Effect of the RN gene on technological and sensory meat quality in crossbred pigs with Hampshire as terminal sire.

The effect of the dominant RN gene (Rendement Napole) was studied in Hampshire crosses (Hampshire sires × Swedish Landrace-Swedish Yorkshire dams). The present material comprised 107 entire male and 52 female pigs slaughtered at 106 kg live weight. Carriers and non-carriers of the RN gene were distinguished on the basis of the glycolytic potential (GP) in post-mortem longissimus muscle, or with the Napole yield (yield after curing and cooking). Compared with the glycolytic potential classification, Napole classification gave 16% misclassified samples. In comparison with non-carriers of the RN gene, gene carriers showed the following significant differences in m. longissimus dorsi meat quality traits: lower pH, higher surface and internal reflectance values, lower protein extractability, lower water-holding capacity, lower Napole yield and greater cooking loss. The high correlation (r = -0.73; p < 0.001) which was found between GP and Napole yield in the total material, was absent in muscle from individuals carrying the RN gene. In addition to the detrimental effect on meat quality, the RN gene also had beneficial effects. Thus RN carriers had a lower (p = 0.02) shear force value (Warner-Bratzler) and, at sensory testing, a stronger taste and smell and greater acidity (9-member untrained panel). No difference was found in sensory evaluated tenderness.