Deoxynivalenol as a contaminant of broiler feed: Intestinal development, absorptive functionality, and metabolism of the mycotoxin

Abstract

Deoxynivalenol (DON) has been recently documented to deteriorate intestinal morphology in chickens at dietary doses that are regarded as safe for this species. The present trial was conducted to explore the significance of these morphological changes in relation to intestinal absorptive functionality and DON metabolism. Ross broilers at 7 d of age were fed either a basal diet (0.265 ± 0.048 mg of DON/kg; 0.013 ± 0.001 mg of zearalenone/kg), a low DON diet (1.68 mg of DON/kg; 0.145 ± 0.007 mg of zearalenone/kg), or a high DON diet (12.209 ± 1.149 mg of DON/kg; 1.094 ± 0.244 mg of zearalenone/kg). The DON diets (to variable degrees) progressively decreased the relative density (weight:length) of the small intestine with increasing exposure length, which could be correlated with a decrease in villus height in the small intestine. Short circuit current of the jejunal epithelium, reflecting transport function of the epithelium per unit area, was reduced (P = 0.001) in the birds fed the high DON diet. The increasing dietary level of DON linearly (P = 0.035) increased the length of the jejunum in wk 4 of exposure, resulting in conservation of macronutrient retention. Upon challenging the birds with a fixed amount of DON after wk 5 of exposure, higher (P ≤ 0.033) amounts of DON and the detoxification metabolite (de-epoxy-DON) were found at 5 h postchallenge in the guts of birds raised on the DON diets. The increasing level of previous exposure to DON linearly (P = 0.040) decreased the plasma level of DON in the birds at 1 h postchallenge. The amounts of zearalenone and its analogs in the gut and plasma also followed a trend similar to that for DON. These data suggest that intestines in chickens may adapt to a chronic DON challenge by morphological and functional modifications. The birds having previous exposure to Fusarium mycotoxins showed moderate detoxification coupled with reduced transfer of the mycotoxins to systemic circulation. Some metabolites of zearalenone found in this study were previously unknown for chickens.

Multiannual mycotoxin survey in feed materials and feedingstuffs

“…Even though the inconsistency with EU Commission guidance values took place in case of 24 samples only, it should be taken into account, that the values are set for single compounds. Moreover, possible productivity and animal health problems connected with mycotoxins present in feed at levels lower than those set by the European Commission have been pointed out before (Rafai et al, 2000;Obremski et al, 2008;Yunus et al, 2012;Grenier and Applegate, 2013). With a view to the fact, that 60% of the complete feed samples as well as 70% of the maize silage samples delivered by veterinary doctors and farmers were examined following some breeding problems, and that other factors' influence had been eliminated, it may be assumed, that the problems could have been associated with the mycotoxins, even though their levels were below the guidance values given by the EU.…”

Invited review: Diagnosis of zearalenone (ZEN) exposure of farm animals and transfer of its residues into edible tissues (carry over)

“…As at the highest ZEN exposure all residue excretions could be explained by ZEN, a-ZEL and b-ZEL (free plus glucuronide forms), it seemed that other RALs are only of minor importance in broilers. The regression coefficients of the linear regression of ZEN exposure on the quantitative excretion of RALs would suggest that 76, 22 and 4% are decreased rapidly by 49e83%, 8e46% and 47e86%, respectively, in the time span between 1 and 5 h after crop administration of the ZEN bolus (Yunus et al, 2012). Moreover, the initial blood concentrations of ZEN seemed to be dependent on the preconditioning of the broilers as birds previously fed a Fusarium toxin-contaminated diet obviously absorbed ZEN less efficiently.…”

Deoxynivalenol as a contaminant of broiler feed: Effects on bird performance and response to common vaccines

“…However, these changes in the adjusted weights of the liver and spleen were only temporary. Both the low and high DON diets affected (P < 0.05) the relative weights and the lengths of various segments of small intestine; these data are presented elsewhere (Yunus et al, 2012).…”