RYR1 and Malignant hyperthermia: Although the incidence occurs at low frequency (less than 1%) these losses are substantial due to added labor and disposal costs, along with loss of full-value product and have been estimated to be over $50,000,000 per year in the U.S. Fatigued, non-ambulatory pigs exhibit acute stress symptoms including open-mouth breathing, discoloration (red to purple) and blotching of skin, muscle tremors, abnormal vocalization and refusal to move, similar to what is observed in pigs with malignant hyperthermia due to a mutation in the ryanodine receptor 1 gene (RYR1) [2].