The effects of CO2 gas stunning on meat quality of cattle compared with captive bolt stunning

The aim of this study is to assess the effect of CO2 gas stunning which has not been conducted until now in comparison with captive bolt stunning on the meat quality of cattle. A total of 40 steers were slaughtered following two stunning processes: CO2 gas stunning (n=20), exposure at 70% CO2 gas atmosphere for 140 sec; and captive bolt stunning (CBS, n=20). The slaughtered steers were classified into Group A (620-710 kg) and Group B (720-790 kg) by their live weight. CO2 gas stunning decreases pH value (p<0.05) but increases lightness (p<0.001) and sarcomere length (p<0.001 and p<0.01 for Group A and Group B, respectively) in all live weight groups. Drip loss was increased with CO2 gas stunning in Group A (620-710 kg of live weight) (p<0.05), whereas WBSF was decreased with CO2 gas stunning in Group B (720-790 kg of live weight) (p<0.001). Therefore, CO2 gas stunning negatively affects muscle pH and water-holding capacity in steers but CO2 gas stunning can improve the tenderness and lightness compared with captive bolt stunning in cattle.