Histochemical analysis of skeletal muscular tissues of pigs according to genotype MYF4

The results of histochemical analysis of three muscles m. triceps brachii (MTB), m. longissimus thoracicus (MLT) and m. rectus femoris (MRF) of two groups of pigs created according to the genotypes MYF 4 are presented. Determination of MYF 4 genotypes was made by PCR method and for histochemical analysis was used 5 animals detected as homozygote MYF 4- AA type and 5 animals of heterozygote genotype myogenin-AB out of the total of 25 individual animals tested. The histochemical analysis proved that homozygotes AA have had bigger fat cells than heterozygotes AB in three studied muscles in average. The size of fat cells in MLT - 41.10μm or 38.50 μm respectively dominated in both groups of animals. Percentage surface representation of interstitial tissues was higher in the studied muscles of heterozygote MYF 4-AB. The volume of ligaments was the highest in MRF (3.80% or 3.90% respectively) in both groups (myogenin - AA and AB). The average thickness was of three studied muscles muscle fibres higher at homozygote genotype myogenin-AA than in heterozygote myogenin-AB. The thickest fibres in both genotypes were in MRF (88.60 μm, and 84.72 μm respectively) and the lowest in MTB (73.30 and 69.40 μm respectively). The highest values of muscle fibres thickness were detected in α-White fibres. Their percentage surface representation corresponded to this in all three types of muscles of both studied genotype myogenin groups.