Muscle fibre types, fat deposition and fatty acid profile of Casertana versus Large White pig

Used were 8 castrated males and 8 entire females of indigenous Casertana and Large White pigs, 4 animals of each breed. In Longissimus dorsi (LD) and Psoas major (PM) muscles the morphometric characteristics of FG (fast glycolytic), FOG (fast oxidative glycolytic) and SO (slow oxidative) fibre types was performed and their percentage determined. Determined was also the area of adipocytes from internal and external layer of adipose tissue from backfat, shoulder, dorsal and loin regions. The SO were larger than FG and FOG fibres (P< 0.05-0.001) and the size of FG fibres was significantly different among the two breeds considered, higher in Large White pigs and lower in Casertana. LD muscle was characterized by FG and SO fibres larger than PM (P<0.001). Males had fibres larger than females in both muscles and breeds. The dorsal region had bigger adipocytes in both the pig breeds (P<0.05-0.01). In comparison with the outer fat layer, the inner and middle layers showed more developed adipocytes. Differences in fatty acid composition were observed between breeds. Particularly, Casertana pigs showed higher level of essential fatty acids than did Large White. The results showed the particular characteristics of the Casertana breed as compared to pig lines intensively selected for growth efficiency.