The HAL-1843 mutation of the RYR gene (commonly called the “Stress” or “Halothane” gene) is associated with increased stress susceptibility and death loss in pigs. Death loss and non-ambulatory pigs during transport are an important economic issue for the swine industry as well as being a major welfare concern. Over the last 10 to 15 years, most breeding stock suppliers have selected against this mutation and there are claims that it has been eliminated from the most commercial populations. This study was carried out to establish the frequency of the mutation in pigs from contemporary U.S. populations that arrived at packing plants either dead or in a non-ambulatory/non-injured condition, and in a random sample of contemporary normal animals.
The results of the study suggest that the mutation is still relatively widespread, being present in pigs from ~11% of farms sampled. However, the frequency of animals with the mutation was low (<3% of animals tested) suggesting that it is not a major causal factor in transport losses (either dead or non-ambulatory/non-injured animals).

For Further Information contact:
Dr. Mike Ellis, 1207 West Gregory Dr., 216 ASL, Urbana-Champaign, 61820
Office: 217.333-6455
[email protected]