Immunotoxicity of ochratoxin A and role of trichosporon mycotoxinivorans on the humoral response to infectious viral disease vaccines in broilers

The present study was planned to evaluate the effects of dietary ochratoxin a (ota) in the presence and absence of a toxin deactivator on the organ weights,humoral immune response of broiler birds vaccinated against newcastle disease (nd),hydropericardium syndrome (hps) and infectious bursal disease (ibd). this was investigated in a 42 day completely randomized trial consisting of 9 dietary treatments with 1 negative control group. birds were vaccinated against nd at 5 and 21,ibd at 11 and 24 and hps at 15 days of age. the serum samples were collected at 14,28 and 42 day of age were then assayed using haemagglutination inhibition (hi) for nd and indirect haemagglutination inhibition test (iha) for hps and ibd,respectively. the exposure of broiler birds to two levels (500 and 1000ppb) of ota reduced their humoral immune response against nd,hps and ibd vaccines significantly (p<0.05) in dose dependent manner. at day 14,only titers for nd were significantly elevated in group supplemented with 2kg/ton of toxin deactivator. while on day 28 and 42 of age the supplementation with 2kg/ton toxin deactivator significantly (p<0.05) ameliorated the deleterious effects of ota on humoral immune response of birds against nd,hps and ibd as reflected by increase in the respective antibody titers. as far as the organ weights are concerned,the results of present study indicated a close interaction of ota with infectious diseases which cause significant (p<0.05) suppression of humoral immune system,even if the birds adequately vaccinated and predisposed to nd,hps and ibd on challenge. copyright 2015 zoological society of pakistan.