The aim of this work was to study the genetic variability among the wild boars, crossbred animals and pigs using microsatellite markers. Five genetic groups were studied. The fragments of three microsatellites developed for Sus scrofa domestica - IGF1, ACTG2 and TNFB - were amplified through PCR technique to evaluate the expected intra populacion variability (He) and observed (Ho) heterozygosity, and endogamy coefficient (F IS ) within each population and inter population variability F IS , testing relationship among five genetic groups to establish the genetic distance among them. The high level of observed heterozygosity values varied between 0.537 and 0.7871. Generally, F IS was low, suggesting that the endogamy did not exist between the tested animals.

The PSS genotypes of 596 F2 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: pHu (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 pH45 (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.

The PSS genotypes of 596 F2 pigs produced by initial mating of Brazilian native boars commercial sows and were characterized by PCR-RFLP and their carcass and performance traits were evaluated. Among the 596 animals analyzed, 493 (82.72%) were characterized as NN and 103 (17.28%) as Nn. With respect to carcass traits, Nn animals presented higher (p < 0.05) right half carcass weight, left half carcass weight, loin depth and loin eye area, and lower shoulder backfat thickness, backfat thickness between last and next to last but one lumbar vertebrae and backfat thickness after last rib at 6.5 cm from the midline compared to NN animals. Nn animals also showed (p < 0.05) higher values for most of the cut yields, indicating higher cutting yields for animals carrying the n allele and lower values for bacon depth, confirming lower fat deposition in carcass. In addition, Nn animals presented (p < 0.05) lower values for the performance trait weight at 105 days of age. These results indicate that animals carrying the PSS gene generate leaner carcasses, higher cut yields, and that the effects of the gene can be observed even in divergent crosses.