Effect of Electrical and Carbon Dioxide Stunning on Stress and Physicochemical Characteristics of Loin in LYD Pigs

The carbon dioxide stunning method is known to induce less stress in slaughtered livestock compared to conventional methods. A reported disadvantage of the carbon dioxide stunning method compared to electrical stunning is that it is associated with softness of meat quality. However, research on the effects of carbon dioxide stunning on stress levels and meat quality in Korean LYD pigs is limited. Therefore, this study examined the effects of gas stunning methods on cortisol content and the physical characteristics of loins in LYD pigs. Ten LYD pigs were used for each treatment, divided into electrical stunning (Elec) and carbon dioxide stunning (CO2) groups. Cortisol content was 3.38 to 4.47 ug/dL for Elec and 2.89 to 3.56 ug/dL for CO2, both before and after stunning (p>0.05). There was no significant difference in pH and myoglobin content between the two methods. The meat color did not differ significantly, with lightness of 51.49 and 52.64, redness of 5.75 and 5.67, and yellowness of 5.59 and 6.18 for Elec and CO2, respectively. TBARS was significantly higher in Elec (0.18 MDA mg/g) compared to CO2 (0.14 MDA mg/g) on day 2, but no significant difference on day 7. Elec had higher moisture and protein, while CO2 had higher fat and ash, due to individual variation. In conclusion, carbon dioxide stunning may induce less stress and has minimal impact on the stress, color, and lipid oxidation of LYD pork, with potential individual variations.