How animals are handled before, during, and after slaughter affects the structure and biochemistry of the muscles, and therefore, the quality of the meat. After an animal's death, the muscle proteins actin and myosin lose their extendibility and the muscles become stiff, a condition commonly referred to as rigor mortis. Stressing animals just before slaughter and chilling the meat too fast afterwards can result in tough, dry meat. On the othet hand, meat that is not chilled quickly enough can experience a rapid postmortem pH decline, making it pasty and mushy. Less stressful slaughter techniques and aging the meat in a properly chilled environment produce meats that are more tender and palatable.