The presence of mycotoxins in feed is a major issue and presents a genuine risk to livestock and animal production across the world. As well as the suffering of animals, the occurrence of contamination in various grain crops has major implications for food and feed safety, food security, and international trade. Around 25 percent of the world’s grain is contaminated with one or more mycotoxins and, according to a European Commission report, it is estimated that mycotoxins are responsible for losses of up to 5 to 10 percent of crop production globally.
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Explore this issueJune/July 2016
Mycotoxins are classified as secondary metabolites and are produced by a wide range of different molds. Moisture is one of the most important factors in determining if and how rapidly these molds will grow in feed and comes from three sources: feed ingredients, the feed manufacturing processes, and the environment in which the feed is held or stored. Mycotoxins can occur in a variety of crops that are colonized with filamentous fungi and can affect a range of food products including cereals, grains, nuts, spices, dried fruits, apple juice, and coffee. Contamination can occur due to weather, possible climate change effects, land use, or crop management.
There are said to be between 300 and 400 mycotoxins in existence, however those that are of most concern based on their toxicity and occurrence are aflatoxins (B1, B2, G1, G2, and M1), deoxynivalenol, zearalenone, fumonisin, T-2 toxin, and T-2-like toxins. Aflatoxins, including aflatoxin B1, are considered the most toxic and while all ages are affected, young animals are most susceptible. Aflatoxins cause a variety of effects in animals, including reduced milk or egg production, gastrointestinal dysfunction, anemia, and jaundice. Other mycotoxins can produce a range of harmful effects in animals, including kidney damage, reproductive disorders, suppression of the immune system, and, in severe cases, death.
For feed producers, the economic impact of mycotoxin contamination is high, especially due to the lower levels that cause more subtle symptoms. Mycotoxins are not only an issue for animal health, but may also be hazardous to human health since animal products that contain residues, including tissues and milk, are consumed by people. Greater awareness of the issue, together with improved screening, is key to effectively controlling the occurrence of mycotoxins in feed and food chains.
In order to protect animal and consumer safety, rules and strict legislative limits for aflatoxins, ochratoxin A, and fusarium toxins in certain foodstuffs are specifically set out in European Commission legislation. The legislation applies to the specified foods, whether they are imported into the U.K. or produced in the U.K. Globally, the requirement for mycotoxin screening is varied. In an attempt to safeguard consumers, there are a number of special import conditions currently in place for some foods from certain third world countries (Africa in particular), where the risk from aflatoxin contamination is increased. Compliance with internationally acceptable limits for mycotoxins can be challenging for the food industry, requiring good plant protection, adequate storage, and good manufacturing practices in order to keep levels below the limits.
A number of studies have demonstrated that mycotoxins occur simultaneously in field situations, which can profoundly affect the toxicity of the mycotoxins present. Producers must be aware that if one toxin is identified in a sample, the chance that other toxins are present is highly likely. Therefore the need to test for multiple mycotoxins simultaneously is vital to ensure that all prevalent toxins are detected quickly and adequately monitored.