Relationship between the Porcine Stress Syndrome gene and pork quality traits of F2 pigs resulting from divergent crosses

The PSS genotypes of 596 F-2, pigs produced by initial mating of Brazilian commercial sows and native boars were characterized by PCR-RFLP and the pork quality traits were evaluated. Among the 596 pigs studied, 493 (82.7 %) were NN and 103 (17.3 %) were Nn. There were no differences between NN and Nn pigs in the following pork qualities: pH(u) (5.71 +/- 0.16 vs 5.70 +/- 0.11), intramuscular fat (1.55 +/- 0.64 % vs 1.65 +/- 0.67 %), shear force (5552 +/- 878 g/1.2 cm vs 5507 +/- 826 g/1.2 cm), lightness (44.96 +/- 2.05 vs 45.01 +/- 1.92), redness (0.64 +/- 0.60 vs 0.79 +/- 0.55), yellowness (6.62 +/- 0.56 vs 6.65 +/- 0.48), hue (84.28 +/- 5.53 vs 83.41 +/- 4.85), or chroma (6.68 +/- 0.52 vs 6.73 +/- 0.52). However, pork from Nn pigs had a significantly (p < 0.05) lower pH(45) (6.41 +/- 0.27 vs 6.51 +/- 0.26) and greater drip (3.92 +/- 1.90 % vs 3.06 +/- 1.60 %), cooking (33.29 +/- 2.26 % vs 32.50 +/- 2.54 %) and total (35.67 +/- 2.48 % vs 34.01 +/- 2.58 %) loss compared to that of NN pigs. These results indicate that, even in divergent crosses, PSS gene carriers produce pork of poorer quality.