HISTOLOGICAL AND HISTOCHEMICAL PROPERTIES OF M. SEMITENDINOSUS IN GERMAN LANDRACE PIGS AT BIRTH AND MARKET WEIGHT

Current intensive pig meat production conditions impose the need to expand the knowledge about skeletal muscle characteristics, with the aim to improve both production of pig lean meat and meat quality. Histological and biochemical characteristics of the muscle highly influence the quality of meat, with muscle fiber number, size and fiber type distribution being important constituents. The objective of this study was to examine the structure of m. semitendinosus of piglets at birth, and slaughter pigs at the end of fattening. Total muscle fiber number was 350 x 10(3) in newborn piglets and increased up to nearly 900 x 10(3) in slaughter pigs. At birth, the muscle consisted of 3.76% primary fibers and 96.24% secondary fibers. At slaughter, slow-twitch oxidative fibers represented 21% of the total muscle fiber number, fast-twitch oxidative fibers represented 28 % while the majority of fibers (52%) in m. semitendinosus were of fast twitch glycolitic type. Obtained results indicate that postnatal muscle growth is accomplished mainly by muscle fiber hypertrophy.