Xavier Malher of INRA in Nantes and co-authors also based in Nantes and in Ploufragan carried out a study investigating the factors associated with carcass contamination by Campylobacter at the slaughterhouse in caecal-carrier broilers. The paper was been published online in International Journal of Food Microbiology.

The study was conducted in 2009 to identify risk factors of Campylobacter spp. transmission from the digestive tract to the carcasses of standard broilers (slaughter age, 37 days; average carcass weight, 1.3kg), explain the authors. Counts of Campylobacter were performed on pools of 10 caeca and 10 neck-skins from 108 Campylobacter caeca-positive batches in three slaughterhouses.

Technical and health data also was collected on the broilers: age, size, carcass weight (mean and standard deviation), condemnation rate, mortality rate and nature of treatment during the rearing period.

Caecal counts varied from 4.8 to 10.2 log₁₀ cfu/g. In 17 batches (15.7 per cent), the skin count was below the detection limit. In the 91 batches with positive neck-skin test results, the counts varied from 2.0 to 5.2 log₁₀ cfu/g.

Standard deviation of carcass weight, condemnation rate, slaughter rate and caecal count were significantly lower and growth rate higher in the 17 batches where neck-skin results were not detected positive.

Multivariate analysis showed that batches with higher standard deviation of carcass weight were five- to nine-fold more at risk of having detectable carcass contamination.

Among the 91 positive neck-skin batches, only slaughter rate and caecal counts were found to have a significant but limited effect on the level of neck-skin contamination, according to Malher and co-authors. As far as body weight homogeneity may be affected by disease, better health control can contribute to a reduction of the contamination of the broiler carcasses in Campylobacter carrier batches.

In their conclusion, the researchers state that the status and level of skin contamination were not related to previous antibiotic treatments and that among skin-positive batches, levels of contamination of skin and caeca were poorly correlated.

Reference

Malher X., M. Simon, V. Charnay, R. Danguy des Déserts, A. Lehébel and C. Belloc. 2011. Factors associated with carcass contamination by Campylobacter at slaughterhouse in cecal-carrier broilers. International Journal of Food Microbiology. article in press. doi:10.1016/j.ijfoodmicro.2011.07.007

Further Reading

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July 2011