Effects of maize naturally contaminated with deoxynivalenol and of dietary anti-oxidants on oxidative stress in fattening pigs

Abstract. A study was undertaken to determine whether dietary antioxidants (AO) could limit oxidative stress and alteration of vaccine immune response resulting from exposure to deoxynivalenol (DON). 160 growing-finishing pigs received for 91 days (d) feeds containing a naturally DON contaminated (1.90 mg/kg) maize or control, and enriched (AO+) or not (AO-) with antioxidants (100 IU Vitamin E; 0.19 mg Se sodium-selenite and 0.20 mg Alkosel® selenium-yeast; 500 mg Fermaid SSR® rich in glutathione-peroxidase; 15 mg Melofeed® rich in superoxide-dismutase). DON concentration in feeds was calculated at 1.49 mg/kg. Pigs were vaccinated on d9 against PCV2 (Ingelvac CircoFLEX®). 48 animals were sampled for ELISA determination of serum IgA, IgG and anti-PCV2 antibody levels at d34 and d75, blood peroxide spectrophotometry and half-haemolyse measurement of whole blood and red blood cells (RBC) exposed to a controlled free-radical attack at d40 and d75. Statistical analysis used a mixed model including fixed effects of DON, AO, sex, sampling-day and interactions, with animal as subject of repeated measurements. Peroxides in blood were unexpectedly lowered by DON at d40 (P=0.15), whereas it was increased by DON at d75 (P=0.35; DON×day interaction, P=0.01). Anti-haemolyse capacity was increased by antioxidant supplementation at d40 for blood (P<0.001) and at d75 for RBC (P<0.001), but was not influenced by DON. Anti-PCV2 antibodies of DON AO- pigs were lower than for other pigs at d34, but were higher at d75 (Expo×AO×day interaction; P=0.04). Serum IgA and IgG concentrations increased between d34 and d75 (P<0.001), and IgG increase tended to be higher for DON pigs than for control pigs (P=0.08). For control pigs, antioxidants tended to decrease IgA levels at d34 (P=0.11), while DON AO+ pigs had numerically higher IgA levels than DON AO- pigs (Expo×AO interaction; P<0.10). In conclusion, DON and antioxidants may have cross-effects on oxidative stress and immune status.

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