Genetic parameters and analysis of factors affecting variations between backfat and Semimembranosus muscle fatty acid composition in heavy pigs

This study was conceived to evaluate the variations between backfat (BF) and Semimembranosus (SM) muscle fatty acid (FA) composition in 789 heavy pigs and to estimate the genetic and phenotypic correlations and the heritability values of these variations. Most FAs showed a common genetic basis controlling their proportion in SM muscle and BF, while the n-6/n-3 ratio, alpha-linolenic and erucic acids displayed a genetic control more oriented towards tissue-specific molecular pathways. All variations between the FA composition of BF and SM muscle showed low-to-medium heritability values, suggesting that there are also genetic mechanisms capable of differentiating the deposition of FAs in BF from those in SM muscle. This result implies that a better knowledge of the genes differentiating the FA composition of BF and SM muscle could provide new tools allowing to select, in a partially independent manner, the FA composition of muscle and subcutaneous fat.