As a consequence, overseas traders and analysts expect that China’s wheat imports 2013/14 will increase from 3.2 million to more than 10 million tons, surpassing Egypt as the world’s top buyer. This will underpin global prices and completely disrupt supplies in the Middle East. Besides China and Egypt, the top importers for wheat are Brazil, Indonesia and Japan.
With 95 % of mycotoxins already produced on the field, it would be almost impossible to predict the range of mycotoxins in feed, which would consist of a combination of different worldwide imported grains and ingredients.
How do we know which mycotoxins to analyze for in imported grain?
BIOMIN, a pioneer in mycotoxin risk management, has been conducting over the years a mycotoxin survey which allows feed and animal producers to assess the risks of using certain feedstuffs/feeds from different regions.
“Mycotoxin occurrence in feed and feed raw materials worldwide: Long-term analysis with special focus on Europe and Asia”
This is the title of a recently published scientific paper by Elisabeth Streit, Karin Naehrer, Ines Rodrigues and Gerd Schatzmayr in the “Journal of the Science of Food and Agriculture“.
In 2004, BIOMIN began an extensive worldwide mycotoxin survey program analyzing aflatoxin, ochratoxin A, zearalenone, deoxynivalenol and fumonisin contamination of feed and feed raw materials. This recent scientific publication evaluates the first 8 years of the survey program, looking closer into the changes in mycotoxin contamination and longterm trends according to region and commodity. This is the first time such a comprehensive survey has been published.
From 2004 till 2011, 17,316 samples were analyzed, out of which 72 % contained detectable amounts of at least one mycotoxin – close to three times more than the frequently-cited FAO estimation of about 25 %. Maize, finished feed, wheat/bran, barley, silage, soy bean meal, dried distiller’s grains and solubles, rice/bran, straw, cotton seed, sorghum and peanuts were included in the survey.
Within this 8-year period, it was reported that on a global level, deoxynivalenol was most dominant (55 % of the samples tested positive), followed by fumonisins (54 %), zearalenone (36 %), aflatoxins (27 %) and ochratoxin A (25 %).
Strong yearly variations were observed in mycotoxin prevalence and contamination levels. In some cases, this was clearly due to unusual weather conditions.
In 2010, above-average precipitation was recorded in almost all of eastern Australia and in the Murray-Darling basin, the main wheat-growing region located in the south of eastern Australia. Lower-than-average temperatures were also measured during this period. As a result, Australian samples displayed a five-fold increase in average zearalenone contamination and a six-fold increase in average deoxynivalenol contamination compared to the year before.
In South-East Asia, aflatoxin occurrence in compound feed increased steadily from 32 % of finished feed samples in 2005 to 71 % in 2011:
Maize is one of the most important ingredients for compound feed and generally regarded to be particularly vulnerable to mycotoxin contamination. In 2005, the average contamination of maize with aflatoxins was 45 ppb, and reached 183 ppb in 2009. The extent of aflatoxin contamination is alarming and it is, not surprising that high levels of aflatoxin M1 are frequently found in dairy products in South-East Asia.
A possible reason for this development could be the increased frequency of droughts and extreme rainfalls over the past decade in South-East Asia, summarized in a report by the Asian Development Bank.
The increasing prevalence of aflatoxins in tropical Asia seems to be a natural phenomenon, but international trading of feed commodities may amplify the problem. An interesting phenomenon was the increase in zearalenone-positive finished feed in North Asia which coincided with the mounting import of US DDGS in this region. Eighty-one percent of the DDGS samples in this survey tested positive for zearalenone.
International trading of feed raw materials makes the prediction of mycotoxin occurrence very difficult. The long-term evaluation confirms the fact that mycotoxin contamination is strongly influenced by weather conditions and the extreme year-to-year variations further emphasizes the need for regular and careful mycotoxin risk management.