News last update:6 Aug 2012

DDGS dangerous source of mycotoxins

A survey carried out by Biomin, showed that all tested samples of dried distiller's grains with solubles (DDGS) were contaminated with at least one mycotoxin.

To understand to what extend the DDGS inclusion in animal diets is safe and to provide customers insights in the occurrence of Biomin initiated and carried out a study with 103 samples mainly received from the United States (67%) and Asia.

Samples were tested for major mycotoxins of interest to animal husbandry – aflatoxin B1, zearalenone (ZON), deoxynivalenol (DON or vomitoxin), T-2 toxin and fumonisins (FUM).

All tests have been conducted by Quantas Analytics Austria, and Romer Labs Singapore.

The analyses were performed using standard procedures. Aflatoxins, ZON and total FUM were analyzed by HPLC (High Pressure Liquid Chromatography) whereas DON values were obtained by TLC (Thin Layer Chromatography).

For the purpose of data analysis, non-detect levels were based on the quantification limits of the test method for each toxin: Aflatoxin B1 <0. 5 µg/kg; ZON <10 µg/kg; DON <150 µg/kg; T-2.

Almost all samples infected
99% of DDGS samples were contaminated with at least one mycotoxin. 92% (ZON), 64% (DON), 87% (FUN) and 26% (T-2) of the samples were contaminated with these "field mycotoxins" produced mainly by Fusarium sp.

The average contamination levels found in the DDGS samples which tested positive for these mycotoxins were 333, 2130, 596 and 113 µg/kg respectively, which can already be considered as high contaminations.

Nevertheless, for the abovementioned mycotoxins, contaminations as high as 8107, 12000, 9042 and 218 µg/kg respectively could be detected.

Aflatoxin B1, produced by Aspergillus sp., was present in 8% of the samples. The average contamination of the positive samples was 24 µg/kg. The highest concentration found for this mycotoxin in the analyzed samples was 89 µg/kg.

The only sample which tested negative for all analyzed mycotoxins was a wheat distiller.

Source concentration
The quality of the resulting by-products such as DDGS, in terms of mycotoxins' contamination depends in a great extent on the quality of the grains purchased by the ethanol plant.

If damaged grains are the most prevalent raw material, higher mycotoxin contamination levels will be found in the by-product, as these are preferred locations for fungi development and subsequent mycotoxin production.

As seen from the results mentioned, the fermentation process for the production of DDGS does not destroy mycotoxins.

On the contrary, it makes them readily available to be absorbed by animals as the maximum inclusion rates for DDGS range from 5% for nursery pigs' to 20% in finishing pigs, developing gilts, gestating sows and lactating sows' diets.

In the case of poultry, these rates go from 10% in broilers' (starters) to 20% in breeders' diets.

No carefree use of DDGS
Although DDGS may be seen as a practical solution for animal producers, enabling them to counteract the rising prices of feedstuffs and feed, the widespread carefree use of these products is still far from reality.

DDGS are a dangerous source of mycotoxins which are toxic compounds with hazardous effects to animal health and productivity.

Monitoring the mycotoxin content of DDGS prior to its inclusion in animals' diets is crucial to avoid the exposure of animals to the negative effects of mycotoxins.

Counteracting mycotoxins' effects can be later on accomplished by adding mycotoxin deactivating products to the problematic feeds to ensure successful animal production.

Editor AllAboutFeed

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