Histochemical Analysis of Musculus Vastus Lateralis in Pigs of Different Genotypes

The histological and histochemical structure of musculus vastus lateralis , thickness and frequency of different muscle fibre types were compared in pigs of various genotypes ( NN, Nn, nn ). As found, pigs with genotypes ( Nn and nn ) have a larger proportions of white muscle fibres ( 57,17 and 61,57 % ) as compared with the group of NN pigs (54,21 % ). On the other hand, this group ( NN ) have a highest relative volume of muscle fibres ( 91,15 % ) and lowest relative volume of intramuscular connective tissue ( 8,85 % ). The lowest relative volume of muscle fibres ( 86,50 % ) and highest amount of connective tissue ( 13,50 % ) was found in pigs of nn genotype. The thickness of muscle fibres in pigs ( Nn and nn ) has higher values than in the dominantly homozygotic ( NN ) pigs. The highest differences were measured in thickness of white and red fibres between recessive homozygotic ( nn ) and dominantly homozygotic ( NN) pigs