Mycotoxins in the food chain: Understanding risks and exploring mitigation strategies

By: Dr. Maloshrie Bora, Program Manager - Feed Safety, Trouw Nutrition South Asia

The safety of animal feed is increasingly compromised by a confluence of global challenges, notably mycotoxin contamination. These toxic metabolites, produced by molds such as Aspergillus and Fusarium, pose significant health risks to livestock and, by extension, to humans consuming animal products. Contributing factors include a shortage of quality raw materials, exacerbated by supply chain bottlenecks and geopolitical disruptions. Climate change further intensifies the issue by altering temperature and precipitation patterns, creating favorable conditions for mold growth and mycotoxin production. Additionally, inadequate storage and transportation facilities, often lacking proper ventilation and climate control, facilitate the proliferation of these harmful fungi. Together, these elements underscore the urgent need for comprehensive strategies to mitigate mycotoxin risks and ensure feed safety.

Even the smallest lapse in post-harvest handling can swiftly trigger the formation of harmful secondary metabolites like mycotoxins. Factors such as delayed drying, inadequate moisture control, and poor storage conditions can create an environment conducive to fungal growth, leading to rapid mycotoxin accumulation. For instance, aflatoxin contamination in maize has been linked to improper drying and storage practices, highlighting the critical importance of stringent post-harvest management to ensure food safety.

Mycotoxin contamination poses a significant threat to various stakeholders in the agricultural and food sectors, including farmers, feed producers, food processors, public authorities, and 

end consumers. These toxic compounds adversely affect animal health by impairing the gastrointestinal tract, suppressing the immune system, and disrupting nutrient absorption, leading to decreased productivity and increased susceptibility to diseases. Implementing a comprehensive 360-degree mitigation strategy—encompassing prevention, detection, regulation, and education—can effectively address this multifaceted issue and safeguard public health and economic interests.

The "Big 6" mycotoxins—aflatoxins, ochratoxins, fumonisins, zearalenone, deoxynivalenol (DON), and T2 toxin—are among the most prevalent and toxic secondary metabolites produced by molds affecting agricultural commodities. These toxins impact various species differently; for instance, aflatoxins primarily affect liver function in mammals, while zearalenone exhibits estrogenic effects leading to reproductive issues in ruminants and pigs. The incidence and severity of mycotoxin contamination are influenced by environmental factors such as temperature, humidity, and rainfall, which can create conducive conditions for mold growth and toxin production. Not all mycotoxins are equally toxic across species; for example, DON is highly toxic to swine, whereas poultry are less affected. Climate change exacerbates the problem by altering weather patterns, potentially increasing the prevalence and distribution of mycotoxins in crops.

Aflatoxins occur worldwide in feed and feed stuffs which results in severe economic loss to poultry and livestock industries. The extent of Aflatoxin contamination varies with geographic location, farming methods and the susceptibility of commodities to fungal invasion during pre-harvest, storage, and processing periods. Numerous studies showed negative effects of Aflatoxin in broiler chickens including a decrease in the efficiency of feed utilization and body weight gain, liver damage, poor immune response, and increased mortality. Aflatoxin is shown to induce pathological alterations in important organs such as the liver, kidneys, and lymphoid organs. Furthermore, the transmission of aflatoxin B1(AFB1) and its metabolites from feed to animal edible tissues and products, such as the liver and eggs, becomes particularly important as a potential hazard for human health. Given the global economic importance of Aflatoxin, many strategies have been tried to minimize their negative impact. A successful prevention strategy must be economical and capable of eliminating all traces of toxin without leaving harmful residues and should not impair the nutritional quality of the commodities. Extensive research has been carried out using adsorbent (binder) materials that adsorbs to Aflatoxin molecule by means of ion exchange and thereby preventing their absorption into blood circulation. Among various binding agents, clays and yeast cell wall materials are the most tested. Silicates are the main group of clays that are studied extensively in terms of Aflatoxin binding. These include tectosilicates (zeolites), 1:1 phyllosilicates (kaolinite), 2:1 phyllosilicates (smectites, vermiculites, chlorites, micas) and sepiolite. All silicates, however, are not the same in terms of their ability to bind Aflatoxin and among the above, smectites have shown greater binding efficacy against Aflatoxin. The ability of smectite clays to bind mycotoxins depends on pH in the gut, molecular arrangements, and its geographic region of origin. Smectite clays possess high Aflatoxin adsorption capacity due to its high surface area, ion exchange capacity, and ability to swell in the presence of water, and the efficacy has been proven in vivo in broiler chickens. The leading hypothesis on the bonding mechanism between adsorbed aflatoxins and smectites is the electron donor–acceptor (EDA) model. Other models such as selective chemisorption, H-bonding, and bonding through furan rings were proposed. The supplementation of smectite clay in feed to aflatoxin challenged broilers considerably reduced the magnitude of toxic effects of aflatoxin and improved growth and immune response. Hence, smectite clay could be successively used in feed to ameliorate the toxic effects of aflatoxins in broiler chickens.

Aflatoxin B1 (AFB1), deoxynivalenol (DON) and ochratoxin A (OTA) are ones of the most common and dangerous mycotoxins. AFB1, produced mainly by Aspergillus, is one of the most poisonous toxins, which is classified as Group I carcinogen by the World Health Organization due to its hepatoxicity, immunotoxicity, mutagenicity, genotoxicity, and carcinogenicity on variety of animals. DON, produced by many Fusarium molds, contamination in feeds induces

anorexia, emesis, and damage to intestinal barrier and immune function in animals through suppressing the synthesis of nucleic and proteins . OTA, a toxic metabolite from Aspergillus and Penicillium molds, possesses hepatoxic, nephrotoxic, neurotoxic, immunotoxic, and teratogenic effects on liver and kidney. Long-term epidemiological investigations have shown that most of the global feed is exposed to more than one mycotoxin, and mycotoxin contamination of food and animal feed is a worldwide problem. Meanwhile, when three mycotoxins co-existed in the poultry feeds, their interaction have been further associated with significant alterations in the productivity and profitability of animals. Therefore, development of remediation strategies to prevent or mitigate the mycotoxicosis is imperative.

Trouw Nutrition's TOXO® range offers a suite of mycotoxin binders designed to mitigate the negative effects of mycotoxin contamination in animal feed. These products are formulated to support animal health and performance by reducing the bioavailability of harmful mycotoxins. These products are part of Trouw Nutrition's comprehensive approach to mycotoxin risk management, aiming to ensure feed safety and optimize animal health and performance.

TOXO®-MX: Precision for Aflatoxins

TOXO®-MX is a specialized binder formulated to combat aflatoxins, particularly Aflatoxin B1, which can adversely affect dairy cows and other livestock. By incorporating purified smectite clays, TOXO®-MX effectively reduces the bioavailability of aflatoxins in the gastrointestinal tract. This reduction leads to a significant decrease in the excretion of Aflatoxin M1 in milk, ensuring compliance with regulatory standards and safeguarding consumer health. Additionally, TOXO®-MX enhances feed efficiency, as evidenced by improved milk production per kilogram of dry matter ingested in dairy cows.

TOXO®-XL: Comprehensive Protection Against Fusarium Mycotoxins

TOXO®-XL is an advanced binder designed to address the challenges posed by Fusarium-related mycotoxins, such as trichothecenes and fumonisins. This product combines smectite clays with specifically selected glucose biopolymers and purified β-glucans, which work synergistically to reinforce intestinal barrier function and modulate the immune response. The result is a comprehensive solution that not only binds and eliminates mycotoxins but also mitigates performance impairments caused by their exposure.

TOXO®: Broad-Spectrum Mycotoxin Binder

TOXO® serves as a versatile, broad-spectrum mycotoxin binder suitable for various animal species. It utilizes smectite clays to effectively reduce the bioavailability of a wide range of mycotoxins, including aflatoxins, ochratoxins, and zearalenone. By preventing the absorption of these toxins, TOXO® helps maintain animal health and performance, making it an essential component of comprehensive mycotoxin risk management strategies.

Collectively, the TOXO® product range represents a holistic approach to mycotoxin risk management, integrating advanced scientific formulations to protect animal health and ensure the safety of the food chain.