Effect of probiotic on humoral immunity of broiler chickens vaccinated against Gumboro disease under experimental aflatoxicosis

The aim of this study was to investigate the effects of supplementing broiler diets with probiotic live yeast, Saccharomyces cerevisiae, (SC) to alleviate the deleterious effect of Aflatoxin B1 on the immunity of broiler chickens after Gumboro disease or Infectious Bursal Disease (IBD) vaccination. A total number of 120 unsexed Hubbard broiler chicks were used in this study. The chicks were randomly divided according to diet supplementation into four groups (30 chicks for each) from 1 day old to 6 weeks of age as follows, G1: Basal diet (control), G2: basal diet + SC 2g/kg, G3: basal diet + AFB1100µg/kg, G4: basal diet + AFB1100 µg/kg + SC 2g/kg. All groups were vaccinated with IBD vaccine at age of 14 and 28 days old. Blood samples were collected to test the immune response by ELISA test at 20 and 35 days old. The addition of SC to the broiler diet G2 revealed significant enhancement of the immune status. While the results of G3 showed that AFB1 at 100 ppb broiler diet caused significant (P