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ARS Home » Research » Publications at this Location » Publication #208170
Title: Effect of processing equipment and sampling methodology on numbers and incidence of bacteria on broiler carcasses

Author
item Smith, Douglas
item Cason Jr, John
item Northcutt, Julie
item Cox Jr, Nelson

Submitted to: Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 2/15/2007
Publication Date: 8/31/2007
Citation: Smith, D.P., Cason Jr, J.A., Northcutt, J.K., Cox Jr, N.A. 2007. Effect of processing equipment and sampling methodology on numbers and incidence of bacteria on broiler carcasses [abstract]. Meeting Proceedings. p. 141.

Interpretive Summary:

Technical Abstract: Processing equipment identified with reducing numbers or incidence of bacteria on broiler carcasses in the US includes inside-outside bird washers (IOBWs) and immersion chillers. A whole carcass rinse (WCR) technique is typically used to recover and enumerate bacteria. Experiments were conducted to determine the effectiveness of IOBWs and chillers to decrease bacteria and to evaluate WCR compared to other methods for recovering bacteria. IOBWs slightly decreased (P<0.05) total bacteria (from 4.9 to 4.8 log cfu/ml rinsate) and Escherichia coli (from 3.2 to 3.0 log cfu/ml rinsate), and decreased the incidence of Salmonella and Campylobacter from 33 to 8%, and 61 to 3%, respectively. The IOBW was more effective in washing internal than external carcass surfaces that were contaminated with feces, as significantly lower numbers of coliforms (0.5 log), E. coli (0.7 log), and Campylobacter (1.0 log) were recovered from post-IOBW carcasses with internal vs. external fecal contamination. Immersion chilling reduced numbers of coliforms and E. coli on carcasses treated with fecal contamination to levels found on control carcasses; however, incidence of Campylobacter and Salmonella increased during chilling from 75 to 100% and 0 to 25%, respectively. All of the preceding data were collected using either WCR or half carcass rinses. Prior studies have shown that WCR provide an estimate of total bacteria on the carcass, but many additional bacteria remain attached and are uncounted. Therefore the potential reductions in bacterial numbers and prevalence due to IOBWs, chilling, and other methods may not accurately reflect true reductions. Surface scraping prior to WCR or incorporation of sand in the WCR were tested for bacterial recovery vs. WCR alone. Scraping one half of a carcass prior to WCR resulted in no difference in coliforms (4.7 log cfu/ml rinsate) or E. coli (4.6 log cfu/ml rinsate) compared to only WCR. Adding sand in the rinse increased recovery of coliforms by 0.6 log cfu/ml and E. coli by 0.7 log cfu/ml rinsate. In summary, IOBWs are effective in reducing numbers and incidence of bacteria, and immersion chilling overall reduces bacteria but increases incidence of pathogens. Scraping carcasses prior to WCR in an attempt to recover more bacteria offered no advantage vs. WCR. However, incorporating sand into WCR did recover higher numbers of bacteria, therefore WCR may be underestimating the total bacteria present on the carcass.