Olmix SA
Olmix SA
06/13/2021 | Press release | Distributed by Public on 06/14/2021 05:21
Nutritional stress due to mycotoxin contamination in feed
Mycotoxins are secondary metabolites produced by moulds under stress conditions. They contaminate food and feed commodities, mainly cereal grains like corn, wheat, and soybean, all over the world. Mycotoxins are small and stable molecules, resistant to chemical and thermal treatments, making them hard to remove from the feed during processing. Efforts are made to reduce the development of mycotoxins in the field and during storage, but contamination of raw materials is still common.
Mycotoxins are toxic compounds, thereby posing a risk for human and animal health. Over 400 different mycotoxins are identified, of which the most toxic and common ones in animal feed are trichothecenes (DON, T-2, HT-2), zearalenone (ZEA), fumonisins (FUM), aflatoxins (AF), and ochratoxin A (OTA). Aflatoxins and fumonisins are the most prevalent mycotoxins in Asia. However, due to the global trade of raw materials, animals are exposed to multiple mycotoxins due to poly-contaminated diets.
The effect of mycotoxins on animal health is dose dependent. With high contamination levels, acute mycotoxicosis can occur leading to clinical symptoms. However most important impact of mycotoxins is due to the subacute mycotoxicosis, a chronic exposure to low doses causing stress to vital organs and to the immune system, and impairing production performance. Mycotoxins are considered to be the most immunosuppressive factors coming from feed, thus a predisposing factor for the development of infectious diseases.
Effect of mycotoxins in poultry species
Poultry diets contain high levels of cereals and cereal by-products, making mycotoxin contamination common. Exposure to mycotoxins is causing stress in animals, affecting their health status, production and economic performance. Among all poultry species, ducks are the most sensitive.
In poultry, aflatoxins are of major concern as 80-90% of this toxin is absorbed in the upper part of the gastrointestinal tract (GIT). Aflatoxins interfere with the protein synthesis within the liver. Ducks are sensitive especially to aflatoxin (AFB1). Likewise, a low chronic exposure to aflatoxins negatively affects broiler performance impacting the feed intake, the growth rate, and the feed efficiency. Similarly, aflatoxins are of major concern in breeders as they affect egg production and hatchability (like ZEA).
Fumonisins and DON are less efficiently absorbed by poultry species, but they exert a synergistic effect upon exposure to the gut lumen by altering the gut morphology, thereby decreasing the villi length and decreasing the synthesis and excretion of mucins. Significant increase in translocation of bacteria across the intestinal barrier have been observed in the presence of fumonisins and DON. Also, it has been shown that DON suppresses the antibody response in broilers to Infectious Bronchitis vaccination and in laying hens to Newcastle disease vaccination.
How to overcome mycotoxin stress?
Several techniques have been developed in order to overcome the deteriorating effect on animal health and performance. The most common technique is lowering the bioavailability of mycotoxins. This is done by supplying binding agents to reduce the uptake of mycotoxins or by transforming them into less toxic compounds by bio transforming agents.
Mycotoxin adsorbing agents are non-digestible compounds, which end up in the faeces. The adsorbing agent must be able to bind the mycotoxins, without dissociating along the intestinal tract. The adsorption mechanism is based on electrostatic and hydrophobic interaction between the binder and the toxin, and on the geometry of the toxin (planar/ non-planar) and the nature of the binding agent. The efficacy in which the binder is able to bind the toxins depends on the mycotoxin size, shape, and 3D-conformation. Aflatoxins are planar molecules that can be bound by unmodified clays or yeast cell walls. DON has a too complex structure to be bound by those unmodified binding agents. Fumonisins are too large and too flexible compounds and the binding agent should be modified in order to bind those mycotoxins effectively.
Olmix has developed a range of natural origin solutions for mycotoxin risk management, to efficiently reduce the impact of mycotoxins, including the most difficult ones.
The technology used is based on Olmix expertise in the use of algae for animal health and nutrition, using algal polysaccharides (ulvans) from green algae Ulva sp. to intercalate montmorillonite clay layers to potentiate mycotoxin adsorption as a result from a complex mechanism involving cation exchange capacity (CEC), surface area of montmorillonite, the polyanionic structure of the ulvans, and the microtubular structure formed in the interlayer space. All this allowing ionic and hydrophobic interactions with mycotoxins.
Duck layer case study: efficacy of toxin binder
The efficacy of Olmix's tools has been shown both in vivo and in vitro. Olmix MT.X+ has been shown to be effective towards a wide spectrum of mycotoxins, including DON and fumonisin as shown by a study performed by the Institute of Animal Sciences for Southern Vietnam (IASVN). They compared a low contaminated (LC) and high contaminated (HC) diet and the effect of the use of MT.X+ (inclusion of 0 versus 0.1% MT.X+) in each of these diets on the performance indicators in 19-weeks-old breeder ducks (2x2 factorial). The diets were contaminated with Aflatoxin B1 (AFB1), DON, and fumonisin B1 (FB1).
The higher the mycotoxin contamination was, the higher was the FCR, as a result of DON and FB1 combined effects on the integrity and functionality of the intestine. MT.X+ supplementation mitigates the harmful effect of mycotoxins, showing a significant improvement in FCR in the HC diet (Figure 1).
Duck laying rate decreased as the level of contamination increased (up to -5.3 pt, P<0.01) as can be seen from Figure 2. MT.X+ mitigated the harmful effect of mycotoxin contamination and helped to prevent this decrease (+4.3 pt in average, P=0.1). When used in the low-contaminated diet, MT.X+ helped to reach a higher peak of laying resulting in an increased laying rate (+0.36 pt on the whole period).
Egg hatchability was improved by MT.X+ supplementation in the LC diet, which may be a sign of protection against the negative effects DON and fumonisin on growth hormone. In the HC diet, hatchability dropped drastically in comparison with LC diet, most likely because of the combined effect of AFB1 on the embryonic development and DON and fumonisin on the inhibition of growth hormones. Supplementing the HC diet with MT.X+ significantly helped to prevent this drop on hatchability.
Mycotoxin contamination showed to have a negative effect on breeder duck productivity. Lower laying and hatchability rates are observed. The use of MT.X+ mitigates the adverse effects of mycotoxins on animal performances. In both low and high poly-contaminated feeds and assist in improving zootechnical performances.
Conclusion
All in all, mycotoxins are a major threat to animal performance due to the toxicity they exert, especially through poly-contamination. Managing mycotoxin stress to prevent any impairment in performances entails the implementation of an adequate control plan, evaluating contamination levels and to take measures in terms of feed formulation and toxin binder usage. Olmix has developed a wide range mycotoxin binder to implement a very effective mycotoxin risk management making animals better resistant to contaminated feeds.