Mycotoxicosis are a common problem in livestock, where a group of six major mycotoxins represents a high risk for animal health and production profits. Mycotoxin binders (MTB) can reduce the mycotoxin burden in the gastrointestinal tract of the animal. Mycotoxin binders are classified in inorganic, as clays and activated carbon (AC), and organic, as yeast cell wall (YCW) and micro-ionized fibers. The adsorption of mycotoxins into MTB is due to: 1) chemical interactions where the cation exchange capacity involves different types of bounds like ion-dipole, Van der Walls forces, or hydrogen bonds; and 2) to physical characteristics of MTB like pore size, or mycotoxin structure and shape. The adsorption capacity of MTB is determined using different in vitro tests that mimic the gastrointestinal tract of the animals. A literature search was conducted to identify in vitro research where the efficacy of adsorption of MTB was determined. The search was based on 8 MTB [AC, bentonite, clinoptilolite, hydrated sodium calcium aluminosilicate (HSCAS), montmorillonite (MMT), sepiolite, YCW and zeolite] and 6 mycotoxins [aflatoxin (AF), deoxynivalenol (DON), fumonisin (FUM), ochratoxin (OTA), T-2 toxin and zearalenone (ZEA)]. Sixty-eight papers with 1842 data were selected and analyzed with the PROC MIXED of SAS. The response variable was the percentage mycotoxins adsorption by MTB, and the model included the fixed effects of MTB, mycotoxins, incubation media, pH and their interactions, and the random effect of the study. Differences were considered significant when P < 0.05 and with tendency when 0.05 < P < 0.10. The mycotoxins adsorption capacity was 83% ± 1.0 for AC, 76% ± 3.1 for MMT, 62% ± 1.0 for bentonite, 55% ± 1.9 for HSCAS, 52% ± 9.1 for sepiolite, 52% ± 4.3 for clinoptilolite and 44% ± 0.4 for YCW. For mycotoxins, the adsorption of AF was 76% ± 0.6, for FUM was 50% ± 1.8, for OTA was 42% ± 1.0, for ZEA was 48% ± 1.1, for DON was 35% ± 1.6, and for T-2 was 27% ± 2.8. The pH affected the adsorption capacity of YCW with higher adsorption at low pH, and the adsorption of OTA and ZEA, where OTA adsorption tended to be lower at intermediate pH, and adsorption of ZEA tended to be higher at the two-steps pH. The potential adsorption of some essential nutrients, including amino acids and vitamins, should also be considered. Results should be used as a guide in the selection of the appropriate mycotoxin binder based on the predominant mycotoxin in feeds.
Keywords: efficacy; interaction; mycotoxin; mycotoxin binder; review.
Animal feeds are highly susceptible to mycotoxin contamination during harvest, storage, and processing. Mycotoxin binders represent an effective strategy to prevent mycotoxicosis in animals when supplemented into the diet. The efficacy of adsorption depends on the type of binder (inorganic or organic) and the physico-chemical properties of binders and mycotoxins. Data reviewed from the literature indicates that activated carbon has the highest adsorption capacity among different binders, and aflatoxins is the most adsorbed mycotoxin. However, the unspecific nature of the binding process results in some essential nutrients being also adsorbed.
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