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Author: Domenick J. Castaldo, PhD Alltech, Inc. USA.
The following article is a special collaboration
from AFMA (Animal Feed Manufacturers Association) www.afma.co.za
We thank their kind support.
Science summary
In many areas of the world, feed grains and forage crops contain inadequate concentrations
of selenium. Livestock require selenium as a cofactor for the antioxidant enzyme
glutathione peroxidase. Supplementation of feeds with selenium has greatly reduced
the incidence of deficiencies. However, in certain situations, sodium selenite,
the most common form of selenium used in animal feed, may be ineffective in preventing
selenium deficiencies.
Dr. Bo Pehrson, of the Swedish University of Agriculture Sciences, says that inorganic
selenium, such as sodium selenite, are not readily transferred to the milk. Therefore,
calves nursing cows fed rations supplemented with sodium selenite may develop
marginal selenium deficiencies. The problem is that rumen microbes convert the
selenite to a less bioavailable form. Dr. Pehrson recommends replacing the sodium
selenite in cattle rations with organic selenium (Sel-Plex). Sel-Plex contains
selenomethionine and other naturally-occurring organic selenium compounds, which
are not affected by rumen microbes. As a result, more of the supplemented selenium
is absorbed and transferred to the tissues.
To compare the effect of the two forms of selenium on cows and their calves, Dr.
Pehrson conducted a study involving 103 cows. The cows were fed a supplement that
contained 30 ppm selenium in either an inorganic (sodium selenite) or an organic
(Sel-Plex) form. The base ration was selenium-deficient. Blood samples were collected
from the cows and their calves for selenium assay. The calves were approximately
22 days of age at the time of sampling. Milk samples were also obtained. The assay
results are summarized in Table 1.
Table 1. Comparison of inorganic (sodium
selenite) and organic (Sel-Plex) on cows and calves.
| |
Cows |
Calves |
| |
Sodium
selenite |
Sel-Plex |
Sodium
selenite |
Sel-Plex |
| Whole
blood selenium, ug/liter |
112 |
146 |
76 |
134 |
| Serum
selenium, ug/liter |
56 |
81 |
32 |
50 |
| GSH-Px
activity, ukat/cell1 |
1869 |
2345 |
1221 |
2255 |
| Milk
selenium, ug/ml |
11.7 |
17.5 |
|
|
1GSH-Px=Erythrocyte glutathione peroxidase activity.
There was no difference in supplement consumption between the two groups. However,
the form of selenium influenced the selenium status of the cows and calves.
Cows fed Sel-Plex had higher concentrations of selenium in their blood, serum,
and milk. Also, these cows had higher glutathione peroxidase activity in their
erythrocytes.
The form of selenium fed to the cows impacted the selenium status of the calves.
Selenium concentrations in the blood and plasma as well as the glutathione peroxidase
activity were higher in the calves from Sel-Plex-fed cows than they were in
calves from cows fed sodium selenite. According to Dr. Pehrson, whole blood
selenium concentrations below 100 ug per liter are indicative of a selenium
deficiency. Under this criteria, calves from cows fed the inorganic selenium
were deficient.
Dr. Pehrson reported the following correlations between the measured variables:
Cow blood selenium and milk selenium (r=0.58);
- Milk selenium and calf blood selenium (r=0.64);
- Calf blood selenium and calf glutathione peroxidase activity (r=0.93);
- Cow blood selenium and calf blood selenium (r=0.78); and
- Cow blood selenium and cow glutathione peroxidase activity (r=0.86);
According to Dr. Pehrson's study, organic selenium improves the selenium status
of cows and calves better than inorganic selenium. He added that his results
are in disagreement with a previous study conducted in another laboratory. However,
in the previous study, he pointed out, the selenium content of the base ration
was nearly 10-times higher.
Author: Domenick J. Castaldo, PhD Alltech, Inc. USA.
Who saw this article? New!
 DISCUSSIONS ON THIS ISSUE.
 
| 01/23/2005 |
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Dr. Prashant Shinde
Veterinarian
Uttar Pradesh - India |
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Effect of supplementation of Selenium and Vitamin E on rumen fermentation, then please provide details. | Answer Checked by Engormix.com  |
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| 12/01/2006 |
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Effect of supplementation of Selenium and fibrolytic enzyme on growth of calf, then please provide details. | | Answer Checked by Engormix.com |
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| 12/20/2006 |
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Its a very interesting article. I have some experiences in the use of organic Selenium in Dairy cattle and Sows and I found a lot of benefits, especially for the reduction of reproductive disease and reproductive failure. | | Answer Checked by Engormix.com |
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| 04/18/2007 |
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Dr Neelesh Sharma
Research/agriculture University
Jammu and Kashmir - India |
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If you have the detail methods of the following then please send to me.
1. Estimation of Se and glutathione peroxidase activity in milk.
| | Answer Checked by Engormix.com |
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