According to Dr. Hall, a mineral expert at the Utah State University
Diagnostic lab (435-797-1895), the normal selenium concentrations for camels are as
- SERUM: 0.1-0.2 ppm (this is equivalent to 100-200 ppb)*
- LIVER (wet weight): 0.33-0.83 ppm (equivalent to 330-830 ppb)
Keep in mind that these values are based on a small number of controls, so
there may be some minor variations. Llama and alpaca normals, which may be
used as a guideline and are based on higher numbers of animals, are as
- SERUM: 0.12 - 0.2 ppm (120-200 ppb)
- LIVER (wet weight): 0.25-0.8 ppm (250-800 ppb)
- SERUM: 0.12-0.2 ppm (120-200 ppb)
Some other species:
- SERUM: 0.14-0.25 ppm (140-250 ppb)
- LIVER (wet weight): 0.3-1.0 ppm (300-1000 ppb)
- WHOLE BLOOD: 0.17-0.3 ppm (170-300 ppb)
- SERUM: 0.08-0.3 ppm (80-300 ppb)
- LIVER (wet weight): 0.25-0.5 ppm (250-500 ppb)
- WHOLE BLOOD: 0.2-1.2 ppm (200-1200 ppb)
According to Thomas Herdt at the Michigan State University Diagnostic Laboratory (517-353-9312),
the normal WHOLE BLOOD (not just serum) concentration for selenium in most species should be 120-250 ng/ml (ppb).
He says that he is not concerned about toxicity unless the selenium level in WHOLE BLOOD approaches 1000 ng/ml (ppb).
He also says that LIVER values (DRY WEIGHT) for most species are adequate if they are over 1000-1200 ppb
(this equals about 300-360 ppb wet weight).
Measuring the serum selenium shows you the adequacy of the present diet of the camel for selenium.
The whole blood measurement shows you how much selenium the camel had in his system when the red blood cells were
formed -- up to three months ago. Thus, the whole blood levels may be a more accurate measure of long-term selenium
According to Dr. Hall, if the selenium concentrations approach the lower end of the normal range,
the camel should be supplemented with selenium, as the animal may be headed for a chronic deficiency situation.
On the other hand, the blood or serum can show quite an increase above the high end of the "normal" range
without any ill effects. For example, he often sees healthy llamas that have SERUM selenium concentrations of
350-520 ppb (normal is considered to be 120-200 ppb). Horses, who have normal SERUM values of 140-250 ppb,
start showing symptoms of chronic selenium toxicosis when their serum values are 1500-5000 ppb.
Cattle will show symptoms of selenosis (selenium toxicosis) when their serum concentrations approach 2000 ppb.
As far as supplementation goes, a good guide is to give 3 mg selenium in the supplement per day
to an adult 1000 pound camel. (An adult average-sized female dromedary usually weighs about 1000 pounds.
A big male may weigh 1500 pounds or more). Adjust the dose according to the animal's weight
(i.e., a young 500 pound camel would get at least 1.5 mg per day). Equine or llama supplements are the best choice.
Cattle supplements should be avoided, as they may contain coccidiostats such as monensin or rumensen which are
poisonous to camels. Some common equine vitamin / mineral supplements provide one mg of selenium per "scoop"
(check the label!), so you would have to give a 1000 pound camel 3 scoops per day.
(However, do not exceed the highest daily dose recommended on the label, as excess supplementation of the other
minerals could cause overall imbalances).
If you cannot find a good vitamin / mineral supplement that supplies enough selenium, add a straight selenium or
selenium / vitamin E supplement as well as the regular vitamin / mineral supplement.
To avoid overdosing, be sure to include all the supplement sources together when calculating the total amount of
supplemented selenium your camel is receiving.
Of course the best thing is to have your hay analyzed and to adjust your supplementation accordingly.
The whole ration should supply about 0.3 - 2.0 ppm (mg/kg) per dry weight of ration per day.
In other words, each kg (kilogram) of whatever feed (dry weight) that the camel eats per day
(either just hay or hay and grain combined) should supply between 0.3 mg and 2.0 mg (milligrams) of selenium.
Thus, if you have a 1000 pound camel that is eating 15 pounds (1/4 of a 60 pound bale) of hay per day,
that equals 7 kg (kilograms) of hay per day (1 kg = 2.2 pounds). Or if he is eating 6 kg of hay and 1 kg of grain,
that is still 7 kg of feed per day. Since hay and grain can average 10% moisture, that means your camel is
really eating 6.3 kg dry weight of feed per day. So he needs to be ingesting between 6.3 x 0.3 and 6.3 x 2.0
(1.89 to 12.6) mg of selenium per day. In other words, your 1000 pound camel who is eating 7 kg of feed daily
should get about 2-12 mg of selenium per day in all his feed combined.
If you have your hay analyzed and it shows that the 7 kg of the hay (or 6 kg of hay and 1 kg of grain, etc.)
you are feeding per day only supplies 1-2 mg of selenium per day, you'd better supplement. On the other hand,
if your hay provides 5 mg selenium per day but you don't know how much it has because you haven't had it analyzed,
you will still be safe giving the camel 3 mg per day in a supplement. Furthermore, if the hay has almost no
selenium in it (this is not uncommon, and is possible NO MATTER WHERE you live -- flood irrigation can leach all
selenium out of the soil!), and you haven't had the hay analyzed, then giving 3 mg per day in the form of a
supplement will keep the selenium levels adequate.
According to Dr. Hall, many species won't get into selenium toxicities until the ration supplies over 5 mg/kg,
but he also states that feed concentrations greater than 2-3 mg/kg should be avoided due to individual sensitivities.
In other words, assuming that camels are like other species in this regard, your hay and supplements would have to
supply over 13-19 mg selenium per day to an adult 1000 pound camel who is eating 7 kg of hay (or hay and grain)
per day in order for potential toxicosis to occur. If you are feeding grain as well as hay,
the selenium content of the grain should be shown on the label, and you can add this figure to the amount of
selenium provided by the hay in determining the total selenium intake.
If the selenium content of the grain is not listed, you can contact the manufacturer.
Some salt mixes have selenium in them also (but don't count on it).
Again, the daily selenium dose of ALL the feeds and supplements combined should be between 2 and 12 mg for a
1000 pound camel who is eating 7 kg of feed per day. Because feeds vary wildly in their selenium content,
having your hay analyzed is important. If you haven't had your hay analyzed, do it!
If you can't get your hay analyzed -- supplement!!! DON'T assume that the selenium content of the hay is
adequate just because you are not in a selenium deficient area. But remember, if you don't have your hay analyzed,
selenium excess is still a possibility. Hay analysis is cheap insurance!
Keep in mind that selenium works synergistically with vitamin E. If you are feeding a supplement,
use one that has a good vitamin E content, especially if the camel never grazes and is eating hay all year.
This is especially important with babies and pregnant or lactating mothers. The supplement should supply
more than 100 mg vitamin E per day (hopefully more), preferably in the natural form, as synthetic forms of
vitamin E may be degraded in the rumen.
Testing your camel's blood several times per year for selenium concentrations as well as testing the feed
is the ideal way to keep track of your camel's selenium status. Drawing blood from camels is fairly easy if
they are properly trained for it.
Since selenium deficiencies can cause heart damage in baby camels that may not show up until later in life
(i.e. a "heart attack"), it is extremely important to make sure that pregnant or lactating camels and babies
get adequate selenium in their diets. However, adequate selenium concentrations are important for the health
of all camels, and selenium deficiencies can have heartbreaking and fatal consequences.
- ppm = parts per million = mg/kg (milligrams per kilogram)
- ppb = parts per billion = ng/ml (nanograms per milliliter) = ug/kg (micrograms per kilogram)
- 1 ppm = 1000 ppb
Other questions about selenium? Contact:
Jeffery O. Hall, DVM, Ph.D.
Utah State University
Utah Veterinary Diagnostic Lab.
950 East 1400 North
Logan, Utah 84322-5700