The current study was conducted to evaluate the effects of natural feed additives containing oxygen-activated chalk on performance of broilers. The certain biochemical parameters were also analyzed to assess the influence of the feed additive on protein, lipid and glucose metabolisms of the broilers. A total of 225 unsexed, one-day old broiler chicks were randomly divided into 3 groups comprising 3 subgroups with 75 chicks of each. The chicks in control group were fed with un-supplemented basal diet. Bioactive feed additive containing oxygen-activated chalk was added to the diet of those groups Bio200 and Bio400 at the levels of 200 and 400 mg/kg, respectively. Feed and water were given to the animals ad libitum for 5 weeks. Feed consumptions and body weights of the birds were recorded and body weight gain and feed efficiency were calculated weekly intervals to assess the growth performance of groups. At the end of the trial, while body weight, body weight gain and feed efficiency were not affected (P0.05), feed consumption significantly decreased by the addition of the bioactive supplement to the diet (P≤0.05). The serum total protein, glucose, triglyceride, LDL and HDL and total cholesterol levels of the groups which may reflect the status of the protein, lipid and glucose metabolisms were not affected by supplementation diet with the feed additive (P0.05). Serum calcium and phosphor levels also were not different between the groups (P0.05). The results of present study indicates that the bioactivated chalk can be considered as a potential feed additive to promote the growth in broilers due to positive effects on feed consumption without compromising the reduction in live weight gain. Consequently, it has been needed to carry out further research on the product as an alternative feed additive could provide more economic production possibility in broilers and organic animal production.