The alternative to measuring mycotoxin levels in feed with expensive tests is mould analysis. Depending on the extent of information needed, further identification of mould species is possible in some commercial labs. Such identification helps in understanding whether the mould identified can produce mycotoxins and if yes, which types of mycotoxins potentially can be present (see Table 2).
Mould |
Potential mycotoxins |
Aspergillus
|
Aflatoxins, ochratoxins
|
Fusarium
|
DON, T-2 toxin, fumonisins, zearalenone
|
Penicillium
|
Ochratoxins, penicillic acid, citrinin, roquefortine C, mycophenolic acid etc.
|
Mucor/Cladosporium
|
Non-mycotoxin producing molds
|
Table 2: Moulds and mycotoxin relationship. Mycotoxins produced by Penicillium species in silages are highly volatile and hard to analyze by conventional methods.
Because there is no cheap and practical way to measure the levels of mycotoxins in a TMR or high-fibre feed ingredient for dairy cows, the alternative is to combine two methods. Ingredients with a low amount of fibre should be analysed for mycotoxins using a rapid mycotoxin test such as the Mycomaster, whereas mould analysis should be used to assess mycotoxin risk of the total TMR or ingredients with high fibre content (see Table 3).
Lastly, there is the option to test feacal samples of dairy cows for moulds. This method is not very accurate, as the presence of moulds only indicates there has been a problem in the recent past and also, it does not provide any information as to where the mycotoxin contamination is coming from, but is is a simple method that can be used to find out if a mycotoxin problem is a likely or unlikely cause of problems with health, performance and fertility in a dairy herd.
Rapid Mycotoxin Analysis |
Mould Analysis |
Grains
|
Silages/high moisture grains
|
Protein Meals
|
Hay/grass
|
Grain by-products
|
TMR
|
Concentrate
|
|
Table 3: Diagnostic tools for understanding total mycotoxin risk in ruminants
What are the tolerance levels for moulds and mycotoxins in dairy cattle?
Based on the combined knowledge of both peer-reviewed research and field experience, Trouw Nutrition has developed “Practical Mycotoxin and Mould Guidance Values” (see Table 4). These values should be considered as a guide to manage raw material and TMR quality, ultimately protecting animal performance and bottom line of operations.
Rapid Mycotoxin Analysis |
Mould Analysis |
Rapid Mycotoxin Analysis |
Mould Analysis |
Mould Analysis |
Total Mould Count |
cfu/g |
104-105 |
105-106 |
>106 |
Aflatoxins |
ppb |
5-10 |
10-15 |
15-20 |
DON |
ppb |
450-900 |
900-1800 |
>1800 |
T-2 toxin |
ppb |
50-75 |
75-100 |
>100 |
Zearalenone |
ppb |
50-150 |
150-250 |
>250 |
Fumonisins |
ppb |
2000-3000 |
3000-4000 |
>4000 |
Table 4: Mycotoxin and mould guidance values for TMR for dairy cows. Aflatoxins recommendations are based on FDA regulation and the values are much lower for EFSA regulation.