The immunosuppressive effect of affatoxin (AF) on the antibody titer level of broiler chicks vaccinated against hydropericardium hepatitis syndrome (HHS) virus was studied . Four groups of chicks were used . The first group was vaccinated with HHS vaccine only; the 2nd group was fed AF contaminated diet and vaccinated with HHS vaccine , the 3rd group fed AF contaminated diet and kept with HHS vacceination ; the 4th group was not treated with AF or HHS vaccination and left as a negative control group .
The results showed that there was a significantly higher antibody titer HHS vaccine in the 1st group compared with the 2nd group . The challenge test with Adenovirus showed 100% protection in chicks of the 1st group compared with 80% in chicks of the second group .