The Muscle Fibre Characteristics and the Meat Quality of m. longissimus thoracis from Polish Native Zlotnicka Spotted Pigs and the Crossbreed Fatteners from the Crossing of Duroc and Polish Large White Boars

The aim of the investigations were to assess the meat raw material of the domestic Zlotnicka Spotted swine breed as well as its hybrids with Duroc and Polish Large White breeds with respect to quality, technological usefulness, and muscle fibre composition and structure. The suitability of individual swine genetic groups (Zlotnicka Spotted x Zlotnicka Spotted, Zlotnicka Spotted x Duroc, Zlotnicka Spotted x Polish Large White, Zlotnicka Spotted x Zlotnicka Spotted/Duroc) for the production of heavy fatteners which can be used as slaughter raw material to manufacture raw and raw-ripening meat products was ascertained. Zlotnicka Spotted pigs were characterised by a statistically significantly smaller proportion of IIB fibres and a higher share of I and IIA fibres in the longissimus thoracis muscle in comparison to the hybrids of this breed with Duroc and Polish Large White breeds. The diameter of all muscle fibre types in the longissimus thoracis muscle of the Zlotnicka Spotted breed was greater than in hybrids. No statistically significant differences were found between the parameters of colour and the free drip and the water absorbability of the loin of the Zlotnicka Spotted breed pigs and their hybrids with Duroc and Polish Large White breeds. The examined meat was characterised by a small free drip and good water absorbability. The hybrid pigs (Zlotnicka Spotted x Duroc) were characterised by the highest content of intramuscular fat (IMF) in the longissimus thoracis muscle, which resulted in the lowest sheer force of roasted loin and the lowest thermal drip compared to other hybrids. Smoked, raw loin obtained from the longissimus thoracis muscle of the Zlotnicka Spotted breed was found to be the most tender, whereas tenderness of the identical loin derived from the longissimus thoracis muscle of the Zlotnicka Spotted bred hybrids with the Duroc and Polish Large White breeds was poorer. Due to the small headage of the Zlotnicka Spotted breed, the appropriate numbers of fatteners of good meat quality parameters suitable to manufacture raw, ripening meat products can only be secured by the crossing of this breed with other meat breeds. Therefore, it appears that crossing the Zlotnicka Spotted pigs with Duroc pigs would be a suitable solution.