The invention relates to a composition for use in the prevention or treatment of Salmonellosis in animals, said use comprising administering the composition to the animal, wherein the composition contains at least 0.01 % by weight of dry matter of rhamnogalacturonan I (RG-I) polysaccharides having a molecular weight of more than 2 kDa and having a backbone consisting of galacturonic acid residues and rhamnose residues, said rhamnose residues being contained in alpha(1-→4)-galacturonic-alpha(1→2)-rhamnose residues, wherein the molar ratio of galacturonic acid residues to rhamnose residues in the RG-I polysaccharides is within the range of 50:1 to 1 : 1. The use of RG-I polysaccharides in the treatment or prevention of Salmonellosis provides an alternative for the widespread use of antibiotics. Furthermore, these RG-I polysaccharides may be used to prevent or treat Salmonellosis caused by Salmonella strains with resistance to antibiotics.
