The aim of this experiment was to study the effects of the dietary addition of different dosage of a natural growth promoter concentrate on performance and organ weights of broilers. Two hundred and forty day-old Ross 308 commercial broiler chickens were randomly divided in four groups with three replicates and 20 chicks each. Diets prepared without additive as Control (CON) (group 1), 0.025% Growth Promoter Concentrate (GPC1) (group 2); 0.05% Growth Promoter Concentrate (GPC2) (group 3) and 0.1% Growth Promoter Concentrate (GPC3) (group 4). Results showed a significant (P<0.05) improvement in weekly body weight, feed intake and Feed Conversion Ratio (FCR) parameters, however, the maximum difference were found in the level of 0.1%, followed by 0.05% and 0.025% levels. The maximum percentage of survivability was recorded in 0.1% level of concentrate. The visceral organ weights of thymus, bursa of Fabricius, liver and pancreas (g/kg live weight) have shown no significant (P>0.05) changes. It can be concluded that dietary growth promoter concentrate increased the performance of broiler chicken and is an option for improving broiler growth and performance. The best level of natural growth promoter concentrate used in this study was found to be 0.1%.
