LIPID-COMPOSITION OF ADIPOSE-TISSUE AND MUSCLE IN PIGS WITH AN INCREASING PROPORTION OF MEISHAN GENES

The purpose of this study was to estimate the effect of the proportion of Meishan (MS) genes upon the lipid composition of longissimus dorsi and trapezius muscles and perirenal and s.c. dorsal adipose tissues. Five groups of 11-15 pigs with 0, 12.5, 25, 37.5 and 50% MS genes were made up from a large herd of crossbred animals (0-100% MS dams x Pietrain sires). Results showed that: (1) the i.m. lipid content was higher in 1/2 MS than in controls and 1/4 MS pigs. Differences in the fatty acid composition of i.m. lipids, as related to genotype, depended more particularly on muscle fatness as the fatty acid compositions of triglycerides and phospholipids were little affected by the genotype. (2) The weight of perirenal and s.c. dorsal adipose tissues increased with the proportion of MS genes. Differences in the chemical composition of the adipose tissues were not related to the proportion of MS genes. The fatty acid composition was little affected by the genotype. Although the levels of polyunsaturated fatty acids decreased with increasing proportion of MS genes, these small variations had no marked influence on adipose tissue quality.