The effect of the Halothane gene on performance, carcass and meat quality in a fat and a lean line of pigs

Abstract

The performance, carcass and meat quality of two lines of pigs in which the halothane allele (n) was segregating were studied. The lines were a lean line selected for rapid lean growth and an unselected fat line. Heterozygous (Nn) and homozygous normal (NN) segregants in both lines were compared in an environment of high temperature and pre-slaughter transport stress. Relative to the fat line, the lean line grew faster, ate more, was a more efficient converter of food and produced leaner carcasses. It also produced less acid and darker lean with less water loss. The halothane allele had a much greater effect in the lean than the fat line. It reduced appetite, growth rate and food conversion ratio and increased the acidity, paleness and water loss from lean. In both lines, but particularly in the lean line, the halothane allele increased the incidence of death in transit to slaughter.