Selected herbal feed additives showing protective effects against ochratoxin A toxicosis in broiler chicks

The protective effects of herbal feed additives Silybum marianum, Withania somnifera and Centella asiatica against the toxic effects of ochratoxin A (OTA) were studied in 70 broiler chicks aged from 11 to 42 days. OTA was given with the feed at levels 5 mg/kg, whereas S. marianum, W. somnifera and C. asiatica were given at levels of 1,100, 4,000 and 4,600 mg/kg, respectively. All chicks were immunised at the age of 14 days against Newcastle disease. A protective effect of all studied herbal additives against the immunosuppressive effect of OTA and associated biochemical or pathomorphological changes was seen. The intensity of macroscopical and histopathological changes, the deviations in relative organs' weight or body weight, the biochemical changes and the decrease of antibody titer were strongest in the OTA-exposed chicks without herbal supplementation; followed by chicks treated additionally with C. asiatica, whereas the same changes were significantly slighter or not seen in chicks additionally treated with the herbal additives W. somnifera or S. marianum. The slight increase in the serum levels of uric acid and the enzyme activity of aspartate transaminase and alanine transaminase also supported the protective effects of both herbs on the kidneys and/or liver. The strong immunosuppressive effect of OTA on humoral immune response against Newcastle disease was completely prevented in the chicks taking the herbal additives W. somnifera or S. marianum, which was supported by the higher relative weight of immunocompetent (lymphoid) organs in the same chicks. A hepatoprotective effect was found in OTA-exposed chicks treated additionally with W. somnifera and S. marianum, whereas a nephroprotective effect was only found in the chicks additionally treated with S. marianum as observed from the biochemical and pathomorphological findings. The same herbs could be used as a practical approach for safely utilising of OTA-contaminated feed.