tips for choosing a good selenium
enriched yeast
Yeast enriched with selenium (Se) imitates what happens in nature, using inorganic Se and transforming it in organic Se like that found in plants. However, all Se-enriched yeasts are not the same: they can differ in terms of production process, visual aspect, purity, quality, and, as a result, in the bioavailability of Se or its assimilation by the animals.
Light color
Result of a continuous control of the whole production process:
1. Specific strain
2. Fermentation 1. Fermentation
3.2. Centrifugation washing
4. Pasteurization 4. Drying
5. Drying 3. Pasteurization
Certificate of analysis
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Proof of good control of the production process to ensure batch-to-batch consistency
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Guaranteed composition of the product
Combination of several organic 
forms
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Se-enriched yeast should contain more than 98% of organic Se
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Bioavailability of Se-enriched yeast appears more important when it combines several forms of Se such as selenomethionine (SeMet) and selenocysteine (SeCys)
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Animals’ selenium metabolism involves different forms of Se
BARBE ET AL, 2017.
High SeMet level
Requirement for Se-enriched yeasts in the European Union
One of the most efficient forms of organic Se
Quality indicator of Se-enriched yeast fermentation
How to calculate the proportion of Se as SeMet?
Total weight
Example
1 kg of Se-enriched yeast product A contains:
- Total Se: 2,000 mg
- SeMet: 3,150 mg
Amount of Se as SeMet = 40% x 3,150 = 1,260 mg
Proportion of Se as SeMet:
= = 63%
63% of selenium in product A is under SeMet form
Reliable bioavailability studies
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Important to make sure the Se from the animals' diet is well assimilated
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Se concentration is not enough. Transfer rate is the most reliable parameter to assess Se assimilation
Transfer rate
Quantity of Se exported in animal products
(tissue Se concentration x tissue weight)
Quantity of Se ingested by the animal
(feed intake x feed Se concentration)
Concentration
Quantity of Se in tissue/kg of tissue. Feed and Se intake are not taken into account in this calculation
Want more information about our selenium enriched yeast ALKOSEL?
Visit LallemandAnimalNutrition.com