Prevention of colonization by Salmonella enteritidis PT4 in broiler chickens

Field experiments in The Netherlands and in Scandinavian countries have shown that an undefined microflora originating from SPF adult poultry will reduce considerably the colonization of young chicks by Salmonella. A commercial product from this so-called Nurmi concept, Broilact, was studied for its effectiveness in preventing infection of broilers with Salmonella enteritidis PT4 (S.e.). Two trials were carried out, in which the birds were exposed to S.e. via 'seeder' birds placed among them. The trial period was 21 days and each week one third of the chicks was killed and their caecal contents examined for salmonellas. The results of the first trial can be summarized as follows. (1) After 2 weeks the number of 'seeder' birds carrying the Salmonella decreased sharply; (2) the proportion of infected chicks in the Broilact-treated group was lower than in the non-treated group; (3) Counts of S.e. in the non-treated group were higher than in the Broilact group. Results of the second trial were comparable, although no salmonellas could be isolated after the second week.