A comparison of texture and quality of breast fillets from broilers stunned by electricity and carbon dioxide on a shackle line or killed with carbon dioxide.

To compare the broiler breast muscle quality resulting from three different slaughter methods, 36 broilers in each of two replicates were randomly divided into three groups receiving CO2 stunning, electrical stunning (ES), or CO2 killing. Carbon dioxide stunning was accomplished in a tunnel with a gradient from 40 to 60% CO2 by allowing the broilers on shackles to pass through the tunnel for 25 s. Electrical stunning was done by passing the bird's head through a charged 1% brine solution (35 mA, 7 s). For CO2 killing, the birds were killed by asphyxiation in an atmosphere of less than 2% oxygen (air displaced by CO2) for 2.5 min. Following slaughter, all breast fillets were harvested at 1.25 h postmortem and analyzed for pH, R value, shear value (SV), expressible moisture, and color (lightness and redness at 1.25 and 24 h postmortem). There were no differences (P<0.05) between treatments in pH, R value, SV, 1.25-h color values, or expressible moisture. There was an increase (P<0.05) in lightness between 1.25 and 24 h postmortem in all treatments, with the CO2 stun exhibiting the greatest increase and resulting in a significantly greater L* value at 24 h postmortem than the CO2 killing treatment. These results suggest that the postmortem metabolism or characteristics of the meat from animals processed with these stunning or killing methods does not differ to a large extent.