The present research trial was carried out to explore the effects of supplementation of gum arabic (GA) and Bacillus subtilis (BS) alone and in synbiotic form on overall growth performance, visceral and lymphoid organs weights along with intestinal histomorphology and selected pathogenic bacteria in broiler chickens. Day -old 200 Ross male chicks were allotted to five groups each subdivided in four replicates with ten birds per replicate. Similarly, five different types of feed i.e., diet A as control while B, C, D and E having 1.5% GA, 30mg/kg BS, 1.5% GA+30mg BS and 0.75% GA+15mg/Kg BS respectively, were offered during 42 days of experimental trial. Statistical analysis was performed by SPSS following CRD design and data was expressed as means along with SEM after performing Tukey's test. Results indicated significantly high feed intake, body weight gain, improved (P<0.05) FCR, livability and EPEF in group D followed by C, B and E. Same pattern of improved weight of heart, liver, gizzard, pancreas, bursa, spleen and thymus was recorded for the groups studied. Significantly higher (P<0.05) VH, lower (P<0.05) CD and higher (P<0.05) VH:CD in duodenum, jejunum and ileum were recorded in synbiotic group D followed by C, E and B. Similarly, supplementation of synbiotic in group D and Bacillus subtilis group C resulted in complete eradication of E. coli, Salmonella and C. perfringens from ileum, caecum and colon of experimental broiler chickens. It was concluded from the present findings that although prebiotic and probiotic can significantly improve the overall performance alone, the best results can be obtained from their combine synbiotic form.
