Mycotoxin occurrence is a significant worry for both the feed and food industries. Climate change exacerbates this problem, increasing safety risks and causing substantial economic losses. To address these concerns, Think Grain Think Feed interviewed Dr Regiane R. Santos, a senior researcher and innovation coordinator at Schothorst Feed Research (SFR). During the e-interview, she discussed recent advancements, research findings, and potential solutions. Below are the excerpts.
Dr Regiane R. Santos
Dr Santos is currently working at SFR as a senior researcher and innovation coordinator. She holds a PhD in Animal Reproduction (Brazil) and another PhD in Biology of Reproductive Cells (The Netherlands). In 2008, she started a post-hoc study at Utrecht University (the Netherlands) focused on the impact of mycotoxins on farm animals. Since 2015, she has been responsible for mycotoxin studies in poultry, swine, and cattle using naturally contaminated feedstuffs. Dr Santos published more than 150 scientific papers, and those have about 3200 citations. She is a reviewer and editor of several peer-reviewed scientific periodicals in mycotoxin research and animal science.
Could you please provide information about the geographical occurrence
pattern of mycotoxins? Which feed ingredients are most susceptible to mycotoxin contamination?
Mycotoxins are secondary metabolites produced by filamentous fungi, which are found worldwide and in several feed ingredients, e.g., corn, wheat, oats, soy beans, barley, rye, etc. The occurrence of mycotoxins will depend on the climate conditions of each region around the globe. Countries with more temperate climate conditions and rainy weather often detect Fusarium mycotoxin deoxynivalenol, while dry areas with high temperatures frequently observe aflatoxins and fumonisins. Besides the feedstuffs, by-products such as bran and hulls can be highly contaminated because a high level of mycotoxins are found in the outer parts of grains and cereals. Therefore, although dehulling aims to decrease mycotoxin contamination, the hulls are commonly used as feed ingredients. The same is true for corn and wheat DDGS. Considering animal diets are produced with several feedstuffs, a free-mycotoxin diet is quite an impossible mission.
Mycotoxin has been a global concern for a long time. With the advancement in research and diagnostic solutions, how have we been able to manage it better now?
The advances in the detection of mycotoxins allowed us to understand that besides the big six mycotoxins, i.e., aflatoxin B1 (AFB1), deoxynivalenol (DON), zearalenone (ZEN), fumonisinis (FUM), T-2/HT-2 toxin, and ochratoxin A (OTA), there are often many other mycotoxins present in diets. For example, corn contaminated with DON will often be contaminated with DON-3-G, which may be hydrolyzed in the intestine, increasing the animal’s exposure to DON. With this knowledge, it is possible to manage dietary levels of DON by calculating a percentage of possible DON-3-G levels. Furthermore, animal diets frequently contain the often neglected so-called emerging mycotoxins, particularly beauvericin and enniatins. Although their levels are usually low, some outbreaks are observed, and there is a lack of information about their toxicity. Diagnostic solutions also support mycotoxin rapid analysis when the feedstuffs arrive in the feed mills and the decision about their use to produce feed for different animal species.
Mycotoxin contamination starts at the field level and can continue to the feed mill. What precautionary measures can be taken to prevent this in the value chain?
During the Mycotoxin Masterclass, we will make a journal about mycotoxin production and its presence in the animal diet, as well as the possible measures to minimise animal exposure. In brief, measures can be taken before fungal infection through adequate agronomic practices, either in conventional or organic farming. The methods include weather forecasting, the selection of plant varieties, crop rotation, tillage, and proper silage preparation and storage. When the feedstuffs are in the feed mill, sometimes a mechanical cleaning can reduce the levels of mycotoxins, and, during diet preparation, feed additives may decrease the animal dietary exposure. We will present and discuss all these options during the webinars and seminar in September.
Can you share information about new mycotoxins and their risk management strategies?
The absence of sensitive analytical methodologies and lack of multi-mycotoxin analysis prevented the measurement of numerous “new mycotoxins” that were consistently present in the feed. Nevertheless, data originating from the 1980s and 1990s has already documented the existence of alternariol, beauvericin, and enniatins in feedstuffs. The lack of sufficient toxicological data impedes the establishment of dietary maximum levels for these mycotoxins. It appears that climate change influences enniatin levels in crops as well.
As an illustration, these mycotoxins were often prevalent in barley, albeit in extremely low concentrations (0.1–0.3 mg/kg). Over the previous three years, we identified instances of barley contamination with enniatins at concentrations varying from 1 to 7 mg/kg. In some cases, none of the major six mycotoxins were present in barley that was highly contaminated with enniatins. The absence of routine analysis for this particular mycotoxin in the feedstuff could result in an erroneous classification of this barley as “clean.”.
How does the increasing use of unconventional feed ingredients impact mycotoxin occurrence? Which alternative has the lowest risk of contamination?
It depends on the type of unconventional ingredients. In one of the webinars, we will discuss the effects of mycotoxins on edible insects and insect larvae, which are rich sources of nutrients to be added to the diet. Prof. Miklós Mézes will present the most recent findings, risks, and recommendations considering mycotoxin contamination. Fiber-rich diets are known for their positive effects on intestinal health, immune function, and microbiota modulation. However, many fiber sources in animal diets are hulls and bran, which might be highly contaminated with mycotoxins. Therefore, their inclusion level must consider not only the nutritional value but also the risk of mycotoxin exposure. For example, oat hulls are fibers with positive effects but can be highly contaminated with T-2 toxin.
Mycotoxin binders are often recommended for mycotoxin management, but how can we ensure their effectiveness?
There are two types of mycotoxin decontaminants: the binders and the biotransforming agents. Their effectiveness can be determined, for example, in toxicokinetic studies, where it must be shown that the decontaminant will avoid the intestinal absorption of the mycotoxin, either by binding the mycotoxin or by its degradation into a non-toxic metabolite. In practice, the mycotoxin decontamination should be able to improve animal production performance without increasing the costs of diet production.
How can the upcoming Mycotoxin Masterclass benefit feed millers? What topics will be covered, and will they be relevant for tropical countries like India?
More than 20 experts from Asia, Africa, Europe, and North and South America wrote the book. Therefore, the masterclass will provide a very global overview of the mycotoxin challenge. Our main goal is to give the basic knowledge of mycotoxins since their synthesis in the field or during storage, their effects in several animal species (poultry, swine, cattle, fish, pets, and horses), the interactions of mycotoxins with other mycotoxins or animal medication, how to detect them in feed materials and animal fluids and tissues, the methods to prevent and remediate them, and the impact of climate change on the increased exposure to these natural contaminants. In summary, nutritionists, veterinarians, and feed millers will be able to finish the course with a book covering mycotoxins from Field to Feed!
Register here for Masterclass Mycotoxins (schothorst.nl)
