The safety and microbiological properties of chickens reared in free-range production systems (according to the EC Directive 1538/91) were compared with those of chickens reared under conventional systems. Free range chickens belonging to medium growing Isa strain were raised for 70 d with continuous daytime access to open-air area from 28 d to slaughter age and an indoors stocking density not exceeding 27.5 kg/sqm. Conventional chickens belonged to a fast growing hybrid (Ross 708) and were raised for 50 d under intensive conditions. During slaughtering, 20 birds per each group (i.e. FR and C) before and after plucking, after evisceration and after refrigeration (i.e. 5 birds per each step) were randomly collected. On each carcass, the enumeration of Enterobacteriaceae and Campylobacter was assessed. In particular on carcasses of birds collected after refrigeration also the detection of Salmonella was performed. All microbiological determinations were performed using ISO based methods. Moreover, the detection of Salmonella was performed on the neck skin and intestine of 10 additional birds per group by ISO standard methods. On the same intestines the enumeration of Campylobacter was assessed by qPCR. The mean value of Campylobacter counts before (i.e. 6.05 vs 7.04 Log CFU/carcass) and after (i.e. 5.09 vs 6.31 Log CFU/carcass) plucking were significantly lower in free range than conventional birds. The Enterobacteriaceae count showed the same trend but only after plucking (i.e. 6.42 vs 7.03 Log CFU/carcass). In both conventional and free-range systems, positive Salmonella neck skin samples collected before refrigeration were obtained (i.e. 2/5 vs 3/5). However, all carcasses tested after refrigeration but one, belonging to conventional birds, turned out as negative. Similarly, all intestines collected from free-range and conventional chickens were Salmonella negative. Regarding Campylobacter gut enumeration, a lower number of Campylobacter cells were determined on free-range chicken in comparison to conventionally reared chicken (5.0 vs 5.6 Log CFU/g).
Enteric bacteria enumeration in free range chickens / Manfreda G.; Pasquali F.; De Cesare A.; Petracci M.; Franchini A.; Cavani C.. - ELETTRONICO. - (2011), pp. 1-8. (Intervento presentato al convegno XIX European Symposium on the Quality of Poultry Meat and XVI European Symposium on the Quality of Eggs and Egg Products tenutosi a Leipzing, Germany nel 4-8 September 2011).
Enteric bacteria enumeration in free range chickens
MANFREDA, GERARDO;PASQUALI, FREDERIQUE;DE CESARE, ALESSANDRA;PETRACCI, MASSIMILIANO;FRANCHINI, ACHILLE;CAVANI, CLAUDIO
2011
Abstract
The safety and microbiological properties of chickens reared in free-range production systems (according to the EC Directive 1538/91) were compared with those of chickens reared under conventional systems. Free range chickens belonging to medium growing Isa strain were raised for 70 d with continuous daytime access to open-air area from 28 d to slaughter age and an indoors stocking density not exceeding 27.5 kg/sqm. Conventional chickens belonged to a fast growing hybrid (Ross 708) and were raised for 50 d under intensive conditions. During slaughtering, 20 birds per each group (i.e. FR and C) before and after plucking, after evisceration and after refrigeration (i.e. 5 birds per each step) were randomly collected. On each carcass, the enumeration of Enterobacteriaceae and Campylobacter was assessed. In particular on carcasses of birds collected after refrigeration also the detection of Salmonella was performed. All microbiological determinations were performed using ISO based methods. Moreover, the detection of Salmonella was performed on the neck skin and intestine of 10 additional birds per group by ISO standard methods. On the same intestines the enumeration of Campylobacter was assessed by qPCR. The mean value of Campylobacter counts before (i.e. 6.05 vs 7.04 Log CFU/carcass) and after (i.e. 5.09 vs 6.31 Log CFU/carcass) plucking were significantly lower in free range than conventional birds. The Enterobacteriaceae count showed the same trend but only after plucking (i.e. 6.42 vs 7.03 Log CFU/carcass). In both conventional and free-range systems, positive Salmonella neck skin samples collected before refrigeration were obtained (i.e. 2/5 vs 3/5). However, all carcasses tested after refrigeration but one, belonging to conventional birds, turned out as negative. Similarly, all intestines collected from free-range and conventional chickens were Salmonella negative. Regarding Campylobacter gut enumeration, a lower number of Campylobacter cells were determined on free-range chicken in comparison to conventionally reared chicken (5.0 vs 5.6 Log CFU/g).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
