6 Bulletin 741 September 1970
CATTLE GAINS FED
INJECTED WITH VITAMIN A
R. L. Shirley
F. M. Peacock
.,-5 A '- > "*:rC:^::::: :::: ::"::
" ",, - ........ .:....
Agricultural Experiment Stations
Institute of Food and Agricultural Sciences
University of Florida, Gainesville
J. W. Sites, Dean for Research
Introduction .-. ----- .............-..... ... ---- --- 3
Literature Review ......-- -..--.... -....- --. -. -- 3
Methods ..-- -----..-----.--------..-------- 4
Experimental Results and Discussion ------- ----- 7
Experiment I. Supplemental Feeding of Vitamin A -----. 7
Production Data ... ----- ---... -------------..---- 7
Vitamin A and B-carotene of Liver ----.....----.. 8
Vitamin A and B-carotene of Blood Plasma ----- 10
Vitamin A in Heart and Copper in Liver and Heart 10
Experiment II. Injection and Feeding Vitamin A .------ 12
Production Data -- --- ---12
Vitamin A and B-carotene of Liver and Plasma 13
Carcass Grade and Dressing Per Cent -- ---------- 14
Summary and Conclusions .....---- ------.---.--.. .-------- 14
Literature Cited ..--------- ----------------------- 15
Cattle Gains Fed and Injected with Vitamin A
W. G. Kirk, R. L. Shirley, J. F. Easley, and F. M. Peacock1
Vitamin A occurs in nature only in animal products. Plants
contain carotenes (along with provitamin A) which are changed
in the animal tissues to true vitamin A. Excessive amounts of
vitamin A in the ration are stored in the liver, fat, and other
tissues and may be utilized in periods of partial dietary defi-
ciency. Early stages of vitamin A deficiency with immature
cattle indicate little or no specific symptoms other than reduced
feed intake and failure to make satisfactory gains. Severe
symptoms of vitamin A deficiency seldom occur unless there has
been mismanagement of cattle and ration formulation.
The purpose of the six trials was:
1. To determine the response of calves and yearling cattle
to supplement feeding of 30,000 I.U. vitamin A daily.
2. To compare the feeding of 30,000 I.U. vitamin A daily
and initial intramuscular injection of 2.7 and 5.4 million I.U.
vitamin A when the basal ration cottonseed hulls, cottonseed
meal, dried citrus pulp, and mineral mixture was deficient
in B-carotene. The measuring criteria were rate of gain, feed
efficiency, and level of vitamin A and B-carotene in liver and
blood plasma and copper in liver and heart tissues.
Morrison (11)2 states that vitamin A is the most important
vitamin in nutrition of beef cattle under farm conditions, but
the need can be met by giving sufficient good quality hay.
According to the National Research Council (NRC) (12), ade-
quate vitamin A is needed to keep epithelial tissue healthy
and promote growth. Maymome (10), in summarizing the known
facts about vitamin A, states that while many of its functions
are not understood, it improves maturity rate, is essential for
"Kirk: Professor Emeritus (Animal Scientist Emeritus), Range Cattle
Shirley: Professor (Animal Nutritionist), Animal Science Department,
Easley: Assistant Professor (Assistant Animal Nutritionist), Animal
Science Department, Gainesville.
Peacock: Associate Professor (Associate Animal Husbandman), Range
Cattle Station, Ona.
"2Figures in parentheses refer to Literature Cited.
many of the physiological activities of other vitamins and hor-
mones, and protects all epithelial tissue from infectious organ-
According to Hale et al. (8), feeding 0 to 2,500,000 I.U.
vitamin A daily to yearling steers on a milo, cottonseed hulls,
and cottonseed meal ration for 169 days did not affect either
feed intake or rate of gain, or cause undesirable effects in the
experimental animals. Perry et al. (13) found that the addition
of vitamin A to a calf ration which met NRC standards increased
feed intake and gains and level of vitamin A in liver and blood
plasma with a decrease of plasma carotene. Feed conversion
improved 7% to 10% when 10 to 50 thousand I.U. vitamin A
were fed daily.
Data from the Range Cattle Experiment Station (RCES)
(9) show that steer and bull calves fed adequate rations of
20% cottonseed hulls, 15% cottonseed meal, 49% citrus pulp,
10% yellow corn meal, 5% alfalfa meal, and 1% mineral mixture
for 140 days had similar levels of vitamin A in liver and B-caro-
tene in blood plasma. NRC (12) shows that only cornmeal and
alfalfa meal of the preceding ration ingredients contain any
appreciable amount of carotene.
According to NRC (12), 1 mg B-carotene equals 400 I.U.
vitamin A for cattle. The council states that the conversion
rate of B-carotene to vitamin A is not constant and varies with
type of carotenoid fed, breed and individuality of cattle, level
of feeding, vitamin E and nitrate in ration, and stress and
previous treatment of animals.
The general experimental design and characteristics of ex-
perimental animals are given in Table 1. Calves fed in Trials
1, 3, and 5 were Shorthorn-Brahman crosses. The yearlings fed
in Trials 2, 4, and 6 were grade Angus, Hereford, Shorthorn,
and Brahman. Calves were placed on experiment after weaning,
while yearlings were fed free choice a dry ration of either pan-
golagrass hay or silage, and a sufficient amount of a mixture of
1 part cottonseed meal and 3 parts citrus pulp to give an
average daily gain of 0.5 to 0.75 pounds from weaning until
placed on trial at 13 to 14 months of age.
Available cattle in each trial were divided into uniform lots
according to weight, grade, and breeding. Cattle were weighed
individually at the beginning and end of each trial.
Table 1. Cattle and experimental design of feeding trials.
Number Initial Previous Lot
Trial cattle age, months Sex treatment 1 2 3 4
Experiment I. Feeding Vitamin A: Vitamin A daily3
1 20 8 F Weaned1 Control Control .30,000 30,000
2 12 13 M Dry feed2 Control Control 30,000 30,000
3 8 8 F Weaned1 Control 30,000 -
C 8 8 M Control 30,000
4 12 13 M Dry feed' Control Control 30,000 30,000
Experiment II. Injection and Feeding Vitamin A: Initial Injection' A daily'
5 16 8 F Weaned' Control 2.7 M 5.4 M 30,000 I.U.
6 16 14 M Dry feed' Control 2.7 M 5.4 M 30,000 I.U.
'Calves placed on test after weaning.
'Kept on dry feed five months after weaning.
"Fed 30,000 I.U. vitamin A daily per animal.
'Lot 2, 2.7 million and Lot 3, 5.4 million I.U. vitamin A.
Table 2. Average percentage feed composition and ration ingredients.
Feed Cottonseed Cottonseed Citrus Mineral
nutrients hulls meal pulp mixture
Dry matter 87.5 90.1 88.3 98.2
Crude protein 3.5 40.9 6.1 2.5
Crude fiber 37.9 10.4 11.4 0.7
Ash 2.6 5.8 4.6 88.7
Calcium 0.12 0.17 1.44 17.08
Phosphorus 0.07 1.10 0.10 9.75
Ether extract 1.2 3.9 4.1 0.8
NFE 42.3 29.1 58.1 5.5
TDN 44 69 71 5
B-carotene1 0.14 0.33 1.06
Experiment I 25.2 15.3 58.5 1.0
Experiment II 26.9 15.2 56.9 1.0
1Mg B-carotene per pound.
The basal ration in all trials consisted of cottonseed hulls,
cottonseed meal (old process, 41% crude protein), citrus pulp,
and mineral mixture (5). Ration ingredients having either
trace amounts or no B-carotene were selected from feedstuff
available in Florida. Average composition of ration ingredients
fed in the six trials and percentage of each in both experiments
are given in Table 2. Cottonseed hulls were decreased from 35%
initially to 20 % near the completion of each trial, being replaced
with an equal weight of citrus pulp to increase ration total
digestible nutrients (TDN). Cattle were fed once daily, as
much of the basal ration as would be eaten in 24 hours.
The ration fed in Experiment I contained 10.7% crude
protein, 18% crude fiber, 1.07% calcium, 0.35% phosphorus,
and 63% TDN. The basal ration fed in Experiment II contained
10.6% crude protein, 18% crude fiber, 1.1% Ca, 0.4% P, and
63% TDN. Citrus pulp furnished 63% of the TDN in rations
fed in Experiments I and II. The two rations were slightly low
in energy nutrients, deficient in B-carotene, and according to
NRC (10) deficient in unknown essential nutrients found in
A premix of 1 gram vitamin A synthetic palmitate (30,000
I.U. per gram) and 19 grams citrus meal per animal was mixed
with the basal ration at feeding time. A liquid carrier3 con-
"Rovimix 250W, containing 500,000 I.U. vitamin A per ml, was furnished
by Hoffman LaRoche, Inc., Nutley 10, New Jersey.
training 500,000 I.U. vitamin A per ml was injected intramus-
cularly at the beginning of each trial in Experiment II to
cattle in Lots 2 and 3.
At the completion of each trial, cattle were hauled 75 miles
to a packing plant, weighed individually, and slaughtered the
same day. Blood, liver, and heart tissues were obtained for
vitamin A and B-carotene assays. Determinations were made
by the Gallop and Hoefer (7) modification of the Carr-Price
SbClI-acetic anhydridemethod (2). Analysis for copper in liver
and heart tissues was by the Cheng and Bray procedure (4).
Dressing per cent was based on live weight at slaughter
plant and carcass weight after 48 hours in the cooler. Each
carcass was graded by an official USDA meat inspector.
EXPERIMENTAL RESULTS AND DISCUSSION
Experiment I. Supplemental Feeding of Vitamin A
Feedlot performance and carcass data for calves and year-
lings fed 0 and 30,000 I.U. vitamin A daily are summarized in
Table 3. There was considerable variation in gain response of
individual calves and yearlings in the control and vitamin A
supplemented groups. The calves gained more slowly than the
yearlings, but made more efficient use of their feed for gains.
Rate of gain in Trial 1 was 1.70 pounds daily for heifer
calves on the control and those fed 30,000 I.U. vitamin A. In
Trials 2, 3, and 4 cattle fed vitamin A supplement made 0.09,
0.17, and 0.11 pounds greater average daily gains, respectively,
than the appropriate controls. Average daily gain for the 30
control animals and those fed vitamin A was 1.59 and 1.68
pounds, respectively, which represents 5.7% increase in rate
of gain in favor of the vitamin A fed cattle. The data, when
subjected to an analysis of variance' and to Duncan's multiple
range test (6) did not indicate any significant difference in
gains between the two groups of cattle.
Rations were palatable, as indicated by average daily feed
intake of 3.0 pounds for calves and 2.8 and 2.9 for yearlings
per 100 pounds live weight. Supplemental feeding of 30,000
I.U. vitamin A daily per animal increased feed efficiency by
5.1% for calves and 7.5% for yearlings.
'Frank G. Martin, Associate Professor (Associate Statistician), IFAS,
University of Florida, Gainesville.
Table. 3. Gain, feed efficiency, carcass grade, and dressing per cent for calves
and yearling cattle fed vitamin A.
Vitamin A supplementation Control 30,000 I.U. daily
Class of cattle Calvese Yearlings2 Calves1 Yearlings"
Number of cattle 18 12 18 12
Initial age, months 8 13 8 13
Feeding period, days 178 163 178 163
Placed on test When After When After
weaned 5 months weaned 5 months
on dry feed on dry feed
Initial weight, lb. 347 483 345 505
Final weight, lb. 623 753 635 810
Daily gain, lb. 1.56 1.66 1.63 1.87
Daily ration, Ib. 14.6 17.7 14.5 18.4
Daily TDN, Ib. 9.3 11.2 9.2 12.3
Daily feed 100 lb.
live weight, lb. 3.0 2.9 3.0 2.8
Feed per lb. gain, Ib. 9.4 10.7 8.9 9.8
TDN per lb. gain, lb. 5.9 6.7 5.6 6.2
Carcass grade3 10 9 10 10
Dressing per cent' 59.5 59.0 59.6 60.1
Liver weight, lb. 8.8 9.2 8.8 9.3
1Heifer and steer calves.
"3Grades: 9, Low Good; 10, Good.
4Live weight at slaughter plant and carcass weight after 48 hours in cooler.
The rations fed in the four trials contained 1.07% calcium
and 0.35% phosphorus. These levels are more than sufficient,
according to NRC (12), to meet the needs of calves and year-
lings with average initial and final weight as indicated in
There were no apparent gross symptoms of vitamin A de-
ficiency other than slow rate of gain in any of the 60 calves and
yearlings. The basal ration contained 0.71 mg B-carotene, equiva-
lent to 284 I.U. vitamin A per pound of feed. NRC (12)
recommends that finishing rations should have 760 I.U. per
pound; thus the basal ration contained only 37% of this amount.
Feeding 30,000 I.U. vitamin A daily raised the average level
of Vitamin A per pound of feed to 2353 I.U. for calves and
1914 I.U. for yearlings.
Vitamin A and B-carotene of Liver
The average vitamin A and B-carotene levels in micrograms
(mcg) per gram of dry liver from cattle fed in Experiment I
are given in Table 4. Supplement feeding of 30,000 I.U. vitamin
A per animal daily resulted in an increase (P<.01) in liver
vitamin A over similar cattle fed only the basal ration with no
essential difference in B-carotene liver content.
The average vitamin A content per gram of dry liver was 14
mcg for the control and 96 mcg for the animals fed 30,000 I.U.
vitamin A daily. Beeson et al. (1) suggests that 23 mcg per
gram of liver is near the level associated with vitamin A defi-
ciency symptoms. There was no apparent vitamin A deficiency,
other than low gains, in any of the 30 control animals.
In Trial 3 (Table 4) heifer and steer calves, fed the control
ration, had 19 mcg and 32 mcg vitamin A per gram dry liver,
respectively, while heifer and steers fed 30,000 I.U. had 83 mcg
and 114 mcg vitamin A per gram dry liver. Steer calves fed
the control and vitamin A supplemented rations had slightly
lower levels of B-carotene per gram dry liver when compared
with heifer calves on the same treatment.
Table 4. Vitamin A and B-carotene in liver of calves placed on trial when
weaned and yearling cattle after five months on dry feed.
Vitamin A supplement Control 30,000 I.U. daily
Lot 1 2 3 4
Number cattle 15 15 15 15
Feeding period, days 172 172 172 172
Vitamin A in liver (mcg/gram dry liver):
Trial 1, 5 calves/lot' 21 13 124 115
Trial 2, 3 yearlings/lot2 11 2 68 89
Trial 3, 4 calves/lot3 19 32 83 114
Trial 4, 3 yearlings/lot' 2 3 80 66
Calves, two trials, 9/lot 20 21 106 115
Yearlings, two trials, 6/lot 7 3 73 78
All cattle 14 96**
B-carotene in liver (mcg/gram dry liver) :
Trial 1, calves 10 10 12 8
Trial 2, yearlings 19 17 13 19
Trial 3, calves 15 12 12 9
Trial 4, yearlings 10 13 15 13
Calves, two trials 12 11 12 8
Yearlings, two trials 15 15 14 16
All cattle 13 12
"5Heifer calves Lots 1 and 3 and steer calves Lots 2 and 4.
"**Significantly (P <.01) greater vitamin A level than for cattle not fed supplement
Liver from calves had a higher (P<.01) vitamin A level
than those from yearling cattle in both control and vitamin A
supplemented lots. Yearling cattle were fed dry rations of
either pangolagrass hay or silage, cottonseed meal, citrus pulp,
and mineral five months after weaning before being started on
the test, which depleted their liver reserve of vitamin A. Raleigh
and Wallace (14) report that calves and yearlings from summer
range had 140 I.U. and 232 I.U. vitamin A per gram of liver,
respectively. Vitamin A values declined to 51 I.U. for calves
and 101 I.U. for yearlings after 100 days on a "bleached hay
Vitamin A per gram dry liver ranged from 0.7 to 83 mcg for
the control and from 32 to 193 mcg for cattle fed 30,000 I.U.
vitamin A daily. Feeding 30,000 I.U. vitamin A daily increased
liver vitamin A levels in calves 439% and yearlings 1410 % or a
mean increase of 586% when both groups were considered to-
gether. In contrast, there was little variation in liver B-carotene
level when either calves or yearlings were fed the basal ration
alone or supplemented with vitamin A (Table 4).
Vitamin A and B-carotene of Blood Plasma
Average vitamin A level in plasma varied from 15 to 89 mcg
per 100 ml plasma in the control cattle and from 35 to 58 mcg for
cattle fed vitamin A (Table 5). Animals fed vitamin A had
a 67% higher concentration of vitamin A in plasma than the
Control cattle in the four trials had a 23% higher level of
plasma B-carotene than those fed 30,000 I.U. vitamin A daily.
Apparently animals whose ration was deficient in vitamin A
were unable to convert ration B-carotene efficiently to vitamin
A; therefore, the small amount of ration B-carotene was not
available as a source of vitamin A. Wing (16) found that the
average digestibility of carotene by cattle was 59.1 6.86%
under the conditions of his trials.
Vitamin A in Heart and Copper in Liver and Heart
Values for vitamin A in the heart and copper in the heart
and liver tissues (mcg/gram dry tissue) for the two groups of
cattle are shown in Table 6. Vitamin A level in heart was
3.0% and 0.7% as much as in liver from control and vitamin
A-fed cattle, respectively. Copper level of heart was the same
Table 5. Vitamin A and B-carotene in blood plasma of calves placed on trial
when weaned and yearlings after five months on dry feed.
Vitamin A supplement Control 30,000 I.U. daily
Lot 1 2 3 4
Number cattle 151 15' 151 15'
Vitamin A in blood plasma (mcg/100 ml) :
Trial 1, calves 39 30 52 57
Trial 2, yearlings 18 18 35 58
Trial 3, calves 24 31 48 38
Trial 4, yearlings 15 35 39 49
Calves, two trials 32 31 50 43
Yearlings, two trials 17 18 36 54
All cattle 27 45
B-carotene in blood plasma (mcg/100 ml):
Trial 1, calves 115 118 65 70
Trial 2, yearlings 64 61 58 52
Trial 3, calves 115 94 84 94
Trial 4, yearlings 68 87 69 78
Calves, two trials 115 106 73 81
Yearlings, two trials 66 64 58 62
All cattle 95 73
'Heifer and steers.
Table 6. Vitamin A in heart and copper in liver and heart tissue (mcg/gram
Vitamin A supplement Control 30,000 I.U. daily
Number cattle 30 30
Vitamin A, liver (Table 4) 14 96
Vitamin A, heart 0.42 0.66
Copper, heart 23 23
Copper, liver 531 592
'Mcg/gram equivalent to parts per million (ppm).
for the 30 animals in both groups, 23 mcg per gram. Shirley
et al. (15) found that feeding 0, 25,000, and 50,000 I.U. vitamin
A daily to steers on winter pasture for 136 days had no signifi-
cant effect on copper content of heart ventricle. They obtained
similar results from steers on summer pasture and fed either
0 or 25,000 I.U. vitamin A daily for 96 days and from steers on
winter pasture injected intramuscularly with 720,000 I.U. vita-
min A every 28 days for 160 days.
It is seen from Table 6 that level of copper per gram of dry
liver increased from 531 to 592 ppm by vitamin A supplementa-
tion, an 11%o increase. These cattle had more than adequate liver
copper as shown by Chapman and Kidder (3), 340 ppm copper,
and stated by Cunha et al. (5), 100 to 300 ppm copper, per gram
dry tissue. Shirley et al. (15) obtained from 360 to 434 ppm
copper per gram dry liver from cattle injected with 720,000 I.U.
vitamin A and 14,000 I.U. vitamin E every 28 days.
Experiment II. Injection and Feeding Vitamin A
Age, previous treatment, and vitamin A treatment of cattle
fed in Experiment II are shown in Table 1. Lot 1, Control, was
fed only the basal ration, while Lots 2 and 3 were injected
initially with 2.7 million and 5.4 million I.U. and Lot 4 was fed
30,000 I.U. vitamin A daily per animal. The results of two
feeding trials are summarized in Table 7.
In Trial 5 a heifer in Lot 3 died the day before the end of
the 172-day feeding period. Daily observation and gain record
Table 7. Gain, feed efficiency, carcass, and tissue data for cattle receiving
injected and orally administered vitamin A.
Lot 1 2 3 4
Injected I.U. Fed 30,000
Vitamin A supplement Control 2.7 M 5.4 M I.U. daily
Number animals1 8 8 82 8
Initial age, months 11 11 11 11
Initial weight, lb. 433 446 439 444
Final weight, lb. 727 745 747 747
Daily gain, lb.3 1.68 1.71 1.76 1.73
100 lb. weight, lb. 2.9 2.8 3.0 2.9
Feed pound gain, lb. 10.2 9.9 10.1 10.1
TDN pounds gain, Ib. 6.3 6.2 6.3 6.3
Carcass grade H. Good Good H. Good Good
Dressing per cent 59.8 60.0 59.6 60.1
(mcg/gram dry liver) 14 58** 145** 158**
(mcg/gram dry liver) 10 11 11 12
(mcg/100 ml plasma)' 12 36** 50** 54**
(mcg/100 ml plasma)' 52 56 58 60
IFour heifer calves and four yearling steers in each group.
2One animal died in Trial 5; data are for seven cattle.
No significant difference in daily gain.
"4Blood samples only in Trial 6.
'*Significant (P<.01) increase in level of Vitamin A in liver and in blood plasma over
failed to detect any unthriftiness, and carcass examination did
not reveal any pathological tissue condition.
Individual daily gains ranged from 1.30 to 1.76 pounds for
calves and from 1.32 to 2.46 pounds for yearlings. Calves fed
30,000-I.U. vitamin A had the lowest and yearling cattle fed the
same ration the highest average daily gain for their respective
trials. The 16 yearling steers, because of larger skeletal develop-
ment and lower initial slaughter grade, had a 21% greater
average daily gain than the heifer calves. Average daily gain
for the two trials was 1.68, 1.71, 1.76, and 1.73 pounds daily for
Lots 1, 2, 3, and 4, respectively. The differences were not
statistically significant. There was no essential variation in
either total feed or TDN per pound gain between the four lots.
Calves in Trial 5, however, utilized their feed more efficiently
per unit gain than did the yearling cattle in Trial 6 as in
Experiment I. Rations were palatable, as indicated by con-
sumption rates of 2.8 to 3.0 pounds daily per 100 pounds live
weight. Yearling steers ate 7% more feed daily per 100 pounds
live weight than did the heifer calves.
The basal ration contained 0.69 mg B-carotene per pound,
equivalent to 276 I.U. vitamin A. Cattle fed the basal ration
alone, Lot 1, received 38% of the daily recommended level of
vitamin A. Animals in Lots 2 and 3 injected initially with 2.7
and 5.4 million I.U. vitamin A, respectively, received 179% and
321% and Lot 4, fed 30,000 I.U. obtained an average of 290%
above the recommended level. There was no apparent difference
in the healthy appearance of the four lots of cattle at the com-
pletion of each of the two trials.
Vitamin A and B-carotene in Liver and Plasma
The livers of control yearling steers in Trial 6 were almost
devoid of vitamin A, 1 mcg/gram dry liver, while those of con-
trol calves in Trial 5 contained 27 mcg vitamin A. The single
injection of either 2.7 and 5.4 million I.U. vitamin A and feeding
30,000 I.U. daily significantly (P<.01) increased liver vitamin
A level by 4, 10, and 11 times over animals not receiving vitamin
A supplement. Plasma vitamin A levels of 36, 50, and 54 mcg
per ml for animals on the same respective treatments were
also (P<.01) higher than the mean value of 12 mcg per ml for
animals fed the Control ration. Liver and blood B-carotene
were not significantly affected by treatments employed.
Carcass Grade and Dressing Per Cent
Calves on feed in Experiment I for 178 days had a High
Good carcass grade, while yearling steers on feed 163 days had
either High Standard or Low Good carcass grade, and dressing
per cent per lot varied from 59.0 to 60.1. Carcass grade for the
four lots in Experiment II ranged from Good to High Good with
a dressing per cent from 59.6 to 60.1. Dressing per cent was
typical for cattle having carcass grades from Low Good to High
Good. Feeding 30,000 I.U. vitamin A daily or giving a single
injection of either 2.7 or 5.4 I.U. vitamin A did not affect car-
cass grade and dressing per cent in these trials.
SUMMARY AND CONCLUSIONS
Sixty cattle were fed in four trials in Experiment I; 30
animals served as control, and 30 were fed 30,000 I. U. vitamin
A palmitate daily per animal for an average of 172 days.
Sixteen calves and 16 yearlings were fed in two trials in Experi-
ment II. Eight animals were controls, eight received 2.7 million
and eight received 5.4 million I.U. vitamin A intramuscularly
at beginning of trial, and eight were fed 30,000 I.U. daily for
an average of 175 days.
The 92 cattle were fed a basal ration of cottonsed hulls,
cottonseed meal, dried citrus pulp, and mineral mixture. These
ingredients were deficient in B-carotene, the precursor of vita-
min A. Calves were placed on trial shortly after weaning, while
the yearling cattle were maintained on dry feed for five months
after weaning before being placed on trial. Ninety-one animals
remained healthy, indicated by average daily feed intake, smooth
hair coat, and absence of eye watering.
The 30 calves and yearlings fed the basal ration in Experi-
ment I gained 1.59 pounds daily and required 6.3 pounds of
TDN per pound gain, while those fed 30,000 I.U. vitamin A
gained 1.68 pounds daily and ate 5.9 pounds TDN per pound
of gain. Experiment II calves and yearlings on the basal ration
gained 1.68 pounds daily; cattle injected with 2.7 million or
5.4 million I.U. or fed 30,000 I.U. vitamin A units daily gained
1.71, 1.76, and 1.73 pounds daily and required 6.3, 6.2, 6.3, and
6.3 pounds TDN per pound gain, respectively. There was no
significant difference in rate of gain due to feeding or injection
of vitamin A.
There was significantly (P<.01) greater concentration of
vitamin A per gram dry liver for cattle fed 30,000 I.U. vitamin
A palmitate (96 mcg) as compared to control animals (14 mcg).
There was no difference in B-carotene content of livers from the
two groups. Vitamin A supplementation increased the vitamin
A level of blood plasma from 26 to 48 mcg per ml with a reduc-
tion from 91 to 72 mcg in B-carotene.
In Experiment II initial injection of 2.7 and 5.4 million I.U.
and feeding of 30,000 I.U. vitamin A daily increased (P<.01)
vitamin A content per gram dry liver from 14 mcg for Control
to 58, 145, and 158 mcg, respectively, with little difference in
level of B-carotene. Blood plasma vitamin A levels for cattle on
the same respective treatments in Trial 6 were 36, 50, and 54
mcg per 100 ml plasma and 12 mcg for Control animals. These
differences were highly significant (P<.01); however, there
was little variation in B-carotene, 56 to 60 mcg per 100 ml
Vitamin A improved rate of gain slightly but did not affect
either feed efficiency, palatability of the basal ration, or ap-
parent health of experimental animals. Nutrients other than
vitamin A added to the basal ration of cottonseed hulls, cotton-
seed meal, citrus pulp, and mineral mixture are required to give
a significant increase in rate of gain.
1. Beeson, W. M., T. W. Perry, W. H. Smith, and M. T. Mohler. 1965.
Effect of different levels of vitamin A on the performance of Hereford
and Charolais x Hereford heifers self-fed on bluegrass pasture. Purdue
Univ. Agr. Exp. Stas. Lafayette, Ind. Res. Progress Rept. 169.
2. Carr, F. H., and E. A. Price. 1926. Color reactions attributed to
vitamin A. Biochemistry 20:497.
3. Chapman, H. L., Jr., and R. W. Kidder. 1964. Copper and cobalt
for beef cattle. Fla. Agr. Exp. Stas. Bull. 674.
4. Cheng, Kwanglu, and Roger H. Bray. 1953. Two specific methods
of determining copper in soil and in plant material. Anal. Chem.
5. Cunha, T. J., R. L. Shirley, H. L. Chapman, Jr., C. B. Ammerman,
G. K. Davis, W. G. Kirk, and J. F. Hentges, Jr. 1964. Minerals
for Beef Cattle in Florida. Fla. Agr. Exp. Stas. Bull. 683. Pp. 40.
6. Duncan, D. B. 1955. Multiple range in Multiple F-test. Biometrics
7. Gallup, W. D., and J. A. Hoefer. 1946. Determination of vitamin A
in liver. J. Ind. Eng. Chem. 18:288.
8. Hale, W. H., Farris Hubert, Jr., R. E. Taylor, T. A. Anderson, and
Bruce Taylor. 1961. The effect of feeding high levels of vitamin A
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