We read with interest the WATTAgNet editorial opinion asking the very good question, “where is aflatoxin?”
Aspergillus is one of the most common fungal species encountered. Each day we breathe in around a thousand Aspergillus spores so it is no surprise that feed commodities are frequently contaminated by the most common aflatoxin producing species (Aspergillus flavus and A. parasiticus). The history of animal feed mycotoxin awareness only really goes back to the 1960’s, but it was aflatoxins that were the first to be identified.
Contamination with aflatoxins is more common in warmer regions and after drought conditions (due to grain damage). The 2015 BIOMIN Mycotoxin Survey reported aflatoxin detection in 18% of feed samples worldwide. That’s enough of a concern, but focus on a hotspot area and the scale of the localized problem can be seen. In South Asia and South East Asia, aflatoxins were detected in 97% and 47% of samples respectively with many of those affected samples being above a 20 ppb health risk threshold for pigs (47% and 24 % respectively of affected samples). Aflatoxins are also a common occurrence in feeds from Africa, South America, Southern Europe, the Middle East and Oceania. Even in the comparatively less affected areas, we need to be aware of the risk of an occasional feed source being contaminated or of imported feed from an aflatoxin hotspot region.
Aflatoxin contamination in milk is a concern for human health even at low feed contamination levels, so much attention on aflatoxins is directed at the dairy industry. Yet for the animals themselves, a pig is more sensitive to the toxic effects of aflatoxin than a mature dairy cow. We also need to take care to avoid aflatoxin contamination in the meat.
It is young pigs and pregnant sows that are often more affected than other stages. Aflatoxin effects can include general symptoms of slow growth, reduced feed intake and immune suppression. Liver toxicity and kidney inflammation and systemic hemorrhages are also characteristic of aflatoxin effects. Last but not least, the aflatoxins are well known carcinogens. The health impacts of this mycotoxin can be huge.
So while the comparatively new “kids on the block” like deoxynivalenol, zearalenone and fumonisins may be more common around the world and pose frequent problems for pig production, we must not lose focus on aflatoxin. For the reasons above, rather than just alphabetical order, BIOMIN usually reports aflatoxin first in tables and graphics of mycotoxin occurrence.