Effet chez le porcelet d'une exposition à un régime co-contaminé en ...

INTRODUCTIONinvolved in the binding process of mycotoxins and that the structural organisation of β-D-glucansmodulates the binding strength (Jouany, 2007).Beneficial effects were verified in counteracting aflatoxins in several animal species with live yeastculture preparations based on a Saccharomyces cerevisiae strain. Yeast glucomannan showed bindingability for various mycotoxins in vitro and/or in vivo (Stanley, 2004; Meissonnier et al., 2009,Pettersson, 2004). A binding capacity trial for T-2 toxin concluded that supplementation of modifiedglucomannan at 1 kg/t of feed is beneficial in preventing the absorption of T-2 toxin. Up to 35% T-2binding capacity was observed in the gastro-intestinal tract of broilers (Reddy et al., 2003). Contrary,yeast glucomannan investigated by Cinar et al. (2008) was not sufficient to prevent or ameliorate theoxidative damage caused by aflatoxins in broilers.An experiment, conducted to determine the effect of non-digestible yeast oligosaccharides (NYO)on milk aflatoxin concentrations in lactating Holstein cows consuming aflatoxins, concluded thatthere were no significant (P>0.25) changes in AFM 1 concentrations in response to NYO (Hopkins etal., 2008). These results are in accordance with a study of Stroud et al. (2006).Several studies have been carried out in order to assess the efficacy of yeast glucomannansagainst multi-mycotoxin contaminations. In vitro mycotoxin binding capacity by a commercialesterified glucomannan on aflatoxins, ochratoxin A and T-2 toxin was performed by Raju andDevegowda (2002). Results showed that the binding values of the mycotoxins decreased significantlywhen they were present in combination. The cumulative binding of the mycotoxins by the productwas dependent on the mycotoxin present.Esterified glucomannan (0.05-0.1%) in chickens reduced or eliminated many of the combinedtoxic effects (on performance, serum biochemistry and haematology) of AF, OTA and T-2 toxin (Rajuand Devegowda, 2000; Aravind et al., 2003). Using 0.5% of the same product also alleviated growthdepression in broilers associated with naturally contaminated diets containing aflatoxins, ochratoxinA, zearalenone and T-2 toxin (Bursian et al., 2006). According to a pig trial carried out byMeissonnier et al. (2009) glucomannan dietary supplementation demonstrated protective effectsagainst AFB 1 and T-2 toxin immunotoxicity. According to Bursian et al. (2004), however, a glucanpolymer product (0.2%) did not alleviate the toxic effects on mink consuming diets contaminatedwith fumonisins B 1 , ochratoxin A, moniliformin and zearalenone.e) Adsorption by bacteriaUntil now, most of the research regarding the use of bacteria as adsorbents has been focused onin vitro tests, and only a few studies have been performed in vivo. Trials with some dairy strains oflactic acid bacteria and bifidobacteria showed that they are able to effectively bind aflatoxins. Cell81