Histochemical fiber type composition in 12 skeletal muscles of miniature pigs

In 12 skeletal muscles of adult miniature pigs histochemical fiber type analysis was performed. Longissimus dorsi, psoas major, diaphragm and fore- and hind-limb muscles were composed from SO, FOG and FG fiber types showing characteristic clump distribution. The muscles differed in the first place by the frequencies of SO and FG types (7-70% and 19-79% respectively); the proportion of FOG type varied considerably less (10-32%). On the other hand in the masseter muscle only SO and FOG types with a mosaic distribution were demonstrated (28% and 72% respectively). In the majority of muscles the prevailing fiber type has also the largest diameter, but the differences between individual types were mostly insignificant. The largest diameter was found in the masseter muscle fibers--around 70 microns, which is 20-30 microns more than in the other muscles.