Recent Food Fortress tests are detecting increased levels of DON and Zearalenone in compound feeds. Information shared by importers indicates that maize by-products (Corn Gluten and US Distillers Grains) are the most likely source of these elevated levels.
Imported feed materials will meet the statuary requirements and guidance levels for a raw material - however formulators need to consider the appropriate inclusion rate of the material in finished feeds for different species and ages of livestock. Livestock performance could be impacted by mycotoxin levels below the guidance indicated – particularly where a combination of toxins are detected.
The table below show the EU Guidance recommendations for maximum levels of these mycotoxins in raw materials and in the finished feed for different species.
This indicates that pigs are particularly susceptible, as are very young animals of all species. Where more than one mycotoxin is present (with potential for a synergistic effect) it is likely that performance will be impacted at levels below that indicated by the guidance.
To enable safe use of these materials it is important to establish the DON and Zearalenone level in your current supply of gluten and distillers. This should be used to calculate the safe inclusion rate of these materials in the finished feed.
Where significant levels of both DON and Zearalenone are present it is recommended that inclusion rates are limited so that no more than half of the guidance level for each contaminant will be present in the finished feed.
Calculation - by dividing the guidance level for compounds for the target species by the level detected in the raw material you can establish the proportion of the diet which can come from that material - Multiply by 100 to convert this figure into the maximum inclusion %.
For example, -
Where a consignment of maize tests with 5,000ug/kg DON
For pigs the maximum inclusion rate is - 900 ÷ 5,000 = 0.18 X 100 = 18%
This calculation does not make any allowance for other sources of DON in the formulation but it will give a useful guide to the risk from this particular material.