Microstructure of Longissimus Lumborum Muscle and Meat Quality of Native Polish Pig Breeds: Złotnicka Sp Otted and Puławska

In 50 fattening pigs representing two Polish native breeds: 24 Złotnicka Spotted, 10 Puławska and 16 F₁ ♀ (Polish Large White × Polish Landrace) × F₁ ♂ (Duroc × Pietrain) crosses microstructure of muscle, carcass and meat quality were studied. Puławska pigs had the thickest backfat, but the loin eye area was smaller only in comparison to crossbreds. Compared to the Puławska breed, the meat of Złotnicka Spotted pigs was darker, which was associated with a greater percentage of type I fibres and a smaller percentage of type IIB fibres. Puławska pigs distinguished themselves from the other groups under study by the greatest density of fibres per mm². Smaller diameter of type IIA and IIB fibres and higher total number of fibres were found in Puławska breed pigs compared to Złotnicka Spotted, despite the absence of differences in the loin eye area. Smaller thickness of the fibres favourably affects meat quality, and might be considered an indicator of a delicate structure of meat.