摘要:The present study aimed at evaluating the effect of the probiotic Primalac, prebiotic Biolex-MB, a combination of the two supplements (probiotic plus prebiotic) and one growth promoter antibiotic (Flavomycin) on performance results of broiler chickens. Three hundred day old Ross 308 broilers were equally distributed into 30 floor pens and reared for 42 day. A basal diet was also supplemented with Flavomycin (650 g/ton-1), Primalac (900 g/ton-1), Biolex-MB (2000 g/ton-1) and mixture of Primalac plus Biolex-MB (synbiotic) for starter (1 to 21 days) and grower (22 to 42 days) periods, resulting 5 dietary treatments were prepared including control group. Each dietary treatment was fed ad-libitum to six replicate group of 10 birds at the beginning of rearing period. Birds and feed were weighed weekly. The daily body weight gain and feed efficiency were significantly (P<0.05) more improved by the synbiotic treatments compared with the control broilers. The birds under antibiotic treatment had higher breast and thigh percent as compared to control birds (p<0.05). Also, supplementation of broiler's diet with prebiotic significantly (p<0.05) increased gizzard percent. The results of present study showed that probiotic and prebiotic can be used as non-antibiotic growth promoter feed additives to improve broiler chickens growth indices.