Major scientific advances made in identifying mycotoxins have enabled scientists, for the first time, to reveal the full extent of the mycotoxin risk now threatening the food supply chain.
“2012’s disastrous harvest has brought the mycotoxin problem to the fore,” says Graeme Smith, Sales Director of leading livestock nutrition company Alltech UK, “in that mycotoxin levels are at an all-time high. Monitoring by the HGCA revealed that 97% of crops were infected by Fusarium mycotoxins and the effects were evident across the livestock sector.”
The majority of producers saw a fall in production with dairy farmers producing 2bn litres below their 14bn litre quota – the greatest shortfall on record. Similarly, beef producers witnessed reduced growth rates and general ill thrift in cattle. Poultry and all classes of pigs are also very susceptible to mycotoxins with breeding animals and young stock being the most severely affected. Whilst the weather was indisputably poor, were mycotoxins really to blame for all the ills of the livestock sector, and to what extent?
““The degree to which animals are affected will always depend on their age and condition,” explains Mr Smith, “but in reality, the whole issue is much more complex than most people realise. Concentrating on just a few common strains still doesn’t give the true picture, especially as there are over 500 known mycotoxins. And mycotoxins can be found in a vast range of materials that can go on to affect all kinds of livestock, even pets. Recent surveys using Alltech’s new 37+ testing have now gone a long way to revealing the true extent of the problem.”
Using sophisticated mass spectrometry analysis – the result of a $1million investment – the Alltech 37+ program can now simultaneously identify more than 37 different mycotoxins out of the potential 500. These include the main Fusarium mycotoxins such as DON, T-2, ZEN, fumonisins and aflatoxins B1, B2, G1 and G2 plus the under reported, but no less significant Penicillium or silage mycotoxins including patulin, mycophenolic acid, penicillic acid and roquefortine C. Low levels of mycotoxins can also be identified and ‘masked mycotoxins’ those disguised by being attached to a simple sugar. The materials tested included:
Materials tested for mycotoxins:
- Wholecrop cereals
- Grass silage
- Moist Feeds
- Brewers grains
- Distillery co-products
- Bio-ethanol co-products
- Cereal based products
- Rice (in pet food)
- Compound feeds
- Sow/piglet diets
- Poultry diets
- Beef/Dairy/Calf rations
- In the survey, 100% of samples analysed came back as contaminated, 96% with fumonisin and 80% with Penicillium mycotoxins. “This is significant”, says Mr Smith in that Penicillium or ‘silage mycotoxins’, whilst often overlooked, are particularly dangerous due to their direct antibiotic effect on rumen micro-organisms which make animals more susceptible to other types of mycotoxin.”
37+ test results
- 103 samples tested
- 100% contaminated
- Up to 6 different types of mycotoxin on each sample
- On average, 3 different groups of mycotoxin per sample
- Even ‘clean’ looking samples, causing no signs of acute outward challenge, can contain harmfulmycotoxin
Minimum, maximum and average mycotoxin levels in silage (including TMR) ppb
“Also, even though the levels of some mycotoxins are quite low, as shown above,” says Mr Smith, “it is the synergistic effect of these low level mycotoxins that can undermine animal performance. This is why we see so few acute cases of mycotoxicosis and yet we observe animals not fulfilling their genetic potential on a large number of units. This is due to low chronic levels of mycotoxins.”
Testing also highlighted not only higher than expected numbers of mycotoxins in each sample, but levels increasing steadily throughout the year, a situation that experts predict to get worse before new crop cereals start entering rations in late August to September.
The symptoms of mycotoxins are diverse and can challenge the health and productivity of most livestock including cattle, sheep, pigs and poultry – even pets when included in pet food in rice and cereals. Symptoms in pigs can range from reduced performance and FCR in finishers to early embryonic loss and rectal/vaginal prolapses.
Mycotoxins – symptoms in pigs
|Fungi||Mycotoxin||Effect of mycotoxin|
|Aspergillus flavus||Aflatoxin B1, B2, G1, G2||Liver necrosis, fatty infiltration of liver, immune suppression|
|Aspergillus ochraceus||Ochratoxin A||Renal nephropathy, immune suppression|
|Pulmonary oedema, immune-suppression|
Vomiting, lethargy, loss of muscle condition
|Fusarium graminearum||Deoxynivalenol (DON etc)||Vomiting, intestinal lesions, immune suppression|
|Fusarium roseum||Zearalenone||Hyper-oestrogenisum, abortion, infertility, prolapses|
In dairy cattle mycotoxins can cause a range of symptoms:
- Poor performance and body condition
- Fluctuating milk yields and feed intakes
- Loose dung
- Swollen hocks
- High cell counts: often as new forages or feeds are introduced
- Poor fertility: cows with early embryo loss or not displaying oestrus
- Mucin tags in manure – a classic symptom
- Skin lesions
Action against mycotoxins?
As with any issue involving animal health and performance, the best place to start is prevention. As poisonous compounds produced naturally by moulds and fungi agronomic best practice can help to limit mycotoxin production, and contamination, in the field.
- Avoid growing cereals after maize and vice versa
- Apply fungicide sprays at the correct time and rates
- Bury trash from previous crops before drilling cereals/maize
- Ensure chop length of between 15-20mm
- Ensure excellent clamp management and filling during ensiling
- Prioritise compaction and sheeting to exclude air
- No additive can completely eliminate mycotoxins in the clamp
Anyone who suspects a problem, farmer, vet or feed compounder, can now use Alltech 37+ testing to identify or confirm the exact cause, whether it be in forage, feed or bedding. “As soon as mycotoxin poisoning is suspected”, says Mr Smith, “adding a mycotoxin binder to feed, by adsorbing harmful mycotoxins, will quickly mitigate the effect of mycotoxins, restoring health and preventing productivity losses.”
“Looking at this year’s cereal harvest”, concludes Mr Smith, “I believe we are going to have a relatively benign mycotoxin challenge from cereals, unlike last year. However in relation to the silage cut, the very dry harvesting conditions may well lead to poor compaction resulting in heating problems when the clamps are opened. This will inevitably lead to penicillium moulds and mycotoxin build up, so livestock farmers need to be vigilant and consider using a penicillium binding absorbant”.
“Given the relatively benign levels of cereal based Fusarium mycotoxins I would suggest livestock producers consider removing any clay based binders from their diets (which only act against Fusarium based mycotoxins). Subsequently look for any response but really the focus this season is definitely on penicillium mycotoxins.
For many years Alltech have applied their yeast based technology to mycotoxin adsorption, producing Europe’s market leading, natural, non-clay based binder and now third generation Mycosorb A+ which offers increased binding capability over an even wider range of mycotoxins, including both Penicillium and Fusarium strains.