PROMOTIONAL ARTICLE

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MOST GRAINS AND FEEDSTUFFS ARE AFFLICTED BY A WIDE VARIETY OF MYCOTOXIN TYPES . RUMINANTS ARE KNOWN TO HAVE SOME CAPACITY TO PROTECT THEMSELVES AGAINST THE HARMFUL EFFECTS OF MYCOTOXINS .

With large amounts of feed comes the risk of increased mycotoxin exposure , higher passage rates and less time available for proper feed digestion . As animals are fed increasing quantities of feed to increase production , it becomes more difficult to guarantee that mycotoxins can be effectively deactivated in the rumen . Complete mycotoxin degradation in the rumen is therefore not possible .

Most dairy farmers are well aware of the dangers posed to cows by aflatoxin-contaminated feeds and the risk of carryover of ingested aflatoxins into milk at a rate ranging from 1 to 6 % that could endanger human consumers . When the price of milk dropped and production cost pressures mounted , farmers tend to cease a mycotoxin risk management programme .

There are 10 important facts to remember about how mycotoxins affect dairy production .

1 . AFLATOXIN IS NOT THE ONLY DANGEROUS MYCOTOXIN Reproductive issues are likely the results of zearalenone , a potent estrogenic mycotoxin linked to a number of reproductive issues . Aflatoxins , zearalenone , deoxynivalenol , T-2 toxin , fumonisins and ochratoxin A are a few of the mycotoxins most commonly found in finished feed , corn ( maize ) and corn silage . These most well-known mycotoxins , recommended risk thresholds and effects are listed in Table 1 .

2 . RUMINANTS ’ LOWER SENSITIVITY TO SOME MYCOTOXINS ? A common misconception is that because cows are less sensitive to the effects of mycotoxins than other livestock species that mycotoxin risk management is optional

Table 1 . Major mycotoxins and the dangers for cows .

Recommended risk threshold ( ppb ) Effects or only necessary in response to a severe mycotoxin challenge . The reality shatters this myth . Many dairy producers across the world have had similar experiences , forgoing a mycotoxin risk management programme when faced with low milk prices or cost pressures , only to have sudden problems relating to insemination rates , lower milk production , diarrhoea , elevated somatic cell counts , and higher incidence of diseases such as hoof disease or mastitis , and reproductive failure .

3 . THE RUMEN ’ S ABILITY TO DEGRADE MYCOTOXINS VARIES A LOT Cows ’ lower sensitivity to mycotoxins is due to their degradation in the rumen . Rumen biotransformation of various mycotoxins happens via certain microorganisms ( e . g . protozoa ) which have certain capacity to metabolise particular mycotoxins . While some researches have postulated that toxin degradation can reach up to 90 % for some mycotoxins , estimates vary widely and differ for

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