H. R. Taheri - Department of Animal Science, Faculty of Agriculture, University of Zanjan, Zanjan, Iran.
M. Kokabi Moghadam - Department of Animal Science, Faculty of Agriculture, University of Zanjan, Zanjan, Iran.
M. Kakebaveh - Department of Animal Science, Faculty of Agriculture, University of Zanjan, Zanjan, Iran.
T. Harakinezhad - Department of Animal Science, Faculty of Agriculture, University of Zanjan, Zanjan, Iran.

The objective of this research was to investigate the efficacy of dietary inclusion of probiotics Primalac® and Bactocell® and prebiotic Fermacto® on broiler’s performance and immune response, individually or in combination. A total of 540 one-d-old male Ross 308 broiler chicks were allocated into 6 experimental treatments with 6 replicates of 15 birds per replicate from 1 to 42 d of age. The birds received a basal diet (control) or the basal diet supplemented with probiotic Primalac® (PP), probiotic Bactocell® (PB), prebiotic Fermacto® (Pre), probiotic Bactocell® + prebiotic Fermacto® (PBPre) or probiotic Primalac® + prebiotic Fermacto® (PPPre). Performance parameters were measured from 1-42 d of age. A suspension of sheep red blood cells (SRBCs) was injected into the breast of 3 birds from each replicate on d 22, and the antibody titer was measured on d 30. At d 22, blood samples (from 3 birds per replicate) were taken for measuring the white blood cells (WBCs), heterophil (HE) percent, lymphocyte (LY) percent, and the ratio of heterophil:lymphocyte (H/L). No significant differences were found between the control and supplemented groups in average daily gain (ADG), average daily feed intake (ADFI), antibody titer against SRBCs, HE percent, LY percent and H/L. Addition of PBPre or PPPre to the diet improved FCR by 8.5 and 12.7%, respectively, compared with the control group, and PBPre supplementation resulted in an increase in WBCs compared to other treatment groups.

broiler, immune response, performance, prebiotic, probiotic, synbiotic