs per head above feed cost than c a t t l e supplemented a t various leve ls 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 he e a r l i e r work with c a t t l e on grass and grain ra t ions concludkd that grass fed c a t t l e of equal fa tness have the same value so far as carcass charac te r i s t ics are concerned (Barbella e t al., 1941).

Research a t t h e University of Tennessee (Duncan,

Dressing Percent and Grades

In a 1953 b u l l e t i n published a t t he Virginia Polytechnic I n s t i t u t e It w a s pointed out that t h e e n t i t l e d "Grain or Grass-Fattened Ca t t l e l "

shrink in t r a n s i t w a s greater f o r grass-fattened c a t t l e than f o r those fat tened on grain. difference was about t he same each year, amounting f o r th ree years t o 23 lbs . or 1.7 percent greater shrink f o r t he grass fed group.

Over a three year period (1938-1940) the average

Also t h e pasture c a t t l e showed a somewhat higher dressing percentage on t h e basis of rnarket weights than d id the grain fed c a t t l e (60.2% compared with 59.4%). c a t t l e was mentioned as t h e probable cause f o r t h i s difference.

The higher shrink i n t r a n s i t f o r the grass fed

Table 2. Average Home, Market and Carcass Weights, Shrink and Dressing Percentages

1938 1939 194 0 Average 3 years Pasture D r y l o t Pasture D r y l o t Pasture Dry l o t Pasture Dry l o t

Home w e i g h t 1338 13 18 1265 1262 1343 1305 1315 1295 Market weight 1250 1251 1127 1149 l-22 5 1212 I201 I204

Pounds 88 66 138 113 118 93 114 91 Percentage 6.55 5 -04 i o .91 8 *95 8 -78 7.13 8 *7 7 00

Carcass weight 750 748 682 699 737 701 723 716

Home w e i g h t 56.1 56.8 53 *9 55 -6 54 -9 53 -7 55 =o 55 0'3 Market weight 60 .o 59 *8 60.5 60.8 60.2 57 07 6s .2 59.4

Shrink i n t r a n s i t :

P w Fu Dress ing percentage :

Taken from Bullet in 458--Agricultural Experiment Station, Virginia Polytechnic Ins t i t u t e . 1953.

13 3

Carpenter -- e t a l . (1968) fed c a t t l e grain on pasture a t 1 percent of body weight f o r 312 days. of t he 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 gra in 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 in i sh ing in dry lo 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 qua l i ty permanent pasture and slaughtered a t an average age of 20 months. The dressing percentages of these c a t t l e were s l i g h t l y l o w but t h e y ie ld grades were almost a l l i n t h e two range indicating a high percentage of trimmed lean cu ts . Approximately 75 percent of these c a t t l e graded Good but none reached Choice. Conversely, research a t Auburn (Huffman, 1975) using Angus-Hereford crosses and s t ra ightbred Herefords allowed about 25 percent of s t ee r s t o Choice grade, on a pasture only regime.

A t t i m e of slaughter (18 months) 45 percent

In a Kansas experiment, Kropf e t - 0 a l . (1975) compared grass fed, shor t fed and long-fed c a t t l e . The carcasses from the long-fed c a t t l e were heavier, f a t t e r , had more marbling, a higher qua l i t y grade and a lower cu tab i l i t y grade than grass fed s t ee r s ( t ab le 3 ) .

Similar r e su l t s were revealed by Shinn e t a l . (1976) a t the University of Missouri comparing three treatments, consisting of grass only, grass plus 56 days and grass plus 112 days of feeding a h i concentrate r a t ion following the 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 age ra t ions produced carcasses grading High Good t o Low Choice. These grades were not s ign i f i can t ly d i f f e ren t f romthose of t he carcasses from c a t t l e fed a conventional high grain fa t ten ing r a t ion f o r a constant time,

Carcass Cut -Out

Str inger -- e t a l . (1968) reported t h a t s t ee r s fu l l - fed on a f in i sh ing r a t ion beyond average t o High Good had a disadvantage in t o t a l percent r e t a i l cuts and in percents of r e t a i l cuts from the high priced primal cu ts . regimes on carcass t ra i ts a t d i f f e ren t stages of growth. Combinations of hay, corn s i l age and corn concentrates were fed t o 104 Angus s t ee 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 yield whereas those fed corn s i l age were approximately intermediate i n these t ra i t s t o t h e hay and corn concentrate fed steers.

Garrigus et e. (1967) studied the e f fec ts of severa l feeding

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 ta t ion (1976) presents t y p i c a l results ( t a b l e 4 ) of pasture vs. g ra in feeding t o s t e e r s . slqughter and possessed more marbling while dressing percentage, conformtion and r i b eye area d i d not d i f f e r appreciably among groups.

In general, t h e steers fed grain tended t o be heavier a t

Table 3. Comparative Data from Carcasses of Short-fed, Grass-Fed and Long-Fed Beef

Least

fed fed fed r a t i o d i f f . Short Grass J-Qng Variance s ig:.

Carcass w t ., lbs . Average 532 95 Range 437-664

9 *3b h t u r i tye 1.9

d Conformation score

Marb l ingf 11 .8b Carcass qua l i t y grade

Av. choice 1 Choice - Good+ 3 Av. good 4 Good- 2 Standard+ Av. standard

Fat thickness, in. 0 .36b Rib eye area 10 .p Rib eye/cwt . 2.05 Yield grade 2.4a

501 .o 396-554

7 *3c

7 -3c 2.1

1 4 2 3

9.5 1 .go 2.2a

0 . y

2 3 4 1

0.53c 20.39w 0.08 11.6" 5 . 6 ~ 0.89 1.82 3 -1 9.75H 0.31

P < 1%.

( p < 5 H * a,b,C Means in same row with same superscr ipt let ters do not d i f f e r

d Conformation score:

e h t u r i t y : A- = 1, A = 2, A+ = 3.

Avg. standard = 5, avg. good = 8, avg. choice = 11, avg . prime = 14.

b r b l i n g : Prac. devoid = 5, t r aces = 8, s l i g h t = 11, smll = 14.

Kropf e t a l . , 1975.

Fat thickness and y ie ld grade were higher f o r s t e e r s that received grain f o r the duration of t h e t r i a l - d i f f e r e n c e s that re f lec ted t h e i r greater slaughter weight and higher t o t a l fa t content. Other workers (Black, Warner and Wilson, 1931; Dorne e t a l . , 1957; Meyer - e t a1 -*, 1960; and Allen -- e t al., 1976) spanning over f o r t y years of research have reported similar results i n quant i ta t ive t ra i t s .

The percent composition of 9-lo-11th r i b from a Texas A & M (Bowling, 1975) study is shown i n t ab le 5 . evaluation of carcasses from seve ra l d i f f e ren t management systems. The grass fed steers i n the long yearling group had s ign i f i can t ly more

This study involved the

13 5

Table 4 . Carcass Character is t ics of Steers Grazing Ryegrass-crimson Clover Pasture with Different Levels of Supplemental Grain

I t e m

Ryegrass-crimson clover pasture Grain fed Grain fed

No throughout f o r last 64 grain trial* days of t r i a l *

Shrunk w t . (lbs . )w Carcass w t . ( l b . ) Dressing '$ c onf orma t i onc Marb lingd Fat thickness ( i n . ) Yield grade Rib eye area (sq. i n . ) Qual i ty gradeC

f Fat color e Muscle color Armour tenderometer ( l b s . )

886.3

58 096 11.5

523 04

4.92 0 .38a 2.46a

10.31 10.25 2 .oo 1 .a

14 .O

937 *3 569 *4 60.63 12 .o

5 *75b 0 57b 3 -03

10.18 10.58 2.17 1.17 14 .O

908 97 543 94 59 075

6.50 0 . 3 8 ~

11.05 10.75 1.92 1 *33

13 *7

12.2

2 -33"

* Grain fed da i ly 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 the same l i n e with d i f f e ren t superscr ipts d i f f e r s ign i f i can t ly (P < .05).

C 10 = Good; 11 = Good+; I2 = Choice-; e t c . 5 = Sl ight ; 6 = Slight+; 7 = Small-; e t c .

e 1 = White; 2 = Creamy white; 3 = Sl ight ly yel1ow;etc. 1 = Normal; 2 = Shady; 3 = Dark cu t t e r .

Bullet in 839, Mississippi Agricul tural Experiment Stat ion, 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 ee r s f inished on gra in or fed grain on grass . The percentages of bone and f a t varied inversely in management groups, with a high percentage of bone indicat ing 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 .

Qual i ta t ive Aspects

Color and Shelf Life

The Kansas group (Kropf e t al., 1975) compared display color and p a l a t a b i l i t y charac te r i s t ics of beef cuts from the three treatment groups referred t o i n t ab le 3 (long fed on concentrates f o r 150 days, short fed f o r 70 days and grass fed on pasture without supplement u n t i l slaughter). i n table 6.

The r e s u l t s of t he f a t and muscle color scores are presented

136

Table 5. Carcass Characterist ics of Steers from Nine Management Systems

Fat Ribeye Age b,nagement Lean" Fata Bonea area thickness'

group system % $ % sq. cm. m.

8-11 mo. Slaughter calves 61.7 22.2 16.7 Drylot, 125 days 63.4: 22.3f 15.ke

Yearling Drylot, 255 days 58.9 26.8e 15.1e

Long Grain on grass 55.1 18.gf 16.4f yearling Drylot 130 days 62,3f 25.2e 14.0g

2-year- Grain on grass 6 0 . 2 ~ 26.2f 15.0e o Id Drylot 9 days 56.5e 30.9' 14.1e

Grass only 70.0; 11.68 17.8e

Grass only 57.6e 25 .8f 1 7 . 0 ~ after grass

after grass

46.4 60 .6f 67.1;

58.1 70 *3e

57.4,

64 .5f 68.4f 77 .4e

9 '3,

5 .3f

7 09 14 .6e 1.5g

18 .5e

13 05: 14.9 18.2'

a Estimation of percentage fat, lean and bone from the 9-10-11 r i b cut by the procedure of Hankins e t a l . (1946). Ribeye area in sq. cm. of a cross-section of the longissimus a t t h e 12-13 r i b juncture. Average fa t thickness i n MIU over the longissimus a t t he 12-13 r i b juncture.

e,f ,g Within t h e same age group, means i n the same column bearing d i f fe ren t superscripts d i f f e r s ign i f icant ly (P < .05).

Bowling e t al., Texas A & M.

Although the grass fed catt le produced steaks that had a s l i g h t l y more yellow color of fat than the fed c a t t l e , it was not considered a serious marketing problem. The muscle color of f reshly packaged beef steaks was most desirable from long-fed c a t t l e and least desirable from grass-fed c a t t l e . t o pre-slaughter feed withdrawal, so shorter fas t ing periods may be appropriate f o r them. vacuum storage on color s t a b i l i t y of grass fed beef, Allen -- e t a l . (1976) concluded that channeling grass finished beef in to boxed beef sa les improved i t s display color, tenderness and t a s t e . The e f fec ts of vacuum storage and display on beef qua l i ty a re presented i n tab le 7.

It appeared t h a t grass-fed c a t t l e were more sensi t ive

In a follow up study comparing e f fec ts of

13 7

Table 6. Fat and Muscle Colors from Short-Fed, Grass-Fed and Long-Fed Beef

Fat and muscle color Least

fed fed fed rat i o d i f f . Short Grass Long Variance S i g .

Fat color 1.35" 2 .2Ob 1.20a 18 .%** 0.256

Day 0 2 .15Jb 3 .ooc 1.94," 8 8 . 6 1 ~ o .117 Day 3 2 .96b 3 .8iC 2.46 171.74* 0 .lo4

Day 3 3 *55b 3.58 3 . w 6.12** 0.128

Muscle color Long is s imus

Psoas major Day 0 2 .44b 2.74; 2,26& 1 9 . 4 8 ~ 0 .l08

Gluteus Day 0 2.34b 2 .72c 1 .9ga 84. oi** 0.080 Day 3 3 .45b 3 .49b 2 . g P 26.86** 0 .I23

-%-E P < .01. a,b,c Means i n same row w i t h same superscr ipt l e t te r do n3t d i f f e r

(P < .OS) . Fa t color: 1 = white, 2 = s l i g h t l y yellow, 3 = mdera te ly yellow.

e Muscle color: 1 = very br ight red, 2 = br ight red, 3 = s l i g h t l y dark red or brown, 4 = dark red o r brown, 5 = extremely dark red or brown.

Kropf e t al . , 1975.

Jennings e t a l . (1975) a t the Colorado s t a t ion , i n i t i a t e d a study t o determine if the l e v e l of concentrate o r length of time concentrate is fed has an e f f e c t on beef carcass qua l i t y and shelf' l i f e cha rac t e r i s t i c s . Steaks from c a t t l e reaching 70 t o 9@ concentrate levels i n 6 weeks displayed lighter muscle color scores than steaks from c a t t l e reaching 70 t o 9076 concentrate levels i n 14 weeks. However, a f t e r 48 hours of storage simihr muscle color scores were apparent between concentrate feeding leve ls . treatments reaching 70 t o 90% levels of concentrate i n 14 weeks had l e s s lean surface discolorat ion than treatments reaching 70 and 90 percent concentrate leve ls i n 6 weeks (table 8 ) .

Some workers have not observed any apparent difference i n f a t color between grass and gra in fed beef (McCampbell e t al., 1972; and B u r r i s e t al. , 1975). Craig e t a l . (1959) reported that beef from dry lo t c a t t l e was br ighter i n color than pasture beef but they pointed out that pasture per s e did not a f f e c t pigment concentration of t he mat.

A t the completion of the two day storage t i m e , the

Table 7. Mean Taste Panel Scores' f o r longissimus (Loin Eye) Muscle and Fat Samples Derived from 55F Conditioned and 3 6 ~ Chilled Carcass Halves Fabricated Before and After

Vacuum Storage and Display (Grass Finished Cattle 18 Months Old)

Treatment Fat Muscle Over -a l l

f lavor flavor Juiciness Tenderness acceptance

3 6 ~ 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 r a t i o (treatment ) Least s igni f icant difference

( p < .os>

5.84 5 .92a 5 0 9 8 5 .63a 6.28 6 .6ib 5 *73 5 *73a

5 6 .ogab 6 . g b 5 *77&

1.57 N.S. 3.52**

6.01 4 .96a 5. 14a 6.51 6 =35b 5 .84bcd 6.56 6 .66b 6 .3ide 6.24 6 .38b 5.72bc

6.44 6.72b 6. iocde 6.49 6 .74b 6.48e 6.45 6.5ib 5.87bcd

6.46 5 .38a 5 .4Pb P w aJ

1.13 N.S. 8 . 9 ~ 4 . 7 w

0.62 0.56

** (P < .Ol); N.S. = non s ignif icant . a b d e Means w i t h i n same column w i t h same or no le t ter superscript are not d i f fe ren t ( P < .05).

Z Flavor, juiciness, tenderness and over-all acceptabili ty evaluated using 9-point scale ( 9 = most desirable, 6 = s l igh t ly desirable, juicy, tender, f lavorful or acceptable).

Allen e t al., Kansas State, 1976.

13 9

Table 8. Shelf Life of Steaks Derived

Concentrate Levels

and Bacter ia l Character i s t i c s from Cattle Fed 70 or 9% fo r Varying Periods of Time

Surf ace Level and t i m e Muscle color discolorat ion TPca P S P required t o reach 0 1 2 0 1 2 0 2 0 2 concentrate l eve l day day day day day day day day day day

7 6 14 wk. 6.6 5.7 6.1 6.8 6.9 7.0 2.54 2.54 3.69 2.71 9076 14 wk 6.2 5.7 5.6 6.9 6.9 6.8 2.28 2.88 3.82 2.82

9& 6 wk. 6.5 6.6 5.8 6.7 6.5 5.9 2.57 2.63 3.79 2.47 7@ 6 wk. 6.1 6.7 6.0 6.9 6.7 6.2 2.33 2.87 3.80 3.01

a TPC = Total p l a t e counts, PSY = psychrotrophic counts.

Jennings e t a l . , Colorado Stat ion, 1975.

Muscle surface discolorat ion scores ( t ab le 9 ) compiled by Wheeling et al. (1975) tend t o support t h e observations of r e t a i l e r s concerning forage -fed beef.

Table 9. Muscle Surface Discoloration Scores on Grain-Fed and Forage-Fed Beef Rib Steaks

H i g h qua l i t y Low qual i ty Forage -f ed

5 5 .7Zb 4.42'

a Mean values based on a scoring system where 4 = 2 5 - 5 6 surface discolorat ion, 5 = 10-255 surface discolorat ion and 6 = < le surface discolorat ion.

s ign i f i can t ly d i f f e ren t (P < .05). bc Means on the same line bearing t h e sam superscr ipts are not

Wheeling e t al., Colorado Sta te , 1975.

14 0

After three day r e t a i l shelf display, forage fed beef was discolored t o a higher degree than the two-grain-fed beef categories. beef which i n i t i a l l y exhibited very br ight and light lean color , discolmed very rapidly once initial discolorat ion s t a r t ed . r e t a i l e r s must s e l l forage fed beef very quickly i n order t o prevent t h i s rapid v i s u a l de te r iora t ion . suggested that grass or grass plus grain increased the myoglobin content of beef beyond that i n meat from animals fed only grain. and Fenton (1955) reported an increase i n redness or hue f o r the semi- membranous due t o l eve l of nu t r i t i on . that grass feeding had no e f f ec t upon t h e color of t h e lean meat.

Forage fed

Thus

One ear ly report (Shenk _.- e t a l . , 1934)

Also Jacobson

Longwell (1936), however, s ta ted

Tender ne s s

Bowling e t a l . (1975) from Texas A & M compared the tenderness of grain fed and forage fed c a t t l e having the same maturity and marbling. They found that t h e beef from the gra in fed c a t t l e were s ign i f i can t ly more tender as measured by a sensory panel and the Warner Bratzler shear. The differences i n tenderness were a t t r i bu ted i n part t o differences in sarcomere length which were affected by carcass cooling due t o var ia t ions i n fa t cover between groups. Smith -- e t a l . (1974) indicated that external f a t a c t s as an insulator which inh ib i t s t he e f f ec t s of cold shortening during ch i l l ing . Several other s t a t ions have reported simihr f indings. s ign i f i can t increase in f lavor and tenderness when c a t t l e were fed e i t h e r 56 or 112 days compared t o those slaughtered immediately off pasture. No difference i n tenderness, however, was noted between the 56 and 112 day fed c a t t l e ( t ab le l o ) .

The Missouri group (Shinn e t al . , 1976) observed a

Table 10. Effects of Pasture and Length of Grain Feeding on Beef Tenderness

Grass Grass + Grass + only 56 days 112 days

Sensory panel score 4 -7 5 04

Warner -Bratzler Shear, lbs . 24 .$ 17 .I.

5 -3

18.1

5 = tender. 4 = s l i g h t l y tender

Shin e t al., University of Missouri, 1976.

14 1

In contrast t o t h e Texas work, Huffmn and Griffey (1975) a t Auburn reported higher (non-signif i can t ) sensory ra t ings and s l i g h t l y lower shear values f o r forage fed beef as opposed t o c a t t l e fed grain f o r 90 days. qua l i t y forage in the 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 fa t ter and ch i l led slower combined t o contribute t o t h e s l i g h t increase i n tenderness of the grass fed group. (1969) showed t h a t nei ther tenderness scores nor shear values of beef were s ign i f i can t ly affected by f in i sh ing c a t t l e on a corn s i l age vs . a high energy corn r a t ion .

It should be noted that these c a t t l e were provided a very high

Bayne -- e t a l .

Workers a t t h e Colorado Stat ion (Wheeling, Berry and Carpenter, 1975) a l s o found that shear force values were lowest and tenderness ra t ings were the highest f o r steaks from forage-fed c a t t l e with the toughest meat coming from t h e low qua l i ty ( t races t o s l i g h t marbling) grain fed group ( t ab le 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 qual i t? Low qua l i ty Forage-fed

Shear force, kg 2. 36de 2 .a4d 1 .9ke

Flavor' 5 e 5 9 5 *25d 4 .50e

Overall s a t i s f a c t ionC 5 .54d 5 *IFe 4 .86e Cooking loss, d /o 19.60de 2 1 h o d 18 .age

Tenderness 5 .5Zd 4 . 9 d 6 .58e

Ju ic ines s 5 .68d 5 . m e 5.02e

a b

Steaks selected from carcasses possess ing modest, moderate marbling. Steaks selected from carcasses possessing t r aces , slight marbling. Based on an eight-point hedonic scale where 6 = l i k e moderately, 5 = l i k e s l i gh t ly , 4 = d i s l i k e s l i gh t ly , and 3 = d i s l i k e moderately.

de Means on t h e same l i n e bearing the same superscr ipt a r e not s i g n i f i - cant ly d i f f e ren t (P < . O 5 ) .

Wheellng e t a l . , Colorado, 1975.

These data would suggest t h a t physiological maturity m y have influenced tenderness more than type of r a t ion s ince t h e forage fed animals were observed t o be younger i n terms of t h e i r meat and bone cha rac t e r i s t i c s .

Johnston (1976) a t t h e University of Keiltucky compared muscle f iber types and diameter from the longissimus muscle of grain vs . grain on grass fed c a t t l e . Although the re was a s igni f icant increase in percent

142

cdi and a decrease i n aW fibers f o r grain on grass c a t t l e , there was no s igni f icant difference i n t h e diameters of these two f iber types between groups. accompanied by a non-significant difference i n tenderness scores f o r t he two groups (table l2).

The s imi l a r i t y i n muscle f i b e r diameter between groups was

Table 12. Effect of Grain Feeding vs . Grain or Grass on LD Muscle Fiber Character is t ics

b $ a&J Tenderness

BRa ma ma $ % Grp diam. diam. diam. BR cdi

GGain

Grain or

fed 43.6 39.9 45.8 29.9 20.3 49 *9 7.5

grass 45.3* 39.0 44.9 29.0 2 3 . 6 ~ 47.4*** 7 -3

a D i a m e t e r i n fl. Sensory scores, 7 = very tender.

* P < .05. * P < .001.

Johnston, Kentuclry, 1976.

The confl ic t ing r e s u l t s from these s tudies on tenderness make it

h c h a t t en t ion has been given t o t h i s subject over t he apparent that the cause(s) f o r post-mortem difference in meat tenderness a r e numerous. years. It seems fa 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 fac tors are not t o be overlooked, by far the most overiding f ac to 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. within limits, t he 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 ec 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 ult imate choice of cookery.

It would a l s o appear that,

Juiciness and Flavor

The l i terature abounds with results showing comparisons of juiciness and f lavor scores between nu t r i t i on experiments. In general, t he highest values f o r juiciness and f lavor usual ly come from grain fed c a t t l e . This is because juiciness and f lavor are more highly associated with the intramuscuhr fat usually found i n grea te r amounts i n grain fed c a t t l e as opposed t o grass fed animals.

Dube -- e t a l . (1971) conducted an experiment whereby s t ee r s were fed on s i l age alone t o 409 kg or on hay t o 340 kg and then s i l age t o 409 kg. This work showed t h a t corn s i l age as compared t o hay during the ear ly feeding period resul ted in more desirable broth and s teak f lavor as wel l as grea te r i n t ens i ty of broth f lavor i n the longissimus.

Purchas and Davis (1974) moreover reported that t h e f lavor of topside r m s t from cerea l fed animals was more acceptable than pasture fed c a t t l e . No difference i n juiciness , f lavor or ove ra l l s a t i s f ac t ion were noted by Burris -- e t a l . (1975) and Bidner e t a l . (1975) who compared the carcass charac te r i s t ics of s t e e r s grazed on pasture with d i f f e ren t levels of supplemental grain. Wheeling e t a l . (1975), however, found t h a t f lavor of forage fed beef w a s ra ted s ign i f i can t ly lower than grain fed beef.

Consumer Acceptance

A very de ta i led marketing study involving consumer acceptance of forage f inished and l imited grain f inished beef has recent ly been completed by the Louisiana Group (1975 ) . and overa l l acceptab i l i ty i n t h i s study were evaluated by two consumer type groups, a laboratory panel and t h e Warner Bratzler Shear. Although t h e r e s u l t s f o r tenderness did not agree, it was concluded that of t h e four methods used two showed no difference due t o animal feeding t r e a t - ments while t he other two methods revealed s m l l differences in tenderness among treatment groups ( t ab le 13). t h a t differences i n r a t ion had l i t t l e e f f ec t on beef tenderness when evaluated by severa l types of panels.

Tenderness, juiciness , f lavor

This led t o the ove ra l l conclusion

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 ign i f icant difference f o r juiciness with the 108 day feedlot c a t t l e having the highest score and the grain on grass c a t t l e t he lowest score. Only t h e r e t a i l purchaser group found a s ign i f i can t difference among feeding treatments f o r f lavor . Household and laboratory panel menibers could not d i s t inguish differences in f lavor among t h e grass f inished and g r a i n f inished c a t t l e . Overall acceptab i l i ty was not found t o d i f f e r s ign i f i can t ly by the r e t a i l purchaser group, household panel or laboratory panel.

From t h e Louisiana Study it was shown t h a t heavy forage finished and l imited grain f inished s t ee r s of predominately English breeding produced beef which can be marketed successfully i n competition with Choice grain fed beef if 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, r ibeye and round steaks together with the bone-in blade chuck roast as representat ive for t h e i r consumer acceptance study. were compared t o USDA Choice grade cont ro l cu ts . USDA t e s t Choice cuts were compared t o cont ro l cu ts of the same grade.

Test cu ts t h a t graded USDA G o d Also, some of t he

144

Table 13. Tenderness Evaluated by Different Methods

Treatment Tenderness

€Pa Laba WBb R R C

Grass 3.11 2 -97 19.4 1.63 Grain on grass 2.89 3 947 19 99 1.78 63 days dry lo t 3.11 3 -27 20.2 1.71 78 days drylot 2.67 2 099 19.4 1.66 108 days dry lo t 2.61 3 017 18.4 1.66

a 1-7 Hedonic scale , 1 = highest r a t ing . l b s . 1-3 Hedonic scale , 1 = highest ra t ing .

Code HP = Household Panel Iab = Laboratory Panel WB = Warner Bratzler Shear RR = Retail Rating

Adapted from I S U Beef k r k e t i n g Study, 1975.

The pr ic ing s t ruc ture used i n the s tores was as follows: Store 1--the s t o r e ' s "normal" p r i ce 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 no rm1 pr ice 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 to re ' s "normal1' p r ice of USDA Good r e l a t i v e t o USDA Choice. Realizing ce r t a in l imitat ions of the study, it was concluded from t h i s work that sa l e s of r e t a i l cuts of beef from the 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 inished on pasture, e i the r with or without grain supplementation (table 14) . In f a c t , consumers favored selected cuts from tes t a n i m l s grading USDA Good a t a l l three pr ice d i f f e r e n t i a l s . It w a s fu r the r concluded that selected cuts from pasture-finished beef grading USDA Good would be competitive with the same cuts of USDA Choice from regular sources of supply even a t more narrow pr ice d i f f e r e n t i a l s than those used in these tests.

C onc lus ions

Certainly quant i ta t ive and qua l i t a t ive differences in beef have been observed from c a t t l e fed various energy regimes.

In general, f in i sh ing c a t t l e on a high forage (low energy) r a t ion r e s u l t s i n lower rates of gain, longer feeding periods, reduced feed costs , 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 qua l i t y grade. The p a l a t a b i l i t y t ra i t s of tenderness, f lavor

14 5

Table 14. Sales of Selected Cuts of Beef, USDA Choice from Regular Sources of Supply and USDA Good from Test Animals, Priced

a t the Store 's tfNormal" Dif fe ren t ia l Between Choice and Good, i n One Jackson, Mississippi, Store, May 23 and h y 30, 1975

USDA Choice beef from USDA Good beef from regular sources of supply t e s t animals

AV . AV . Cut and date Pr ice Displayed Sold w t . Price Displayed Sold w t .

$/ lb. Number lb s . $/ l b . Number lbs . T -bone

b y 23 2 .og 23 14 1.07 1.79 32 21 1.06 May 30 2.09 23 5 1.13 1.79 69 60 1.11 Total 46 19 1.08 101 81 1.09

Round May 23 1-99 25 15 1.65 1.59 30 22 1.83 b y 30 1-99 22 io 1.92 1.59 32 20 1.96 Total 47 25 1.75 62 42 1.89

Ribeye May 23 3 -69 6 0 -- 2.89 15 9 1.14 b y 30 3 069 9 2 1.18 2.89 22 8 1.01 Total 16 2 1.18 37 17 1.08

Bone-in-blade Chwk roas t

May 23 99 32 3.61 .89 16 8 3.28 b y 30 .89a 29 8 4.05 .89 17 10 3.29 Total 61 20 3.79 33 18 3.29

a Price was reduced by the s t o r e manager.

Bulletin 839, Mississippi Agricultural Experiment Station, 1976.

and overa 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 the energy intake of c a t t l e within reasonable limits. However, color of f a t and juiciness appear t o be affected adversely by prolonged forage feeding without some supplemental grain. 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.

146

Literature 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 qua l i ty of grass-fed beef. 1776-1976 "Buffalo t o Beef . ' I

Sta t e University. p. 79. In 63rd Annual Cattlemen's Day Report. Kansas

Barbella, N . G . , B . Tannor, 0 . G . Hankins and R . E . Hunt. 1942. Comparative ripening of beef from grass -fattened and grass -fattened s t e e r s . J. Anim. Sc i . 64:517.

Barbella, N . G., Bernard Tannor, 0 . G. Hankins and R . E . Hunt. 1941. Quality of beef from grass fed and grain 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 Stat ion, Texas. p. IE.

Bayne, Barbara, H . Bernadine, H. Meyer and J. W . Cole. 1969. Response of beef roasts d i f f e r ing in f in i sh , location and s i ze t o two r a t e s of heat appl icat ion. J. Anim. Sci . 29283.

Beeson, W. M., T . 14. Perry and M. T . Mohler. 1967. Self-feeding s t ee r s i n Wsture with d i f f e ren t levels of energy and supplement A vs . Purdue 64. Purdue University Agr. Exp. S t a . Res. Progress Rpt . 301.

Bidner, T. D . 1975. A comparison of forage -f inished and grain-f inished beef . Proc. 29th Annual Recip. Meat Conf. p. 301.

Bidner, Thorns, John Carpenter, Jr ., W i l l i a m Mcfiight, Alvin Schupp and David Smith. 1976. Consumer acceptance of forage f inished and l imited grain f inished beef . D .A .E. Research Report. Louisiana S ta t e University and Agricul tural and b c h a n i c a l College.

Black, W..H., K . R . Warner and C . V . Wilson. 1931. Beef production and qua l i ty as affected by grade of s t e e r and feeding grain supple- ment on grass . U.S.D.A. Tech. Bul. 217.

Black, W . H., R . L. Hiner, L. B. Burk, Lucy M. Alexander and C . V . Wilson, 1940. Beef production and qua l i ty as affected by method of feeding supplements t o s t e e r s on grass in Apphchian Region. U.S.D.A. Tech. Bul. 717.

Bowling, R . A., J. K . Riggs, Z . L. Carpenter, R . L. Reddish, G . C . Smith and 0. D. But ler . 1975. Production, carcass and sensory character- i s t i c s of s t e e r s produced by d i f f e ren t management systems. Unpublished paper from Texas Agr. Exp. Sta .

Bowling, R . A. , T. R . Dutson, Z . L. Carpenter and G . C . Smith. 1975. Sensory evaluation of beef of i den t i ca l physiological maturity and marbling-finished on forage or grain. J . Food Sc i . (Submitted)

Bradley, N . V. and J. A . Boling. 1972. Four-phase pasture beef . Beef Cattle Day Reports. University of Kentucky. p. 17.

Bray, G . I. 1938. Fattening of s t ee r s of d i f f e ren t ages i n pasture with and without grain and influence of feeding method i n qua l i ty of meat. Louisiana Agr . Exp. Sta . Bul. 296.

Broaclbent, P. J., C . B a l l and T . L. Dodsmith, 1976. Effect of using ra t ions 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. British SOC. Anim. Prod. 22 : 207.

Brown, W . L. 1954. Beef carcass charac te r i s t ics as 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 beef . I l l i n o i s Agr . Exp. Sta . 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 Agricul tural and Forestry Exp. S t a . Bul . 839.

Carpenter, Z . L. 1975. Consumer acceptance of forage-fed beef. Paper presented a t 67th Annual Meeting Am. SOC. Anim. Sc i .

Carpenter, J. C . Jr., R . H . Klet t , P . B. Brown’ and G . L. Robertson. 1968. Producing qua l i ty beef with grass and grain. Louisiana S ta t e University, Agr. Exp. S ta . Bul. 627.

Craig, H. B., T . N . Blumer and E. R . Barrick. 1959. Effect of severa l combinations of grass and grain i n the r a t ion of beef s t e e r s on the color charac te r i s t ics of lean and f a t . J. Anim. Sci . 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 year l ing s t e e r s in pasture and i n dry l o t . Iowa Agr. Exp. S t a . Leaflet 148.

Dome, T . W., J. Iktsushima and V . H. Arthaud. 1957. Full feeding vs. Univ. l imited feeding f o r beef production i n dry lo t and on pasture.

of Nebraska Agr. Exp. Sta . 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 ec t s on beef composition. J . Food Sc i . 36:147.

14.3

Duncan, H. R . 19%. Producing beef on grass from yearl ing and two- year-old s t ee r s w i t h and without supplemental feeds. Tennessee Agr. Ekp. S t a . Bul le t in 283.

University of

Foster and Miller. 1933. The e f f ec t s of management and sex in carcasses of year l ing 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 .

Report t o NC-58 Judge. 1967. Effect of feeding regime on bovine body composition. I. Quantitative and qua l i t a t ive carcass t r a i t s . Tech. Comm. Furdue University. Ia faye t te , Indiana.

Hams, 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 fa t ten ing beef c a t t l e . J. Anim. Sc i . 23:795.

Huffman, D . L. and Id. Griffey. 1975. Cat t le f inished on winter pasture r a t e high i n carcass qua l i ty . Highlights of Agr . R e s . Alabama Agr. Exp. S t a . 2 2 ~ 3 .

Hunt, R . E., C . 14. Kincaid and R C . Carter . 1953 Grain or-grass- fa t tened c a t t l e ? Agr. ~ x p . S t a . 458 Virginia Polytechnic I n s t i t u t e .

Jacobsen, Marion and Fa i th Fenton. 1955. Effects of th ree leve ls of nu t r i t i ve and age of animal on t h e qua l i t y of beef . iron content and pH.

11. Color, t o t a l Food Res. 21:427.

Jennings, T. G., B . W . Berry and J. K. lktsushima. 1975. Beef carcass and shelf l i f e charac te r i s t ics as affected by time on varying levels of concentrate. "Alternative Beef Production Systems . I '

Progress Report f o r Regional Project W-145.

Johnst on, David. Ph .D . Thesis. Unpublished da ta .

Kelly, Robert F. 1975. Carcass charac te r i s t ics , meat qua l i ty and consumer acceptance. Qua l i t a t ive aspects : tenderness, f lavor , juiciness , color of lean and fa 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. Report. Kansas S ta t e University. p. 78.

I n 62nd Cattleman's Day

Lofgreen, G . P. 1968. The ef fec t of nu t r i t i on on carcass cha rac t e r i s t i c s . 4 th Annual Arizona Feeds--Elanco Seminar. p . 7.

Longwell, J. H. feeding.

bhlphrus, L. D . and grain. Proc. 13th Res. Conf. Am. Meat Inst. Foundation. I l l i n o i s .

1936. Color of lean meat as affected by grass and grain W . Virginia Agr. Bkp. Sta . Bul. 274.

1961. Consumer preference f o r beef fa t tened on grass Chicago,

14 9

Meyer, B., J . Thomas, R. Buckley and J. W. Cole. 1960. The qua l i ty of grain-finished beef as a f fec ted by ripening food. 1:4.

Technol.

McCampbell, H. C . , B . E. Greene and R. S . Lowrey. 1972. Cooking and p a l a t a b i l i t y of beef from Winter pasture with and without grain and dry l o t fed c a t t l e . J. Anim. Se i . 35:200. (Abstr .)

Moody, W. G., J . E . L i t t l e Jr., F. A. T h r i f t , L. V. Cundiff and James D. Kemp. 1970. Influence of length of feeding a high roughage r a t ion on quant i ta t ive and qua l i t a t ive charac te r i s t ics of beef. J. Anim. Sci . 31:866.

Pearson, A . M. 1976. Personal cormmication.

Preston, R . L. 1971. Effects of nu t r i t i on on the body composition of c a t t l e and sheep. Proc . Georgia Feed Mfg. Conf. p. 26.

Purchas, R . W. and H. L l q d Davis. 1974. Carcass and meat qua l i t y of Fr ies ian s t ee r s fed on e i the r pasture or barley. Res. 25:183.

Aust. J. Agric.

Shenk, J . B., J . L. H a l l and H. H . King. 1934. Spectrophotometric charac te r i s t ics of hemoglobin. I. Beef blood and muscle hemoglobins. J. Biol. C h e m . 105:741.

Shinn, Je r ry , Charles Walsten, J. L. Clark, G . B . Thompson, H. B. Hedrick and W . C . Str inger . of g r in feeding on charac te r i s t ics of beef. J. Anim. Sc i . (Abstr. Midwestern Sect ion) .

1976. Effect of pasture and length

Smith, G . C. , T. R . Dutson, R . Hostetler and Z . L. Carpenter. 1974. Subcutaneous fa t thickness and tenderness of l a n i b . J . Anim. Sei . 39:174. (Abstr.)

Str inger , I!. C., H. B. Hedrick, C . L. Cramer, R . J . Conley, A . J . Dyer, G . F. Krause and R . H. White. various periods and s i re influence on quant i ta t ive and qua l i t a t ive beef carcass cha rac t e r i s t i c s .

1968. Effect of ful l - feeding f o r

J. Anim. Se i . 27:1547.

Trmbridge, P. E , , T . H. Hopper, Dorothy Berrigan and J. T. Sarvis . 1934. Conf. on Cooperative Meat Inv. North Dakota Exp. S t a .

Range pasturing and dry l o t feeding experiments with steers.

Wheeling, M. R., B . N . Berry and J. A. Carpenter, Jr. 1975. Effect of breed and forage vs . g ra in feeding on beef p a l a t a b i l i t y and shelf l i f e . Proc. Western Sec. J. Anim. Sci . 26:98.

Wilson, Charles V . 1931. Fattening two-year old s t e e r s on grass with and without a grain supplement. Mimeographed Report. West Virginia Agricul tural Experiment S ta t ion Conf . on Coop. Meat Invest .

Dave Anderson: If the speakers would come forward and be seated, w e ' l l begin our discussion period. discussion of t h e four papers.

We'll take twenty minutes f o r our Are there any questions?

Zerle Carpenter, Texas A & M: Are there cer ta in l imitat ions, as you see it, on working with d i f f e ren t types of c a t t l e r e l a t i v e t o the net energy table?

Earle Klosterman: The bigger type c a t t l e , f o r some reason, do require more feed t o put on a pound of gain. I covered it ra the r quickly, but I th ink th i s is related, perhaps, t o physiological age of a difference i n composition. In other words, a larger type animal of a given w e i g h t is probably physiologically younger and perhaps has a larger maintenance need than another animal that is nearly the same age, but physiologically more m t u r e . It may be due t o t h e f a c t that t he re ' s r e a l l y a difference i n maintenance r a the r than a difference i n the energy required f o r gain.

A 1 Pearson, Michigan Sta te : This i s not a question. I just th ink it ought t o go on record. those of you who were there m y not remember it, but a t that t i m e S l ee t e r Bull was ta lk ing about "those grass-fed c a t t l e " and he kept repeating, "those grass-fed ca t t l e . " back of the room got up, he is from Texas you know, and said, "down where I come from 'grass ' is not an obscene word."

Back a t the second Reciprocal Meat Conference,

So f i n a l l y , 0 . D . Butler, a t the

Robert A. Merkel: I have a question f o r D r . Keesey. You alluded t o hormonal involvement i n the weight e f f ec t s of your hypothalamic lesions but did not e laborate . I w a s wondering i f insu l in is involved?

R . E . Keesey: Most of our wsrk t o date has focused upon the gonadal hormones. Cur r e s u l t s indicate that the weight reduction following l a t e r a l hypothalamic lesions is independent of gonadal influences . In both males and females t h e changes i n body weight resu l t ing from gona- dectomy and l a t e r a l hypothalamic lesions a r e simply addi t ive.

The picture is somewhat d i f f e ren t i n animals w i t h ventromedial hypothalamic lesions Gonadectoqy modestly augments t he weight gain normally seen following ventromedial hypothalamic les ions in females. Castrated m l e s , however, gain near ly twice as much as gonadally-intact males following VMH les ions. The gonadal hormones do, therefore , play an important r o l e i n determining t h e l e v e l of obesi ty i n ventro-medial hy-pothalamically les ioned animals.

Robert A. Merkel: Do you how if there a re insul in changes associated w i t h these hypothalamic lesions?

g . E. Keesey: Hyperinsulinemia is a consis tent component of the obese syndrome i n ventromedial hypothalamically lesioned animals. Unfortunately, t he avai lable da t a do not answer t h e question of whether t h i s hyperinsulinemia is primary or whether it is instead a secondary consequence of t he hyperphagia and increased adiposi ty . noting i n t h i s respect t h a t vagotomy has recent ly been reported t o reverse ventromedial hypothalamic obesity. influence over pancreatic be ta c e l l secret ion is exerted v i a the Yagus, t h i s observation would tend t o favor t h e view that the insu l in ro l e is a primary one.

It may be worth

Since the cen t r a l nervous

L i t t l e is known about t he insu l in levels i n l a t e r a l hypothalamically l e s i m e d animals. One might, f o r various reasons, expect the insul in leve ls t o be lowered in such animals. Basal levels of insulin i n rats a r e already low, however, and I doubt we w i l l see s igni f icant differences in t h i s measure. The insul in response curve of the l a t e r a l hypothala- mically lesioned animal seems a more l i ke ly place t o look f o r meaningful deviations from the normal pat tern.

Allen, Minnesota: Howard, t h i s i s i n regard t o your statement about growth of the Longissimus muscle. Two questions: one, when you fast an animal, do you have a shortening of the f a s c i c u l i accompanied by a decrease i n t h e i r diameter; secondly, what are your thoughts concerning the possible l i m i t s t o fascicular length in animals that never get any depth developing i n t h e i r eye muscle?

H. J. Swatland: Regarding the f i r s t question, I mentioned i n t he t a l k the work of Joubert (J. A g r . Sci., Camb. 47:59, 1956) who found t h i s change in t h e depth of the eye muscle i n lambs on a low plane of nu t r i t i on . nu t r i t i on was imposed while animals were growing, it slowed down muscle growth while the skeleton might have continued normally. i s so spec ia l about t he longissimus d o r s i muscle is that, in contrast t o most muscles which extend from a tendon t o a bone, the longissimus muscle has greater a rch i t ec tu ra l freedom f o r f iber arrangement t o change. If you s t r i p off t he f a t from the back of a pig, as you're going down toward t h e longissimus d o r s i muscle, you come across a g l i s ten ing aponeurosis of connective t i s s u e which t h e muscle f a s c i c u l i connect onto dorsal ly . t h e length of i t s f a s c i c u l i without in te r fe r r ing with its mechanical function t o any great extent . I th ink t h i s is why there is such tremendous v e r s a t i l i t y i n the eye muscle depth. Thus, the longissimus d o r s i muscle is a l s o an odd one when it comes t o growth pa t te rns . I th ink as w e l l as being extremely important commercially, i t ' s possibly the m o s t sens i t ive muscle on the carcass t o change. Which, I guess, is why everybody i n t h e industry uses eye muscle areas s o much t o evaluate t h e carcass, becmse it may be the most sens i t ive , changeable muscle which r e f l e c t s t o t a l muscularity. I t h i n k it i s changeable because i t s area is la rge ly determined by the length of i t s f a s c i c u l i and I th ink fasc icu lar length may be a major d i rec t ion of growth as animals reach s laughter weight .

A possible explanation is t h a t when t h e low plane of

W h a t I think

So, t h i s muscle may have a unique opportunity t o change

Allen, Minnesota: But in your model, the diameter of muscle f ibe r s a l s o has a bearing on the cross-sectional a reas .

H. J Swatland: Certainly. But i n t h e pig, according t o Chrystal l -- e t al . (Growth 33:361, 1969) the re ' s very l i t t l e r a d i a l myofiber growth after 150 days. However, if you keep them longer than 150 days t h e y ' l l ce r t a in ly keep put t ing on muscle. t he length of the fasc icu l i , carcass weight and longissimus depth right up t o a very heavy weight. i n other words, muscle growth continues a f t e r cessation of radial myofi'cer growth. off a t about 150 days.

I d id a simple correlat ion between

There's a g o d cor re la t ion a l l t h e way. So,

If you were t o p l o t t h e diameters, they would f l a t t e n If you p lo t fasc icu lar length, they ju s t keep

152

growing. So, i n other words, t h i s i s the explanation f o r where the ex t ra muscle mass is coming from i n a heavier pig. I think t h i s is the r e a l importance of fasc icu lar length--i t keeps going when other things have stopped.

Allen, Minnesota: Did the fasc icu lar length decrease during f a s t ing in the study t h a t you made?

H . J. Swatland: I haven't ye t studied the e f f ec t s of f a s t ing on fasc icu lar length. I took a simple muscle and expected t o f ind tha t , according t o t h e literature, the number of fibers a t t he mid-length of t he muscle would be constant. It wasn't. During growth the 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 animals and found t h a t the numbers stopped increasing, even though the animals were ge t t ing older . So, fiber number was a function of growth and was not necessar i ly a function of age. I t 's qui te important t o separate these two biological ly .

In the f a s t ing study I did on the pig sa r to r ius ,

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 the fibers r e l a t i v e t o the contribution made by longitudinal growth.

H. J. Swatland: I see. I don't know the answer t o t h i s question i n terms of percentage of muscle weight. I guess it could be calculated. I hadn't thought t o do tha t . But i n terms of t heo re t i ca l importance, I th ink ear ly growth (prena ta l ) occurs by an increase i n t h e r e a l f i be r number. Muscle growth of t h e younger animal occurs by increases i n lqyofiber diameter and length. Muscle growth in the older an imal is j u s t by f i b e r length alone. In terms of diameter, t he r e a l l y important thing t o r e a l i z e is that d i f f e ren t f i b e r types show growth a t d i f f e ren t times w i t h t he red f ibe 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 iber growth separately from body w e i g h t . white f i b e r s . W h a t r e a l l y in t e re s t s me is the difference between red and white f iber growth. t o be manipulated.

To increase muscularity would be t o increase the growth of

I t 's the white f ibe r s whose growth may be f r ee

R . A . Merkel, Michigan Sta te : So, w e have t o be concerned w i t h what f iber types w e are measurlng when w e study animals a t d i f f e ren t ages.

H. J. Swatland: Absolutely, yes.

J i m Pr ice , Michigan: W h a t accounts f o r the difference in eff ic iency that you can see? other things?

Is t h a t a difference of absorption of energy o r of

R . E. Keesey: O u r lateral-hypothalamically l e s ioned animals absorb the same percentage of t h e i r ingested food as normals. Since t h e i r da i ly intake levels a r e a l s o normal, it appears that they a re in 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.

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 levels of l a t e r a l hypothalamically lesioned and cont ro l a n i m a l s , though we s t i l l have not looked in to the 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 ca lo r i c intake by as much as half in order t o lower i t s s t ab le l e v e l of body weight t o that maintained by a n i m l s with lateral hypothalamic les ions. Thus, I doubt that differences 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, is there any data that you have which show an e f f ec t of body type on t h e b io logica l var ia t ion i n converting feed t o body weight? That is, do you f ee l that differences i n feed conversion have a s igni f icant genetic component which i s r e l a t ed t o body type?

Earl-. Klos terman : Variation in maintenance requirement, or var ia t ion i n e f f ic iency of e n e r a use above maintenance has approxirnately a six or seven percent coef f ic ien t of var ia t ion . The absolute r a t e of gain among d i f f e ren t types of ca t t l e , however, has approximately a 15% coef f ic ien t of var ia t ion . The var ia t ion in e f f ic iency then is about half t h a t of the var ia t ion in rate of gain among c a t t l e of d i f f e ren t s i zes .

Michael Dikeman, Kansas S ta te : I have a question f o r D r . Klosterman. In your opinion, would t h e ove ra l l picture have changed if the la rger type c a t t l e had given above average milk?

k r l e Klosterman: There's no question that if the la rger types gave more milk t h e i r calves would gain a t a grea te r rate. takes feed t o produce milk as wel 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 eff ic iency.

However, it

Harold Herring, Armour: Do you th ink there is anything in grass- fed beef that serves as a pro-oxidant on myoglobin and, therefore , causes discolorat ion 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 fa t could possibly cause an excess of free rad ica ls which m i g h t have a pro-oxidant e f f e c t on the myoglobin and, therefore , r e s u l t in a darker color of t he forage-fed beef. However, t h i s is only speculation.

J. D . Kemp: May I have your a t ten t ion , please. Here a re the r e s u l t s of the elect ion: O u r new President-elect i s Larry Borchert; our new R E Chairman is Don Kinsman; and the new Directors a re : Vern Cahill, Jim Stouf'fer and Lowell Walters . Congratulations, gentlemen.

* * *

B i l l Str inger: I t ' s 8:io. k t ' s get s t a r t ed 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 report is the By-products Ut i l iza t ion Commitee. Dr . Tony Kotula w a s the 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 the members of the committee f o r t h e i r suggestions and D r . Tony Kotula, who acted a6 coordinator fo r the committee and d id most of the work on t h i s program.

I n keeping with yesterday's session on the h is tory of meat as a food, I think it is especial ly f i t t i n g tha t t h i s year's conference includes a review on by-products u t i l i za t ion . It is t h i s aspect of by-product u t i l i z a t i o n that has been especial ly important in the development of the meat industry since C i v i l War days. In 1935 the following anonymous passage was wri t ten: I n no l i n e of industry has science worked a more wonderful transformation during the last s i x t y years than i n the u t i l i z a t i o n of t he by-products of meat packing.

11

To go on, "Today, packinghouse by-products are inseparably linked up w i t h modern c iv i l iza t ion , since in one form or another, they are used by almost everyone every minute of t he day; they 'enter i n to the 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 eve the suffer ing of the s i ck and that go t o improve the education of humanity."

Un t i l about 1870, the 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 the plants, or disposed of i n dumps, trenches, or on p ra i r i e s

In 1875, a t about t h e same time as the developFent of the re f r igera t ion cars , as w e l l as oleomargarine, and the use of meat canning, things began t o change. Uses were found for edible and inedible by-products. Through the unceasing researchbythe packing industry, the number of useful products derived from l ivestock has l i t e r a l l y multiplied by the hundreds if not thousands.

Whole new industries were s t a r t ed from some of the by-product areas. These include companies engaged in the manufacture of soaps, others i n pharmaceuticals and veter inary products, ag r i cu l tu ra l chemicals and fe r t i l i zers , i ndus t r i a l chemicals, leather, adhesives and abras ives , cas ings , rendering and ge la t in .

By-Products have been and s t i l l a re being used t o support countless other industr ies . For example, h a i r is used i n sea ts , rugs and cushions and animal feed, bones and loins i n novelty f i e lds , meat scraps and tankage i n animal feeds, inedible o i l s i n lubricat ion, wool i n wearing apparel, lanol in In ointments and more recent ly collagen is 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 ac t , mny are qu i t e costly--but they are continued f o r the good of t he public.

Today w e have f i v e excel lent speakers f o r this session on by- products. We're going t o cover by-product value, blood and p lasm, pharmaceuticals, rendering and in te rna t iona l marketing.

The f irst top ic w i l l be Value of By-Products t o be presented by He was born and reared i n Mr. Donald Ferguson of Swift and Company.

DeKalb, I l l i n o i s , on a farm. He obtained hi6 B.S. from t h e University of I l l i n o i s and received h i s Ph.D. from Cornell University in Agricul tural Economics. He served four years in Agricul tural Economics Extension a t Cornell and then joined Swift and Company, where he's presently Director of Business Research. Dr. Ferguson.

Donald Ferguson: Thank you, D r . Herring. Good morning.