effect of dietary supplementation by synbiotic and different zinc sources on broiler chicken performance, immune system and intestinal morphology

background: use of synbiotic and zinc sources had synergetic effects on broiler chickens performance and immune response improvements. objectives: this experiment was carried out to evaluate the effect of synbiotic and zinc sources on broiler chickens performance, immune response and gut morphology. methods: a total of 780, one-day old male broiler chicks were randomly assigned in factorial methods to 13 different experimental diets with 15 birds per replicate and 4 replicates per experimental diets for 7 weeks. the experimental diets contain unsupplemented basal diet and basal diets supplemented with varying concentrations of symbiotic (1-1.5g /kg of diets) and zinc oxide/bioplex zn (50-150mg/kg of the diets). results: in the unsupplemented basal diet weight gain was lower, feed intake and feed conversion ratio were greater than others (p