134.
R E L A T I V E GROWTH WI T H I N THE B O V l N E M U S C U L A T U R E
R.
T.
U N I V E R S l TY
BERG
OF
ALBERTA
...........................................................................
Important f a c t o r s i n c a r c a s s composition a r e t h e p r o p o r t i o n s of
t h e major t i s s u e s , muscle, f a t and bone and t h e d i s t r i b u t i o n , p a r t i c u l a r l y
of muscle and f a t over t h e c a r c a s s . D i f f e r e n t i a l growth p a t t e r n s of
muscle, f a t and bone as w e l l as t h e major f a c t o r s c o n t r i b u t i n g t o t h i s
d i f f e r e n t i a l growth have r e c e n t l y been d e s c r i b e d by Berg and B u t t e r f i e l d
(1968). Normally t h e percentage of muscular t i s s u e i n a c a r c a s s i n c r e a s e s
following b i r t h , t h e n d e c r e a s e s as t h e f a t t e n i n g phase b e g i n s . F a t
percentage continuously i n c r e a s e s and bone percentage d e c r e a s e s . The
r e l a t i v e p r o p o r t i o n s of muscle, f a t and bone i n a c a r c a s s can t h u s be
g r e a t l y influenced by s t a g e of development or weight a t s l a u g h t e r . I n normal
s l a u g h t e r ranges, as weight i n c r e a s e s muscle percentage decreases, f a t
percentage i n c r e a s e s and bone percentage d e c r e a s e s . Major v a r i a t i o n occurs
between t h e p r o p o r t i o n s of muscle and f a t with bone percentage remaining
r e l a t i v e l y more c o n s t a n t .
Plane of n u t r i t i o n , genotype, and sex a l s o i n f l u e n c e c a r c a s s
composition. A high plane of n u t r i t i o n i n c r e a s e s t h e percentage of f a t ,
a low plane r e t a r d s f a t and p o s s i b l y muscle development. So c a l l e d e a r l y
maturing breeds of c a t t l e e n t e r t h e f a t t e n i n g phase of growth at l i g h t e r
weights t h a n l a t e maturing breeds and have a h i g h e r p r o p o r t i o n of f a t a t
similar weights. H e i f e r s f a t t e n a t l i g h t e r weights t h a n s t e e r s and s t e e r s
a t l i g h t e r weights t h a n b u l l s o t h e r f a c t o r s being equal. Knowledge of
r e l a t i v e t i s s u e growth and t h e v a r i o u s i n f l u e n c i n g f a c t o r s can l e a d t o
feeding and management systems which are designed t o produce optimum c a r c a s s
composition from a l l breeds, t y p e s and sexes of c a t t l e .
Perhaps of g r e a t e r importance t h a n gross c a r c a s s composition i s
t h e d i s t r i b u t i o n of muscle and f a t i n t h e v a r i o u s p a r t s of t h e c a r c a s s i n
r e l a t i o n t o t h e p o s s i b i l i t y of i n c r e a s i n g t h e p r o p o r t i o n of high-priced c u t s
a t t h e expense of lower-priced r e g i o n s . F a t d i s t r i b u t i o n and/or muscle
d i s t r i b u t i o n may a f f e c t p r o p o r t i o n s of wholesale or r e t a i l c u t s from a
c a r c a s s . It i s w e l l known t h a t f a t i s deposited d i f f e r e n t i a l l y i n v a r i o u s
r e g i o n s . L u i t i n g h (1962) showed how t h e f a t t e n i n g process affects proport i o n s of d i f f e r e n t c u t s by a r e l a t i v e l y g r e a t e r i n c r e a s e i n t h e v e n t r a
p a r t s and i n t h e areas of major f a t depots. 'Although f a t d i s t r i b u t i o n i s
implicated as t h e most important f a c t o r c o n t r i b u t i n g t o d i f f e r e n c e s i n
c a r c a s s proportions, it w a s long thought and s t i l l h e l d by some t h a t muscle
d i s t r i b u t i o n a l s o h a s a major i n f l u e n c e . The remainder of t h i s paper w i l l
attempt t o examine v a z i a b i l i t y i n muscle d i s t r i b u t i o n and f a c t o r s which
influence r e l a t i v e muscle growth and p r o p o r t i o n s i n t h e bovine c a r c a s s .
RELATIYE MUSCLFI GROWTH
R e l a t i v e muscle growth has been s t u d i e d by anatomical d i s s e c t i o n
of slaughtered animals of v a r i o u s ages, weights and b r e e d s ( B u t t e r f i e l d and
Allometric growth c o e f f i c i e n t s were c a l c u l a t e d f o r i n d i v i d u a l
Berg, 1966a)
muscles and c l a s s i f i e d i n t o growth impetus groups i n d i c a t i n g t h e i r r e l a t i v e
.
135.
growth. Muscles which showed a steady growth impetus r e l a t i v e t o t o t a l ,
muscle were given t h r e e monophasive growth impetus c l a s s i f i c a t i o n s of
"high" "average" aid "low"
"High impetus" i n d i c a t e d a p r o p o r t i o n a t e l y
f a s t e r rate of growth t h a n t o t a l muscle and a growth c o e f f i c i e n t g r e a t e r
t h a n 1 . 0 , ''low impetus" muscles grew a t a p r o p o r t i o n a t e l y slower r a t e t h a n
t o t a l . muscle with a growth c o e f f i c i e n t of l e s s t h a n 1 . 0 and "average
impetus" muscles maintained a c o n s t a n t p r o p o r t i o n r e l a t i v e t o t o t a l muscle.
The monophasic growth impetus groups are schematically i l l u s t r a t e d i n
Figure 1 on 8 log-log s c a l e used for c l a s s i f i c a t i o n purposes and i r , Figure
2 as a percentage of t o t a l muscle.
,
.
Some muscles were found t o have d i p h a s i c growth p a t t e r n s i n t h a t
t h e i r p a t t e r n of growth changed a t some stage i n p o s t n a t a l development.
Diphasic growth p a t t e r n s c l a s s i f i e d were "high-average", "average-high"
and "low-average" and t h e i r growth p a t t e r n s a r e i l l u s t r a t e d i n Figure 3 .
Most of t h e muscles which showed d i p h a s i c p a t t e r n s f i n i s h e d t h e i r i n i t i a l
s t a g e of d i f f e r e n t i a l growth e a r l y i n p o s t n a t a l l i f e . Berg and B u t t e r f i e l d
(1968) r e p o r t e d t h a t over t h e f i r s t age phase (0-84 days of age) 2 1 muscles
r e p r e s e n t i n g 41.4% of t h e t o t a l musculature, showed growth impetus p a t t e r n s
I n t h e remaining f o u r age phases,
s i g n i f i c a n t l y d i f f e r e n t from "average".
from t h r e e t o e i g h t muscles r e p r e s e n t i n g from 4 t o 9% of t o t a l muscle
showed growth impetus p a t t e r n s s i g n i f i c m t l y d i f f e r e n t from "average". T h i s
w a s t a k e n t o i n d i c a t e t h a t major d i f f e r e n t i a l growth w i t h i n t h e musculature
t a k e s place soon after b i r t h and would p l a y a minor r o l e i n a f f e c t i n g t h e
composition of animals of norma3 s l a u g h t e r weights. A s t h e foregoing results
were obtained from animals of vaxiable n u t r i t i o n a l . arid g e n e t i c background,
d a t a from more c o n t r o l l e d experiments w i l l be necessary i n order t o s o r t out
any n u t r i t i o n a l , g e n e t i c or o t h e r e f f e c t s .
IlUFZUENCE OF RALCE OF GROWTH ON MUSCL;E WEIGHT DISTRIBUTION
It w a s once widely held t h a t rate of growth would i n f l u e n c e muscle
weight d i s t r i b u t i o n and t h u s c a r c a s s p r o p o r t i o n s . The l o i n as a high-priced
a r e a w a s c l a s s e d as l a t e maturing and r a p i d growth w a s supposed t o r e s u l t i n
i n c r e a s i n g t h e p r o p o r t i o n of t h i s region. Since n o s t d i f f e r e n t i a l muscle
growth seems t o occur soon a f t e r b i r t h , t h i s w a s considered an a p p r o p r i a t e
phase i n which t o i n v e s t i g a t e t h e e f f e c t of r a t e of growth on d i f f e r e n t i a l
muscle growth. An i n i t i a l experiment involving c a l v e s grown 'a.t two r a t e s w a s
d e s c r i b e d by Berg and B u t t e r f i e l d (1968). The rates of muscle growth i n t h e
two groups i s shown i n Figure 4. Muscles with "high-average" growth impetus
are p l o t t e d i n Figure 5 a g a i n s t t h e age of t h e animal and i n Figure E
a g a i n s t t o t a l muscle weight. When comparisons were made on an age b a s i s t h e
d i f f e r e n t i a l growth of t h i s group of muscles w a s r e t a r d e d b u t , when compared
on t h e b a s i s of t o t a l muscle weight, r a t e of growth had no d i f f e r e n t i a l .
e f f e c t . Slow growth merely slowed t h e whole process down i n a normal a l l o m e t r i c manner r e l a t i v e t o t o t a l muscle growth. S i m i l a r l y , muscles with a
r ' l o ~ lgrowth
l
impetus p a t t e r n take l o n g e r t o d e c l i n e t o t h e i r adult proport i o n s i n animals on a poor n u t r i t i o n a l regime and t h e p r o p o r t i o n of "average"
impetus muscles i s unaffected by plane of n u t r i t i o n .
B u t t e r f i e l d , Johnson and Berg (1968) r e p o r t e d a f u r t h e r experiment
where 3 groups of c a l v e s were grown at widely d i f f e r i n g r a t e s , oce group
very f a s t , one a t a moderake r a t e and t h e t h i r d group held at t h e i r b i r t h
weight f o r 70 days and t h e n grown moderately f a s t . S e r i a l s l a u g h t e r w a s
done based on l i v e weight and i n d i v i d u a l muscles were d i s s e c t e d and weighed.
136.
"High", "average" and r r l o ~ impetus
rr
groups of muscles were examined from
animals on each of t h e t h r e e p l a n e s of n u t r i t i o n . A growth c o e f f i c i e n t of
1 . 1 2 f o r "high" impetus muscles w a s common t o all 3 p l a n e s of n u t r i t i o n ,
while 1 . 0 described t h e "average" muscles and 0.89 t h e "lowff impetus
muscles. These results emphasize t h e need t o compare r e l a t i v e muscle
weight on t h e b a s i s of similar t o t a l muscle weights.
INFLUENCE OF RF,LfiTIVE MUSCLE GROWTH ON PROPORTIONS OF COMMERCIALLY IMPORTART
MUSCU GROUPS
B u t t e r f i e l d and Berg (196613) described growth impetus p a t t e r n s f o r
9 anatomical groupings of muscles and compared t h e s e t o p r e v i o u s l y described
comparisons on a percentage b a s i s ( B u t t e r f i e l d , 1963). Both c l a s s i f i c a t i o n s
axe l i s t e d i n Table 1. An experiment i s underway at t h e U n i v e r s i t y of
A l b e r t a t o attempt t o a s s e s s t h e v a l i d i t y of t h e i r importance r e l a t i v e t o
muscle d i s t r i b u t i o n . Four c a l v e s were slaughtered and d i s s e c t e d s h o r t l y
a f t e r b i r t h (from 1 2 t o 27 days of age) t o e s t a b l i s h a base f o r d i f f e r e n t i a l
muscle growth. S e r i a l s l a u g h t e r of h e i f e r s , s t e e r s and b u l l s was t h e n
c a r r i e d out f o r animals i n t h e range of 250 t o 500 kg. l i v e weight and 8 t o
1 4 months i n age. All animals were s i r e d by Shorthorn bulls from a v a r i e t y
of dams of 2 y e a r s of age. C a v e s were nursed on t h e i r dams t o approximately
6 months of age (except t h o s e slaughtered e a r l y ) and were t h e n s e l f - f e d u n t i l
s l a u g h t e r on a 73% b a r l e y , 22% o a t s , 5% protein-mineral-vitamin-supplemented
r a t i o n . Brome-alfalfa hay w a s l i m i t e d t o 2 lb. p e r head p e r day.
The percentages of t o t a l muscle i n each of t h e standard muscle
groups a r e shown i n F i g u r e s 7 t o 1 0 f o r c a l v e s ( C ) , h e i f e r s ( H ) , s t e e r s ( S ) ,
and b u l l s (B) r e l a t i v e t o t h e t o t a i l muscle weight i n one s i d e of t h e
c a r c a s s . Each p o i n t r e p r e s e n t s 4 animals except t h e 3 h e a v i e r groups f o r
each sex r e s p e c t i v e l y where only 2 animals per group were a v a i l a b l e t o d a t e .
There i s good agreement of t h e growth p a t t e r n s i n d i c a t e d i n
F i g u r e s 7 t o 1 0 and t h o s e proposed i n Table 1 f o r 6 of t h e 9 standard
muscle groups. However, Group 1 (proximal p e l v i c limb) i s l i s t e d as highaverage or low i n Table 1 b u t f o l l o w s a low or average-low p a t t e r n i n
F i g u r e 7. P l o t t i n g of o t h e r d a t a from B u t t e r f i e l d and Berg (1966a) has l e d
us t o t h e t e n t a t i v e conclusion t h a t t h i s group of muscles may have a very
early r i s e i n percentage followed by a continuous decrease i.e. a high-low
p a t t e r n . The d a t a i n F i g u r e 7 axe not complete enough t o d e t e c t such a
rise if it exists. Group 2 muscles ( d i s t a l p e l v i c limb) appear t o follow a
reasonably c o n s t a n t low impetus p a t t e r n .
Group 3 muscles (surrounding s p i n a l column) seem t o follow a highaverage p a t t e r n of growth i n Figure 8 r a t h e r t h a n average a s shown i n
Table 1. The growth c o e f f i c i e n t f o r t h e M. longissimus d o r s i ( t h e l a r g e s t
muscle i n t h i s group) w a s given by B u t t e r f i e l d and Berg (1966a) a s 1 . 1 2
(high) i n t h e f i r s t phase of growth and not s i g n i f i c a n t l y d i f f e r e n t from 1 . 0
t h e r e a f t e r and t h e growth p a t t e r n shown i n F i g u r e 8 for Group 3 corresponds
agree i n
t o t h e p a t t e r n of t h i s muscle. Group 4 muscles (abdominal WU)
F i g u r e 8 and Table 1 with a high p a t t e r n f o r h e i f e r s and t e n d i n g toward
high-average f o r s t e e r s and b u l l s .
Group 5 muscles (proximal t h o r a c i c limb) show a low-average
growth impetus p a t t e r n i n Figure 9 i n agreement with Table 1. The muscles
of t h e d i s t a l t h o r a c i c limb (group 6) have a s i m i l a r p a t t e r n t o t h e proximal
group and low-average impetus appears t h e b e s t d e s i g n a t i o n .
137.
Growth p a t t e r n s of muscles of t h e t h o r a x and neck a r e p l o t t e d
i n Figure 10. Group 7 ( t h o r a x t o t h o r a c i c limb) h a s a high growth impetus
and group 8 (neck t o t h o r a c i c limb) follows an average-high p a t t e r n both i n
agreement with Table 1.
Group 9 (neck t o thorax) i s l i s t e d as low-average i n Table 1 but
Figure 1 0 shows a high impetus p a t t e r n for b u l l s and a near average p a t t e r n
f o r h e i f e r s and s t e e r s . B u t t e r f i e l d (1963) described t h i s group as very
l a t e developing and t h e r e f o r e t h e expected upturn may not have developed i n
t h e r e l a t i v e l y young animals represented i n Figure 10.
The t h r e e sexes appear t o have s i m i l a r p r o p o r t i o n s i n muscle
groups 2, 5, 6, 7 . B u l l s seem t o have h i g h e r p r o p o r t i o n s i n muscle groups
8 and 9 and h e i f e r s show h i g h e r p r o p o r t i o n s i n groups 3 and 4. These t r e n d s
have not been t e s t e d s t a t i s t i c a l l y .
Although t h e preceding results show t h a t p r o p o r t i o n s of i n d i v i d u a l
muscles and anatomical muscle groupings do change during t h e course of
normal development due t o d i f f e r e n t i a l muscle growth, it would be premature
t o comment on t h e economic i m p l i c a t i o n s of t h e s e changes except t h a t those
changes which do occur a r e not i n t h e d i r e c t i o n of more d e s i r e a b l e c a r c a s s
p r o p o r t i o n s i . e . group 1 and group 3 do not i n c r e a s e a f t e r t h e i n i t i a l
phase. It should be mentioned also t h a t o n l y weight of muscle h a s been
considered and composition changes i n i n d i v i d u a l muscles must be determined
before f i n a l i n t e r p r e t a t i o n s can be made.
These preliminary r e s u l t s i n d i c a t e t h e need f o r e s t a b l i s h i n g
normal growth p a t t e r n s of muscles and muscle groups previous t o s e t t i n g up
comparisons involving muscle d i s t r i b u t i o n between breeds sexes and n u t r i t i o n a l or o t h e r t r e a t m e n t s . It seems adviseable t o make comparisons a t an
equal t o t a l muscle weight or along curves e s t a b l i s h e d by s e r i a l s l a u g h t e r
of experimental groups. B u t t e r f i e l d (1965) compared t h e muscle d i s t r i b u t i o n
of f i v e breeds from d i v e r s e backgrounds and found l i t t l e d i f f e r e n c e i n
p r o p o r t i o n s of any of the staxdazd muscle groups except t h e abdominal muscle
group. T h i s may i n d i c a t e t h a t a t normal s l a u g h t e r weights muscle proport i o n s a r e reasonably c o n s t a n t over a d i v e r s i t y of genotypes and environmental c o n d i t i o n s . More c o n t r o l l e d experiments a r e necessary t o r e s o l v e
t h e s e and o t h e r q u e s t i o n s .
REFERENCES
Berg, R . T . and R. M. B u t t e r f i e l d . 1968. Growth p a t t e r n s of bovine muscle,
f a t and bone. J. Animal S e i . 27: 611 - 619.
B u t t e r f i e l d , R. M. 1963. R e l a t i v e growth of t h e musculature of t h e ox.
I n symposium on c a r c a s s composition and a p p r a i s a l of m e a t animals.
Melbourne, A u s t r a l i a .
(Ed. Tribe, D. E . ) . 7-1. C.S.I.R.O.,
B u t t e r f i e l d , R . M. 1965. P r a c t i c a l i m p l i c a t i o n s of anatomical r e s e a r c h i n
beef c a t t l e . Proc. N.Z.
SOC. An. Prod. 25: 152-162.
B u t t e r f i e l d , R. M. and R. T . Berg. 1966a. A c l a s s i f i c a t i o n of bovine
rnuscles based on t h e i r r e l a t i v e growth p a t t e r n s . Res. Vet. S c i .
7: 326
332.
-
138.
B u t t e r f i e l d , R. M. and R . T. Berg. 1966b. R e l a t i v e growth p a t t e r n s of
commercially important muscle groups of c a t t l e . R e s . Vet. S e i .
7 : 389 - 393.
B u t t e r f i e l d , R . M., E. R. Johnson and R. T. Berg. 1968. The e f f e c t of
r a t e of growth on r e l a t i v e growth of muscles. Meeting of Anatomical
S o c i e t y of A u s t r d i a and New Zealand, Brisbane, A u s t r a l i a . ( A b s t r .
J. Anatomy, i n p r e s s )
.
Huxley, J.
1932.
Problems of r e l a t i v e growth.
Methuen, London.
L u i t i n g h , H. C . 1962. Developmental changes i n beef s t e e r s as influenced
by f a t t e n i n g , age and type of r a t i o n . J. Agric. S e i . , 58: 1 47.
-
COMPARISON OF INTERPRETATION OF ANALYSIS OF GROWTH OF 'STANDARD MUSCL;E
GROUPS' USING GROWTH COEFFICIEECS (HUXLJCY, 1932) AND DlRECT COMPARISON OF
PERCENTAGE VALUES
Muscle group
Growth c o e f f i c i e n t
"b"
D i r e c t c ompar ison
of p e r c e n t age s
( B u t t e r f i e l d , 196313)
1. P r o x i m a l p e l v i c limb
High-average or low
Late
2 . D i s t a l p e l v i c limb
Low
Early
3. Surrounding s p i n a l column
Average
Average
4. Abdominal w a l l
High-average or high
Late
5. P r o x i m a l t h o r a c i c limb
Low-average
Early
6. D i s t a l t h o r a c i c limb
Low-average or low
Early
7. Thorax t o t h o r a c i c limb
High
Very l a t e
8. Neck t o t h o r a c i c limb
Average-high
Very l a t e
9. Neck t o t h o r a x
Low- aver age
Very l a t e
1)
From B u t t e r f i e l d and Berg, 196613.
139.
/
GROWTH IMPETUS
HIGH
AVER AGE
LOW
Y
A
/ y=a+
( b = growth
b Xcoefficient)
X
LOG TOTAL MUSCLE
Figure 1:
Schematic Representation of Monophasic Muscle Growth
Impetus Groups on a Log-log Scale.
140.
GROWTH IMPETUS
HIGH
AVERAGE
LOW
(B=
'/'e
a t Birth)
TOTAL MUSCLE
Figure 2:
Schematic Representation of Monophasic Muscle Growth
Impetus Groups as a Percentage of Total Muscle.
141.
GROWTH IMPETUS
HIGH AVERAGE
/
B
AVERAGE HIGH
i
LOW AVERAGE
(B=
at
Birth)
TOTAL MUSCLE
Figure 3:
Schematic Representation of Diphasic Muscle Growth Impetus
Groups as a Percentage of Total Muscle.
142.
M - (HIGI-1 P L A N E ) ----1 - (LOW PLANE)
---a-
/*
/”
H
7
6
8
LLA
I
0
I
4
/
/
L’
I
8
I
I
I
12 15
I
22
AGE (WEEKS)
Fig. 4:
Muscle growth i n calves fed two planes of nutrition
(Berg and Butterfield, 1968).
143.
H - (HIGH PLANE)
L - (LOW PLANE) - - - -
L
35
34
33
32
31
B
I
0
Fig. 5:
I
4
I
I
I
12 IS
AGE (WEEKS)
E
I
22
High-average impetus muscles as a percentage or' total
muscle in carcasses of calves fed t w o planes of nutrition
(Berg and Butterfield, 1968).
144.
H - (HIGH PLANE)
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149.
L. E. WALTERS: On behalf of t h e Committee and t h e Conference, I
would l i k e t o say 2 s p e c i a l thank-you to t h e t h r e e speakers on our program,
and we w i l l now t u r n t h i s over t o D a l e Zinn f o r t h e d i s c u s s i o n .
D. W. ZINN:
Thank you, Lowell.
I t h i n k t h e t h r e e papers which have been presented t o u s t h i s
afternoon should have r a i s e d a number of questions i n our minds concerning
t h e e v a l u a t i o n of c a r c a s s composition, t h e growth and development of t h e
animal. They might s t i l l l e a v e u s room t o t h i n k about t h e f a c t t h a t while
at t h e same weight, we may have similar composition i n t h e animal, t h e age
of t h e animals a t which t h e y reach t h a t weight may be a very important
f a c t o r as far as t h e economy of production of m e a t i s concerned. I t h i n k
t h a t Dr. Berg i n d i c a t e d t h a t he does not q u i t e b e l i e v e t h a t all animals a r e
of t h e same composition if of t h e same weight. I t h i n k t h a t t h e papers have
presented u s a number of important t h i n g s t h a t we need to consider now or
l a t e r , and I t h i n k it a l s o i n d i c a t e s what w a s pointed out by one of t h e
speakers, D r . Caster, t h i s morning, t h a t we a r e going t o have t o l e a n an
awful l o t more about how t h e animal grows and develops and how t h e i n t e r a c t i o n of g e n e t i c s and n u t r i t i o n and environment and management influence
growth and development i f we a r e t o continue t o produce meat and p r o t e i n f o r
consumption i n t h i s world. I t h i n k Dr. Caster i n d i c a t e d t h i s morning t h a t
we wouldn't be feeding g r a i n t o l i v e s t o c k t o o much longer. If we are, we
are going t o have t o become much more e f f i c i e n t i n doing so.
Do we have any questions from t h e audience? If you do, please
speak up loud--there me some microphones spotted wound t h a t w i l l p i c k it
up. I understand I have about f o u r minutes l e f t f o r questions, s o l e t ' s
have them.
BOB KAUFFMAN from Wisconsin: T h i s i s d i r e c t e d t o D r . Reid, and I
guess 1 am r e p r e s e n t i n g a b m t 75% of t h e group t h a t i s here--1 d o n ' t know
about t h e o t h e r 25%. J u s t r e c e n t l y at our s t a t i o n , we looked at t h e compos i t i o n of some c a r c a s s e s on a r a t h e r r o u t i n e r a t h e r n e g l i g i b l e b a s i s on t h e
e only had 70 and you had hundreds. But I wonder i f
b a s i s of your work. W
you could e x p l a i n t o me how we happened t o f i n d when we looked at t h e p i g
c a r c a s s e s on a f a t - f r e e muscle b a s i s t h a t w e were able t o o b t a i n as much as
1 0 kilograms d i f f e r e n c e i n p i g s of t h e same weight, and also another observ a t i o n of about 55 c a t t l e i n which we obtained a c o e f f i c i e n t of a l i t t l e b i t
above zero between body weight and composition of t h e c a r c a s s .
J. T. REID: F i r s t l e t me c l a r i f y what appears t o be a misconcept i o n which I hadn't recognized u n t i l Dr. Berg's comment. The context i n
which I a m d e a l i n g and i n which I f e e l q u i t e corcfident i n t h a t with m e a t producing animals we a r e dealing with r e l a t i v e l y immature a n i m a l s - - w e are
d e a l i n g with p i g s t h a t d o n ' t weigh more t h a n perhaps 250 pounds and c a t t l e
perhaps no l a r g e r t h a n 1200 or so. W
e are d e a l i n g with r e l a t i v e l y immature
animals. Now another t h i n g t h a t I t h i n k can lead t o misconceptions: t h a t i s
when we a r e d e a l i n g with anatomical groups, i f we a r e d e a l i n g with c u t s , or
d e a l i n g with separated f a t s from c u t s , we are not r e a l l y comparing separated
f a t s t o e t h e r e x t r a c t e d f a t s nor me we comparing muscle t o p r o t e i n . On t h e
chemical basis, t h e y found no d i f f e r e n c e , and it was on t h i s b a s i s t h a t I
showed you t h e i r d a t a . Most of t h e d a t a 1 showed you are based on chemi c a l l y analyzed substances, not p h y s i c a l l y s e p m a t e d . Now i n some i n s t a n c e s
150.
I showed you some t h a t were physically separated, but which were a t t h e same
t i m e , chemically analyzed.
D. W. ZINN: Thank you, Dr. Reid f o r t h e s e additional. comments.
Do we have any other questions?
QUESTION: I ' m W a l t Kinnick from Oregon S t a t e . I would l i k e t o
address a question t o Richard Waldman. D i d you hold age constant i n your
analysis? I n other words, are you t a l k i n g about a n u t r i t i o n a l difference or
an age difference?
RICHARD WALDMAN: I t h i n k t h a t you are r i g h t i n t h a t we d i d not
hold age constant i n t h i s a n d y s i s , but we haven't r e a l l y gone t o o f a r i n
t h e a n a l y s i s of t h i s data. what you s a w w a s j u s t t h e f i r s t attempt t o g e t
it on some kind of l o g i c a l setup, and I would say t h a t age possibly i s i n fluencing t h e d a t a on t e s t s of t h i s , and also t h a t t h e highs were always
f a t t e r t h a n t h e mediums and so we hope t o come up with some of t h e explanat i o n s of why we do not f i n d l a r g e d i f f e r e n c e s i n tenderness between all t h e
animals of such varied age groups. These animals never were over 23 months
of age. I d o n ' t know whether 2 3 months of age i s going t o a f f e c t tenderness
or not, but it might; but t h i s w a s analyzed with animals at d l d i f f e r e n t
ages.
D. W.
ZINN: Thank you Dick.
One more question.
DP;LE HUFFMAN:
I am i n sympathy with what Bob Kauffman has said
here, but D r . Reid I would l i k e t o ask you. Perhaps t h e f a c t t h a t we are
looking a t only one component of t h e animal, r a t h e r t h a n t h e e n t i r e animal.,
could cause some of t h e experiences here.
DR. REID: Yes, I t h i n k t h i s i s possible, e s p e c i a l l y i f you only
use one body p a r t , say, a l o i n , and estimate t h e mean t o t h e t o t a l body. So
far, as accounting f o r t h i s major difference, I'm not sure, because it i s
not r e a l l y c l e a r whether t h i s i s one p a r t or whether it i s one side, and a s
I pointed out t h e r e are some n u t r i t i o n a l d i f f e r e n c e s which have been
described. The mere f a c t t h a t we haven't found some doesn't m e a n t h a t t h e r e
a r e n ' t any.
D. W. ZINN: I t h i n k we could continue t h i s discussion t h e rest of
t h e afternoon, but they t o l d me t o cut it off i n seven minutes, and it i s
t h a t time. Please reassemble i n here a t t h r e e - t h i r t y .
Thank you.
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