MYCOTOXINS CONTAMINATE THE BY-PRODUCTS OF GRAINS USED IN ANIMAL FEED

The global food crisis is a complex issue that has been exacerbated in recent years due to climate change and the armed conflict between Russia and Ukraine. As expected, environmental conditions have changed, and in several areas or regions of the world, the repercussions of global warming are being observed.

In the production of crops and cereals, severe droughts and floods have led to the bankruptcy of businesses. Environmental conditions conducive to specific habitats have amplified the prevalence of mycotoxigenic fungi, which, due to their adaptability, dominate crop ecosystems (Medina et al., 2017). Periods of both humidity and drought significantly impact the fungal life cycle, and conditions of stress contribute to increased mycotoxin production (Medina et al., 2017). Regions characterized by high temperatures and limited rainfall experience substantial aflatoxin production. Conversely, in cold and excessively humid areas, there is a greater occurrence of DON and ZEN. As a result of climate change and rising temperatures, it’s possible that countries situated in colder or temperate climates will detect increased aflatoxin contamination (Pinotti et al., 2016).

A clear example can be observed in Serbia, where no contamination with aflatoxins in corn was documented between 2009 and 2011. However, due to an extended hot and dry period in 2012, 69% of the collected samples were found to be contaminated with aflatoxins. Similarly, Hungary reported an escalation in the concentrations of these mycotoxins (Medina et al., 2017). By contrast, in tropical countries, the environment is expected to be unfavorable for fungal growth and the conventional production of mycotoxins (Pinotti et al., 2016).

According to the European Food Safety Authority, the potential consequences of climate change in Europe will result in regional effects that could be either detrimental or beneficial based on the geographical area. The Mediterranean region is projected to encounter elevated temperatures along with drastic shifts in rainfall patterns, increased flooding, and higher concentrations of CO2, all of which will impact food production (Medina et al., 2017).

Armed conflicts contribute to the increase in food prices

Regarding the armed conflicts, these began at a critical juncture for global food markets, coinciding with escalating prices due to huge global demand and disruptions in the supply chain post-pandemic. Both countries involved in the conflict, Ukraine and Russia, play a vital role in the fertilizer market, in addition to marketing 70% of sunflower, 30% of wheat, and 20% of corn worldwide. Many countries in Africa, Asia and the Middle East depend on Russia for accessible crops. Consequently, the war has impacted not only global energy markets but also food security, leading to soaring fuel expenses and elevated food prices. This poses a substantial threat to the stability of global food markets and presents adverse implications for post-pandemic businesses (Galanakis, 2023).

Apart from climate change and war, the additional challenge for food production is food-feed competition. It is expected that more than one billion tons of cereals will be used for animal feed, and the demand for animal products will cover up to 70% by 2050 (Galanakis, 2023). Given the numerous dilemmas concerning food security and the present circumstances, cereal by-products have been suggested as a potential alternative for animal feed.

The use of cereal by-products as an alternative in animal feed

Supporting animal production in Europe requires approximately 475 million metric tons of feed annually to ensure adequate animal nutrition. This significant demand prompts producers to seek alternative options to alleviate pressure on food resources. Consequently, the food industry has undertaken the task of converting grain by-products into animal feed. Approximately 20 million tons of cereal by-products are consumed each year, representing 11.5% of food ingredients. Among the cereal by-products, there are those from the production of bioethanol, where the distiller’s dried soluble grains lie. This represents a high-value food source and particularly replaces the high cost of protein with a competitive price within the industry (Pinotti et al., 2016). Additionally, other food by-products are derived from beer manufacturing. The most common by-products are barley stems, spent grains and surplus yeast. Barley stems and spent grains are important feed ingredients due to their high levels of protein and fiber, as well as their low price (Pinotti et al., 2016).

Mycotoxin contamination in cereal by-products

The feed industry plays a pivotal role in the sustainability of the food processing system by transforming by-products into premium-quality animal feed. In addition to providing an outlet for co-products and by-products derived from food and biofuel production, the feed sector contributes to minimizing waste generated during the production process. The main barriers to greater acceptance of cereal by-products as feed ingredients include high variability in nutrient composition and the ever-present problem of mycotoxins (Pinotti et al., 2016).

In the United States context, dried distillers’ grains contaminated with a particular mycotoxin (fumonisin) are reported to contribute to economic losses in pork production exceeding $147 million annually. Total losses can be significantly high due to the additive and synergistic effects of mycotoxin co-contamination on animal health. The level of mycotoxin contamination in dried distillers’ grains depends on the original grain contamination, processing techniques, storage conditions, fermentation process, yeast properties, and year of production. During the ethanol fermentation process or the production of dried distillers’ grains, mycotoxins cannot be destroyed (Pinotti et al., 2016).

Barley grains and malt production can also be greatly affected by fungus contamination, mostly from the Fusarium species, with an impact on the safety and quality of malt and beer (Pinotti et al., 2016). Exposure to mycotoxins in beer manufacturing by-products is mostly attributed to the characteristics of the raw material and poor handling procedures during storage (Pinotti et al., 2016).

For effective management of mycotoxin risks associated with by-products on an industrial scale, rapid analysis tests are a valuable tool. Based on the contamination levels of the by-products, additional actions can be considered to manage the risk of mycotoxins at the industrial feed level, such as the evaluation of the economic value of the by-products and the appropriate levels of their inclusion in compound feeds. 

Sampling is the critical step to obtaining reliable results on the presence of mycotoxins and, in turn, it also represents the primary source of error in quantifying mycotoxin contamination, which may be due to the difficulty in obtaining samples from large shipments of grain or the uneven distribution of mycotoxins in the products (Pinotti et al., 2016). 

Costs of mycotoxin contamination in animal feed

Contamination by mycotoxins is a global risk that compromises the health and economic status of countries without exception. The large losses generated in the market are related to the damage caused to agricultural production, the elimination of contaminated feed and food, the detriment of production, human and animal mortality, the increase in health and therapeutic treatment and investment costs and the economic cost of the control and regulation of mycotoxins. The livestock industry is one of the most affected by mycotoxins, since animals are more suceptible to diseases because mycotoxins weaken their immune systems and decrease the response to vaccination (Assefa & Geremew, 2018). Due to the complexity of these toxic metabolites, it remains difficult to evaluate and calculate the cost or economic impact they have on international trade (Pinotti et al., 2016).

Current agricultural practices do not guarantee the ability to predict or prevent the occurrence of mycotoxins during harvest, storage and food processing. It is estimated that 30 to 100% of feed samples are co-contaminated with mycotoxins (Rodrigues & Naehrer, 2012). Whole grain lots like corn, wheat, rye, barley, and oats face repeated destruction due to mycotoxin contamination, resulting in annual economic losses ranging from hundreds of millions to billions of dollars (Mavrommatis et al., 2021). The globalization of agricultural commodity trade has raised awareness about mycotoxin levels entering the feed supply chain. Consequently, regulations have been established in over 100 countries, with acceptable limits varying between nations (Pinotti et al., 2016). These regulations primarily aim to safeguard consumers from the adverse effects of mycotoxins by setting acceptable or tolerable daily intake levels. The limits are established based on several factors, such as toxicity, exposure time, distribution and concentration of mycotoxins in products or commodities, methods of analysis, legislation in other countries, and the quantity of feed supplied (Milicevic, Skrinjar, & Baltic, 2010). However, it’s important to note that existing regulations do not cover modified or emerging mycotoxins.

Therefore, detecting and controlling these types of toxins is expected to become a priority in the future (Pinotti et al., 2016). Despite the limits placed on mycotoxin levels in feed, one of the current major concerns is co-contamination. The additive and synergistic effects of multiple mycotoxins have harmful consequences for animal health, representing a significant challenge in feed safety (Rodrigues & Naehrer, 2012).