Aim: The effect of a specific combination of a 
                              soluble β (1-3) D-Glucan and Propionibacterium 
                              granulosum was investigated on productive 
                              performance, immune response and immune 
                              dysfunction caused by cyclophosphamide (CP) in 
                              broiler chickens. 
               Materials and Methods: 
                              Three hundred and sixty one-day-old broiler chicks 
                              were randomly allocated into four groups for 5 
                              weeks. Betamune® supplementation of 0.25 ml / L 
                              drinking water (presence or absence) for the first 
                              7 days of age and CP (presence or absence) 
                              subcutaneous inoculation with 4 mg / chick for the 
                              first 3 days of life was done. 
               Results: 
                              Treatment of broiler chicks with Betamune® 
                              improved productive performance variables as 
                              compared with the blank control birds, where there 
                              were 10 points less in cumulative feed conversion 
                              ratio and significant increase (P<0.05) in final 
                              body weight, both intestinal length and diameter, 
                              and European production efficiency factor (EPEF). 
                              It also modulated the immune response, where there 
                              was non-significant improve in haemagglutination 
                              inhibition (HI) antibody titers against Newcastle 
                              disease (ND) virus vaccine and significant 
                              increase (P<0.05) in phagocytic % and phagocytic 
                              index. The lesion score after ND challenge reached 
                              only 70 in β (1-3) D-Glucan group as compared with 
                              80 in blank control group. The histomorphological 
                              examination of Betamune® treated chickens at 5 
                              weeks of age revealed lymphoid hyperplasia in 
                              bursal follicles, lymphoid cells of cortical 
                              portion of thymus glands and lymphoid cells in the 
                              white pulps of spleen. CP did affect bird's weight 
                              and suppressed immune system. Treatment CP 
                              suppressed birds with Betamune® significantly 
                              increased (P<0.05) final body weight, dressing 
                              weight %, giblets weight %, intestinal diameter, 
                              improved FCR (28 points less than untreated 
                              group), decreased cumulative mortality and 
                              improved EPEF. Betamune® counter attacked immune 
                              dysfunction caused by CP, where there was 
                              significant increase in HI antibody titer against 
                              ND vaccine, no significant increase in phagocytic 
                              % and phagocytic index and improve in the lesion 
                              score after ND challenge (99 as compared to 133). 
                              Betamune® supplementation reduced microscopic 
                              lesion scores associated with CP immune 
                              dysfunction. 
               Conclusion: It could be 
                              concluded that administration of a specific 
                              combination of soluble β1.3, D-Glucan and 
                              Propionibacterium granulosum (Betamune®) to 
                              broiler chickens improved chicken zootechnical 
                              performance response variables, had a potent 
                              immunomodulatory effect (potentiated immune 
                              response), evoked their immune response and 
                              enhanced their vaccination effectiveness. 
               
                              Keywords: chickens, cyclophospha-mide, 
                              Propionibacterium granulosum, β (1-3) D-Glucan