Selection of Mycotoxin binder

Mycotoxins are small and stable metabolites produced by fungi which can contaminate a wide variety of crops. The contamination of food and feed by mycotoxins is a global safety issue due to their adverse effects on human and animal health..

Tools to decrease mycotoxin bioavailability

A wide range of products is available in the market to counteract the negative effects of mycotoxins in the livestock industry. These products range from single mycotoxin adsorbing agents to more complete and elaborate products. One common point between these products is, at least, their capacity to ‘adsorb’ or ‘bind’ mycotoxins, in order to decrease mycotoxin bioavailability within the animals and to reduce their absorption in the systemic circulation.

Objective and reliable criteria to select products

Over the past few years, there has been an increasing knowledge on mycotoxins pathogenic potential (co-contamination, impact on animal health and productivity, interaction in gut). In the meantime, the abundance of available products on the market, with variable physicochemical and biological properties, brings complexity and sometimes confusion for the selection of products. It appeared necessary to find objective and reliable criteria to select products with the best potential to limit mycotoxins effects on animals. After years of research on the subject, Mix science highlighted five key criteria to evaluate the efficacy of the products: 1. Adsorptioncapacitytowardsawiderange ofmycotoxins,invariouspHconditions 2. Adsorption capacity towards other toxins 3. Specificity 4. Velocity 5. Strict control plan of products. These criteria are mainly based on in vitro analysis, which are powerful tools to screen products before in vivo studies.

Adsorption capacity toward a mycotoxin

Toxin binding capacities can differ significantly between one product to another, due to the complex and diverse structure of adsorbing materials and the variety between the different mycotoxins. Aflatoxins have received much attention due to their frequent occurrence in agricultural commodities and health issues in a wide variety of animals. However, the occurrence and negative impact of various other mycotoxins and the reality of co-contamination strengthen the consideration that a product should bind a wide number of mycotoxins. Moreover, the conditions of the action site of the product are important to consider. For example, pH values vary greatly along the digestive tract of animals, from acidic conditions (pH 3 or 4) to more basics ones (pH 6 or 7). Binding capacities of products may be influenced by pH changes, leading to the risk that the toxins are adsorbed at one part but released at another part of the digestive tract. The percentage binding of AF, OA and T2 by binder, either singly or in combination differences were noted in binding of different mycotoxins among the different dietary treatments. In diets containing the individual toxins, a significantly higher binding of AF was recorded when compared with that of T-2 and OA. At pH 4.5, the highest percentage binding of mycotoxins was noticed for AF (90.68%), whereas the lowest binding ability was recorded for OA (61.73%). Results also indicate that at

Dr. Yogesh Paharia

B.V.Sc , M.V.Sc ( Nutrition )

the pH of 4.5 in the combined treatments, the highest binding ability was noticed for AF+OA (62.30%) when compared with AF+OA+T-2 (5.33%). At pH 6.5, highest binding percentage of mycotoxins was recorded for AF (94.71%); while on the contrary, treatment with OA provided the lowest binding percentage of 63.13%. In diets containing the combined treatments with pH of 6.5, the binding ability for AF+OA (65.80%) was much higher when compared to that of AF+OA+T-2 (6.26%)

Adsorption capacity toward other toxins

Some products have also demonstrated the capacity to bind more than toxins produced by fungi, which may help the animal to fight against various stress occurred in their environment. Bacterial toxins, which can be involved in various diseases such as colibacillosis, necrotic enteritis in poultry or neonatal diarrhoea in piglets, may also be bound by some products. This is interesting in a context of bacterial resistance because the targets are the metabolites of the bacteria and not the bacteria themselves. It is also recommended to test these compounds (endo and exotoxins), in order to provide maximum protection to animals. The diatomaceous earth is a powerful natural adsorbent and it might adsorb the toxins effectively through their polar ends of toxin (Gowda et al., 2008)