Mycotoxin contamination in Indian feed commodities in the last decade: key takeaways

Mycotoxin contamination is always evolving and thanks to advances in analytical methods the picture is getting more and more accurate. Twelve years ago, the FAO published a report stating that 25% of world’s crops were contaminated by mycotoxins. Only one and half years ago, a new study reported mycotoxin occurrence in the level of 60-80%, more than double! Thanks to advances in mycotoxin analysis, we can now be more accurate on the real risk animals and humans are facing. In addition, the creation of large datasets allowed us to understand where the trends are going andwhat actions to take.
India has always suffered from high levels of storage mycotoxins such as aflatoxins and ochratoxins, partially due to hot and humid climate coupled with poor grain storage management, partially because mycotoxin levels in feedstuff are not controlled. Authorities are now looking at improving food and feed safety by introducing new regulations on minimum acceptable levels for aflatoxins and pesticides. Although this move might bring some benefits to final consumers, it will certainly put more pressure on feed and animal producers that will need to take action to meet more stringent requirements on mycotoxin contamination.
This article will provide an overview of what happened in India in the last ten years and will give some ideas on how to revert the trend.
Ten years in a nutshell
Between 2011 and 2021 we have analyzed over 1400 samples in India. Aflatoxins (Afla) have been the most prevalent mycotoxins, detected on average in 83% of samples analyzed and their prevalence never dropped below 77%. Fumonisins (FUM)have been the second most prevalent mycotoxins detected in India, followed by ochratoxin A (OTA) and deoxynivalenol (DON) in third and fourth positions respectively (figure 1).
The average concentrations of Afla, DON, FUM and OTA detected in the 2011-2021 period were medium to high risk for all livestock. Aflatoxin B1 average concentration was 52 ppb (way higher than the 5 ppb European limit), reaching peaks of over 1200 ppb. It is no mystery that those levels could be of particular concern for the local dairy industry, given the ability of aflatoxin B1 to accumulate into milk as aflatoxin M1.
The average concentration of DON in the last ten years was 339 ppb, with peaks that went over 3600 ppb. The average value is considered medium risk for poultry and young ruminants, but its peaks are of great concern, especially taking into consideration the documented ability of this mycotoxin and other trichothecenes to undertake synergistic interactions with other Fusarium and storage mycotoxins.
The average concentration of FUM in the last ten years was 726 ppb, with peaks that almost reached 10.000 ppb. While the average value alone is generally considered low risk for poultry and ruminants, one must not underestimate the high prevalence that could lead to potential synergistic interactions with other mycotoxins. The maximum values recorded in India are of great concern for livestock production and could lead to severe performance issues and profitability losses.
The average concentration of OTA in the last ten years was 17 ppb, with peaks that almost reached 600 ppb. OTA is a potent carcinogen; it can accumulate in animal tissues and could potentially reach the food chain. This average value is considered low risk for poultry, but as for FUM, one must not underestimate the high prevalence that could lead to potential synergistic interactions with other mycotoxins. The maximum value detected is considered high risk for both poultry and ruminants and could lead to severe performance losses.
Indian corn 2011-2021
For the last 10 years FUM was the most prevalent mycotoxin in corn, and it was detected in 93% of the samples analyzed. Afla was the second most prevalent mycotoxin, detected in 67% of samples analyzed, followed by DON and OTA (27% and 26% prevalence, respectively). The average concentrations of FUM and DON represented a medium risk for livestock. Afla has always remained constantly high, representing a problem for the poultry and dairy industries. The corn summary for the last ten years is shown in figure 2.
Indian soybean 2011-2021
Soybean is the undisputed champion for storage mycotoxins, with 95% of the samples collected in the past 10 years being contaminated with OTA, and 83% with Afla. The average levels of these two mycotoxins were considered of medium concern for livestock, but the maximum levels reached worrying levels, suggesting that the danger can be high at times in soybean too. As for Fusarium mycotoxins, the prevalence ranged between 21% and 29%. The soybean summary for the last ten years is shown in figure 3.
Indian finished feeds for all species
One of the most common mycotoxin myths is that the latter are not resistant to processing methods. Unfortunately, most mycotoxins are, and the fact that we always find them in finished feeds confirms that. As shown in figure 4, Afla was detected in 95% of the samples analyzed in the last ten years, followed by OTA (92%) and FUM (91%). The average concentrations of mycotoxins are considered medium risk for all livestock, except for Afla that recorded an average of 36 ppb and a peak of over 1200 ppb, representing a high risk for all livestock. DON and FUM reached peaks of almost 3.000 ppb, worrying numbers that could lead to severe performance losses and confirm the fact that mycotoxins are not degraded during processing.
Co-contamination, the overlooked threat
Although it is important to pay attention to single mycotoxins, we must not forget that those only represent part of the picture. Mycotoxin co-contamination often leads to synergistic and additive interactions that aggravate the overall toxicity.When estimating mycotoxin toxicity, official guidelines do not take into consideration synergism, as this concept has only been largely investigated in the last years, thus they do not offer a representative picture of the reality. Mycotoxin co-contamination is not an exception but the rule, which is why it is of outmost importance to invest in solutions that offer a complete protection. By having a look at the graphs on the right-hand side in figures 1 to 4,we can notice how mycotoxin co-contamination never fell below 70%, indicating a high potential for synergism.
Reverting the trends
It is clear how India has been dealing with high levels of mycotoxins for the last ten years and how storage mycotoxins represent the biggest source of contamination. Improving the storage conditions is the first action that feed and animal producers can do to mitigate the risk. Mitigation strategies include the use of stringent protocols within the framework of good agricultural practices (GAP) and good manufacturing practices (GMP). Testing grains regularly before storage and managing batches that are too contaminated will contribute to keep the mycotoxin levels low. Fungicides should be used with caution as they do not deactivate mycotoxins, but only control mold growth. Furthermore, some of these products are highly toxic, and that toxicity can be taken up by the animals, affecting their health and performance.
Is there a silver bullet to fight mycotoxins?
The answer is no. Mycotoxin mitigation requires action at multiple steps, however the use of feed additives to bind and deactivate mycotoxins directly in the gut of the animal is the most effective way to tackle mycotoxins currently. When choosing a product stay away from marketing claims and look at the science behind. We know that there is no such a thing as broad-spectrum mycotoxin binders, simply because not all mycotoxins can be bound. In the vast majority of cases, broad spectrum binding is an indicator of a very unspecific product that will deplete the feed from vitamins and nutrients, resulting in even poorer performance. Looking at products that have been evaluated by third parties and approved by government authorities such as the EU, represent a guarantee of efficacy and safety, delivering value for money and protecting performance and profitability.

by Michele Muccio, Mycotoxin Risk Management Expert, Biomin Singapore