Research Note: Automated Droplet Application of a Competitive Exclusion Preparation

An automatic dosing cabinet similar to that used for infectious bronchitis vaccination was used to treat newly hatched chicks with a commercial competitive exclusion product, BROILACT. Randomly selected boxes of treated and untreated (control) chicks were taken to the laboratory and challenged with either Salmonella infantis or Salmonella enteritidis (PT4) using the seeder bird technique. Three experiments were carried out with each serotype. Twelve days after challenge, the ceca of the chicks and, in one experiment, also pooled samples of other organs were examined for Salmonella. Automatic droplet application of BROILACT protected the chicks effectively in all six trials. The average number of Salmonella was about 10 cfu/g of cecal contents in the treated groups and 1,000,000 cfu/g in control groups. The pooled organ samples were found to be free from Salmonella in the treated groups whereas virtually all organs from the control groups tested positive for Salmonella.