Currently there is a need to develop management and/or nutritional strategies that will contribute to efficiently reducing the incidence of post-weaning diarrhoea (PWD) among weaner pigs which are suitable for use in commercial production systems where antimicrobial growth promoters (AGPs) are not routinely supplemented in pigs feed. From the results obtained in this thesis, we propose that: Feeding weaner pigs with a diet supplemented with a combination of benzoic acid and inulin, and without AGPs could be used to reduce the incidence of PWD and increase weaner pig performance under the conditions of commercial production systems where young pigs might be exposed to environmental pressure by Enterotoxigenic Escherichia coli.