A biological trial was designed on broilers up to 42 days to study the influence of supplementing feed additives either antibiotic (colidox), probiotic (T-Loc plus) or their combination with respect to body weight, feed consumption, feed efficiency, livability and relative economics.  Significant (P<0.05) improvement in body weight and feed efficiency was seen in birds fed with antibiotic or probiotic alone when compared to control and antibiotic plus probiotic combination group. Antibiotic plus probiotic combination group performed lower than the control group fed with basal diet alone. Higher mortality rate of 8.90% was seen in control group followed by antibiotic plus probiotic combination (5.70%), probiotic alone (4.73%) and antibiotic (4.46%) group alone. Relative economics revealed higher returns in probiotic group followed by antibiotic supplemented group and least in probiotic plus antibiotic combination group. In general, birds fed with antibiotic or probiotic alone performed better than their combination and control groups.