a1 Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
Poultry meat and eggs are important sources of human pathogens. Salmonella is a major cause of human foodborne infections following consumption of poultry products. The original ambition of the EU to eradicate zoonotic agents from the animal production chain has been tempered to reducing the infection pressure of specified zoonotic agents at all levels of the production chain. This can be done by a combination of pre-harvest, harvest and post-harvest measures. Feed additives constitute an important group of pre-harvest measures which can help in controlling Salmonella on the farm. Feed additives used for the control of Salmonella can be of different types, including antibiotics, prebiotics, probiotics and synbiotics. Public concerns regarding possible antibiotic resistance transfer lead to the ban of antibiotics as growth promoters in monogastric diets within the EU. Experimental and practical use of pre-, pro- and synbiotics, as well as volatile fatty acids as feed additives are discussed in this review. The effects of these additives on resistance to infection, on the extent of excretion and on the persistence of infection are reviewed. Attention is paid also to possible undesirable effects of some of these products. Taking into consideration the underestimated high level of contamination of poultry, the feed additives reviewed in this article can certainly play a valuable part in control strategies during the pre-harvest phase aiming at reducing the infection pressure and thus limiting the risk of contamination of poultry products.