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Beef/Cattle Extension Program
How did we discover that trace minerals were necessary
for livestock?
Part V
by John Paterson, MSU Extension
Beef Specialist
| "I
think you might enjoy some of the history of trace
mineral research. " |
One of the textbooks I routinely use to answer questions
about trace minerals is Minerals in Animal and Human
Nutrition by Lee McDowell from the University of Florida.
Dr. McDowell's book is fascinating, because he gives
the history of our knowledge of trace minerals and how
scientists and livestock producers described symptoms
of both deficiencies and toxicities. I think you might
enjoy some of the history of trace mineral research.
Copper, molybdenum and sulfur:
-
The necessity of copper for cattle was first established
in the 1930's with the discovery in Florida that
cattle that had a wasting disease were deficient
in cobalt, iron and copper. Researchers in Northern
Europe described this wasting disease by animals
as having diarrhea, loss of appetite, and anemi
-
In the late 1930's, scientists in England described
a severe scouring disease of cattle called "teart"
that was caused by ingestion of forage with high
levels of molybdenum. Later scientists discovered
that large doses of copper sulfate could prevent
this condition. Still later it was shown that molybdenum
lim - ited the retention of copper in the body especially
in the presence of adequate amounts of inorganic
sulfate in the diet (water?). It was this discovery
that led to numerous studies on the relationship
among copper, molybdenum and sulfate. We can summa
- rize these interrelationships as:
-
Molybdenum in the presence of sulfate reduces
the deposition of copper in organs and increases
the excretion of copper in the urine.
-
An increase of dietary copper reduces molybdenum
deposition in the liver.
-
When the copper to molybdenum ratio of forages
in the presence of adequate sulfate was less than
2.8 to 1, then copper deficiency is evident. A copper
to molybdenum ratio of no less than 4:1 has been
pro - posed to ensure that the copper requirement
will be met.
-
High levels of dietary zinc and iron depress copper
absorption and tend to increase the requirements.
High dietary levels of zinc (100 ppm) reduce liver
copper storage.
-
Cattle can die from copper poisoning; these ani
- mals may experience nausea, vomiting, salivation,
abdominal pain, convulsions, paralysis, and death.
The usual cause is improperly formulated supple
- ments or diets.
Zinc:
-
Zinc is widely distributed through the body, but
animals have a limited ability to store zinc in
a form that can be mobilized to prevent a deficiency
In cattle, the highest concentrations of zinc were
found in the following order: pancreas, liver, pitu
- itary gland, kidney and adrenal gland. Additional
reports have shown that the testicles and accessory
sex glands contain high concentrations.
-
It is suspected that zinc was applied as an for
skin lesions by several cultures, including the
Egyptians.
-
In 1960 scientists discovered that a skin disorder
cattle could be cured with zinc therapy.
-
Loss of appetite is one of the first signs officiency
and in calves, a bowing of the hind stiffness of
the joints is noted.
-
In lab animals, severe zinc deficiency duringnancy
has resulted in offspring with impaired learning
ability.
-
Additional clinical signs of a zinc deficiency
in cattle include: inflammation of the nose and
mouth with submucous hemorrhages unthrifty appearance
rough hair coats stiffness of the joints with swelling
of the feet front of fetlocks cracks in skin of
coronary bands around the hooves dry scaly skin
on the ears5 protein. These findings contradict
those stated in the petition to list the prairie
dog as a threatened species. The impacts of these
effects will depend on the goals of land managers.
MSU's findings suggest that prairie dog colonies
may not be ideal for grazing cattle due to a decrease
in total standing crude protein. Unlike other findings
that suggest prairie dogs may have beneficial or
neutral effects to native rangeland, the MSU study
indicates that prairie dogs may have detrimental
effects for some species. The unique area created
by the pres - ence of prairie dog colonies may have
beneficial effects gnashing of the teeth red, scabby
and wrinkled scrotal skin
-
In grazing animals, a marginal zinc deficiency
re - sults in subnormal growth, fertility, low serum
zinc values, resistance to infection and stress.
Selenium:
During the 1930's selenium was identified as the toxic
element in some forages that caused animals to lose
hair, nails and hooves. Selenium is now known to be
required by food animals and humans. Consumption of
feedstuffs containing both toxic and deficient concentrations
of selenium presents a problem for grazing livestock.
-
Marco Polo in his travels in western China (ca.
1295) described a syndrome resulting from the ingestion
of seleniferous plants. He reported that when horses
ate this poisonous plant, hooves dropped off.
-
In 1860 an army surgeon in South Dakota also described
a fatal disease in horses grazing near Fort Randall.
The horses exhibited extreme tenderness and inflammation
of the feet, accompanied by loss of hair from the
mane and tail.
-
Some speculate that many horses of the U.S Calvary
commanded by General Custer exhibited selenium toxicity
during the summer of 1876.
-
Pioneers on the northern Great Plains in the 1890s
also described selenium toxicity of their livestock.
They associated the disease with alkali seeps and
waters of high salt content. It became known as
alkali disease.
-
In the 1950s, selenium was reported to be beneficial
for livestock and shown to prevent liver necrosis
swine and muscular dystrophy in calves and
-
Selenium is closely linked to vitamin E; both
- ents protect biological membranes from degenera
- tion. Lack of these nutrients results in tissue
- down.
-
Selenium deficiency in ruminants is called muscle
disease and is a degeneration of striated muscles.
Animals with it have generalized weak - ness, stiffness
and muscle deterioration. Animals have difficulty
standing.
-
There are a couple of clinical patterns. The a
congenital type of muscular dystrophy in which calves
are stillborn or die within a few days of after
sudden physical exertion such as nursing running.
It is observed in calves between 1 and months of
age.
-
Poor reproductive performance also is a symptom
of selenium deficiency and includes retained - centa.
Work from Ohio showed that the incidence retained
placentas was reduced from a mean of percent to
9 percent when cows were injected a combination
of selenium and vitamin E.
-
When consumed in sufficient amounts causes toxicity.
Alkali disease generally happens when animals graze
forages with selenium in the range of 5 to 40 parts
per million. Certain selenium - mulating plants
have between 100 and 9,000 selenium.
-
Animals suffering from selenium toxicity have
loss of appetite, lack of thriftiness, cirrhosis
of the loss of hair, lameness and elongated hooves.
If you would like additional information on these
or other minerals, call John Paterson at 406.994.5562.
Beef:
Questions & Answers is a joint project between
MSU Extension and the Montana Beef Council. This
column informs producers about current consumer
education, promotion and research projects funded
through the $1 per head checkoff. For more information,
contact the Montana Beef Council at (406) 442-5111
or at beefcncl@mt.net
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