Probiotics in broiler production - a review

As a result of a public food poisoning from infection with S. enteritides eggs in England in 1988-1989, egg consumption decreased by 90% and caused serious economic losses for the government and the producers. That anxiously put the question on effective Salmonella resistance, especially as the different analyses presented that 67% of the feed containing animal proteins and 69% of the feed mixtures were contaminated with Salmonella. Probiotics are biological products, which stimulate the immunity system and increase its defensive activity against pathogenic bacteria. Probiotics competitively exclude the Salmonella bacteria from the intestinal tract of the treated chicken and stimulate natural resistance of the organism through increasing the number of antibodies and increasing the effectiveness of macrophages. The reviewed evidences in this study, present main sources of information for identifying the possibilities to use different alternatives "probiotics" instead of antibiotics in poultry production. The reviewed topics include modes of action of probiotics in poultry, methods of administration, effects on growth performance, effects against Salmonella contamination, and influence of antibiotics on the effectiveness of probiotics. It is concluded that probiotics represent the feed additives of the future under the politics of banning growth promoters (feed antibiotics). The complex microflora present in the gastrointestinal tract of the birds is effective in providing resistance to disease, but this protective flora can be altered by dietary and environmental influences. The probiotic treatment is re-establishing the natural condition which exists in the wild animals but which has been disrupted by modem trends in condition used for rearing birds, and in modem approaches to nutrition and disease therapy.