How Real is the Threat of Mycotoxins for Feed and Animal Producers in Asia? (Part 1)
Mycotoxins are now well established as dangerous compounds in animal feed, where they cause a multitude of confusing symptoms. These typically cause poor performance and can result in disease, with the added danger of being passed into the human food chain via meat, offal and milk.
As with any - natural toxic compound that is influenced by environment and climate, it is important to keep a regular check on the current situation.
This helps feed manufacturers to be prepared to control the potential problems in viva by applying a suitably efficacious binder, by blending to reduce levels of raw materials sourced from especially problematic regions or by avoiding purchasing particularly contaminated batches.
Mycotoxin survey results
Alltech has conducted a mycotoxin survey of Asian grains and complete feeds. The Alltech survey involved analysis of approximately 800 samples collected mainly from China and SouthEast Asia between January 2006 and December 2007, and included corn and its by-products, seed meals, other grain by-products and complete feeds. Samples were subjected to analysis for aflatoxin, T-2 toxin, zearalenone (ZEA), ochratoxin, fumonisin and Deoxynivalenol (DON, vomitoxin) using ELISA methods (Chen, 2007).
The result of the survey showed that the main problems in the Asian region were from ZEA, DON, fumonisin and aflatoxin. Corn is the main source of contamination of ZEA, fumonisin, DON, and aflatoxin. Corn by-products, such as DDGS, corn gluten meal, and corn germ meal, could contaminated with high level of ZEA, fumonisin, DON, and ochratoxin. Soybean meal is in general low in mycotoxins, except for ZEA. However, contamination of mycotoxins in soybean meal is highly dependent upon the level of soy hulls, because sov hulls are more concentrated with mycotoxins. Hence, the higher the level of soy hulls, the higher the level of mycotoxins in soybean meal. Usually corn, soybean meal, and corn byproducts account for more than 70% of a diet. As the result, complete feed is contaminated with mainly ZEA, fumonisin, DON, and aflatoxin. The analytical survey clearly demonstrated that the major threats were from ZEA, DON, fumonisins and aflatoxin, whereas T-2 occurrence was relatively lower. They also confirmed that many samples were contaminated with more than one toxin, which co-existed at high levels in some samples. By-products typically contained much higher levels of toxin contamination compared to whole raw materials.
Fusarium mycotoxins are the biggest challenge
Fusarium mycotoxins are economically the most significant mycotoxins in foods and feed on a global scale. They remain a key threat to animal health and performance, a threat that has been isolated in samples from all 2005, 2006 and 2007 harvests. The main Fusarium toxins of concern for animal feed compounders and producers include ZEA, fumonisins, and DON, with most of these experiencing an increase in average level and incidence of contamination from 2006 to 2007. Aflatoxin remains a concern, but is limited to certain countries, such as India and countries in South East Asia.
The surveys also confirmed the n continuing problem of contamination ot multiple mycotoxins in single samples, an extra complicating problem that r researchers have shown has a cumulative effect in terms ‘of severity and complexity of symptoms in affected animals. By-products show particularly high levels of toxins, which is not surprising as many of them are derived from either particularly vulnerable parts of the grain or the toxins become concentrated due to processing.
In order to control potential intoxication in animals given contaminated feed formulated, it is essential to use a proven broad spectrum adsorbent. The effectiveness of a mycotoxin binder can be verified based on a seven-point check-list:
1. Has the efficacy of the active component been verified by specialist researchers?
2. Does it have a low effective inclusion rate suitable for animal feed applications?
3. Is it stable over a wide pH range?
4. Does it demonstrate a good capacity to adsorb high concentrations of mycotoxins?
5. Is there a high affinity to adsorb low concentrations of mycotoxins?
6. Has the chemical interaction between mycotoxin and adsorbent been established?
7. Is there proven and published in-vivo data?
To be continued…
