Dt—Lancaster Farming, Saturday, May 23,1981
Penn
UNIVERSITY PARK - Levels
of iodine in milk have become a
concern of people in medicine and
the dairy industry. Some data
indicate that the iodine content of
milk has increased by 17 percent or
so in recent years.
While these levels have not been
shown to be harmful to consumers,
it is felt that voluntary steps should
be taken to avoid further increases
and alleviate the relatively high
levels found in milk from some
farms, reports R.S. Adams, Penn
State Science professor.
Already some dairies are testing
milk from their shippers for iodine
content to determine which farms
may be problem ones, and to en
courage lowering levels. Ten
tatively a maximum iodine content
of 5 ppm or 500 nucrograms per
liter is being recommended for
milk.
Most cases of high iodine content
in milk have been traced to ex
cessive iodine supplementation in
rations for dairy cows. Some of the
problem may stem from the
widespread use of organic iodine
(EDDI) in dairy feeds, con
centrates, mineral mixtures and
sometimes trace mineral salt.
In other cases the high iodine
levels result from use of several
items in the ration which contain
supplemental iodine in either
inorganic or organic form. When
several such items are used at
generally recommended levels,
considerable doubling up of iodine
intake may occur.
Proper use of iodine-based teat
dips does not appreciably add to
the iodine content of milk. On some -
farms, however, careless use of
iodine in sanitizing equipment,
udder washing and backflushing
may considerably increase iodine
levels in milk.
Levels of iodine intake must be
State dairyman discusses
iodine leveb in dairy feeds rations
limited to not over 40 mg per head
daily to maintain an iodine content
in milk of under .3 ppm, says
Adams. This is approximately 4.5
times the amount of total iodine
intake which is necessary to meet
nutritional needs for this element.
Some farms with high iodine
milk may have average intakes of
iodine which may exceed 100-200
mg daily.
the effects of reasonably high
iodine intakes on cattle is
somewhat controversial. Some
studies suggest no adverse effects
may result fron intakes which are
10 times nutritional needs. At
somewhat higher intakes, an in
crease in the usual problems which
afflict cattle may be expected
according to some field studies.
lodine toxicity may occur when
rations consistently contain 50 ppm
in the dry matter, or 100 times the
nutritional needs for dairy cows.
Young stock and calves generally
are more susceptible to iodine
toxicity than adults.
Symptoms of iodine toxicity in
clude excessive tears, increased
salivation, watery nasal
discharge, tracheal congestion and
coughing. Conjunctivitis and
blood-shot eyes also may be noted.
Hair loss may occur around the
eye, over the neck and at the base
of the ears. Protruding eyeballs
also may be found. Milk produc
tion, feed intake and growth may
be depressed. Animals may be
more susceptible to infection.
Symplons usually subside quickly
after reductions are made in iodine
intake.
The National Research Council
recommends an iodine content of .5
ppm in the total ration dry matter
for cows under normal conditions.
If a strongly goitrogenic crop
furnishes over 20 percent of the
total dry matter, the iodine level in
the ration should be 1.0 ppm.
Members of the Brassica family
such as kale, rape and turnips are
quite goitrogenic. Interest in these
crops has returned in recent years
as a means of increasing carrying
capacity in pastures.
An iodine deficiency of long
standing may result in calves
being born with-goiter, even when
no outward signs may be present in
their dams. Milk production may
be depressed when iodine is
deficient for a prolonged period/
Symptoms of hypothyroidism also
may appear.
Most forages and feed
ingredients may contain .2-.3 ppm
of natural iodine on a dry matter
basis. Somewhat less may be found
in areas with extremely low levels
in soil and water. Items grown in
areas with appreciable levels in
soil and water may contain 1.0-2.5
ppm iodine.
In the past, it has been a practice
to use somewhat higher levels of
iodine than recommended by NRC.
This was done largely to provide
more safety factor and, especially,
to counteract the slightly
goitrogenic properties of soybean
meal.
Experience now indicates that
current NRC allowances provide
adequate iodine, even on rations
high in soybean. In view of the
doubling up of iodine sources
which may occur and the apparent
need to avoid excessive levels of
iodine in milk, it is recommended
that iodine supplementation be
limited to levels which provide a
total intake of natural and sup
plemental that is closer to NRC
A BALANCED NUTRITIONAL SUPPLEMENT '
MADE FROM UNJOINTED CEREAL GRASSES
WITH HIGH LEVELS OF NATURAL PROTEIN,
VITAMINS. MINERALS AND ENZYMES. NAT
URALLY BALANCED. EXCELLENT SOURCE
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CEROGRAS HELPS BUILD RFD BLOOD
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STRONGER ANIMALS AM) LIDS IV DIC.ES
TION AND ELIMINATION
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• NO PRESERVATIVES
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4722 Broadway Kansas City Missouri 64112
Cerogras* is a registered trademark of Agri-Tech Inc
ANIMAL MEDIC ABM PRODUCTS
Manchester, PA Chester Springs, PA
In PA-1-800-632-1831 215-827-7686
Out of PA: 1-800-233-1956
allowances.
Accordingly, it is recommended
that the ration contain .8 ppm total
iodine on a dry matter basis
(natural plus any supplemental).
Assuming that the naturally
occurring iodine content is .3 ppm,
it is recommended that sup
plemental iodine be provided at a
level of .5 ppm of the total ration
dry mater (forage plus con
centrate). A level of .1-2. ppm
iodine in milk may result at this
intake.
Adams reports one of the major
factors which is thought to have
contributed to high iodine intakes
on some farms is the widespread
use of ethylene diamine
dihydriodide (EDDI) in
manufactured feeds, concentrates,
some trace mineral salts and
' mineral or mineral-vitamin
products. This organic iodine
source has been used in medicated
products to aid in the prevention of
foot rot and lumpy jaw.
Preventitive levels call for 50 mg
per head daily. This would furnish
about 40 mg of iodine from this
source alone, compared to a need
of around 9 mg. EDDI also has
been used for treatment of these
problems at levels of 400-500 mg
per head daily for a period of 2-3
weeks.
In other cases the material has
been used to allegedly help
reproduction in cattle and horses.
While many products containing
EDDI carry a medicated label, it
has been included at comparable
or sometimes lower levels for
routine iodine supplementation.
Thus non-medicated products may
cerogras
*. I if.
be a source, as well as medicated
ones.
It is now recommended that use
of EDDI at preventive and
treatment levels be confined to
non-milking animals, Adams
notes.
“EDDI is a readily utilized
source of iodine, he adds. “It ap
pears that it may result in slightly
higher iodine levels in milk than
inorganic iodine from potassium
lodate, another community used
source m supplements.
- “Because of its mention in
connection with higher than
necessary iodine intake' at
medicated levels, there might be
some competitive advantage to
using another source of
manufactured feeds and sup
plements. lodine levels do not need
to be stated on guarantees for
somd feeds and concentrates, but
the source of supplemental iodine
generally is given in the ingredient
listing.”
Alternatives
There ai*e alternative methods to
the control and prevention of foot
problems in dairy cows, treat
ment aids such as foot baths and
boxes containing \ wet or dry
mixtures which include copper
sulfate-are effective. Hoof trim
ming and monitoring of the con
dition of the feet are important in
control and prevention of problem,
Adams points out.
Low level feeding" of
tetracyclines may be used in some
cases. An intake of .1 mg per lb. of
bodyweight daily for milking
NATURAL ANIMAL
FEED SUPPLEMENT
NATURAL NUTRIENTS
FOR SETTER
GROWTH, MAINTENANCE
AND REPRODUCTION
NATURALLY PALATABLE
YOUNG ANIMALS START ON FEED SOONER
HIGH LEVELS OF CAROTENE
AIDS IN DIGESTION
AIDS IN KEEPING ANIMALS ON FEED
EXCELLENT CALCIUM PHOSPHORUS RATIO
CHLOROPHYLL HEL& ELIMIATEODORS
HIGH ENERGY LEVELS
EASY TO FEED
REUSABLE PLASTIC CONTAINER
- TYPICAL ANALYSIS -
Crude Protein
Crude Fat
Crude Fiber
Moisture
Calcium
Phosphorus
Vitamin A (Carotene)'
Thiamine (Vitamin B-1)
Riboflavin (Vitamin B-2)
Niacin
Vitamin C (Ascprbic Acid)
Vitamin E
Vitamin K (phylloqumone)
Choline Chloride
Magnesium (Mg)
Manganese (Mn)
Cobalt (Co)
Copper (Cu)
Zinc (Zn)
Iron (Fe)
Chlorophyll
Carbohydrates
Potassium (K)
Sodium (Na)
'Carotene has shown to be beneficial to animal
reproductive functions Note the high carotene content
in Cerogras
FEED 2 4 OUNCES DAItY
(Turn to Page D 9)
18.0%
3.0%
' 17.0%
8 50 %
0 35 %
0 41 %
144 350 00 IU per lb
3 17 mg per lb
5 35 mg per lb
19 98 mg per lb
300 00 mg per lb
102 00 mg per lb
15 00 mg per lb
1 186 00 mg per lb
018 %
0 0095 %
0 002 %
0 013 %
0 031 %
224 00 mg per lb
3 400 00 mg per lb
35 00 %
0 50 %
0 20 %