Competitive exclusion (CE) cultures, given as a single dose on the day of hatch, together with good hygienic practices has been shown to be a novel approach to control Salmonella in poultry. The ability of the CE product Broilact and 2 probiotics, FloraMax-B11 and Colostrum, to prevent Salmonella colonization in newly hatched chickens was evaluated employing a slightly modified Mead-model chicken assay. In a parallel study the effect of the 3 treatments on the production of volatile fatty acids in the ceca were determined. In the Salmonella study 2 separate experiments were done. In the first experiment all 3 treatment materials were given as a single dose on d 1. In the second experiment, which consisted only of Broilact and FloraMax-B11, the latter was given in the drinking water during the 3 first d after hatch. In both experiments the chicks were challenged with Salmonella enterica serovar Infantis on d 2. The results of the present study show that Broilact was superior to the 2 other treatment materials in protecting the newly hatched chickens against Salmonella colonization. The parallel study showed only minor differences among the different treatments. Based on the results of the Salmonella challenge study, it was concluded that Broilact was the only treatment material that was established in the gut of the newly hatched chickens in such a way that the colonization of Salmonella was prohibited.