EFFECT OF A CHARACTERIZED CONTINUOUS-FLOW CULTURE OF CECAL BACTERIA ON SALMONELLA-TYPHIMURIUM CROP COLONIZATION IN BROILER CHICKS

Broiler chicks were inoculated orally at 1 day of age with a continuou s-flow (CF) culture of anaerobic cecal bacteria and challenged with 10 (4) Salmonella typhimurium 48 hr (at 3 days old) after inoculation to determine the effect of the CF culture (CF3) on Salmonella crop coloni zation. Chicks were assigned to four groups: 1) untreated control chic ks, 2) challenged at 3 days old with Salmonella, 3) inoculated at 1 da y old (day-of-hatch) with CF3, and 4) inoculated at 1 day old with CF3 and challenged at 3 days old with Salmonella. Crop pH decreased signi ficantly (P < 0.05) 24 hr after inoculation in chicks provided with CF 3. The pH of crops at 24 hr from control chicks (group 1) was 5.4 and the pH of crops from inoculated chicks (group 3) was 4.7. Decreased pH was accompanied by a significant increase (P < 0.05) in crop lactic a cid from approximately 0.1 mmol/ml in control chicks to about 0.2 mmol /ml in chicks given the culture. Salmonella crop colonization decrease d (P < 0.05) 4 hr after challenge from a 2.6 log(10) colony-forming un its (cfu) in Salmonella-control (group 2) chicks to 0.6 log(10) cfu in CF3-inoculated (group 4) chicks. Although at 4 and 8 hr after challen ge, there were decreased (P < 0.05) numbers of crops resting culture-p ositive for Salmonella regardless of treatment, Salmonella colonizatio n decreased (P < 0.05) in chicks inoculated with CF3 as compared with controls. The results indicated that CF3 can effectively reduce Salmon ella crop colonization.