Management of Mycotoxins upon Detection in Raw Materials
Mycotoxins are naturally produced substances by fungi that contaminate raw materials (cereals and byproducts) used in food production and manufacturing. The fungi responsible for producing these mycotoxins are:
- Aspergillus, which produces aflatoxin, classified as B1, B2, G1, G2. It can develop in warm climates, and contamination occurs during pre-harvest and storage of raw materials.
- Aspergillus and Penicillium, which produce ochratoxin (OCH). This develops in tropical climates with high humidity. Contamination happens during the storage of raw materials.
- Fusarium, which produces mycotoxins posing a high risk to pig health:
Type A Trichothecenes (or T2) and HT2 can originate in cool climates with humidity above 70%, and contamination occurs during pre-harvest.
Type B Trichothecenes, including:
- Deoxynivalenol (DON), 15-ADON, 3-ADON, and Zearalenone (ZEA), develop in cool climates or fluctuating temperatures with high humidity.
Contamination occurs during pre-harvest.
- Fumonisins (FUM) classified as B1, B2, B3, develop in warm climates with low precipitation during the maize growth stage when the silk emerges from the cob.
This stage makes the plant more susceptible to Fusarium infection. Contamination occurs during pre-harvest.
Since mycotoxins are unevenly distributed or found in batches of ingredients, it’s crucial to apply good sampling methods throughout the year. Frequent sampling is critical for mycotoxin management and overall animal health.
Establishing Ingredient Rejection Levels
It’s essential to define rejection levels for ingredients entering food plants such as maize. FDA recommended risk levels for DON are 5ppm for grains and byproducts, with a suggestion not to use more than 20% of these ingredients in the diet.
Segregation and Dilution
If highly contaminated corn is accepted, it’s recommended to feed it to adult animals like growing and finishing pigs.
Recently weaned pigs are more susceptible to the negative effects of mycotoxins. Diluting feed rations with alternative ingredients can reduce mycotoxin concentrations. For example, bakery meal, an energy-rich byproduct, can be included up to 500 pounds per ton to reduce a portion of highly contaminated maize.
Use of Mycotoxin Binders
To safeguard pig health and performance, detoxifying and binding agents can be used. Several products on the market target specific mycotoxins or have a broad spectrum. For example:
- Bentonite clay, a naturally occurring clay from volcanic ash, known for its adsorbent properties and effective ability to bind mycotoxins in the digestive tract.
- Sodium and calcium hydrated aluminosilicate (HSCAS), a synthetic material formulated specifically to bind a broad spectrum of mycotoxins in the digestive tract, including aflatoxins, ochratoxins, and trichothecenes.
- Enzymes like fumarase that convert fumonisins into less toxic substances within the digestive tract.
- Sodium metabisulfite, a chemical compound used to detoxify DON. However, it should be noted that this compound destroys thiamine (vitamin B1) over time, which can cause a deficiency.
The strategy to follow may include additionally supplementing thiamine in the diets of sows and newly weaned piglets, as these are the two production phases where this vitamin is typically supplemented.
Knowing the type of mycotoxin and the contamination level in ingredients is important for decision-making. Strict protocols for rejecting incoming ingredients to the feed mill save time and money while reducing the negative risk on animal performance due to mycotoxins.
After implementing a mycotoxin management program, it’s essential to observe clinical signs and animal performance to determine if other approaches are necessary.
Research on mycotoxin toxicity, tolerance levels, and binder technology has been extensively studied and is up to date, making it crucial to stay updated with the newest technology for mycotoxin analysis.
You may also like to read: “Mycotoxin levels in soybean meals”