Single or Combined Effects of Prebiotic and Probiotic on Performance, Immunity Response and Gut Flora of Broiler Chickens

In order to investigate the effects of probiotic, prebiotic and a mixture of these feed additives (at different ratio) on the performance, immunity response and cecal microflora of broiler chickens, in a complete random design, a total of 360 ond-day-old broiler chicks (Cobb 500) were randomly distributed among 6 experimental treatments with four replicates. Experimental treatments (diets) were: 1- a basal diet without any additive, as control (Ctrl) 2- basal diet added with prebiotic (Pre) 3- basal diet added with probiotic (Pro) 4- basal diet added with a mixture of probiotic and prebiotic at ratio of 1:1 (M1), 5- basal diet added with a mixture of probiotic and prebiotic at ratio of 2:1 (M2), 6- basal diet added with a mixture of probiotic and prebiotic at ratio of 1:2 (M3). Probiotic and prebiotic were added to diets in amounts as recommended by producer. During 42 d rearing period, birds were fed starter and grower diets form 1 to 21 and 22 to 42 days of age, respectively. Performance traits were measured weekly. On d 21 and 42, one bird from each replicate pen, was slaughtered and cecal content was collected, under sterile condition, to determine the E. coli and Lactobacillus count. In addition, immunity respose to SRBC was measured at the end of the experiment. Data were subjected to one way analysis of variance, by SAS sotware. The results indicated that in the starter phase, birds fed diets M1 or M3 achieved more gain compared to the control group (P