Bacterial counts and characterization of intestinal flora in organic and conventional chickens

The aim of this study was to count, isolate and identify by traditional methods the major bacteria colonizing the intestinal tract of organic and conventional chickens. The study was performed in 2 conventional and 2 organic chicken farms. Intestinal samples (24 from ileum and 24 from caecum) were collected from organic reared chickens during the production cycle (40 days of age) and at slaughter (80 days of age). Twenty four intestinal samples were also collected from conventional chickens at slaughter (40 days of age). Facultative anaerobic bacteria (enterobacteria, enterococci, staphylococci, lactobacilli) and anaerobic obligate bacteria colonizing the ileum and the caecum were counted, isolated, identified and expressed as n. x 10. Results showed that at 40 days the aerobic count was higher in the caecum than in the ileum in both conventional and organic chickens (respectively 296.4 and 307.2 for the caecum vs 46.7 and 57.5 for the ileum). The anaerobic flora was higher in the caecum than in the ileum of both conventional and organic chickens (P<0.05). Data related to organic intestinal samples (ileum and cecum), collected at 40 and 80 days, were characterized by the values of aerobic population (more represented in cecum than in ileum) lower than the values of anaerobic organisms at 80 days . The biochemical characterization of enteric flora did not identify large differences in organic and conventional chickens. Further investigations are necessary to better assess the role and the effect of the enteric flora on the productive performance and on the health status of reared chickens. ___________________________________________________________________________