This experiment aimed to investigate the effect of incorporating graded levels (0, 0.2, 0.4, and 0.6%)  of Agrimos^® (Mannan Oligosaccharide and β-glucans as a source of antibiotic growth promoters (AGP) addition to growing chicken diets on growth performance, blood haematological and biochemical parameters throughout the fattening period of broiler chickens.A total number of 192 broiler chicks (Cobb500) were individually weighted and randomly assigned to four equal groups (48 each treatment). Each group is divided into four replicates, with 12 birds in each. Birds given 0.4 and 0.6% Agrimos® powder were substantially (P≤ 0.05) better in terms of body weight at 42 day and body weight gain through 0-21 days and at 42 days of age, as well as feed conversion ratio, than birds fed 0% and 0.2% Agrimos® powder through 0-21 days.The obtained results of the experiment showed that broiler chicken fed with 0.4 and 0.6% feed Agrimos^® powder were substantially (P≤ 0.05) better in terms of final body weight and body weight gain, as well as feed conversion ratio, than birds fed 0% and 0.2% Agrimos^®. Furthermore, the data revealed that birds fed a meal enriched with 0.6% Agrimos^® powder had considerably (P≤ 0.05) higher feed conversion ratio at 42 days. The mean values of red blood cells, hemoglobin, packed cell volume, and white blood cells were within the normal range, and will not negatively impact on the health status of broiler chickens. Furthermore, total protein, globulin, and HDL-cholesterol concentrations in the diet containing 0.4 or 0.6% Agrimos^® enhanced compared with the 0.0 and 0.2% treatments.While the opposite is observed with ALT, AST, glucose, total cholesterol, triglycerides, and low-density lipoprotein concentrationsGenerally, it can be concluded that Agrimos^® level 0.6% an alternative to antibiotic growth promoters in broiler chickens diet at the fattening period had a beneficent effect of productive performance and improved the physiological status and blood parameters.