Use of two vaccines (live G30D or killed RW16) in the prevention of Salmonella typhimurium infections in chickens

Abstract

Several properties of a galactose epimerase mutant strain (G30D) of Salmonella typhimurium were investigated in white leghorn and white rock chickens. More chickens shed G30D when it was administered orally at 1 day of age than when given at 1, 2, or 4 weeks of age. In another experiment, the mean cumulative data obtained for 52 days on the shedding rate of virulent RW16 in the unvaccinated challenged controls were significantly higher (P less than 0.05) than data in challenged groups that had been vaccinated subcutaneously with live G30D. In a third experiment, chickens vaccinated twice with live G30D or killed RW16 were less likely to shed RW16 than unvaccinated controls following challenge with live RW16. Vaccination with both live G30D and killed RW16 was significantly more beneficial (P less than 0.05) than using either vaccine alone twice. The route of administration of the vaccines made no difference in the reduction of shedding.