Effect of halothane genotype on growth parameters, carcase and meat quality traits in the Pietrain Breed of the French National Pig Breeding Program

The halothane allele (n) is segregating in the French national Pietrain breed. Records from the three French central test stations were available for 1,557 Pietrain pigs of known halothane gene status (128 NN, 334 Nn and 1,095 nn). Production traits, carcase composition and meat quality measurements were studied to compare the three genotypes and assess the allele effects. Water holding capacity was the trait most affected by the halothane allele (-0.76 phenotypic standard deviations, sd) followed by the length of the carcase (-0.62 sd) and by carcase traits related to leanness and fatness: dressing percentage, fat and muscle depth and weights of back leg, loin, and fat and rind above loin. The magnitude of the effect of the halothane allele varied from 0.21 to 0.47 phenotypic standard deviations for these carcase traits. In addition, performance of the heterozygous genotype was more similar to the homozygous (NN) genotype. Significant differences between the three genotypes were found for ultimate pH but not for colour. Colour (L*-value) was the only trait for which the heterozygous genotype was more similar to the superior homozygous genotype. In comparison to carcase and meat quality traits, the halothane allele effect was lower for production traits (from -0.12 to 0.02 sd).