Prevention of Salmonella infection by contact using intestinal flora of adult birds and/or a mixture of organic acids

ABSTRACT

This study was carried out to assess the ability of competitive exclusion and a mixture of organic acids to prevent "Salmonella" infection by contact between newly hatched chicks. A bird infected with "Salmonella" was placed in a box containing non-infected birds, previously treated with a broth culture of faeces of adult birds (CE) and/or a mixture of organic acids. The number of "Salmonella" organisms in the caeca of the contact birds was estimated at 4 and 8 days post-challenge. The birds were infected with "Salmonella" Typhimurium, "Salmonella" Enteritidis (both repeated 5 times), "Salmonella" Agona and "Salmonella" Infantis (3 repetitions). The same approach was used to test the mixture of organic acids alone. In this case the birds recieved feed containing 0.8(per cent) of a mixture of formic acid (70(per cent)) and propionic acid (30(per cent)). Also, a third trial was carried out with birds inoculated with the broth culture of faeces and fed with feed containing the mixture of organic acids. Appropriate controls were included. Whereas the birds from the control groups and the groups treated with the mixture of organic acids were heavily infected with "Salmonella", those pre-treated with CE or CE plus the mixture of organic acids had no viable cells per gram of caecal contents.