In pigs, the best-known gene which has so
far been used in commercial breeding is the
“halothane” gene. It was known that a number
of pigs could not handle stressful situations
(e.g. transportation to the slaughterhouse). A
(recessive) gene – a natural mutation, called the
“halothane” gene – was found to be responsible
for this defect. Using a DNA test that detects
whether a pig has the “defective form” of the
gene, it has been possible to eliminate this gene
completely from several breeds (Fuji et al., 1991)