Mycotoxins and Ruminants

 

The Threat

 

Ruminants consume feed that is likely to be contaminated with mycotoxins. Mycotoxins are extremely widespread in all feeds containing grains, maize, fruit and forage.  There are many different mycotoxin molecules; over 500, including derivatives. 

We know that feeds usually contain multiple types of mycotoxin molecules that may work together to increase detrimental effects.  A number of mycotoxins also resist the process of being broken down by the rumen.

Complex diets and feed transitions that combine forages, by-products and fermented feeds all present a root of risk to ruminants.  Straw and other grown bedding materials can also present risk to ruminants.

Most symptoms of mycotoxin contamination come from sub-acute effects: lower productivity, growth rates, feed conversion, milk volume, fertility or higher disease incidence.

The animal can never reach its full potential when adversely affected by mycotoxins.

    At worst, milk and meat may be unsuitable for human consumption by exceeding regulatory levels allowed into the food chain.

    KNOW YOUR RISK. TAKE CONTROL.

     

    Sources of Mycotoxin

     

    Complex feed systems like TMR, commonly used in dairy ruminants where forage, grain and other processed feeds are combined, present a significant risk of multiple mycotoxin risk to ruminants.

    Such feeds are commonly found to contain DON, ZON and FUM toxins, and can show up as chronic health issues affecting performance and overall productivity in a herd.

    maize cob

    Forage

    Maize infected with Aspergillus fungus, which can be most prevalent in warm dry conditions.  Associated mycotoxins include: Aflatoxin B1, B2, G1 and G2.  Aflatoxin levels in feeds are regulated [link to table].  Patulin and Ochratoxin can also be found in maize affected by Aspergillus.  Maize can also be affected with Fusarium mould, favouring cool, wet conditions, and is associated to mycotoxins: Fumonisin (B1, B2 and B3), Fusaric acid, type A Trichothecenes: T-2 toxin, HT-2 toxin, type B Trichothecenes: Nivalenol, Deoxynivalenol (DON), Zearaleone (ZON).

    wheat

    Cereal grains (wheat, barley, oats, sorghum)

    Affected by Fusarium fungi, favouring cool, wet conditions, and is associated to mycotoxins: Fumonisin (B1, B2 and B3), Fusaric acid, type A Trichothecenes: T-2 toxin, HT-2 toxin, type B Trichothecenes: Nivalenol, Deoxynivalenol (DON), Zearaleone (ZON).

    Affected by Penicillium fungi, favouring moderate growing and storage conditions, associated to mycotoxins: Ochratoxin, Citrinin and Patulin.

    Bedding - sleeping with the enemy?

    Tests on straw samples have shown to provide a host for fungi and their associated mycotoxins.  Find out more from our 2018 survey for mycotoxins in straw. [link]

     

    Effects of mycotoxins on ruminants

     

    Reduced milk production

    Milk quality affected

    Udder health issues

    Impaired rumen function

    Poor growth and reduced body weight

    Immune suppression

    Reduced fertility, abortions

    Skin lesions

    Liver & kidney damage

    Locomotion issues

    Foot health

    Faecal stability

    Aflatoxins
    • Aflatoxins are commonly found on Maize (Corn)
    • There are many types (B1, B2, G1, G2, M1, M2, H,D,B2a)
    • These are heavily regulated and tested for in the human food chain as they can be related to liver cancer, hepatitis B and lung cancers
    • They are more common in hot, dry countries but climate change may change this profile
    Fumonisins
    • Fumonisins generally come from Fusarium species, usually on grains (Wheat, Barley, Oats, Sorghum)
    • Their derivatives are FUM B1, B2, B3, B4, A1, A21
    • They have been related to lower body weights, liver pathology and blood and bile changes
    • Affect growth weights and productivity
    • They mimic and disrupt sphingolipid (ceramide) production
    Tricothecenes (T2/HT2)
    • From Fusarium species, so found in Grain moulds
    • Other derivatives may be diacetoxyscirpenol (DAS), monoacetoxyscirpenol (MAS), neosolaniol, 8-acetoxyneosolaniol, 4-deacetylneosolaniol, nivalenol, 4-acetoxynivalenol (Fusarenone-X), DON (vomitoxin), and 3-acetyldeoxynivalenol
    • They interrupt DNA/RNA synthesis and therefore protein synthesis
    • Lower growth rates and production performance
    Zearalenone (ZON/ZEA)
    • From Fusarium species, so can be found on wheat and grain moulds
    • Derivative is Zearalenol 
    • Mimic Oestrogen hormones in animals
    • Affects fertility
    Ochratoxins
    • Comes from Aspergillus and Penicilium species of moulds
    • Most common molecule is Ochratoxin A (OTA)
    • Interferes with DNA and RNA synthesis as well as renal carbohydrate metabolism
    • Can affect weakness, anaemia, renal damage, poor growth and performance
    Deoxynivalenol (DON)
    • Comes from Fusarium species of mould
    • Many derivatives
    • Found in grain varieties, especially when moisture content rises in storage
    • Has immunomodulatory effects, affects gut integrity and villus height
    • Affects feed conversion ratio, weight gains and productivity
    Ergot alkaloids
    • These come from the Claviceps moulds (purpurea, paspalli and fusiformis)
    • Found on wheat, rye and barley grains
    • Can have potent effects in poultry
    • Can reduce weight gain, fertility and in high levels, blood flow and cause secondary gangrene
    Patulin
    • Comes from the Penicillium and Aspergillus species
    • Commonly found in fruits and fruit pulps
    • Causes weight loss, neurotoxicity, intestinal changes and renal impairment
    Hidden mycotoxins
    • These are modifications of the main mycotoxin molecules that can still be toxic
    • They look like the major mycotoxin molecule but have an added or deleted chemical group (like –OH, -CH4, -NH3)
    • They can have an additive or even synergistic effect
    • Mycocheck LC-MS Mass Spectrometry is able to detect them, whereas many of the ELISAs or diffusion tests cannot

     

    “Getting a test done for mycotoxins was well worth it. We identified the source of the outbreak and saved ourselves £1000s in lost milk revenue”

    John Smith
    Any Farm UK

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