Abstract Introduction: To investigate the comparison effects of Serendipita indica (SI), and lactobacilli spp. probiotic (LP) and autoclaved Serendipita indica (prebiotic) (AS) on performance, biochemical, and, intestinal microbial population parameters. Purpose: The purpose of this investigation is to use the autoclaved Serendipita fungi, with non-autoclaved form and a commercial probiotic (Parsi Lact®) on performance, biochemical, and intestinal microbial population parameters. Materials and methods: The experiment was performed with 240 male, one-day-old chicks (Ross 308) were fed completely randomly in 4 experimental groups and 6 replications and in each replication, 10 chickens were fed with corn and soy-based diets, and experimental groups included: group 1: basal diet (without any feed additives), group 2: basal diet with 6% of SI, group 3: basal diet with 6% of autoclaved SI (AS), group 4: basal diet with 2% of LP. Results: Results showed that the addition of SI and LP caused a significant increased in body weight gain, and the LP group, increased feed intake significantly, and FCR was not significantly different between the control group to other treatments (P<0.05). Conclusion: Finally, the use of the LP group led to the increased humoral immunity titer of ND, and All experimental groups showed fewer coliforms, e.coli, and salmonella spp. compared with the control group(P<0.05). Keywords: Broiler, Lactobacillus, Performance, Serendipita indica.
