• TABLE OF CONTENTS
HIDE
 Front Cover
 Table of Contents
 Main
 Back Cover














Title: Copper and cobalt for beef cattle
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00049934/00001
 Material Information
Title: Copper and cobalt for beef cattle
Alternate Title: Bulletin - Univerity of Florida Agricutlrual Experiment Stations ; 674
Physical Description: Book
Language: English
Creator: Chapman, H. L.
Kidder, R. W.
Publisher: Agricultural Experiment Station, University of Florida
Publication Date: 1964
 Record Information
Bibliographic ID: UF00049934
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.

Table of Contents
    Front Cover
        Page 1
    Table of Contents
        Page 2
    Main
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
    Back Cover
        Page 16
Full Text
BULLETIN 674


A-


and COBALT


for Beef Catti


H. L. Chapman, Jr.
R. W. Kidder


University of Florida
Agricultural Experiment Stations
J. R. Beckenbach, Director, Gainesville


tf-

d


MAY 1964






















CONTENTS

Page

F OREW ORD ....... ............................... 3

COPPER DEFICIENCY SYMPTOMS ................................ .... ...... .... 4

COPPER SULFATE TOXICITY ......................... 7

COPPER SOURCES ...... ....... ...... ... .. 8

COBALT DEFICIENCY .... ................... ... .. 8

COPPER-COBALT INTERRELATIONSHIP ...... ...... ........................... 9

COBALT SOURCES ..... ......... ............... 11

SUM MARY ...... ..... ... ...... ...................... ... 13

A CKNOW LEDGM ENTS ... ....................................................... 14

LITERATURE CITED ............ ............................ ...... ..... 14









COPPER AND COBALT FOR

BEEF CATTLE

H. L. CHAPMAN, JR. AND R. W. KIDDER1


FOREWORD
Copper was first proved to be essential for the utilization of
iron hemoglobin formation 35 years ago (14).2 Shortly after-
wards the need for copper in livestock production in Florida
was reported (3,19). In 1941 it was demonstrated that copper
sulfate would overcome one phase of mineral deficiency symp-
toms in cattle on the organic soils of south Florida (15). This
was verified in 1946 (11). Similar results have been reported
from other areas of the world (4, 20). Since these early reports,
considerable research has been conducted to define the role of
copper in animal nutrition. Detailed discussions of copper, its
deficiency symptoms, and interrelations with other nutrients are
available (1, 10, 12, 18). In addition, information obtained by
Florida workers prior to 1953 is available (2, 3, 19).
The primary role of cobalt in cattle nutrition has been attrib-
uted to its being essential for the formation of vitamin B,, in
the rumen. There are indications that cobalt is also involved
in erythropoiesis (5, 8, 16, 18). A forage survey by Kretschmer
et al. (17) indicated that many forages grown on organic soil
are relativley low in cobalt. Some of the mineral soils of the
coastal areas of south Florida are also deficient in cobalt.
This bulletin presents the results of experiments at the Ever-
glades Station since the report of 1953 (2). The purposes of
the experiments were to obtain more information related to cop-
per deficiency symptoms in cattle; to determine the degree of
toxicity of copper sulfate to beef cattle; to compare various
copper containing materials for absorption and utilization of cop-
per; to study the interrelationship of copper and cobalt; and to
evaluate heavy, cobalt-containing pellets for furnishing the co-
balt requirement of beef cattle. Also presented are copper
deficiency and toxicity symptoms that have been observed in
commercial herds in south Florida since the 1953 report (2).

Animal Nutritionist and Animal Husbandman, Everglades Station.
2 Numbers in parentheses refer to Literature Cited.







Florida Agricultural Experiment Stations


COPPER DEFICIENCY SYMPTOMS
Many symptoms of copper deficiency are similar to those
caused by other nutritional deficiencies. Symptoms that have
been observed in copper-deficient cattle include loss in body
weight, roughness of hair coat, and loss of color or bleaching
of hair. However, many copper-deficient animals may be in
good flesh and have a smooth, normal appearing hair coat. A
more specific symptom observed on the organic soils of south
Florida is the effect of the deficiency upon skeletal tissue. As
shown in Figure 1, young cattle commonly develop a bony ring
just above the ankle joint. Also, the bones of copper-deficient
cattle are porous and fragile, and will break easily, often with-
out any apparent cause. The reasons) for these abnormal bone
developments have not been clearly defined, but is apparent that
a deficiency of copper and,'or an excess of molybdenum inter-
feres with the proper bone development of growing animals.
Another symptom sometimes found in extremely copper-deficient
animals is "paces" (Figure 2a). The copper-deficient animal
may run like a pacing horse, rather than like normal cattle
(Figure 2b).
Occasionally copper-deficient cattle die suddenly when excited
in any fashion. There are two apparent reasons for this. Cop-


Fig. 1.-Calf showing typical copper-deficiency symptoms.







Copper and Cobalt for Beef Cattle


per-deficient cattle become anemic, and undue exertion demands
more oxygen that the blood of the anemic animal can carry.
Also, post-mortem exami-
nation sometimes reveals
4 many small lesions (pe- t
techiae) in the myocardium,
indicating that lack of cop-
per may affect the proper
function of the heart.
As mentioned earlier, any
S of the symptoms thus far A
discussed can be found
in copper-deficient cattle. Fig. 2.-(a) Steer with the "paces".
However, not all copper-
deficient cattle demon-
strate all of these symp-
toms. Also, these symp-
toms can have other causes.
The best means of diagnos-
ing copper-deficiency in cat-
tle is to chemically analyze
a sample of liver tissue.
(7). This sample can be
obtained without injuring
Fthe ania atte that ig. 2.-(b) A steer traveling in nor-
the animal. Cattle that are mal manner.
denied sufficient copper de-
velop characteristic levels of copper and iron in liver tissue (Fig-
ure 3). Generally, if the animal is originally in a good state of
copper nutrition (as were the six animals in Figure 3) 8 to 12
months are required to deplete its reserve body stores of copper.
There will be a gradual decrease in liver copper during this
period. Usually the external symptoms already discussed are
not found consistently until after the liver copper level is below
25ppm. Some individuals may show symptoms when the level
is below 75 ppm, but the extent of symptoms will be variable.
Also the level of total blood copper will usually be in the normal
range of 0.75 to 1.00 mcg per ml of blood until the liver copper
level falls below 25 ppm, at which time the liver apparently
loses its ability to maintain normal blood copper levels. As the
liver copper level decreases, the liver iron level increases. When
the iron becomes bound in the liver tissue, there will be a subse-
quent decrease in hemoglobin content of the blood. This is a






Florida Agricultural Experiment Stations


6000

5000

4000

3000

2000

1000

0-
0 12 24
Time


36
(wks.)


48 60


Cu
ppm


400


300


200


100


0


0 12 24 36 48 60
Time (wks.)
Fig. 3.-Iron and copper content of livers from cattle becoming deficient
in copper.


Fe
ppm







Copper and Cobalt for Beef Cattle


symptom that was discovered many years ago and has been
demonstrated in many kinds of animals.

COPPER SULFATE TOXICITY
One of the materials most commonly used in mineral mixtures
to furnish copper for beef cattle is cupric sulfate (CuS04), com-
monly referred to as bluestone. This material has been reported
to be toxic, but recent experiments (9) demonstrated that its
toxicity to beef cattle is related to the manner it is given to
the animals. Levels of cupric sulfate ranging from 0.5 to 12.0
gms per animal were given to beef cattle daily as a dry form
material in a gelatin capsule for 16 months without having any
significant effect on the animals. However, 12 gms a day
given as a water drench was lethal to two experimental animals
within 65 days.
Ante-mortem symptoms of copper toxicity include loss in body
weight, weakness, incoordination, dull appearance, yellow pig-
mentation of the mucous membranes, and red urine. Post-
mortem symptoms include a general yellow color in the body
cavity, hemolysis, hemoglobimuria, thick bile, and hemorrhages
in the gall bladder and kidneys. None of these symptoms
appeared in the cattle that received dry copper sulfate.
These results indicate that there is little danger of toxicity
of copper sulfate when it is supplied in a mineral mixture to
furnish 1 to 2 gms per animal daily. However, copper sulfate
should not be put in drinking water for a prolonged period of
time. When copper sulfate is put in drinking water, rigid con-
trol is needed so that the material is accurately measured and
completely dispersed. Also, if copper sulfate is put in drinking
water, it should not be used in feed, molasses, drench, or any
other way, unless directed by a veterinarian or other qualified
persons. Copper sulfate should not be force-fed unless precau-
tions are taken to minimize the danger of toxicity.
The amount of copper to include in a mineral mixture is
directly related to the rate of mineral consumption. A mineral
that is consumed at the rate of 35 to 40 pounds per animal per
year should contain a minimum of 0.75 percent copper (3.0
percent copper sulfate) for cattle on organic soils and 0.15 per-
cent (0.60 percent copper sulfate) on mineral soils. If a more
palatable mineral is fed, the level of copper can be adjusted to
compensate for the increased mineral consumption.







Florida Agricultural Experiment Stations


COPPER SOURCES
As mentioned earlier, copper sulfate is one of the materials
most often used to provide copper in beef cattle minerals. There
are a number of other copper-containing materials that can be
used to furnish this element. A recent study (6) indicated the
absorption and excretion patterns of copper from cupric sulfate,
cupric nitrate, cupric chloride, and cupric carbonate to be rela-
tively comparable. More copper was absorbed from these four
materials than from cuprous oxide, cupric oxide, or copper wire.
However, more copper was absorbed from finely ground than
from large particles of cupric oxide, indicating utilization of
copper from cupric oxide to be related to particle size. It is
possible that utilization of copper from cupric oxide could be
further aided by using even finer particles of the material.
Copper from copper wire was relatively unabsorbed. The hygro-
scopic nature of cupric nitrate and cupric chloride might affect
the use of these materials in mineral mixtures.

COBALT DEFICIENCY
Many areas of south Florida are deficient in cobalt, and it
is possible that most cattle in these areas are to some degree
deficient in this element, unless provided supplemental cobalt.
The symptoms of cobalt deficiency are similar to those observed
from other nutritional deficiencies-mainly, loss of body weight,
loss of appetite, anemia, and dull appearing hair coat. Weak
calves may be born. The degree to which these symptoms are
apparent may vary considerably. Diagnosis of cobalt deficiency
is often difficult. However, cobalt-deficient cattle respond quickly
to cobalt treatment, recovering their appetite and subsequently
their weight and vigor.
Much of the benefit from cobalt for beef cattle is related to
its being an essential element for vitamin B12 synthesis by
rumen microorganisms (18). Vitamin B12 contains cobalt. The
normal requirements of beef cattle for Vitamin B12 are met by
the synthesis of this vitamin by bacteria in the rumen if ade-
quate amounts of cobalt are available. Recent experiments (8,
16) indicate that cobalt also is related to copper utilization.







Copper and Cobalt for Beef Cattle


COPPER-COBALT INTERRELATIONSHIP
Two experiments at the Everglades Station indicated cobalt
to be related to copper utilization. In the first experiment 50
S grade Brahman steers were divided into 10 lots of five steers
each on the basis of weight, age, type, and previous treatment.
The groups were randomly allotted to the experimental treat-
ments presented in Table 1 and maintained there for 12 months.

TABLE 1.-COMPOSITION OF MINERAL MIXTURES FED TO THE DIFFERENT
EXPERIMENTAL GROUPS (0).

Group Steamed Cobalt Cupric Cupric Manganese
Number Salt Bonemeal Carbonate Sulfate Oxide Sulfate

1 -
2 100.0 -
3 50.0 50.0 -
4 50.0 50.0 .06 -
5 47.5 50.0 .06 2.5 -
6 45.0 50.0 .06 5.0 -
7 42.5 50.0 .06 7.5 -
8 48.4 50.0 .06 1.6 -
9 40.0 50.0 .06 5.0 5.0
10 35.0 50.0 .06 5.0 10.0



The animals grazed Roselawn St. Augustinegrass pastures.
The minerals were fed free-choice. At the end of the experi-
ment liver tissue was obtained from each animal and analyzed
for manganese, copper, molybdenum, zinc, and cobalt by spectro-
graphic technique. The results are presented in Table 2. No
external differences among the cattle could be related to experi-
mental treatment. However, there were significant differences
in the results of the liver tissue analysis. These differences
were particularly significant in the case of copper and cobalt.
All three lots receiving no cobalt had less than 3 ppm copper in
liver tissue. When 0.06 percent cobalt carbonate was added, the
cattle had a level of 51.0 ppm of copper in their livers. These
figures are on a fresh weight basis, and if they were converted
to a dry matter basis, they would be approximately four times
this level (7). When copper was added to the mineral mixture,
the level of copper in liver tissue was further increased. The
inclusion of 0.06 percent of cobalt carbonate in the mineral mix-
ture also increased the level of cobalt stored in the liver tissue,








Florida Agricultural Experiment Stations


It was difficult to relate variations in levels of zinc, molybdenum,
and manganese to experimental treatment.

TABLE 2.-MINERAL CONSUMPTION, WEIGHT GAIN AND LIVER CONTENT
OF MANGANESE, COPPER, MOLYBDENUM, ZINC, AND COBALT.

Mineral Average Liver Analysis (ppm)*
Consump- Daily
Group tion Gain Molyb-
Number (lbs/yr) (lbs.) Copper** denumt Cobalt** Zinct Manganese**

1 0 0.76 2.1 1.1 0.05 60.0 1.5
2 14 0.76 2.0 1.6 0.06 64.0 2.1
3 48 0.78 2.6 1.7 0.06 57.0 1.5
4 66 0.78 51.0- 1.1 0.12 57.0 2.0
5 41 0.92 59.0 1.6 0.11 69.0 1.9
6 39 0.83 81.0 5.0 0.10 68.0 2.1
7 36 0.58 157.0 2.0 0.11 58.0 2.2
8 44 0.81 84.0 1.8 0.12 61.0 2.5
9 39 0.84 121.0 1.6 0.12 73.0 2.4
10 33 0.81 93.0 1.7 0.09 85.0 2.2

*Analyses presented on a fresh weight basis.
** Effect of treatment significant at P < .01.
t Effect of treatment significant at P < .05.

During the second experiment 32 Brahman x Angus heifers
were divided into four groups of eight animals each and ran-
domly allotted to the experimental treatments presented in
Table 3. The purpose of this experiment was to determine
whether cobalt was involved in the molybdenum-copper interre-
lationship. Cobalt was given at a rate of 8 mg and molybdenum
at 250 mg per animal daily. Both were administered as a drench.
The cattle received no supplemental copper. All of the cattle
were kept together as a group and grazed forage that was pre-
dominantly Roselawn St. Augustinegrass having an average an-
alysis of 0.24 percent phosphorus, 13.5 ppm copper and 0.53 ppm
molybdenum. Common salt and dicalcium phosphate were fed
free choice. Shortly after the experiment began, one heifer was
injured and removed from the study. The experimental results
are presented in Table 3. The level of blood hemoglobin was
reduced less for both groups that received cobalt. Similar results
were evident in packed cell volume. Another result that indi-
cated cobalt to be involved in copper metabolism was found in
the level of copper and iron present in liver tissue. The average
level of copper in liver tissue decreased in every group except the
group receiving cobalt with no molybdenum, which also had the
least increase in liver iron. These results indicate that cobalt







Copper and Cobalt for Beef Cattle


was involved in copper metabolism but did not offset the effect
of the molybdenum.

TABLE 3.-AVERAGE BLOOD AND LIVER ANALYSIS CHANGE AND AVERAGE
RATE OF GAIN OF BRAHMAN-ANGUS HEIFERS.

Treatment
Cobalt &
Molyb- Molyb-
None Cobalt denum denum

Blood analysis
Hemoglobin (gm%)* -1.20 +0.30 2.60 -0.60
Packed cell volume (%)* -9.10 -3.00 -12.70 -4.60
Serum inorganic P (mg%) +1.32 +0.94 + 0.71 +1.41
Total copper (mcg/ml)* +0.12 +0.03 + 0.03 +0.01
Liver analysis
Copper (ppm)** 40 +36 -101 -128
Iron (ppm)** +185 +62 +212 +165
Total gain per heifer
(pounds) 153 189 152 194

Effect of treatment significant at P < .05.
** Effect of treatment significant at P <.01.


COBALT SOURCES
Information is not available concerning the availability of
cobalt from different materials. However, it appears that cobalt
oxide, cobalt carbonate, cobalt chloride, or cobalt sulfate can
be used to satisfactorily furnish the cobalt requirements of beef
cattle. The cobalt needs of cattle in south Florida can be fur-
nished by 0.03 percent cobalt in a mineral mixture that is con-
sumed by cattle at a rate of 35 to 40 pounds a year.
Cobalt is potentially toxic to livestock, although the tolerance
of ruminants may be greater than that of non-ruminants (18).
Until more information is available, care should be taken not to
force feed cobalt or to give cattle more than that amount nec-
essary for good health.
Another method of providing cobalt to cattle is to give a
heavy pellet that contains cobalt. Theoretically, the heavy pel-
let will stay in the stomach (recticulum) of cattle for several
months and slowly release a continuous supply of cobalt. Three
field tests were conducted to evaluate this material. In each
test the cobalt pellet was used in addition to all other manage-
ment practices.







Florida Agricultural Experiment Stations


In the first experiment, which was conducted on a predomi-
nantly Immokalee sandy soil, mature Hereford cows were divided
into two groups, one group receiving the cobalt pellet. All of
the cattle were kept together and managed under range condi-
tions. At the end of the experiment the cows were weighed.
The weight changes during the study, using only the 61 animals
for which there was a final weight, are presented in Table 4.

TABLE 4.-WEIGHT CHANGES OF HEREFORD COWS (LBS.).*

No Cobalt Cobalt
Pellet Pellet

Number of animals 32 29
Initial weight per animal 833 814
Final weight per animal 761 779
Weight change per animal 72 35

Collier Cattle Company, Immokalee, Florida, 7-28-59 to 3-22-60.

Weight loss was less for the cows that received the cobalt
pellet.
A second experiment, conducted on a mucky-sand soil, in-
volved 153 yearling grade Brahman steers. The steers were
divided into two groups, one of which received the cobalt pellet.
The steers had been treated twice for liver flukes before receiv-
ing the cobalt pellet and were drenched twice with phenothiazine
at the beginning of the experiment. The two groups were kept
in a single herd and subjected to the normal management prac-
tices followed at the ranch. At the beginning they grazed pan-
golagrass and were fed blackstrap molasses, free choice. In
addition they received 300 pounds of 41 percent cottonseed meal
a day. A mineral mixture was fed free choice. The weight
changes of the steers are presented in Table 5. The steers

TABLE 5.-WEIGHT CHANGES OF YEARLING, GRADE BRAHMAN
STEERS (LBS.).*

No Cobalt Cobalt
Pellet Pellet

Number of animals 73 80
Initial weight 343 343
Final weight 553 561
Total gain 210 218

Hayes Ranch, Clewiston, Florida, 2-3-60 to 9-7-60.







Copper and Cobalt for Beef Cattle


receiving the cobalt pellet gained an average of 8 pounds more
than the steers not receiving the pellet.
In the third experiment, conducted on muck soil, 76 yearling
Brahman-Angus steers were divided into two groups, one of
which received the cobalt pellet. The animals were managed
as they would have been otherwise. When given supplemental
feed during the winter, each of the steers in this experiment
received a daily intake of 0.1 pound of a complete mineral that
included .03 percent cobalt. When the cattle received no supple-
mental feed, they were provided the same mineral free choice.
The weight gains for this experiment are presented in Table 6.

TABLE 6.-WEIGHT CHANGES OF YEARLING BRAHMAN X ANGUS
STEERS (LB.).*

No Cobalt Cobalt
Pellet Pellet

Number of animals 38 38
Initial weight 528 508
Final weight 838 802
Total gain 310 294

Everglades Experiment Station, Belle Glade, 11-23-59 to 8-17-60.

There was no weight gain advantage from the administration
of the cobalt bullet in this experiment.
The results of these three studies indicate the heavy cobalt
pellet had merit when used for cattle grazing cobalt-deficient
range, where a mineral mixture containing adequate cobalt
was not supplied. When adequate management practices were
followed, the pellet was of marginal or not economic benefit. A
later experiment (13) confirmed these results.


SUMMARY
Results of experiments conducted during the past 10 years
at the Everglades Station relating to copper and cobalt require-
ments of beef cattle are presented. Symptoms of copper and
cobalt deficiencies are described, and also symptoms of copper
toxicity. Several copper sources are utilized efficiently, but cop-
per sulfate is the principal source recommended for furnishing
copper to beef cattle. The amount of copper in a mineral mixture
should be adjusted to the rate of consumption. A mixture that







Florida Agricultural Experiment Stations


is consumed at a rate of 35 to 40 pounds per animal yearly
should have a minimum of 0.75 percent copper for cattle on
organic soil and 0.15 percent on sandy soil. The extra copper
is needed for cattle on organic soil because of the relatively high
level of molybdenum present in the soil and in forage grown on
this soil.
Mineral mixtures used on either mineral or sandy soils should
contain 0.03 percent cobalt. Cobalt is important for vitamin B,,
synthesis in the rumen but also is involved in proper utilization
of copper.
ACKNOWLEDGMENTS

The authors wish to acknowledge the efforts of many people
who assisted in these studies, including T. C. Erwin, D. W.
Beardsley, C. E. Haines, R. V. Allison, J. V. McLeod, Enrique
Tomeu, H. B. Brough, R. H. Lewis, L. V. Morris, R. M. Hooker,
M. C. Bell, S. L. Nelson, W. L. Sippel, C. W. Kidder, and Howard
Hill. They also wish to recognize the grant-in-aid assistance fur-
nished by Moorman Manufacturing Company, Quincy, Illinois.
Reagent grade copper sulfate was furnished by Tennessee Cor-
poration, Atlanta, Georgia; dicalcium phosphate by Shea Chem-
ical Corporation, Columbia, Tennessee; cobalt "bullets" by Nich-
olas of America Limited, 200 South Michigan Avenue, Chicago 4,
Illinois. The assistance of personnel of Collier Cattle Company,
Immokalee, Florida; Hayes Ranch, Clewiston, Florida; and Daley
Ranch, Belle Glade, Florida, was invaluable.
Some of the data included in this bulletin have been published
elsewhere, including Everglades Station Mimeo 61-4; Journal
Animal Science 22: 82; Journal Animal Science 21: 960; and
1953 Proceedings of Southern Agricultural Workers Meeting.

LITERATURE CITED

1. Alcroft, R., and G. Lewis. Copper nutrition in ruminants. Journal
Science Food Agriculture 8 supply issue): 96: 1957.
2. Becker, R. B., P. T. Dix Arnold, W. G. Kirk, G. K. Davis, and R. W.
Kidder. Minerals for dairy and beef cattle. Florida Agricultural
Experiment Stations Bulletin 513. 1953.
3. Becker, R. B., W. M. Neal, and A. L. Shealy. Salt sick, its cause and
prevention. Florida Agricultural Experiment Stations Bulletin 231.
1931.
4. Bennetts, H. W., and H. T. B. Hall. The investigation of "falling
disease" of cattle in the Southwest of Australia. Journal Department
Agriculture of West Australia 16: 156. 1939.








Copper and Cobalt for Beef Cattle 15

5. Cartwright, G. E. The relationship of copper, cobalt, and other trace
elements in hemopoiesis. American Journal Clinical Nutrition 3:11.
1955.
6. Chapman, H. L., Jr., and M. C. Bell. Relative absorption and excretion
by beef cattle of copper from various sources. Journal of Animal
Science 22 (1) : 821. 1963.
7. Chapman, H. L., Jr., D. H. Cox, C. E. Haines, and G. K. Davis. Eval-
uation of the liver biopsy technique for mineral nutrition studies with
cattle. Journal Animal Science. IN PRESS. 1963.
8. Chapman, H. L., Jr., and R. W. Kidder. Oral administration of moly-
bdenum and cobalt to Brahman-Angus heifers. Journal Animal Science.
IN PRESS. 1963.
9. Chapman, H. L., Jr., S. L. Nelson, R. W. Kidder, W. L. Sippel, and
C. W. Kidder. Toxicity of cupric sulfate for beef cattle. Journal
Animal Science 21 (4): 960. 1962.
10. Cunningham, I. J. Copper and molybdenum in relation to disease of
cattle and sheep in New Zealand. Copper Metabolism Symposium
Edited by W. D. McElroy and B. Glass. Johns Hopkins Press, Md.: 246.
1950.
11. Davis, G. K., R. W. Kidder, and C. L. Comar. Copper deficiency in
cattle. Journal Animal Science 5: 393. 1946.
12. Davis, G. K., and J. K. Loosli. Mineral metabolism. Annual Review
Biochemistry 23: 459. 1954.
13. Haines, C. E. Additional information concerning the value of cobalt
bullets to yearling steers on muck soil. Everglades Station Mimeo
62-25. 1962.
14. Hart, E. B., H. Steenbock, J. Waddell, and C. A. Elvehjem. Iron in
nutrition VI. Copper as a supplement to iron for hemoglobin building
in the rat. Journal Biological Chemistry 77: 797. 1928.
(/15. Kidder, R. W. Mineral requirements of beef cattle. Florida Agricul-
tural Experiment Stations Annual Report: 176. 1941.
16. Kidder, R. W., T. C. Erwin, R. V. Allison, D. W. Beardsley, and H. L.
Chapman, Jr. Copper storage in the livers of cattle from feeding
mineral mixtures containing different levels of copper. Proceedings
Southern Agricultural Workers Meeting: 62: 1953.
c17. Kretschmer, A. E., Jr., V. A. Lazar, and K. C. Beeson. A preliminary
survey of the cobalt contents of south Florida forages. Soil Science
Society of Florida 14: 53. 1954.
18. Marston, H. R. Cobalt, copper, and molybdenum in the nutrition of
animals and plants. Psysiological Reviews 32: 66. 1952.
19. Neal, W. M., R. B. Becker, and A. L. Shealey. A natural copper
deficiency in cattle rations. Science 74: 418. 1931.
20. Sjollema. B. Lack of copper as the cause of sickness among animals.
Biochemische Zeitschrift 267: 151. 1933.




















O OF





CIE~




University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs