|Byrd Ii, James - Allen|
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/26/2000
Publication Date: 2/1/2001
Interpretive Summary: Salmonella and Campylobacter bacteria can cause illness and death in humans consuming contaminated poultry products. Salmonella and Campylobacter have been shown to increase in broilers when feed is removed before the chickens are transported to the processing plant. Previously, we found that the crop of chickens often contains Salmonella and Campylobacter bacteria that may spread to other chickens and to the machinery in the slaughter plant. Earlier studies have shown that beneficial bacteria decrease in the upper gastrointestinal tract as the feed is removed from the chickens prior to transport to the slaughter plant. Some of these beneficial bacteria in the upper gastrointestinal tract produce lactic acid that may help reduce Salmonella. In the present study, we evaluated the effects on Salmonella and Campylobacter contamination of adding lactic acid to the drinking water of broilers when feed is removed. The results of our study suggest that the use of lactic acid in the drinking water before slaughter may lower the number of Salmonella and Campylobacter contaminated broilers.
Technical Abstract: The crop is a known source of Salmonella and Campylobacter contamination. Presently, we evaluated the use of selected organic acids (0.5% acetic, lactic, or formic) in the drinking water during a simulated 8 h pre- transport feed withdrawal (FW). All broilers were challenged with 10**6 Salmonella typhimurium (ST) by oral gavage 24 to 48 hours prior to FW in a total of five experiments. Salmonella typhimurium was recovered from 53/100 control crops and from 45/100 of crops from acetic acid-treated broilers. However, treatment with either lactic (31/100) or formic (28/76) acids caused reductions in incidence. Reductions in incidence were also associated with reduced numbers of ST recovered (e.g. control: log 1.45 cfu/crop; lactic acid: 0.79 cfu/crop). In a commercial farm study, broilers were provided 0.44% lactic acid during a 10 hour FW (4 hours on the farm and 6 hour transport) and pre-FW crop, post-FW crop, and pre- chill carcass wash samples were collected for Campylobacter and Salmonella detection. Crop Salmonella contamination was reduced by lactic acid treatment (6/175) as compared to controls (29/175). Salmonella incidence in pre-chill carcass rinses was reduced 52.4% by the lactic acid (26/175 VS. 55/176). Crop contamination with Campylobacter was reduced by lactic acid treatment (62.3%) as compared to the controls (85.1%). Lactic acid also reduced the incidence of Campylobacter found on pre-chill carcass rinses by 14.7% compared to the controls. These studies suggest that incorporation of lactic acid in the drinking water during pre-transport feed withdrawal may reduce Salmonella and Campylobacter contamination of crops and broiler carcasses at processing.