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

This study was carried out to assess the ability of competitive exclusion a nd a mixture of organic acids to prevent Salmonella infection by contact be tween 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 numbe r of Salmonella organisms in the caeca of the contact birds was estimated a t 4 and 8 days post-challenge. The birds were infected with Salmonella Typh imurium, Salmonella Enteritidis (both repeated 5 times), Salmonella Agona a nd Salmonella Infantis (3 repetitions). The same approach was used to test the mixture of organic acids alone. In this case the birds received feed co ntaining 0.8% of a mixture of formic acid (70%) and propionic acid (30%). A lso, a third trial was carried out with birds inoculated with the broth cul ture of faeces and fed with feed containing the mixture of organic acids. A ppropriate controls were included. Whereas the birds from the control group s and the groups treated with the mixture of organic acids were heavily inf ected with Salmonella, those pre-treated with CE or CE plus the mixture of organic acids had no viable cells per grain of caecal contents.