,) Recent Developments in !inerals for Beef Cattle and Swine
T. J. Cunha*
', L .' Department of Animal Science
University of Florida-
While many developments have occurred in the mineral nutrition field during the
past 25 years, it is apparent that only the surface has been scratched in determining
the mineral needs of beef cattle and swine. As one studies the available data, it
becomes apparent that many gaps exist in the present knowledge available.
Until the many mineral interrelationships are understood, it will be difficult
to determine mineral needs on a very exact basis. The requirement for a specific
mineral element will, in many cases, be dependent on the level of other mineral
elements in the diet. For example, the zinc needs will be especially influenced by
the level of calcium and possibly other mineral elements in the ration. Interrela-
tionships exist between calcium, phosphorus and magnesium. Vitamin D also influences
this interrelationship. Excessive iron may influence phosphorus utilization. Copper
is needed for the utilization of iron. The level and kind of protein in the ration
influences copper toxicity as well as utilization. Molybdenum influences copper
utilization and needs and sulfur affects this interrelationship. There is some
interrelationship between zinc and copper. Many more such examples could be cited.
Suffice it to say that this is just a start on the many known mineral interrelation-
ships and undoubtedly there are still many which are undiscovered as yet.
Probably one of the most challenging areas of nutrition research lies ahead in
unraveling the many aspects of mineral interrelationships and interactions and their
affect on specific mineral needs of animals. The complexity of the problem is
obvious when one realizes that it involves intestinal absorption, enzyme activity,
*Address given at the Salt Institute, Chicago, Illinois, on February 23, 1966.
metabolic function, blood and tissue functions and so many other essential body
activities. The old saying that "if a little is good, a little more is better" is
most likely to be false when dealing with minerals. A good balance of mineral ele-
ments is needed. Until more is learned about mineral interactions or interrelation-
ships, one should stay close to recommended levels of minerals in animal rations.
The problem of mineral availability is complicated by organic and/or inorganic
chelates. Mineral elements may be chelated by a compound which will either increase
or decrease its availability. Much remains to be learned to determine which che-
lates are beneficial and which are not and what can be done to control their action.
Until chelates and chelation is thoroughly understood, it will be difficult to
understand and predict with real accuracy mineral needs and requirements with cer-
tain type rations since many chelates will vary in their content in different feeds.
Glycine, cysteine, oxalic acid and phytic acid are only a few examples of chelates
present in feeds which will effect the availability of certain mineral elements.
Swine mineral needs
Following are some recent developments on the mineral requirements of the pig.
Calcium and phosphorus
Probably the most interesting recent development is the finding by Cornell
workers (1) that atrophic rhinitis can be produced by feeding diets low in calcium
or by an imbalance of calcium and phosphorus. They found some atrophic rhinitis
when pigs were fed the NRC nationall Research Council) recommended levels of 0.8
per cent calcium in the ration (2). Their findings suggested that dietary calcium
for the growing-finishing pig should be increased above the level currently recom-
mended by the NRC since levels of 1.0 to 1.2 per cent calcium in the ration promoted
higher bone ash and better integrity of the nasal turbinates. It will be important
to follow further Cornell and other University research along this line in order to
determine the final outcome of these studies and what their effect will be on the
recommended levels of calcium and phosphorus in swine rations. If the Cornell
studies can be substantiated higher calcium levels right be recommended for swine
rations in the future. On the other hand, a few investigators have been able to use
lower levels of calcium than those recommended by NRC for the growing-finishing pig
with good results. The reason for this is not known. It is possible that the level
of calcium in the drinking water may have had some effect on the level needed in the
ration. It is important to determine the level of minerals in the drinking water
when studying mineral needs. This level can vary considerably and could have a big
influence on the minerals needed in the ration since pigs will consume from 2 to 4
pounds of water per pound of feed. It is important that proper calcium levels be
used since excess calcium increases the need for zinc, unidentified factors and
The information in table 1 shows the levels recommended by the National
Research Council (2). Included in this table is information on requirements,
tolerance level as well as the toxic level of minerals for the pig.
Table 1. Trace Minerals for Swine
Requirement Tolerance level Toxic level
Mineral Element mg./kg. feed mg./kg. feed mg./kg. feed3
Copper 101 100 250
Iron 801 1,000 4,000
Iodine 0.20 --
Magnesium 400 --
Manganese 40 80 500
Zinc 502 1,000 2,000
Selenium 0.10 -- 5
1Baby pig requirement.
2Higher levels may be needed if excess calcium is fed.
3Mg. per kg. is the same as ppm.
The requirement for copper has been established as 10 ppm. The tolerance level
has been set at 100 ppm. This level could probably be safely increased to 125 ppm.
The toxic level has been set at 250 ppm. There is some disagreement on calling
this a toxic level. The use of copper sulfate at levels of 250 ppm. in the ration
has occasionally resulted in toxic effects at the Florida and lachigan Stations.
Other Experiment Stations in the U.S. and in England have not reported such a toxic
effect. There evidently is a reason for the differences involved. Research to
date indicates some interrelationship between the level and source of protein as
well as the zinc level and copper toxicity. This may account for the differences
obtained in the U.S. and England.
Most of the results obtained to date show that a favorable response to copper
feeding occurs during the early part of the growth period and this benefit tends to
disappear later on. This indicates that copper feeding might be limited to the early
growth period of the pig.
Research to date indicates that copper has bactericidal properties in addition
to being needed for hemoglobin formation and other metabolic processes in the body.
These bactericidal properties are the reason why there is considerable interest in
using copper at levels higher than 10 ppm. It is interesting to note that levels
of copper of 250 ppm. in the ration seems to always decrease the hemoglobin level
a little. This is something which almost all investigators have reported.
Since a level of 250 ppm will occasionally cause toxicity,the writer would
presently not recommend this level in swinerations. If occeaionlly -pi~- wvll
die, as occurred in the Florida and Michigan studies, it is logical to assume that
deaths may also occur elsewhere. Since almost the same results are obtained with
125 ppm of copper in the ration, the writer would recommend this level whenever
copper feeding is indicated.
A great deal of work has been done on iron fumarate in recent years. It was
shown that pigs nursing sows receiving ferrous fumurate in their rations had higher
hemoglobin levels. However, it is now pretty well established that this was not
caused by an increase of iron in the sow's milk. The data indicate that the pigs
received the iron from the sow's feces or from her diet. Cornell workers (6) were
not able to increase the iron content of milk when they fed 1,984 ppm of ferrous
fumarate in the sow's ration. Thus, it appears that finding an iron compound which
will appreciably increase the level of iron in the sow's milk still eludes us.
Purdue (5) recently compared ferrous fumarate versus ferrous sulfate in a
creep ration for pigs from birth to three weeks of age. The pigs fed the ferrous
sulfate were slightly heavier (22 vs. 20 lbs.) and had a higher hemoglobin level
(11.4 vs. 9.7) at three weeks of age. Thus, the ferrous sulfate seemed to be at
least as good as ferrous fumarate and its cost is considerably less. The Illinois
Station (4) also showed that pigs receiving ferrous sulfate mixed with their Illinois
16 ration gained faster than the pigs on other iron treatments. Thus, present know-
ledge does not show any special advantage for ferrous fumarate over other iron com-
pounds which are effective sources of iron supplementation.
The iron requirement of the baby pig is somewhere between 60 to 125 ppm. The
National Research Council (2) has established 80 ppm as the requirement. English
workers (7) have shown that the young pig must retain 21 mg. of iron per kg. of live-
weight increase in order to maintain a satisfactory level of iron. Suitable iron
preparations, injected at levels of 150 to 200 mg. into baby pigs at 1 to 3 days
of age, will prevent anemia due to iron deficiency. Uith present knowledge there
should be no reason for iron deficiencies to occur. However, they are still being
found on many farms throughout the country.
Parakeratosis or dermatosis can be prevented or cured by zinc. High levels of
calcium increase the need for zinc in some manner as yet unknown. The data in
table 1 show the zinc requirements to be 50 ppm in the ration. If excess calcium
is used, then higher levels of zinc may be needed. Studies at Yichigan (8) showed
that when the calcium becomes too excessive (1.5 to 2.0 per cent in the ration) the
use of zinc at 100 ppm will not always completely prevent the growth depression and
poor feed conversion associated with parakeratosis, although it will prevent the
typical skin lesions. Since so many pigs still receive more calcium than they need,
it is recommended that levels of at least 100 ppm of zinc be used in swine rations.
This level might be even increased to 125 to 150 ppm if for some reason the level
of calcium used may be too high.
The writer recently spoke at a conference in Indiana attended by over 100
practicing veterinarians. Over one-third of them indicated they were still seeing
parakeratosis on swine farms in various Midwest states. This indicates that we must
make an even greater effort to control this disease which can be easily done with
proper levels of zinc.
There is some interrelationship between the copper and zinc needs. Under
certain conditions copper will alleviate some of the symptoms of parakeratosis in
Purdue workers (9) showed that the zinc in soybean protein is less available
than that in casein. This is due to the phytic acid in soybean protein forming a
complex (chelation) which makes the zinc less available. This is a good example
to point out the fact that a chemical analysis of a feed is only a guide as to the
availability of that nutrient to the animal. There is a difference between the avail-
ability of a nutrient as determined by a chemical analysis or a microbiological
assay and as determined by the use the pig will make of it. Thus, the only sure way
to know whether a ration lacks a certain nutrient is to add it to the ration and
determine whether or not the addition is beneficial. This does not mean that feed
analyses are not valuable. They definitely are. It does point out, however, that
they should be used as a guide and not as the final answer always.
In the past, selenium has been thought of only as a toxic substance. Then it
was found to prevent a yellowish-brown discoloration of the body fat, necrosis of
the liver and death in the young pig. Of considerable importance is the fact that
both selenium and vitamin E prevented these symptoms which indicates an interrelation-
ship between the two in this syndrome. One must be very careful in using selenium,
however, since 1/10 ppm is beneficial, whereas 5 to 10 ppm will cause some toxic
New Zealand workers (10) have reported that selenium has been helpful in at
least 20 piggeries. Except where complicating factors have occurred, their losses
have been stopped by giving the pigs an oral dose of 5 mg. of selenium.
The magnesium requirements are shown in table 1. As far as is known, however,
there is still no need to supplement practical rations with magnesium since they
contain adequate amounts.
The best way to supply it is through the use of iodized salt which has been
stabilized to protect the iodine from destruction. Florida studies have shown that
excess iodine is harmful to rabbits, hamsters and rats (25). Swine were not affected
by levels which were toxic to rabbits and rats. Since excess iodine, even for short
periods of time can be toxic, these studies indicate that caution should be used in
avoiding excesses. It should be pointed out, however, that levels of hundreds of
times the required amount were needed to get harmful effects.
It is doubtful if cobalt needs to be added to swine rations if they contain
adequate amounts of vitamin B12.
The exact level of manganese needed in swine rations is not known. The levels
shown in table 1 can be used as a guide. Excess manganese is toxic, however, and
caution should be used in feeding too high a level. There are indications that
excess calcium and phosphorus will increase the need for manganese. This is an area
which needs more study with the pig.
Beef cattle mineral needs
Following are some recent developments on the mineral requirements of beef
Copper deficiencies have been encountered in Florida, California, Nevada and
other areas. They can be found where the soil is low in copper or where excess
molybdenum is present. Excess molybdenum in the forage increases the need for
copper. In Florida, where it is assumed that cattle will consume from 35 to 40
pounds yearly of a complete mineral mixture, the copper is added to the complete
mineral mixture as follows:
(1) For organic (muck) soils 0.75% copper (or 3.0% copper sulfate)
(2) For mineral (sandy) soils 0.15% copper (or 0.6% copper sulfate)
These recommended levels of copper should be adjusted up or down if the rate
of mineral consumption varies much from 35 to 40 pounds per animal yearly. The
higher level of copper recommended for the organic soils is to counteract the effect
of excess molybdenum in those soils.
A recent Florida study showed that the toxicity of copper sulfate is related to
the manner in which it is given to cattle. Levels as high as 8.0 grams of copper
sulfate per animal daily were administered in a dry form to steers for 12 months,
followed by 12.0 grams to the same steers for the next 12 months with no toxic effect.
Twelve grams a day given in a water drench, however, was lethal to two animals
within 65 days. These levels compare to the recommended minimum average daily in-
take of copper of 1/8 of a gram (or 1/2 gram of copper sulfate) per animal in the
organic soil pastures in Florida.
The best means of diagnosing copper deficiency in cattle is to chemically
analyze a sample of liver tissue. The values in table 2 indicate when a deficiency
Areas with excess molybdenum have been shown to occur in Florida, California,
Nevada and elsewhere. Excess molybdenum increases the need for copper. Supplementa-
tion with copper will counteract excess molybdenum. It is necessary, however, to
have adequate sulfate present to control molybdenum toxicity by copper in the ration.
The copper requirements of cattle appear to be between 4 to 8 ppm in the total
ration. With good fertilization practices the copper content of forages seldom
exceeds 9 to 12 ppm. This level of copper will not prevent molybdenum toxicity
when the forage contains above 4 to 6 ppm of molybdenum. Molybdenum levels in
forage from the organic (muck) soils in Florida varies from 3 to 20 ppm. These
figures emphasize the need for continuous supplementation with extra copper in the
mineral mixtures in excess molybdenum soil areas in Florida. Copper deficiencies
will usually occur when the level of molybdenum exceeds 3 ppm and the copper level
is below 5 ppm in the feed.
Molybdenum is most readily available to plants under alkaline conditions of
the soil which also reduces the availability of copper. Therefore, molybdenum
toxicity is more a problem of alkaline than of acid soils.
Cobalt is an essential part of vitamin B12 and the normal requirements
of this vitamin are met by rumen synthesis if adequate cobalt is available in
the ration. Vitamin B12 injection will also relieve a cobalt deficiency. Many
grazing areas in Florida are deficient in cobalt. Cobalt deficiencies have
- 10 -
also been shown to occur in Michigan, Wisconsin, l ew Hampshire, ;New York, North
Carolina and Western Canada. Other areas of the U.S. are also thought to be
deficient in cobalt.
In Florida it is recommended that complete mineral mixtures should contain
0.03 per cent cobalt (0.12 per cent cobalt sulfate). This will satisfy cobalt
needs if the cattle consume 35 to 40 pounds of the complete mineral mixture annually.
This recommended level of cobalt should be adjusted up or down if the rate of min-
eral consumption varies much from 35 to 40 pounds per animal yearly.
Cobalt deficiency is often difficult to diagnose. Liver values shown in table
2 can be used as a guide as to when a deficiency exists. Cattle respond quickly
to cobalt treatment so this is a good indicator of a deficiency.
Recent Florida data (13) showed that iron oxide is very poorly available to
the animal. When iron sulfate was assigned a value of 100, the relative avail-
ability of iron oxide was only 4 per cent. On the other hand, when both sources
of iron were applied to the soil and then fed via St. Augustine grass, the iron oxide
availability was increased to 80 per cent that of iron sulfate. This is a good
example to show that a plant, through its own metabolism, can change the availability
of a mineral element for the animal.
The use of supplementary iron is recommended in Florida because some sandy soils
are low in iron and many cattle carry a heavy internal and external parasite load.
A number of investigators have tried iron injections with cattle to see if it
would benefit them. Negative results have been obtained to date. The Arizona
Station (18) actually showed that reduced gains were obtained when iron injections
(1 and 3 gram levels) were given 364 pound calves fed for 169 days in dry lot.
The Purdue Station (26) also showed that the injection of 1 gram of iron at the
beginning and on the 119th day of an experiment decreased rate of gain of fattening
- 11 -
Zinc has been shown to be a dietary essential for cattle. The Purdue Station
(14) has shown increased gains in fattening cattle with zinc supplementation. Aver-
age daily gains were increased 0.2 of a pound when zinc oxide was added at either
138 or 235 ppm of zinc in the total ration. Workers in Finland (24) have reported
an itch, hair licking, alopecia and general unthriftiness with cattle which occurred
due to a deficiency of zinc if the copper level is low and the calcium level is
high. More studies are needed with beef cattle to more clearly define its need
under U.S. conditions. Preliminary indications are that it will be needed under
Grass tetany has become a serious problem in the last few years in South
Georgia and Alabama and parts of North Florida (16). It has occurred with small
grain (oats and rye) pastures during the winter and spring. Dr. Poitevint (17)
reported that practicing veterinarians have also experienced isolated cases of grass
tetany on millet and other temporary grazing crops during the summer and early fall
in South Georgia and Alabama. These cattle show very low serum magnesium levels of
0.5 to 1.0 mg. per cent. A complete mineral mixture containing 14 per cent magnes-
ium has been effective in preventing the condition. The cattle need to get about
15 grams of magnesium daily.
Grass tetany also occurs in other areas of the country. A condition referred
to as wheat poisoning has been reported with cattle in the Texas panhandle and
adjacent areas. In many cases, what is referred to as grass tetany is not just a
simple magnesium deficiency but may be a complicated problem involving other fac-
The magnesium problem is not a simple one to understand. Research is needed
to provide information necessary to fully understand this syndrome.
- 12 -
Washington Station workers (15) recently reported that a deficiency of manganese
in the cow caused the birth of calves with enlarged joints, stiffness, twisted legs
and a general physical weakness. The deficient cows, although exhibiting regular
estrous cycles, required an average of four services per conception as compared to
two for the controls. Rate of gain, feed efficiency and feed consumption of the
cow was not affected by the manganese deficiency. The control ration contained
25.1 ppm of manganese. Manganese deficiency symptoms were obtained with manganese
levels of 15.8 and 16.9 ppm. Thus, a level of 25.1 ppm was adequate for reproduc-
tion, but the exact level needed is not known.
The Purdue Station obtained increased rate of gain and feed efficiency by
feeding 1 mg. of selenium per steer daily in 1964 but not in 1965 (20,21). The
Iowa Station (22) likewise reported a benefit from using selenium at 0.1 ppm in the
ration of fattening steers in 1962 and 1963 but not in 1964. The year differences
in response could be due to the ration containing enough selenium during the years
when no response was obtained although the reason could be more complicated than
Some reports have occurred of selenium deficiency occurring under natural feed-
ing conditions in Florida, Oregon and other Western States. Selenium has been
helpful with white muscle disease in calves. In Florida, the condition has occurred
occasionally with calves from beef cows on good clover pastures.
The selenium story is now starting to unfold. This mineral element needs care-
ful study and observation to determine its importance and role in supplementing
A recent trial by Iowa Station workers (19) showed that feeding sulfur (0.03
lb. of sulfur per animal daily as sodium sulfate) increased gains 6 per cent and
- 13 -
feed efficiency 3 per cent and decreased cost of gain by 3 per cent. The sulfur
was added to a steer fattening ration containing high level of urea. The Iowa
workers caution that additional trials are needed to verify this preliminary finding.
As urea is used as a larger part of the ration, there is the possibility that
sulfur may be lacking with certain types of rations. The rumen bacteria can utilize
the sulfur to build the sulfur containing amino acids. Without sulfur these amino
acids cannot be synthesized by the rumen microorganisms. A complete ration should
contain a ratio of 15 parts of nitrogen to 1 part of sulfur.
As high concentrate and low roughage rations increase in use for finishing
cattle, the possible need for potassium supplementation with certain rations should
be investigated. The grains are lower in potassium than roughages and as the rough-
age content of rations decreases or is even eliminated in some cases, the possibility
of a potassium deficiency could occur.
Guide on blood and liver mineral levels
Table 2 gives values which the Florida Station (23) has established as a guide
on the approximate normal level of mineral elements in the blood and liver. Infor-
mation is also given on the approximate level below which a deficiency begins and
below which an extreme deficiency exists. These figures can be used as a guide by
those working with cattle.
- 14 -
Table 2. Blood* and Liver** Values of Minerals in Cattle
to Use As a Guide
Approximate level at
level below which an
Approximate which a extreme
Mineral normal deficiency deficiency
Element level begins exists
*All blood values are per 100 ml. of blood.
**All liver values are in ppm. on a dry matter basis.
- 15 -
1. Crock, L., W. G. Pond and U. R. Brown. 1965. Proceedings of Cornell Nutrition
Conference. Page 18.
2. Beeson, W. 11., D. E. Becker, E. U. Crampton, T. J. Cunha, N. R. Ellis and R. U.
Luecke. 1964. National Research Council Publication 1192. Washington, D. C.
3. Veum, T. L., J. T. Gallo, a. G. Pond, L. D. Van Vleck and J. K. Loosli. 1965.
J. Animal Sci. 24:1169.
4. Harmon, B. G., H. F. Nickelson, A. H. Jensen and D. E. Becker. 1965. Illinois
Agr. Exp. Sta. AS-623.
5. Froseth, J. A., R. A. Pickett, W. Pt. Beeson and AI. P. Plumlee. 1965. Purdue
Agr. Exp. Sta. Research Progress Rep. 201.
6. Pond, W. G., T. L. Veum and V. A. Lazar. 1965. J. Animal Sci. 24:668.
7. Braude, R., A. G. Chamberlain, i. Kotarbinska and K. G. iHitchell. 1962. British
J. Nutrition 16:427.
8. Luecke, R. 1957. Abstracts of Texas Nutrition Conference.
9. Smith, W. H., M. P. Plumlee and W. H. Beeson. 1961. J. Animal Sci. 20:128.
10. Hartley, TT. J. and :. Grant. 1U61. Federation Proceedings. 20:679.
11. Smith, D. L. T. 1957. Amer. J. Vet. Res. 18:825.
12. Chapman, H. L., Jr. and R. W. Kidder. 1964. Florida Agr. Exp. Sta. Bul. 674.
12. Ammerman, C. B. 1965. Feedstuffs 37:18.
14. Smith, U. H., W. M. Beeson, T. H. Perry, P. B. Harrington and Y. T. MIohler.
1963. Purdue Agr. Exp. Sta. Feeders Day Rep.
15. Rojas, M. A., I. A. Dyer and W. A. Cassatt. 1965. J. Animal Sci. 24:664.
16. Miller, J. G. 1965. Proceedings of Georgia Nutrition Conference. Page 1.
17. Poitevint, L. 1965. Proceedings of Florida Nutrition Conference. Page 28.
18. Hale, W. H., B. Taylor, F. Hubbert, Jr., and W. J. Saba. 1964. Arizona
Cattle Feeders Day Rep. Page 15.
19. Burroughs, W., W. Kuhl, D. Wolf, J. Shively and A. Trenkle. 1965. Iowa Agr.
Exp. Station AS Leaflet R71.
20. Beeson, 1. M., M. T. Mohler and T. U. Perry. 1964. Purdue Agr. Exp. Sta.
Cattle Feeders Day Rep.
21. Smith, W. P., W. N. Beeson, 1i. T. l1ohler, R. B. Harrington and T. W. Perry.
1965. Purdue Agr. Exp. Sta. Cattle Feeders Day Rep.
- 16 -
22. Burroughs, W., R. Kohlmeier, R. Barringer, J. Shively, A. Mukhtar and A. Trenkle.
1964. Iowa Agr. Exp. Sta. Cattle Feeders Day Rep.
23. 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. Florida Agr. :xp. Sta. Bul. 683.
24. Haaranen, S. 1965. Uord Vet. Hed. 17:36.
25. Arrington, L. R., R. N. Taylor, Jr., C. B. Ammerman and R. L. Shirley. 1965.
J. Nutrition 87:394.
?6. Smith, U. I., T. W. Perry, M. T. Mohler, H. E. Parker and U. n. Beeson. 1963.
J. Animal Sci. 22:1131.