his experiment was conducted to study the effects of different levels of Perlite on performance of 240 day-old male Arian chickens. The experiment was performed in a completely randomized design (CRD) with four treatments and three replicates for each treatments. The experimental treatments included 0, 1, 2 and 3 percent Perlite in diets, and were respectively designated as diets A, B, C and D, fed to chickens at 1 to 42 days of age. All of the experimental groups were iso-caloric and iso-nitrogenous. Average feed intake, weight gain were measured in the end of each week of experiment and mortality was measured throughout the trial. For comparison between means Duncon s method (P<0.05) was used. The results show that , adding perlites to the diets of broilers from 1 to 42 days of age, produced significant differences (P<0.05) in terms of live weight gain and feed conversion ratio (FCR). Based on these results numerically, group B (fed 1% perlite) and group A (fed 0% perlite) had the highest (1624g) and the lowest (1397g) weight gain in whole period of study respectively. Statistical differences indicated non-significant differences in feed consumption and mortality between all experimental groups (P>0.05).
