Carcass Composition and Quality of Meat of Pulawska and Pulawska x PLW Crossbred Pigs Fed Rations with Naked Oats

The study aimed to determine the impact of a 60% inclusion of naked oats in feed rations for Pulawska pigs and Pulawska x Polish Large White (PLW) crossbreds on the fattening performance, carcass composition, and meat quality. It was demonstrated that—independent from their diet—Pulawska pigs showed a daily weight gain about 14.5% lower (p ≤ 0.05), with about 15% higher feed conversion rate. The experimental factors showed no impact on the dressing percentage, meatiness, and backfat thickness, except that the “eye” of the loin was significantly smaller (by 4.55 cm²) in Pulawska pigs. There was no interaction effect (diet/breed) for the pigs’ performance results and carcass composition. A 60% inclusion of naked oats in the pigs’ diet did not affect the weight of primal cuts in the right-side half-carcass. Compared to Pulawska pigs, crossbreds featured a significantly lower weight of bacon and ribs (by 1.17 kg) but a higher (p ≤ 0.05) weight of fillet (by 1.0 kg) and ham with shin (by 0.43 kg). The diet had no impact on the evaluated muscles, except a reduction (by 2.3 points) in colour lightness (L) of musculus semimembranosus in fattening pigs receiving feed rations with a 60% share of oats. Both muscles in Pulawska pigs showed significantly better (p ≤ 0.05) water-holding capacity and reduced colour lightness (L) in comparison to crossbred pigs. Moreover, the longissimus lumborum muscle of Pulawska pigs had a higher chroma (C) and a lower hue (H). The contents of essential nutrients in the evaluated muscles did not depend on the pigs’ diet and breed, except that a higher by 0.3% (p ≤ 0.05) intramuscular fat content was found in the longissimus lumborum muscle of Pulawska pigs. Neither of the experimental factors showed significant impact on the total saturated fatty acids (SFA) and total unsaturated fatty acids (UFA), or on neutral or hypocholesterolemic (DFA) and hypercholesterolemic fatty acids (OFA) in the evaluated muscles. The muscles of Pulawska x PLW pigs contained more (by 1.77% FA in the longissimus lumborum and 1.16% in the semimembranosus) polyunsaturated fatty acids (PUFA) than the muscles of the Pulawska breed (p ≤ 0.05). In addition, naked oats included in the pigs’ diet increased (p ≤ 0.05) the share of PUFA in intramuscular fat. The muscles of Pulawska pigs, in comparison to the muscles of crossbreds, showed a significantly improved ratio: by 66% and 69% in the longissimus lumborum and the semimembranosus muscles, respectively. To sum up, a 60% inclusion of naked oats is recommended in the rations of both Pulawska pigs and Pulawska x PLW crossbreds, since it allows satisfactory carcass composition and meat quality to be maintained. Pulawska pigs had worse productivity ratios but showed improved meat quality traits in terms of the n-6/n-3 ratio.