Citation
Vitamins A and E in steer fattening rations

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Title:
Vitamins A and E in steer fattening rations
Series Title:
Bulletin - University of Florida Agricultural Experiment Station ; 748
Creator:
Chapman, H. L. Jr.
Shirley, R. L.
Palmer, A. Z.
Carpenter, J. W.
Place of Publication:
Gainesville, Fla.
Publisher:
Agricultural Experiment Stations, Institute of Food and Agricultural Sciences, University of Florida
Publication Date:
Language:
English

Subjects

Subjects / Keywords:
Vitamins ( jstor )
Vitamin E ( jstor )
Fats ( jstor )

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University of Florida
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All applicable rights reserved by the source institution and holding location.

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Bulletin 748
o314bBulletin 748


December 1971


Marston Sciec-

MAR 2 5 1993

University of Florida


VITAMINS

A and E


ie..


H. L. Chapman, Jr.
R. L. Shirley
A. Z. Palmer
J. W. Carpenter


Florida Agricultural Experiment Stations
Institute of Food and Agricultural Sciences
University of Florida, Gainesville
J. W. Sites, Dean for Research














CONTENTS


Page


Vitamin A and E Supplementation on Pasture ..-.................... ........... 3

Experiment 1. Levels of Vitamin A and E .........3... ....... 3

Experiment 2. Effect of Level of Concentrate Intake ................ 6

Experiment 3. Orally Administered Vitamins A and E ............-- 7

Experiment 4. Injected Vitamin A and E ............................... 10

Experiment 5. Oral vs. Injected Vitamin A and E ................... 12

Experiment 6. Different Forms of Vitamin E ..... .............. 13

Vitamin A and E in Drylot ............................................ 16

Experiment 7. Vitamin A with and without Pangola Hay............ 16

Experiment 8. Vitamin A and Vegefat -......... ............... 17

Experiment 9. Orally Administered Vitamin A and E ............. 17

Experiment 10. Orally Administered Vitamin A and E .............. 19

D discussion ......... ..... ........ ...... ....-.-. ...-......... .._ ...... ............ 21

Sum m ary ... ..... ...................... ..... ..--........-... .......- 24

L literature C ited ..............- ................. ......--. .....-... .... ....- --- 25

Appendix -- --... ...... ............ ................ .............. 26

Formulas Used To Calculate Carcass Data ................................... 26

Codes Used at Meats Laboratory .......................... .- .... ---- ..- 26

Acknowledgements -........................ ...... .. ...... ...... .... .... 29








VITAMINS A AND E IN STEER FATTENING RATIONS
H. L. Chapman, Jr., R. L. Shirley,
A. Z. Palmer and J. W. Carpenter1

Many changes have occurred in beef cattle feeding practices
since 1935 when the Vitamin A requirement was first established
(8).2 Recent information indicates that the requirement for
synthetic A is larger than formerly thought (2, 10, 15). It has
been demonstrated that many factors affect the utilization of
vitamin A by cattle (6, 9), including fat and vitamin E content
of diet, physical well-being of the animal, and body stores of
vitamin A. Other factors that may be involved in vitamin A
utilization include thyroid activity. (3, 17), phosphorus (13),
and dietary nitrate nitrogen (4, 12).
Forages have been thought to contain sufficient vitamin E
to furnish the need of beef cattle, and it has not been considered
necessary to provide supplemental vitamin E in beef cattle
rations (9). However, recent reports (4, 12) emphasized that
a possible vitamin A and E interrelationship may exist for beef
cattle under certain conditions.
This bulletin presents the results of experiments conducted
from 1962 to 1970. The purpose of these experiments was to
determine if an interrelationship of vitamins A and E existed
for beef cattle; determine the optimum level of each vitamin
for beef cattle; determine if season of the year or level of con-
centrate feed intake affected response to either vitamin; and
determine if pangolagrass hay or vegetable fat affected the
utilization of vitamin A.

VITAMINS A AND E SUPPLEMENTATION ON PASTURE
Experiment 1. Levels of Vitamin A and E
The purpose of this experiment was to determine if vitamins
A and E would stimulate the rate of gain of steers being
fattened on Roselawn St. Augustinegrass during the winter
months, what level of each vitamin should be used, and if there
was an interrelationship between the two vitamins. Seventy-
1Dr. Chapman is Professor (Animal Nutritionist) and Center Director,
University of Florida, Agricultural Research Center, Ona. Dr. Shirley is
Professor (Animal Nutritionist), Dr. Palmer is Professor (Meat Scien-
tist), and Dr. Carpenter is Professor (Meat Scientist), University of
Florida, Animal Science Department, Gainesville.
2 Numbers in parentheses refer to literature cited.














Table 1. Summary of weight gain, carcass and feed consumption data as affected by different levels of vitamins A and E on
winter pasture. (Experiment 1, 136 days on test.)

Lot number 1 2 3 4 5 6 7 8 9
Level of A (I.U.) 0 25,000 50,000 0 25,000 50,000 0 25,000 50,000
Levels of E (L.U.) 0 0 0 50 50 50 250 250 250

Number of animals 8 8 8 8 8 8 8 8 8
Final weight (Ibs) 1078 1118 1137 1088 1089 1111 1084 1114 1102
Initial weight (Ibs) 758 761 762 759 758 759 756 757 761
Total gain (Ibs) 320 357 375 329 331 352 328 357 341
Daily gain (Ibs)* 2.35 2.62 2.76 2.42 2.44 2.59 2.41 2.62 2.51
Dressing per cent 61.3 59.1 59.6 61.2 60.8 60.4 62.0 60.7 60.6
Final slaughter grade 15 14 15 15 14 15 15 15 14
Initial slaughter grade 10 10 10 10 10 10 10 10 10
Increase 5 4 5 5 4 5 5 5 4
Daily feed intake (Ibs) 23.0 23.3 24.1 23.2 23.3 23.0 22.2 24.0 23.4
* Effect of vitamin A significant at P<.01.








two two-year-old steers of mixed breeding were divided into
nine equal groups on the basis of weight, grade, and breed. The
groups were randomly allotted to the treatments presented in
Table 1. The concentrate feed was comprised of 48.8% ground
snapped corn, 40% dried citrus pulp, 10% cottonseed meal
(41%, old process), 0.8% urea-262, and 0.4% mineral mix-
ture.3 Vitamins A and E were mixed in the ration daily to
furnish the desired average daily intake per animal. No di-
ethylstilbestrol or other feed additives were used.
Prior to being placed on experiment the steers were treated
twice, at 21-day intervals, with 6 ounces each of phenothiazine
and hexachlorethane for gastro-intestinal parasites and liver
flukes.
An initial slaughter grade was placed on each animal by a
grading committee. The final grade was the carcass grade given
by a USDA meat grader. Procedures for collecting carcass data
are given in the Appendix.
Samples of heart, liver, and gracilis muscle tissue were ob-
tained post mortem for vitamin A, ash, dry matter, and copper
determination. Forage samples were obtained monthly for prox-
imate analysis, carotene, and nitrate nitrogen determinations.
Carotene was determined by AOAC method (1) and nitrate
nitrogen by the method of Nelson et al. (11). Vitamin A was
determined by the method of Gallup and Hoefer (7).
Weight changes, carcass data, and feed consumption are
presented in Table 1. Vitamin A had a highly significant effect
on rate of gain. Twenty-five thousand units of A stimulated
the rate of gain 11.5% and 50,000 units slightly over 17% as
compared to the steers receiving no vitamin A. There was less
response in growth rate to vitamin A when it was given together
with vitamin E. The latter vitamin did not significantly affect
rate of gain. Vitamin A or E did not significantly affect dress-
ing per cent or slaughter grade.
The level of carotene and KNO3 in the forage is presented
in Table 2. The average carotene level was 56.0 milligrams per
pound of dry matter, and the average KNO3 level was 0.35%.
The results of heart and liver tissue analyses are presented
in Table 3. Vitamin A significantly (P<.01) affected the level
of vitamin A stored in the liver. Vitamin E significantly affected

' The same mineral mixture was used in all experiments, except the last two.
The mineral mixture consisted of 40% defluorinated phosphate, 22.5%
steamed bonemeal, 24.5% common salt, 2.5% ferrous sulfate, 3.2% cupric
sulfate, 0.15% cobalt sulfate, and 7.15% millrun blackstrap molasses.








the level of this vitamin stored in the liver (P<.05) and also
the amount of copper (P<.01).

Table 2. Average carotene and KNO, content of forage1.
Experiment Carotene KNO,
number (mg/lb) (%)

1 56.0 0.35
2 19.2 0.30
3 76.7 0.18
4 74.0 0.22
5 53.7 1.03
Expressed on an oven-dry basis.


Experiment 2. Effect of Level of Concentrate Intake
The purpose of this experiment was to determine if the level
of concentrate feed intake affected the value of vitamin A and
E for steers being fattened on Roselawn St. Augustinegrass.
Sixty-four two-year-old steers of mixed breeding were divided
into eight groups on the basis of breed, grade, weight, and
previous treatment. The groups were randomly allotted to the
treatments presented in Table 4. Limited fed groups received
6.0 pounds of feed a day per steer, and full-fed groups received
all the feed they wanted. The limited-fed concentrate was com-
prised of 40.35% ground snapped corn, 40% dried citrus pulp,
18% cottonseed meal (41%-old process), and 1.65% mineral
mixture. The full-fed concentrate was the same as that used in
experiment 1. Experimental procedure was identical with ex-
periment 1, except that dressing per cent was calculated as
follows:

Warm carcass weight x 97.5
Dressing % = x 100
Packing house weight

Average weight gain, carcass data, and feed consumption
data per steer are presented in Table 4. Both vitamin supple-
mentation (P<.05) and concentrate feed intake (P<.01) sig-
nificantly affected rate of gain. Steers receiving a limited intake
of concentrate gained 0.43 pound more per day when vitamin
A was fed and 0.63 more daily when vitamin E was fed, as com-
pared to the steers not receiving the supplemental vitamins. As
during the first experiment, the response in gain was less when
the two vitamins were fed together. The steers on full feed had








less gain increase than the limited-fed steers when the vitamins
were added, being 0.04 pound when vitamin A was added and
0.30 pound when vitamin E was added. When the two were fed
together the additional increase in weight gain was 0.25 pound.
The two vitamins had no significant effect on slaughter grade,
intransit shrink, or dressing per cent.
The average forage carotene level was 19.2 mg/Ib, and
KNO3 was 0.30% on an oven-dry basis (Table 2). The KNO3
level was approximately the same as experiment 1, but the
carotene was lower.

Experiment 3. Orally Administered Vitamins A and E
The purpose of this experiment was to determine if vitamins
A and E affected the performance of steers being fattened on
summer pasture. Thirty-two Brahman x Angus yearling steers
were divided into four groups on the basis of weight and grade.
The groups were randomly allotted to the treatments presented
in Table 5 and full-fed for 98 days.
The experimental procedure was the same as that used in
experiment 2, except that additional carcass measurements were
made. Two steaks, each 1-inch thick, were removed from the
anterior end of the short loin for tenderness evaluation. The
steaks were broiled to medium well done (165F), then cored
and cross-sectioned for Warner-Bratzler shear and taste panel
evaluations, respectively. Marbling scores and fat thickness
measurement over the rib-eye were made by the USDA meat
graders. Numerical values for color of carcass fat, carcass
maturity, and marbling of the rib eye are listed in the Appendix.
Samples of heart, liver, and gracilis muscle tissue were ob-
tained for dry matter, vitamin A, ash, and copper determination.
Liver, thyroid glands, and heart weights were obtained.
Vitamin A and E did not have a significant effect on average
daily gain or slaughter grade (Table 5). The steers receiving
vitamins A and E had a slightly higher dressing per cent than
those receiving the basal ration, but the differences were not
significant. The vitamins had no significant effect on carcass
conformation and maturity, on color of fat or lean tissue, or on
marbling, fat cover, and tenderness of the rib-eye muscle.
Vitamin A and E supplementation each increased vitamin A
storage in the liver when fed separately but not when used in
combination and in the heart when fed separately or together
(Table 6). Copper levels in liver tissue were also increased
when vitamin A and/or E were added to the ration and in the














Table 3. Summary of liver and heart tissue analysis, Experiment 1. (dry weight basis)

Lot number 1 2 3 4 5 6 7 8 9
Level of A (.U.) 0 25,000 50,000 0 25,000 50,000 0 25,000 50,000
Level of E (I.U.) 0 0 0 50 50 50 250 250 250

Liver


Vitamin A (mcg/gm dry wt)*
Vitamin E (mg/100g)t
oo Ash (% wet basis)
Dry matter (%)
Cu (ppm, dry basis)$
Heart
Ash (%)*
Dry matter (%)t
Cu (ppm, wet basis)


1500
5.81
1.26
28.9
1090


1722
5.19
1.25
29.1
745


1.06 1.10
22.3 22.1
417 351


2698
6.27
1.27
28.6
870


1.08
21.4
450


1294
6.20
1.13
28.0
892


1.03
21.5
421


1601
5.72
1.12
29.3
698


1.02
21.6
377


1848
6.50
1.18
29.2
942


1.08
22.2
448


1245
6.94
1.32
28.4
1122


1.04
21.4
509


1647
6.71
1.24
28.5
1159


2326
6.66
1.10
28.0
1519


1.04 1.14
21.8 22.6
445 441


*Effect of A significant P<.01.
j Effect of E significant P<.05.
$ Effect of E significant P<.01.













Table 4. Summary of weight gain, carcass, and feed consumption data as affected by vitamin A and E and level of concentrate
feed intake on winter pasture. (Experiment 2, 117 days on test.)

Concentrate feed intake Limited Full
Vitamin supplement* 0 A E A+E 0 A E A+E

Number of animals 8 7 8 8 8 8 8 8
Final weight (Ibs) 918 973 991 934 1113 1119 1148 1144
Initial weight (Ibs) 800 804 799 798 800 801 799 801
Total gain (Ibs) 118 169 192 136 313 318 349 343
c Daily gain (Ibs)t,S 1.01 1.44 1.64 1.16 2.68 2.72 2.98 2.93
Final carcass grade 8 10 9 10 13 13 14 14
Initial slaughter grade 11 11 10 11 11 11 11 10
Increases -3 -1 -1 -1 +2 +2 +3 +4
Intransit shrink (%) 6.54 6.58 6.36 6.21 5.93 6.17 7.40 6.20
Dressing per cent* 54.7 54.6 53.7 54.9 60.6 60.5 61.9 60.2
Daily feed intake (Ibs) 6.0 6.0 6.0 6.0 24.9 23.9 25.6 25.2

Vitamin A supplemented at the rate of 25,000 I.U. per animal daily and vitamin E at the rate of 50 I.U. per animal daily.
t Effect of vitamin supplementation significant at P<.05.
t Effect of feed intake level significant at P<.01.








Table 5. Summary of weight gain feed consumption and carcass data as
affected by feeding vitamin A and E to steers on summer pasture.
(Experiment 3, 98 days on test.)
Vitamin treatment *
0 A E A+E
Number of animals 8 8 8 8
Final weight (Ibs) 1009 1014 1011 1011
Initial weight (Ibs) 796 794 795 795
Total gain (Ibs) 213 220 216 216
Daily gain (Ibs) 2.17 2.24 2.20 2.20
Final carcass grade 16 16 16 16
Initial slaughter grade 10 10 10 10
Increase 6 6 6 6
Intransit shrink (%) 5.95 5.81 5.04 5.34
Dressing per cent 60.9 61.6 62.0 61.6
Daily feed intake (Ibs) 20.9 22.0 21.3 21.6
Carcass conformation 16.25 17.00 17.00 17.12
Carcass maturity 3.62 3.50 3.88 4.00
Color of carcass fat 4.1 3.5 4.0 3.8
Marbling in rib eye 14 13 14 14
Fat over rib eye (in.) 0.30 0.35 0.45 0.41
Tenderness score
(a) Shear 12.27 11.40 11.93 12.21
(b) Panel 5.32 5.92 5.58 5.53
* Vitamin A supplemented at the rate of 25,000 l.U. per animal daily and
vitamin E at the rate of 50 I.U. per animal daily.


heart tissue when vitamin A was fed. Animals receiving vita-
min A had heavier thyroid glands and hearts than those not
receiving the vitamin, but the difference was not significant.
Vitamin E levels in heart tissue were increased by vitamin E
supplementation.
The average carotene and KNOs levels of the forage were
76.7 mg/lb and 0.18%, respectively (Table 2).

Experiment 4. Injected Vitamin A and E
The purpose of this experiment was to determine if an in-
jectable form of vitamin A and E would affect the performance
of cattle being fattened on summer pasture. Thirty-six two-
year-old crossbred steers were divided into four equal groups
on the basis of weight, grade, and breed. The groups were
randomly assigned to the treatments shown in Table 7. Animals
were fed 10 pounds of concentrate feed per head daily. The ex-
perimental feed was comprised of 38.75% ground snapped corn,
40% dried citrus pulp, 20% cottonseed meal (41% old process)
and 1.25% mineral mixture. The vitamins were injected at









Table 6. Summary of liver, heart, and thyroid data from steers fed vitamins
A and E on summer pasture. (Experiment 3.)
Vitamin Treatment
0 A E A+E

Liver
Moisture (%) 72.4 73.4 72.4 72.5
Ash (%) 1.37 1.31 1.34 1.37
Vitamin A (mcg/gm dry wt.) 261 308 357 266
Cu (ppm dry wt. basis) 371 490 442 453
Cu (ppm/ash wt.) 7434 9970 9147 9041
Weight (Ibs) 14.28 14.19 13.78 14.69

Heart
Moisture (%) 79.5 80.0 79.8 79.9
Ash (% wet wt.) 1.03 1.03 1.03 1.02
Vitamin A(mcg/gm dry wt.) 1.9 2.4 2.1 2.5
Carotene (mcg/gm dry wt.) 9.8 10.8 11.3 12.3
Vitamin E (mcg/gm wet wt.) 88.4 101.3 104.7 105.0
Cu (ppm, dry wt. basis) 20.3 21.3 17.2 19.9
Cu (ppm, ash basis) 494 516 422 488
Weight (grams) 1495 1596 1517 1574

Thyroid
Weight (gm, fresh wt.) 22.5 27.6 22.8 24.3



Table 7. Summary of weight changes and carcass data as affected by in-
jectable vitamin A and E. (Experiment 4, on test 115 days.)
Vitamin treatment


Number of animals
Final weight (Ibs)
Initial weight (Ibs)
Total gain (Ibs)
Daily gain (Ibs)

Intransit shrink (%)
Dressing per cent

Liver weight (%)

Carcass conformation
Carcass maturity
Carcass grade
Lean tissue color
Lean tissue texture
Lean tissue firmness
Fat color
Rib-eye area (sq. cm.)
Marbling of rib eye
Adj. fat over rib eye (cm)
Est. kidney fat (%)


0
9
1016
804
212
1.84

4.81
59.45

1.05


14.22
3.33
14
4.4
4.8
5.0
2.6
27.2
10.33
0.90
2.39


A
9
1063
803
260
2.26

7.23
58.39

1.13


14.22
3.78
13
3.8
4.8
4.7
2.2
27.9
9.33
0.78
2.44


E A+E


9
1030
797
233
2.03

6.26
58.17

1.07

13.33
4.11
13
4.0
4.8
5.2
2.8
26.1
10.00
0.71
2.56


9
1039
805
234
2.03

6.72
59.59

1.11

14.56
3.78
14
3.9
4.4
4.9
2.7
27.8
10.33
0.90
2.89


Vitamin A was supplemented at the rate of 25,000 I.U.
vitamin E at the rate of 50 I.U. per animal daily.


per animal daily and








28-day intervals to provide an average daily dose of 25,000 I.U.
of vitamin A and 50 I.U. of vitamin E per animal. All steers
received 24 mg implants of diethylstilbestrol at the beginning
of the experiment.
In addition to the carcass measurements made in experiment
3, measurements were made on the texture, firmness, and color
of lean tissue and for carcass maturity. Codes used in these
measurements are given in the Appendix.
The daily gain of steers receiving the injectable vitamin A
was approximately 23% greater than the control group. The
steers receiving the injectable E or the combination of A and E
gained 10 % more than the cattle receiving neither vitamin. The
groups of cattle receiving the supplemental vitamins each had
a higher average intransit shrink than the control animals.
There were no trends in other carcass measurements related to
experimental treatment. Forage KN03 level was 0.26%.

Experiment 5. Oral vs Injected Vitamin A and E
The purpose of this experiment was to compare the relative
value of vitamins A and E administered orally and by injection
to steers being fattened on winter pasture. Fifty-six two-year-
old steers were divided into seven equal groups on the basis of
weight, grade, breed, and previous treatment. The groups were
allotted to the following treatments:

Lot
Number Experimental treatment
1 None.
2 Vitamin A, administered orally.
3 Vitamin E, administered orally.
4 Combination of 2 and 3.
5 Vitamin A, injected.
6 Vitamin E, injected.
7 Combination of 5 and 6.

Eight pounds of concentrate were fed per head daily. The
concentrate was comprised of 37.5% ground snapped corn, 40%
dried citrus pulp, 20% cottonseed meal (41%, old process), and
2.5% mineral mixture. All experimental procedures were the
same as earlier experiments except for dressing per cent de-
termination. Warm carcass weights were not obtained, so dress-
ing per cent was calculated as follows:








72-hour chilled carcass weight
Dressing % -== x 100
packing house weight

The results of this experiment are summarized in Tables 8
and 9. Gains were not statistically different, although there was
an increase in gain for steers receiving orally-administered
vitamin E. The vitamin supplementation did not have a sig-
nificant effect on various carcass measurements, including dress-
ing per cent, fat color, fat thickness over the rib-eye, per cent of
kidney fat, rib-eye marbling, and carcass grade.
The effect of vitamins on the liver copper was variable.
Steers receiving both forms of vitamin E had less increase in
vitamin A storage in the liver than those receiving vitamin A.
The oral supplemented steers had less increase in vitamin A
storage than the injected group.

Experiment 6. Different Forms of Vitamin E
The purpose of this experiment was to determine if alpha
tocopherol (vitamin E) would affect the performance of steers
being fattened on grass pasture and to determine if the rate of
intake, method of administration, and form of alpha tocopherol
(d vs dl) altered its effect on steer performance.
Seventy-two two-year-old steers of mixed breeding were di-
vided into nine equal groups on the basis of weight, grade and
breed. The groups were randomly allotted to the following ex-
perimental treatments:

Lot
Number Treatment
1 None
2 20 I.U., d-alpha, orally
3 50 I.U., d-alpha
4 20 I.U., dl-alpha
5 50 I.U., dl-alpha
6 20 I.U., d-alpha, injected
7 50 I.U., d-alpha
8 20 I.U., dl-alpha
9 50 I.U., dl-alpha

The steers received 10 pounds of concentrate per head daily,
on winter pasture. The feed was comprised of 38.75% ground
snapped corn, 40% dried citrus pulp, 20 % cottonseed meal, and












Table 8. Summary of weight and carcass data from steers receiving oral and injected vitamins A and E. (Experiment 5.) *


Final weight (Ibs)
Initial weight (Ibs)
Total gain (Ibs)
Daily gain (Ibs)

Intransit shrink (%)
Dressing per cent

Fat
Color
Thickness over rib eye (in.)
% kidney fat


Carcass
Conformation
Rib eye marbling
Maturity
Rib eye area (sq. in.)
Est. per cent yield
Quality grade
Federal grade

* Vitamin A was supplemented


13
8
4
9.96
51.26
14
13

at the rate


12
6
4
8.78
50.10
13
12

of 25,000 I.U. per


12
7
4
9.54
50.49
13
13

animal


13
9
3
8.99
49.80
14
13

daily and vitamin


13 12 13
10 8 7
4 4 4
9.82 9.55 9.71
50.58 50.53 51.06
15 14 13
14 12 13

E at the rate of 50 I.U. per animal daily.


Oral
E


A+E


Injected
E


949
816
133
1.18

6.53
58.78


3.0
0.22
2.8


952
823
129
1.14

6.93
58.51


3.0
0.29
2.6


950
806
144
1.27

7.26
59.59


3.0
0.30
2.7


941
791
150
1.33

6.91
59.93


3.0
0.28
3.0


953
817
136
1.20

6.72
60.07


3.0
0.30
2.9


941
811
130
1.15

6.48
60.34


3.0
0.27
3.0


A+E


956
814
142
1.26

6.69
59.19


3.0
0.23
2.6










Table 9. Summary of liver and heart data from steers receiving oral and injected vitamins A+E. (Experiment 5.) *

Oral Injected
0 A E A+E A E A+E

Liver dry matter (%) 28.2 28.0 28.2 28.3 27.8 28.3 28.5

Liver copper (ppm dry wt. basis)
Final 569 600 515 574 526 556 607
Initial 181 156 221 225 244 257 279
Difference 388 444 294 349 282 299 328

Liver iron (ppm dry wt. basis)
C Final 177 198 183 233 200 172 208
Initial 298 332 320 467 283 537 359
Difference -121 -134 -137 -234 -83 -365 -151

Liver A (mcg/gm dry wt.)
Final 587 666 413 631 778 770 852
Initial 414 271 336 354 207 468 304
Difference 173 395 77 277 571 302 548
Liver B-carotene (mcg/gm) 122.4 122.6 139.9 136.6 154.4 135.5 110.97

Heart dry matter (%) 20.9 20.9 21.1 21.3 20.8 20.9 20.8
Heart, copper (ppm, dry matter) 19.2 16.4 19.7 16.9 16.0 17.1 17.6
Heart A (mcg/gm dry matter) 0.37 0.45 0.49 0.28 0.37 0.50 0.36
Heart B-carotene (mcg/gm dry matter) 17.3 18.3 17.1 19.9 20.0 18.8 18.3

Vitamin A was supplemented at the rate of 25,000 I.U. per animal daily and vitamin E at the rate of 50 I.U. per animal daily.








1.25% mineral mixture. Each steer received 12 mg of diethy-
stilbestrol at the beginning of the experiment. Other experi-
mental procedures were the same as outlined in experiment 4
except for dressing per cent. Weights were not obtained when
delivered to the packing house or on warm carcasses. Therefore
dressing per cent was calculated as follows:

Chilled carcass weight
Dressing per cent = weight sx 100
Final weight shrunk 3%

The results of the experiment are summarized in Table 10.
All groups receiving oral vitamin E gained more than the group
receiving no vitamin supplementation. All injected groups had
less gain than the control group. The differences were highly
significant. There was no significant effect of level of vitamin E
or of kind of vitamin E on rate of gain. Vitamin supplementa-
tion had no significant effect on carcass measurements. There
was further indication that oral vitamin E was interrelated with
the copper metabolism, as all groups receiving the vitamin orally
had higher levels of copper in liver tissue.

VITAMIN A AND E IN DRYLOT

Experiment 7. Vitamin A, with and without Pangola Hay
The purposes of this experiment were to determine if vita-
min A would stimulate the rate of gain of steers being fattened
in drylot and if Pangolagrass hay altered the effect of the vita-
min. Thirty-two two-year-old Angus steers were divided into
four equal groups on the basis of weight, grade, and previous
treatment. The four groups were then randomly allowed to the
treatments shown in Table 10.
The experimental rations were the same as that used in
experiment 1. Other experimental procedures were the same as
those used in experiment 2.
The summary of average weight changes, carcass data, and
cost data per steer are presented in Table 11. Supplemental
vitamin A increased rate of gain slightly when Pangola hay was
not fed, but the difference was not statistically significant. The
inclusion of Pangola hay significantly increased rate of gain.
The differences in rate of gain of each group were related to
the intake of dry matter. Vitamin A and/or Pangola hay did
not significantly affect intransit shrink, dressing per cent, or
change in grade.








Vitamin A and/or Pangola hay steers had a higher increase
in slaughter grade than steers receiving no vitamin A or hay,
which was expressed in higher returns per steer over initial
steer value and feed costs.

Experiment 8. Vitamin A and Vegefat
The purpose of this experiment was to determine if Vegefat
altered the effect of vitamin A for yearling steers being fat-
tened in drylot. Forty-eight Brahman x Hereford steer calves
were divided into four equal groups of 12 animals each on the
basis of weight, grade, and sire. These groups were randomly
allotted to the treatments presented in Table 12, and full-fed
for 168 days. The composition of the experimental rations were
similar to the full-fed mixtures in experiment 2. Vegefat was
added to the ration at a rate of 1.5%, replacing ground snapped
corn. Vitamin A was added at a rate of 25,000 I.U. per animal
daily. Pangolagrass hay was fed at a rate of 2 pounds per ani-
mal daily. Experimental procedures were the same as those
used in experiment 2. Results are summarized in Table 12. The
rate of gain was not increased by any of the experimental treat-
ments. Carcass grade, rib-eye marbling, and dressing per cents
were higher for the two groups receiving the vegefat. Vitamin
A did not affect any carcass measurements.

Experiment 9. Orally Administered Vitamin A and E
The purpose of this experiment was to determine if orally
administered vitamins A and E would affect the performance
of steers being fattened in drylot during the summer months.
Thirty-six yearling Santa Gertrudis steers with an average
weight of 812 pounds were divided into four equal groups of
nine animals each on the basis of weight, grade, and sires. The
groups are randomly allotted to the treatments shown in Table
13. The complete feed, composed of 32.3% dried citrus pulp,
32.3% steamed, rolled corn, 13.8% rice bran, 6.9% cane mo-
lasses, 4.6% dehydrated alfalfa pellets, 4.6% cottonseed hulls,
1.8% salt, 1.4% urea, 1.4% animal fat, and .9% dicalcium phos-
phate, was fed free-choice, for 118 days. Vitamin A was fed
to furnish 25,000 I.U. and vitamin E to furnish 50 I.U. per
animal daily. The initial weight was the purchase weight at
the ranch, and the final weight was a 14-hour shrunk weight.
All other experimental procedures were the same as in former
experiments.












Table 10. Summary of weight gains and carcass data for steers receiving vitamin E. (Experiment 6, 101 days on test.)


Oral E


Final weight (Ibs)
Initial weight (Ibs)
Total gain (Ibs)
Daily gain (Ibs)

Dressing per cent
Carcass conformation
Carcass maturity
0 Marbling of rib eye
Carcass grade
Fat over rib eye (in.)
Kidney fat (%)
Rib-eye area (sq.in.)
Estimated yield (%)

Color of lean
Texture of lean
Firmness of lean
Color of fat

Liver copper (ppm)
Liver iron (ppm)

Forage nitrate (%)


Control

1004
812
192
1.90

56.59
14
3
10
14
0.34
3.1
9.6
49.91

4
3
3
3

423
197


20
d

1026
814
212
2.10

56.40
15
3
10
14
0.38
3.0
9.8
49.77

4
3
3
4

496
233


50
d

1020
812
208
2.06

57.65
15
3
11
15
0.41
3.4
9.6
49.17

4
3
3
3

524
190


20
dl

1030
812
218
2.16

57.17
15
3
10
15
0.39
3.1
9.3
49.20

4
3
3
3

479
210


50
dl

1014
812
202
2.00

55.31
14
3
8
14
0.32
2.8
9.0
49.71

4
3
3
3

456
230


20
d

984
812
172
1.70

55.27
14
2
8
14
0.34
2.2
9.6
51.13

3
3
3
3

551
235


Injected E
50 20
d dl

986 962
811 813
175 149
1.84 1.42

54.53 56.29
14 14
3 3
9 10
13 14
0.29 0.39
2.7 2.8
9.1 9.5
50.20 50.45

4 4
3 3
3 3
3 3

416 432
189 218


50
dl

980
811
169
1.89

55.65
14
3
8
13
0.26
2.2
9.9
51.20

4
3
4
4

507
243


0.62 0.59 0.75 0.47 0.08 0.55


0.55 0.55 0.55









Table 11. Summary of average weight changes, and carcass data per animal
as affected by vitamin A and Pangola hay in drylot. (Experiment 7,
116 days on test.)
No Pangola hay Pangola hay
Vitamin supplements 0 A 0 A
Number of animals 8 8 8 8
Final weight (Ibs) 968 968 997 979
Initial weight (Ibs) 712 706 708 708
Total gain (Ibs) 256 262 289 271
Daily gain (Ibs) 2.21 2.26 2.49 2.34
Final slaughter grade 15 16 16 16
Initial slaughter grade 11 11 11 11
Increase 4 5 5 5
Intransit shrink (%) 4.13 3.82 3.81 3.88
Dressing per cent 60.0 60.3 61.6 60.9
Daily feed intake (Ibs)
Concentrate feed 20.5 21.7 22.6 22.2
Pangola hay 3.0 2.6

Vitamin A supplemented at rate of 25,000 I.U. per animal daily.


The experimental results are presented in Table 13. The
inclusion of either vitamin by itself did not increase the rate of
gain, but the combination of the two vitamins increased gain
approximately 6%o. There was no consistent effect of vitamin
treatment on any carcass measurement, although the vitamin
treated groups did have slightly more marbling in the rib-eye
muscle and averaged one-third of a grade higher in Federal
grade. Feed intake was higher for the three groups receiving
the vitamins treatments, so the increased grade was probably
related to feed intake. Feed efficiency was not increased for
the vitamin-supplemented groups.

Experiment 10. Orally Administered Vitamin A and E
This experiment was identical with experiment 9, except
that younger steers were used, and they were fed for a longer
period of time. Thirty-six yearling Santa Gertrudis steers hav-
ing an average weight of 721 pounds were divided into four
equal groups on the basis of weight, grade, and sire. The groups
were randomly allotted to the treatments shown in Table 14.
All experimental procedures were the same as for experiment
9 except for the length of the feeding period.
The experimental results are presented in Table 14. As in
experiment 9, the rate of gain was lower than expected, prob-










Table 12. Summary of weight gain and carcass data for steers receiving vita-
min A and vegefat. (Experiment 8, 168 days on test.)


0 Vitamin Vitamin A
A Vegefat and vegefat

Number of steers 12 12 12 12
Final weight (Ibs) 907 886 896 893
Initial weight (Ibs) 552 552 551 548
Total gain (Ibs) 335 334 341 345
Daily gain (Ibs) 2.11 1.99 2.03 2.03

Intransit shrink (%) 5.51 4.97 5.02 5.38
Dressing per cent 60.50 60.58 61.26 61.99

Carcass conformation 13 13 14 14
Carcass maturity 2 2 2 2
Marbling of rib eye 7 7 8 8
Fat over rib eye (in.) 0.27 0.29 0.32 0.29
Kidney fat (%) 2.8 3.0 3.2 2.9
Estimated yield (%) 50.89 51.16 50.84 51.42
Rib eye area (sq. in.) 9.84 10.34 10.09 10.70
Carcass grade 14 14 15 15




Table 13. Summary of average weight, feed, and carcass data for steers fed
vitamin A and E in drylot. (Experiment 9, 118 days on test.)
Treatment
0 A E A+E

No. animals 9 9 8 9
Purchase weight (Ibs) 812 812 812 812
Final weight (Ibs) 1066 1063 1058 1081
Total gain (Ibs) 254 251 246 269
Daily gain (Ibs) 2.15 2.13 2.08 2.28
Feed/lb. gain (Ibs) 10.26 11.25 11.15 10.59
Intransit shrink 3.3 3.8 3.7 4.3
Per cent hide 9.6 8.6 9.3 9.6
Dressing per cent 60.8 61.3 62.5 60.5
Rib eye area (sq. in.) 11.1 11.4 11.6 10.9
% Kidney fat 3.1 2.9 3.1 2.8
Fat over rib eye (in.) 0.28 0.27 0.43 0.30
Conformation G G+ G+ G+
Carcass maturity A A A A
Marbling TR+ S1- S1 S1-
Lean tissue
Color 3.9 3.8 3.9 3.9
Texture 2.4 2.7 2.9 2.7
Firmness 2.3 2.2 2.8 2.4
Color of fat 2.0 2.0 2.0 2.0
Quality grade G- G G G-
Federal grade G- G G G
Estimated per cent yield 50.72 51.01 50.07 50.55
Yield grade (%) 2.7 2.5 3.0 2.8
Warner Bratzler 11.1 10.9 12.4 10.4
Taste panel 5.0 5.1 4.6 5.1










Table 14. Summary of average weight and carcass data for steers fed vita-
mins A and E in drylot. (Experiment 10, 145 days on test.)

Treatment


No. of animals
Purchase weight (Ibs)
Final weight (Ibs)
Total gain (Ibs)
Daily gain (Ibs)
Feed/lb. gain (Ibs)
Intransit shrink (%)
Per cent hide
Dressing per cent
Conformation
Maturity
Marbling
Lean Tissue
Color
Texture
Firmness
Color of fat
Quality grade
Federal grade
Rib eye area (sq. in.)
Per cent kidney fat
Fat over rib eye (in.)
Estimated per cent yield
Yield grade


721
978
266
1.83
11.68
6.1
9.0
62.9
14.9
2.0
6.3

4.2
3.0
2.9
2.0
G-
G-
10.9
2.9
0.24
51.0
2.5


8
720
1032
323
2.23
10.12
5.8
9.6
62.9
15.2
2.0
6.2

4.1
3.4
3.1
2.0
G-
G-
10.8
2.9
0.31
50.5
2.8


E A+E

9 9
722 721
1037 1005
328 296
2.26 2.04
9.95 11.02
5.8 6.1
9.5 9.4
62.5 61.8
15.1 14.9
2.0 2.0
9.6 6.6


4.0
2.8
2.8
2.0
G
G
10.8
2.8
0.31
50.5
2.8


3.9
2.4
2.6
2.0
G
G
10.8
2.9
0.29
50.6
2.8


ably due to the very hot, humid weather experienced during the
feeding period. The steers receiving either vitamin A and E,
alone, had 22% more gain than the steers receiving no vitamins.
When the two vitamins were fed together, the rate of gain was
increased 11% over the control animals. Feed efficiency was
directly related to the rate of gain. There was no consistent
significant effect of vitamin treatment on carcass measurements,
although the groups receiving vitamin E had an average of 1/3
grade higher carcass grade than the steers receiving no supple-
mental vitamins.


DISCUSSION

It has been over 30 years since the need for vitamin A by
beef cattle was established and over 40 years since vitamin E
was discovered. Vitamin A is present in green forage in the
form of a precursor called carotene, and for many years it was
assumed that the presence of adequate carotene in the ration
would furnish the vitamin A needs for beef cattle. Vitamin E
is also present in green forage in amounts that have been con-








sidered adequate for beef cattle. However, recent research de-
velopments have demonstrated that supplemental vitamin A
and E will increase efficiency in fattening cattle.
All of the reasons for this are not clear. More information
is available for vitamin A than for vitamin E. The need for
increased supplements for vitamin A is due to a combination
of factors. Vitamin A requirements are higher because of stress
of faster growth by young cattle. Also, the conversion of caro-
tene to vitamin A is easily inhibited and appears to have been
over-estimated in the past. For example, it has been reported
that nitrate nitrogen will interfere with carotene conversion
(12) and that thyroid activity is involved in the conversion
(3, 17). The conversion of carotene to vitamin A occurs within
the intestinal walls, and anything that will prevent its absorp-
tion or which upsets the well-being of the intestinal wall will
inhibit vitamin A production. Such factors as disease, stress
factors, nutritional deficiencies, and hot weather all tend to in-
hibit vitamin A metabolism. Also there are different chemical
forms of carotene present in plant material, and these differ
in their biological availability to beef cattle.
Acute vitamin A deficiencies are typified by night blindness,
respiratory disorders, reproduction disorders, muscular inco-
ordination, swollen brisket, stiffness, diarrhea, and abnormal
bone development. However, of possibly more economical im-
portance is the marginal deficiency that manifests itself pri-
marily by an often undetectable reduction in growth.
Results reported herein along with numerous other reports
(2, 4, 10, 12, 13, 14, 15) prove conclusively that supplemental
vitamin A will increase the rate of gain of cattle being fattened
for slaughter. Not all reports are in agreement, however, and
additional research is needed to elucidate the conditions requir-
ing extra vitamin A. For example, the principal benefit of
vitamin A on gain in these studies was on pasture. During
work at Purdue (16) no increased gain was obtained when steers
being fattened on pasture were given additional vitamin A.
Also, in experiment 7 and 8 the rate of gain of steers full-fed
in dry-lot was not increased by vitamin A, and yet it was in-
creased in experiment 10, and research in the Midwest has
repeatedly demonstrated increased feedlot gains when vitamin
A was added to the rations.
Vitamin A does not always increase gain of steers fattened
on the same type of pasture. For example, rate of gain was
greatly increased during experiments 1, 2, and 4, but there was








little if any increase in experiments 3 and 5 that could be at-
tributed to vitamin A.
Vitamin A supplementation is relatively inexpensive, and
there is little danger from toxicity due to overfeeding recom-
mended levels. Results in experiment 1 as well as reports from
other research reports indicate that 25,000 I.U. of vitamin A
should be fed per steer per day. It is possible recommendations
will become more specific as additional information accumulates
concerning requirements for this vitamin, but until then this
level is recommended.
The value of vitamin E for beef cattle being fattened is not
as well defined. In these experiments gain was often increased
as much or more by vitamin E as by vitamin A. Yet when they
were fed together, the rate of gain was often lower than the
rate for either one alone (experiment 1, 2, 10).
It has been known for some time that vitamin E is a
physiological antioxidant and adequate amounts are necessary
for efficient conversion of carotene to vitamin A. This was some-
times apparent in experiments 1, 3, and 5, where levels of vita-
min A in liver tissue were increased when vitamin E was added
to the ration. Vitamin E is also related to copper metabolism
in beef cattle, as indicated by the increased copper levels in
liver tissue when vitamin E was fed (experiments 1, 3, 5, 6).
However, the lack of synergestic effect and actual decrease in
gain in experiments 1, 2, and 10 when the two vitamins were
simultaneously supplemented is difficult to explain. It appears
that vitamin E will spare vitamin A deficiencies in beef cattle
rations but will not express its effect if vitamin A is adequate.
It is also possible that an excess of vitamin E may actually in-
hibit vitamin A metabolism, and this was indicated in experi-
ments 1 and 5 where oral vitamin supplemented groups had less
vitamin A stored in the liver than the control cattle. Injected
vitamin E in experiment 5 did not affect liver vitamin A stores.
It is possible that much of the so-called vitamin A deficiency
in beef cattle is actually a combination of vitamin A and E short-
age. Additional research is needed to determine the interrela-
tionship of these two vitamins with various kinds of beef cattle
and under various management and environmental conditions.
After the results of experiment 1, a level of 50 I.U. of vita-
min E was used in the experiments 2, 3, 4, and 5. However
results obtained in experiment 6 indicated that 20 I.U. per ani-
mal per day gave better results orally and 50 I.U. gave better
results when injected. Additional research is needed to clarify








the level of supplemental vitamin E needed by beef cattle. Also
additional work is needed using lower levels of vitamin E in
combination with vitamin A. However, these results indicate
that 20 I.U. per day of vitamin E will stimulate rate of gain of
fattening cattle.

SUMMARY
Results have been summarized for a series of experiments
conducted to determine the value of supplementing beef cattle
rations with vitamin A and E. More response was obtained to
vitamin A on pasture than in drylot. Each vitamin stimulated
gain on pasture, but the degree of response varied between
experiments and was not additive. Vitamin E increased the
level of vitamin A and copper in liver and heart tissue but did
not affect the liver iron level. Levels of 25,000 I.U. of vitamin
A and 20 I.U. of vitamin E appeared best. Both the d-alpha
and dl-alpha form of vitamin E increased weight gains. Neither
vitamin A or E consistently influenced various carcass measure-
ments.









LITERATURE CITED


1. AOAC. 1960. Official Methods of Analysis (9th edition), Washington,
D. C.
2. Beeson, W. M., T. W. Perry, M. T. Mohler, and W. H. Smith. 1961.
Levels of supplemental vitamin A for fattening beef steers. Purdue
Univ. Agr. Exp. Sta. Mimeo A.S. 296.
3. Burroughs, W., R. Cooley, W. E. Hammond, and F. H. McGuire. 1961.
Vitamin A levels and tapazole addition to beef cattle rations. Iowa
State U.A.H. leaflet R-36.
4. Chapman, H. L., Jr., R. L. Shirley, A. Z. Palmer, C. E. Haines, J. W.
Carpenter, and T. J. Cunha. 1964. Vitamins A and E in steer fattening
rations on pasture. J. Anim. Sci. 23:669-673.
5. Chapman, H. L., Jr., R. L. Shirley, G. H. Taki, A. Z. Palmer, and J. W.
Carpenter. 1965. Value of injected and orally administered vitamins
A and E for steers. J. Anim. Sci. 24:878. (Abstract).
6. Everhart, E. L. 1958. Vitamin A in nutrition. J. Amer. Vet. Med.
Assoc. 132-344.
7. Gallup, W. D., and J. A. Hoefer. 1946. Determination of vitamin A in
liver. Ind. Eng. Chem. 18:288.
8. Guilbert, H. R., and G. H. Hart. 1935. Minimum vitamin A require-
ments with particular reference to cattle. J. Nut. 10:409.
9. Maynard, L. A., and J. K. Loosli. 1956. Animal nutrition. McGraw-
Hill Book Co., Inc., New York.
10. Mitchell, G. E., A. L. Neumann, R. R. Garrigus, W. M. Durdle, and
K. A. Kendall. 1960. Observations on vitamin A deficiency in feedlot
steers. Ill. Cattle Feeder's Day:12.
11. Nelson, J. L., L. T. Kurtz, and R. H. Bray. 1954. Rapid determination
of nitrates and nitrites. Anal. Chem. 26:1081.
12. O'Dell, B. L., Z. Erek, L. Flynn, G. B. Garner, and M. E. Muhrer. 1960.
Effects of nitrite containing rations in producing vitamins A and
vitamin E deficiencies in rats. J. Anim. Sci. 19:1280.
13. Pope, L. S., F. H. Baker, and R. W. MacVicar. 1961. Vitamin A studies
with beef cattle. Okla. Agr. Exp. Sta. Bull. B-578.
14. Perry, T. W., W. M. Beeson, W. H. Smith, and M. T. Mohler. 1967.
Injectable vs oral vitamin A for fattening steer calves. J. Anim. Sci.
26:115-118.
15. Perry, T. W., R. C. Burns, M. T. Mohler, and W. M. Beeson. 1957.
Mixed supplements of soybean meal for fattening cattle self-fed ground
corn. Purdue Univ. Agr. Exp. Sta. Mimeo A.H. -201.
16. Perry, T. W., W. H. Smith, W. M. Beeson, and M. T. Mohler. 1966.
Value of supplemental vitamin A for fattening beef cattle on pasture.
J. Anim. Sci. 25:814-816.
17. Smith, G. S., W. M. Durdle, J. E. Zimmerman, and A. L. Neumann.
1964. Relationships of carotene intake, thyroactive substances and soil
fertility to vitamin A depletion of feeder cattle fed corn silages. J.
Anim. Sci. 23:625-632.








APPENDIX

Formulas Used To Calculate Carcass Data


Intransit shrink (%)


Dressing % =1


Final wt. packing house wt.
n= x 100
Final weight


Warm carcass weight x 97.5
Final weigx 100
Final weight shrink 3%


Codes Used at Meats Laboratory
Animal Science Department
University of Florida


1. Quality Grade,

Prime
Choice
Good
Standard
Utility
Cutter
Canner


Conformation

19
16
13
10
7
4
1


and USDA Grade
+
20 21
17 18
14 15
11 12
8 9
5 6
2 3


2. Maturity
A-
A
A+
B-
B
B+
C-
C
C+
C4+


3. Marbling

Devoid
Practically devoid
Traces
Slight








Marbling (continued)
Small 10 11 12
Modest 13 14 15
Moderate 16 17 18
Slightly abundant 19 20 21
Moderately abundant 22 23 24
Abundant 25 26 27


4. Color of Fat
1. White
2. Cream
3. Slightly yellow
4. Very yellow


5. Color of Lean
1. Dark pink
2. Very Light Cherry Red
3. Light Cherry Red
4. Cherry Red
5. Moderately Dark Red
6. Dark Red
7. Very Dark Red


6. Texture of Lean
1. Very Fine
2. Fine
3. Moderately Fine
4. Slightly Coarse
5. Coarse
6. Very Coarse
7. Extremely Coarse


7. Firmness of Lean
1. Very Firm
2. Firm
3. Moderately Firm
4. Slightly Soft
5. Soft
6. Very Soft
7. Extremely Soft








8. Method of Cooking 13th (Steak A) and 14th (Steak B)
Rib Steaks
Frozen (0F) steaks are thawed 48 hours in individually
wrapped freezer paper in a room approximately 320-360F.
Each steak is on a flat surface without touching adjacent
steaks.
Steaks are coded and placed unwrapped on broiling pan
30 minutes before cooking in a room 750-780F. Ovens are
preheated 10 minutes (dial on "Broil") with pan on third
holder from coils or with 1" steaks 4 inches from coils. They
are cooked 9 minutes on first side and 8 minutes on second
side. Broiler is rotated 1800 after 41/2 minutes on first side,
after 4 minutes on second side. Position of steaks on pan is
changed when turning from first side to second side. Cool.
Core.


9. Tenderness, Juiciness, Flavor, by
1. Too tough to be edible.
2. Extremely tough
3. Very tough
4. Below average
5. Average
6. Above average tender
7. Very tender chews easily
8. Extremely tender grainy
9. Mushy fibers not distinguish,


Taste Panel









ible.

















ACKNOWLEDGEMENTS


Many people have assisted in these experiments. The help of Charles
Batchelor, J. V. McLeod, R. W. Kidder, Enrique Tomeu, Ed Hicks, and J. F.
Easley is gratefully acknowledged. Some of the experimental animals were
furnished by Alto Adams and Son, Ft. Pierce, Florida; the Bar-G Ranch,
Vero Beach; and the Big-B Ranch, Belle Glade, Florida. Vegefat was
furnished by Vegefat, Inc., P. O. Box 157, National Stock Yards, East St.
Louis, Illinois. Vitamins A and E were furnished by Distillation Products,
Inc., Rochester, N.Y., and by Hoffman LaRoche, Inc., Nutley, New Jersey.
Some of the studies were supported by a grant-in-aid from Hoffman La-
Roche, Inc. The assistance of all of these companies is appreciated and
gratefully acknowledged.