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| Hey - i know this is a long post - but here's an article for those of you interested in Mycotoxins...Hope it helps.
More to Mycotoxins than Just Aflatoxin
[Lexington, Kentucky] – If you can remember the droughts of 1977 and 1980 in the Southeast United States, then you most likely remember the infectious toxins that accompanied the low moisture season. In those two years, the aflatoxin problems in both corn and peanuts reached extreme proportions, damaging the sale of crops and causing severe losses in livestock where the contaminated products had been fed. The 1980 outbreak alone is estimated to have cost $100 million to the agricultural industry.
While aflatoxins continue to be a sore subject in the Southeast, most producers have learned some type of damage control for avoiding repercussions. By keeping the feed fresh and equipment clean, using proper storage techniques and establishing programs for testing and sampling, many producers have educated themselves as to how to combat the infamous toxin. But what most agricultural professionals in the South have missed in their attack plan is their awareness and defense plan against other types of mycotoxins.
One family of mycotoxins that producers should be more attentive to is the Fusarium toxins. While Fusarium molds normally thrive in temperate climates and are more common in the Cornbelt and Southern Canada, this species can make its way south through interstate commerce. The mycotoxins produced by Fusarium are less eminent than the Aspergillus-produced aflatoxin, but can be more harmful to animal health.
A faculty member for more than 30 years at Guelph, Dr. Trevor Smith has devoted much of his research to the characterization and dietary treatment of Fusarium mycotoxicoses. While mycotoxins are nothing new to the animal feed industry, the research on toxins has greatly expanded. Once thought of as individual toxins, scientists have now determined that mycotoxins can form compounds and increase toxin responses in livestock.
For example more than 100 tricothecenes have been chemically identified. The most common is deoxynivalenol, vomitoxin or as it is often referred to, DON. DON and its associated compounds can influence behavior causing reduced feed intakes resulting in reduced milk production. The compounds can also trigger bleeding and ulcers in the digestive tract leading to reduced nutrient absorption. Finally the compounds are known to initiate immunosuppression and increased susceptibility to diseases including mastitis and increase somatic cell counts in milk.
“The greatest cost arising from feeding these materials is reduced disease resistance, failure of vaccination programs and lack of response to medications,” Smith said.
With research on these types of molds continuing each year, scientists are finding more and more harmful effects that can be linked to the notorious toxins. According to the 2007 Journal of Dairy Science article, “Effects of Feedborne Fusarium Mycotoxins on the Performance, Metabolism, and Immunity of Dairy Cows” by Korosteleva, Smith and Boermans, feeding a combination of Fusarium mycotoxins in naturally contaminated feed can increase the incidents of immunosuppression and reduced utilization of nitrogen.
According to Smith, while DON is the most prevalent Fusarium mycotoxin, livestock producers should also be on guard against zearalenone and fumonisins. Zearalenone is estrogenic and causes infertility and abortions in dairy cows. Fumonisin is a recently discovered mycotoxin that can cause kidney and liver damage, decrease animal performance; impair the immune system and even cause death.
Mycotoxins are never found in isolation. The mycotoxins mentioned above and much more can be present together in the feed ingredients and complete feed. When they are present together, they exert additive or synergistic interactions and cause significant adverse effects on livestock and poultry. DON has been shown to interact with T-2 toxin, fusaric acid and aflatoxin, while fumonisins interact with T-2 toxin and diacetoxyscirpenol (Devegowda and Murthy, 2005).
With the increased research in mycotoxins each year, the agricultural industry is also improving their knowledge in finding solutions to the mycotoxin problem. Mycotoxin control begins by managing mold growth from pre-harvest to post-harvest and sustaining a low mold count throughout feeding.
In the recent article, “Methods for preventing, decontaminating and minimizing the toxicity of mycotoxins in feeds,” Jean Pierre Jouany made mention of twenty-one different areas in the battle to prevent and then deal with molds and mycotoxins throughout the production and feeding chain. During pre-harvest, he suggests examining areas such as crop rotation and tillage, chemical and insect control and plant breeding, as these can potentially have a large impact on the crop.
During harvest and post-harvest, the producer must consider the age of the plant, combine harvester setting, humidity and temperature level during storage, the physical treatment of the grain, biological treatments and adsorbents. Biological methods such as bacteria, enzymes and live yeast have shown the ability to detoxify certain mycotoxins. One challenge with these technologies is their high degree of specificity that is not always applicable to the wide degree of possible mycotoxin contamination found typically in feedstuffs.
Adsorbents are seen as the last step. When all preventative measures have been taken the use of adsorbents is the final chance of preventing the mycotoxin negatively impacting animal health and productivity.
For Smith, there is only one absolute answer to mycotoxicoses.
“The only complete solution to the problems arising from mycotoxins in dairy feeds is to avoid the feeding of mycotoxin-contaminated feedstuffs,” Smith said.
Mycotoxins are a leading area of study at Alltech. Through 28 years of research-driven product development, Alltech has created a range of natural solutions for the feed and food industries. For more information, please visit the Web site at www.alltech.com or www.knowmycotoxins.com.
Devegowda, G. and T.N.K. Murthy. 2005. Mycotoxins: their effects in poultry and some practical solutions. In: The Mycotoxin Blue Book. Ed. Duarte Diaz. Nottingham University Press. 25-56.
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