Comparison of M. semitendinosus morphometry and structure in gilts and barrows at market age.

The aim of this paper was to investigate the differences in morphometric characteristics and histological structure of m. semitendinosus, between gilts and barrows of German Landrace breed at the end of the fattening period. Morphometric characteristics (weight, length, diameter and cross sectional area) of m. semitendinosus were not significantly different, while gender as a factor influenced the histological properties of this muscle. A very high statistical difference (p<0.01) in the total number of muscle fibers in m. semitendinosus was determined, with gilts having a higher total fiber number. The cross sectional area of fast twitch oxidative (FTO) fibers was significantly higher (p<0.05) in barrows. Gender did not affect the distribution of different fiber types: in both gender, the most present fiber types (48-52 %) were fast twitch glycolitic (FTG), FTO fibers represented 27-30 % of the total fiber number, while slow twitch oxidative fibers (STO) were the least represented (approximate to 20 %).