This experiment was conducted to evaluate feed withdrawal and addition of citric acid in drinking water on the pH and microflora of gizzard, ceca and feces in preslaughter broiler chickens. A total of 24 male Ross 308 broiler chickens at the age of 42 days with almost equal weight were randomly divided into six treatments with four replicates each. Control group had free access to feed and water, but without supplemental citric acid during preslaughter period. Another group was kept 8 h without feed, but with ad libitum access to unsupplemented drinking water. For other treatments, four concentrations of citric acids were added to the drinking water (1.5, 3, 4.5, and 6%) of broilers with feed withdrawal for 8 h. Fecal samples were collected 1 h before slaughter. After slaughter, gizzard and cecal contents were obtained and used for microbiological studies. The number of clostridium, bacillus, coliform and other bacteria were enumerated on appropriate bacterial media. The pH of gizzard, ceca and feces was significantly (P<0.05) lessened in birds that drank acidified water particularly at 4.5 and 6% citric acid as compared with control and feed withdrawal groups without citric acid supplementation. Also, the addition of citric acid to drinking water resulted in significant (P<0.05) reduction of bacillus, clostridium, coliform, facultative aerobic, and other bacteria in gizzard, cecal and fecal contents of birds with acidified water in comparison to the control and feed withdrawal treatments. Under the condition of this study, addition of citric acid in the drinking water 8 h before slaughter could reduce intestinal microflora colonization and might be a fruitful strategy against bacterial contamination of broiler products during processing.

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