A total of 180 day-old unsexed Ross 308 broiler chicks were randomly distributed in a completely randomized experimental design with three treatments and four replications of fifteen chicks each. Diets prepared without additive as Control; Probiotic(containing live yeast from mannan oligosaccharides (MOS) for 8x10 7 in each gram of product, vitamins and antioxidants) @ 0.1% and Acidifier (containing citric acid, acetic acid, propionic acid, lactic acid)@0.1%.The results ofcholesterol, LDL, HDL, triglyceride, AST, total protein, globulin, Alkaline phosphatase (Alk. Phos.)and glucose showed improvement by addition of probiotic and acidifier in to the basal diet, whereas the findings in albumin and ALT levels were remained nonsignificant. Also significant improvement for antibody titers again Newcastle Disease (ND) and Infectious Bursal Disease (IBD) were noticed in acidifier feed additive treatment while in Avian Influenza (AI) titer values, were significantly altered by addition of both probiotic and acidifier. It can be concluded that dietary probiotic and acidifier could have a clear positive effect on immune response and could partially improve the biochemical parameters studied in current experiment
