Happy Pigs and Industrial Robots. In China, do pigs get high on carbon dioxide, enjoying a brief buzz of happiness before slaughter? Then, poof, they are sent to a robotic execution chamber for a clean and efficient process. In modern large-scale slaughterhouses, high concentrations of carbon dioxide are indeed used to stun pigs. Once lowered into a chamber filled with CO₂, the pigs lose consciousness within seconds due to severe hypercapnia and oxygen deprivation, allowing the slaughter process to proceed more efficiently.