•••• PROMOTIONAL ARTICLE
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10 lessons on mycotoxins > CONTINUED FROM PAGE 25
each mycotoxin . Several studies have shown that in the presence of some mycotoxins , rumen microorganisms are altered and do not have the expected detoxification capacity .
4 . MYCOTOXINS CAN BECOME MORE HARMFUL IN THE RUMEN IN SOME CASES Ruminal degradation does not always render mycotoxins harmless . In the case of zearalenone , which is metabolised via protozoa to a- and ß-zearalenol , the beta form has been shown to be a less-toxic metabolite , whereas the alpha metabolite results in an even more estrogenic compound compared to zearalenone itself .
5 . HIGHER THROUGHPUT LEAVES LESS TIME FOR THE RUMEN TO WORK The level of zearalenone degradation in the rumen seems to be strongly connected to the level of feed intake and the resulting retention time of the feed . Highproducing dairy cows with a daily feed intake of 26 kg dry matter , for example , have higher throughput which reduces the time allotted for detoxification .
6 . NOT ALL MYCOTOXINS CAN BE DETECTED BY TRADITIONAL METHODS Masked mycotoxins ( because of their changed chemical structure ) cannot be detected by conventional analytical methods ( HPLC , ELISA ). During digestion , the intestinal enzymes may cleave the masked mycotoxins and the parent mycotoxins are released . After release , the mycotoxins can be absorbed into the blood circulation and become again toxic for the animal . The most advanced , commercially available mycotoxin detection methods ( Spectrum
FEB / MAR 2017 • SENWES Scenario
Table 2 . Factors impeding mycotoxin deactivation in the rumen . |
Factor |
Description |
High productivity |
Higher throughput reduces time for detoxification |
Partial / unfavorable degradation |
Higher toxicity metabolites released in the rumen |
Masked mycotoxins |
Increased bioavailability of the parental mycotoxin |
Multiple mycotoxins in rumen |
Microorganisms have lower degradation capacity |
Acidosis |
Dysbiosis results in lower degradation capacity |
380 ®) can identify over 380 different mycotoxins and metabolites , including many masked mycotoxins .
7 . ACIDOSIS IMPACTS RUMEN FUNCTION A well-known problem within ruminants is subclinical or acute acidosis ( SARA / ARA ). This syndrome of low rumen pH often occurs in high-producing dairy farms , especially when the feeding regime is impaired or stress situations impair the ruminal flora and lead to dysbiosis . It is assumed that during acidosis the numbers of protozoa decline and as one of the most important mycotoxin-degrading agents , this leads to a decreased degradation and therefore , higher levels of mycotoxins can pass to the intestine and exert toxic effects .
8 . SEVERAL FACTORS CAN IMPAIR THE RUMEN ' S ABILITY TO DEGRADE MYCOTOXINS Table 2 explains several factors that influence the degradation of mycotoxins in the rumen . Taken either separately or together depending on the circumstance , these can lead to greater mycotoxin exposure and harm to animals .
9 . PROTECTION AGAINST A BROAD SPECTRUM OF MYCOTOXINS GUARDS AGAINST A SHIFTING MYCOTOXIN THREAT A number of common moulds found in the field produce a variety of harmful mycotoxins that impair dairy cow health and performance . Different groups of mycotoxins differ structurally from one another and therefore a robust mycotoxin risk management program is needed which combine several strategies , or modes of action , to counteract a broad range of different mycotoxins .
10 . MYCOTOXIN RISK MANAGEMENT IN 3 STEPS
Robust mycotoxin risk management comprises several steps : detection , prevention and mitigation . Regular analysis of feed components and silage can help to uncover potential threats to animals . Good silage management is essential to avoid further growth of moulds and thereby prevent the production of mycotoxins . Regular application of a mycotoxin deactivator cannot be overlooked .
The Mycofix ® product line of BIOMIN combines three modes of action — adsorption , biological degradation of non-adsorbable mycotoxins , and protection of the liver and immune system . Accurate feeding of dairy cows in combination with continuous mycotoxin risk management is the key to managing the optimal performance of the livestock business .
A proper mycotoxin risk management is essential to avoid unpredictable losses and maintain a high producing dairy herd . Avoiding mycotoxin formation must begin on the field , should continue in the silage production process and end with correct management of the open silo and feedstuffs .