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Climate change and mycotoxins: untangling a complex web
Click below to listen to the Mycotoxin Matters podcast episode with Dr. Mark Lyons hosted by Nick Adams. You can also hear the full audio or listen to the episode on Apple Podcasts or Spotify. You can find an edited transcript at the bottom of the page.
Author: Nick Adams, Global Director, Alltech Mycotoxin Management
In a December interview focused on the European feed industry in 2021, the FEFAC President Asbjørn Børsting expressly referred to mycotoxin control and “the evolution of legal standards for mycotoxins in feed” as critical topics as we move forward. Why? Because the “occurrence of mycotoxins in cereals in Europe and beyond is clearly on the increase and many of the tools available to farmers to control mycotoxins are actually threatened by the EU Farm to Fork strategy” (FeedNavigator.com).
There are many parts to this puzzle. I have tried to touch on many in this blog, starting with the potential impact of climate change on mycotoxin production before moving on to the consequences and possible control mechanisms.
Changing weather patterns
As the globe warms because of climate change, the obvious thought is around the impact of warmer temperatures on the growth of mold and mycotoxin production. However, the reality is far more complex, as is discussed by various authors (Paterson and Lima, 2009, 2011; Magan et al., 2011; Miraglia et al., 2009; Moretti et al., 2018; Van der Fels-Klerx et al., 2016). Factors such as carbon dioxide concentration, drought stress and extreme weather events will all impact the delicate relationship between mold, its plant host and its environment, including that between pest species and plants that influences how the mold gains access to developing grains.
The impact of climate change will not be consistent but, rather, will depend on local environmental conditions and the specific crops grown. These factors will establish important criteria such as planting, flowering and harvest dates that, along with agricultural practices, such as tillage, crop rotation and fungicide use, will determine the level of mold presence and mycotoxin production (Vogelgsang et al., 2019). In this regard, models are being developed to help predict potential outcomes. While many point toward increased risk from key mycotoxins such as aflatoxin, deoxynivalenol (DON) and fumonisin, certain scenarios predict a reduction in mycotoxin risk (Battalini et al., 2016; Van der Fels-Klerx et al., 2016).
Perhaps this is not much of a surprise: The feed industry media regularly reports on mycotoxin contamination levels along with published data. Battalini et al. (2016) refer to aflatoxins as a threat that only really started to be recognized in European crops in the early 2000s, with models predicting a greater threat, particularly in a +2°C climate increase scenario. Data collected over the past eight years using Alltech 37+® mycotoxin analysis (unpublished) shows a general trend for increasing Fusarium mycotoxins, particularly the type B trichothecenes and the emerging mycotoxins group.
In this regard, the advent of analytical procedures based on mass spectrometry techniques (LC-MS/MS) has dramatically increased the ability to detect multiple mycotoxins (Jackson et al., 2012; Weaver et al., 2019). Therefore, while more sensitive mycotoxin analysis is certainly allowing for a forensic evaluation of grains, the changing climate is likely playing a significant role in their evolving presence.
Environmental sustainability: A new view on animal productivity?
What does this mean? In recent years, several published meta-analyses have evaluated the effects of individual and multiple mycotoxins on animal performance in species where sufficient data exists (Andretta et al., 2015). These have shown that in pigs and poultry, individual mycotoxins have varying degrees of impact on average daily gain through their ability to affect feed intake and feed efficiency, with the impact of multiple mycotoxins being greater than individual toxins.
Historically, we would view this predominantly as lost economic performance (i.e., animals that do not perform to their optimal ability are less profitable than their cohorts). However, it is now increasingly important to also view this through the lens of reduced environmental sustainability because of the increased resource requirements, primarily feed, needed to achieve target slaughter weight. This is particularly relevant for monogastric species, where the contribution of feed to the overall carbon footprint of the system is significant. Mycotoxin presence has a net effect of increasing the carbon footprint of production by reducing feed efficiency and any additional impact on animal health. The scale of the challenge, along with any other resources needed, will determine the overall impact on the carbon footprint. While environmental sustainability is not currently monitored consistently around the world, new initiatives, such as Europe’s Green Deal, will start to force the food and feed industry to focus more attention on this metric of production efficiency.
The Green Deal and mycotoxins
The recently launched Green Deal is the European Union’s plan to make the EU economy more sustainable, with a climate-neutral goal for 2050. Within this, governments will take ownership of country-based targets for reducing greenhouse gas emissions and work with industry to achieve these, with a requirement that levels can be measured, verified and reported. This initiative will force the agriculture industry to focus on environmental sustainability in order for countries to meet their goals. Emphasizing the changing landscape, up to 40% of the Common Agriculture Policy (CAP) funding will support these aims moving forward.
Are mycotoxins a big deal within this? The answer depends on many factors, but it is worth stepping back, for a moment, and examining the comments made by the FEFAC President, Asbjørn Børsting, regarding the tools currently available to farmers to combat the mycotoxin threat.
Jouany (2007) described various pre- and post-harvest factors that will ultimately influence the level of mycotoxins in the final finished feed. Of the pre-harvest strategies — seed variety, tillage methods, crop rotation and pesticide usage — all are known to affect the level of mycotoxin contamination in the next crop. Given plans within the Green Deal to increase carbon capture through more ecologically friendly tillage practices and reductions in chemical use, the number of pre-harvest management strategies that help to reduce the mycotoxin risk will be reduced or removed from the farmer’s toolbox.
Therefore, it is difficult to predict with any great certainty exactly what mycotoxin levels will be in the future. Although, as noted above, changing weather patterns and agricultural practices do have the potential to increase the risk. As Jouany reflected, and as remains the case today, there is no one strategy that will render feed free of mycotoxins. Given the changing landscape, both from an environmental point of view but also, in the future, from a legislative point of view, it is inevitable producers will have to adapt their businesses.
Novel methods for a mycotoxin management program
There have also been positive developments: from biopesticides and biostimulants (Lagogianni and Tsitsigiannis, 2019) through to competitive exclusion strategies using nontoxigenic strains of Aspergillus molds (Pitt, 2019). While these methods are not perfect, they do offer positive tools for the control of aflatoxin, which is of particular concern from a food safety and security standpoint (Medina et al., 2017).
Other post-harvest concepts include grain cleaning and processing, which has different connotations depending on the exact nature of the grain, mycotoxin and processing step. Generally speaking, processing steps, such as sieving, cleaning, thermal treatment and others, can positively affect the level of mycotoxins. Still, the outcomes vary and do not result in mycotoxin-free grains (Colovic et al., 2019).
In this area, Alltech continues to innovate around technologies that can help producers both pre- and post-harvest. Alltech Crop Science products offer grain producers chemical-free alternatives to manage pests and improve crop health to help reduce fungi load and mycotoxin contamination. Post-harvest, Alltech’s Mycosorb® product range offers livestock producers different solutions based on species and mycotoxin risk, assisted by the Alltech 37+ and Alltech® RAPIREAD™ analytical programs. A recent meta-analysis conducted on published studies where Mycosorb was fed to laying hens consuming diets with and without mycotoxins demonstrated that the contribution Mycosorb makes to environmental sustainability is also significant, as calculated by Alltech E-CO2. Based on the increased performance as a result of feeding Mycosorb, it found that for every 100,000 layers, Mycosorb helped reduce the overall carbon footprint by 3.76%, equal to the impact of removing 124 cars from the road, grounding 221 round-trip transatlantic flights or planting 190 trees.
In wrapping up, on the one hand, grain producers will potentially face a restricted set of crop management tools when it comes to reducing the mycotoxin threat. Livestock producers will be expected to understand their production metrics from an increasingly environmental viewpoint. Between these two sets of producers, there will be a requirement for the food and feed industry to better understand mycotoxin contamination levels and act accordingly with respect to the prevailing legislative regulations in its jurisdiction.
Planet of Plenty™
To better align with the focus toward the WHO Sustainable Development Goals, as well as the push towards climate neutrality, Alltech officially launched its Planet of Plenty™ initiative in May 2019. While this program covers many different aspects, the work carried out by the Alltech Mycotoxin Management platform and Alltech Crop Science specifically focuses on the reduction of mycotoxins in finished feed and their impact on animal health, performance and profitability, subsequently helping the global agricultural industry work toward a Planet of Plenty.