Four similar trials were conducted to evaluate the effects of dietary inclusion of an alcoholic solution of propolis and ethyl alcohol on the control of salmonella artificially added to the feed offered to groups of 10-16 day-old broiler chicks. Salmonella typhimurium Nalr - Specr (resistant to Nalidixic acid and Spectinomicin) were used in the first three experiments and Salmonella enteritidis Nalr - Specr in the fourth. In every experiment the antibacterial agent was added in the proportion of 2%of the feed. When using hydroalcoholic solution of propolis (experiment 1), 120 hours after the challenge on the chicks, the presence of bacteria was in detected cecal contents. In the next experiment (experiment 2) an alcoholic solution of propolis and ethyl alcohol was tested: 96 hours after the challenge on the chicks the presence of bacteria in cecal content of the birds was not observed (< 2.0 log10 FCU/g). In the third experiment, a propolis solution and ethyl alcohol was evaluated when added to the feed 14 days and 28 days before the chicks consumed the experimental ration. Seventy-two hours after the chicks consumed the Salmonella contaminated ration, the plaque counts showed the presence of bacteria in cecal contents of the chicks. Within the last period (72 hours), a powdered propolis sample was evaluated (dehydrated extract) and, this extract in an aqueous solution, added to the feed 48 hours before the birds started ration consumption; the results confirmed the presence of the bacteria in cecal contents. In the fourth experiment, only ethyl alcohol in the feed artificially contaminated with the following serotypes: S. agona, S. enteritidis and S. infantis was evaluated . The results indicated zero count (< 2.0 log10 , FCU/g) only with the last serotype. Under this experimental conditions, propolis showed action over S. typhimurium only when in alcoholic solution and 48 hours before the birds consumed the contaminated ration, showing that bactericidal effect was due to ethyl alcohol present in the solution rather than to the propolis action per se. Ethyl alcohol showed bactericidal effect over two of the serotypes S. typhimurium and S. enteritidis artificially added to the feed, pointing that a standardized response did not occur.
Salmonella; poultry ration; control; propolis; ethyl alcohol; broilers