Effects of long distance transportation and CO2 stunning on critical blood values in pigs

The aim of the study was to evaluate the effect of two stressful stimuli, long transportation and 80% CO2 stunning on metabolic–physiological variables, hemodynamic and gas exchange in slaughter pigs imported from the U.S. to Mexico City with a journey time of 27 h, with 8 h of lairage at the abattoir. A total of 589 pigs from three genders were monitored. Overall results show that both stimuli caused metabolic and physiological disturbance. Gilts were more efficient in controlling glycemia after a long transport journey (24 h), than castrated males (P < 0.05), whose glucose was increased above the 30 mg/dL basal level. Females on arrival had 23 mg/dL more lactate compared to basal levels (P < 0.05). Stunning caused more physiological effects compared to transportation. Regarding the gender factor, females and entire males were more susceptible to transport stress and stunning compared to the castrated pigs, and entire males showed more complications restoring the gas exchange compared to females and barrows.

► Stunning in CO2 chambers caused physiological disorders.
► Stunning method caused more physiological disorders compared to transportation.
► Females and entire males were more susceptible to transport stress and stunning.
► Entire males showed more complications restoring the gas exchange.