In this study, three kinds of commercial probiotics were studied to maximize broiler chickens performance. 160 male broiler plots, commercial strain, 308 vertexes in randomly plan having 4 treatments and 4 replications were divided to 10 groups having similar average weight. Chickens were divided into four groups: 1- control group (without probiotics), 2- experimental group containing Protexin, 3- experimental group containing Primalac, and 4- experimental group containing Calciparine. The effects of probiotics on carcass and some internal organs were measured and results shows that feeding broilers with probiotics have significant effects (P < 0.05) on full carcass weight, empty carcass weight, head weight, neck weight, brain weight and also ileum weight, while it appeared insignificant on other results. According to the results, it can be concluded that feeding chicken broilers with these probiotics have positive effects on growth and carcass traits of chicken broilers. Thus, the use of these probiotics for broiler plots, commercial strain, 308 vertexes is recommended.
