Salmonella colonisation of laying hens following vaccination with killed and live attenuated commercial Salmonella vaccines

The aim of this study was to determine the efficacy of a killed Salmonella vaccine and three live vaccines in preventing caecal colonisation of Hy-line Brown pullets by Salmonella Enteritidis PT 4. The lowest number of Salmonella-positive birds following the largest challenge (10(B) cfu) was recorded for live vaccine 1. However, birds treated with the killed vaccine had a significantly lower number of salmonellae in their caeca compared with both the control group and the other vaccine groups (P<0.05).