Epidemiology and Infection

Routes for salmonella contamination of poultry meat: epidemiological study from hatchery to slaughterhouse

M.  HEYNDRICKX  a1 , D.  VANDEKERCHOVE  a2 , L.  HERMAN  a1 c1 , I.  ROLLIER  a3 , K.  GRIJSPEERDT  a1 and L.  DE ZUTTER  a4
a1 Center for Agricultural Research, Department for Animal Product Quality, Brusselsesteenweg 370, B-9090 Melle, Belgium
a2 Veterinary and Agrochemical Research Center, Groeselenberg 99, 1180 Brussels, Belgium
a3 European Commission, Directorate General Health and Consumer Protection Wetstraat 200, B-1049 Brussels, Belgium
a4 Department of Veterinary Food Inspection, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium


Data were collected on the prevalence of salmonella at different stages during the life cycle of 18 broiler flocks on different farms as well as during slaughter in different poultry slaughterhouses. For the isolation of salmonella, the highest sensitivity (93.9%) was obtained by enrichment in the semi-solid agar Diasalm. The ‘overshoe method’ utilizing several pairs of overshoes provided the highest sensitivity for determining the salmonella status of the broilers during rearing. A clear decrease of the relative importance of the first production stages was demonstrated for the salmonella contamination of the end product, whereas horizontal transmission of salmonella to broilers during rearing and to broiler carcasses in the slaughterhouse was shown to be the main determinative factor. Ten of the 18 flocks received a salmonella positive status with the highest shedding occurring during the first 2 weeks of rearing. The shedding of the animals was significantly negatively influenced by the use of subtherapeutic or therapeutic doses of antibiotics. The intake of portable material in the broiler house was identified as the most important risk factor for horizontal transmission. Significant associations were found between the contamination level of a flock and hygiene of the broiler house, feed and water in the broiler house and both animal and non-animal material sampled in the environment. No correlation was found between contamination during the rearing period and contamination found after slaughtering. The presence of faecal material in the transport crates and predominantly the identity of the slaughterhouse seemed to be the determining factors for carcass quality. Improved hygiene management during transport of broilers and in some slaughterhouses could significantly reduce the risk of salmonella contamination of poultry meat.

(Accepted April 22 2002)

c1 Author for correspondence.