Stresnil is an alternative trade term for the sedative azaperone, a tranquilizer used in pigs to reduce aggression, fighting, and transport stress. Calmer animals mean fewer injuries, less carcass damage, and better meat quality, since pre-slaughter stress and exhaustion cause defects such as pale, soft, exudative pork and dark, firm, dry meat. Its use is strictly veterinary, administered at defined doses, with withdrawal periods ensuring no residues reach the food chain. Managing animal stress is both a welfare obligation and a meat-quality strategy, and Stresnil is one tool among handling and housing improvements.