Immunopathological effects of ochratoxin A and T-2 toxin combination on broilers

The purpose of this study was to investigate the immunopathological effects of combinations of ochratoxin A (OTA) and T-2 toxin on broilers. Four hundred eighty 1-d-old broilers were randomly assigned to 4 groups, each group consisting of 4 duplicates each with 30 broilers. The 4 groups were fed the following diets for 4 wk: group 1=basal diet (control, mycotoxin-free); group 2=basal diet+2,000 mg/kg of Mycofix Plus; group 3=basal diet+0.25 mg/kg of OTA and 0.5 mg/kg of T-2; and group 4=basal diet+0.25 mg/kg of OTA and 0.5 mg/kg of T-2+2,000 mg/kg of Mycofix Plus. The feeding of OTA-T-2 toxin diets reduced (P<0.05) the level of anti-Newcastle disease virus antibody titers by 10.4%. When broilers were administered lipopolysaccharide, the results of real-time PCR showed that broilers fed OTA-T-2 toxin reduced the cytokine mRNA expression levels of interleukin-2 and interferon-gamma to some extent but not significantly (P>0.05). The concentrations of interleukin-2 and interferon-gamma in serum were significantly decreased (P<0.05) by OTA-T-2 toxin combination. Histopathological studies demonstrated that OTA-T-2 toxin combination caused abnormalities in the thymus, bursa of Fabricius, spleen, and liver. Ochratoxin A-T-2 toxicity could be counteracted by Mycofix Plus partially but not significantly (P>0.05). The concentrations of OTA and T-2 toxin used in this study are under the maximum tolerated levels recommended by Canadian Food Inspection Agency. Our study clearly put the standard and detoxification method for these toxins into question. We suggest that it may be time to reduce the maximum allowable limits of OTA and T-2 mycotoxins in feeds to improve animal health and the safety of the food chain.