Genetic influences on pork quality

The genetic influences on pork quality including that of the major genes, the halothane gene and the RN gene, are discussed in this paper. Breed differences and genetic parameters for meat quality traits are summarise. In addition, genetic influences on boar taint and further developments in genetic improvement of meat quality are discussed. The effect of the halothane gene on meat quality traits and the relationship between this gene and muscle morphology is discussed. In addition, the RN gene is described which has a high frequency in Hampshire and marker information to this gene is presented. lndications for further major genes influencing meat quality traits are summarised. Breed differences in meat quality are due to different levels of the halothane gene as well as different levels of leanness. Special reference is given to Durocs, the breed with a higher intramuscular fat content. The summary of genetic parameters shows moderate heritabilitics for meat quality traits pertaining to PSE and dark, firm, dry (DFD) while intramuscular fat content is highly heritable. Genetic correlations between meat quality traits reflect characteristics of PSE and DFD meat. Components of boar taint differ between breeds. In addition, these components are highly heritable and might be influenced by major genes. Currently, DNA tests exist for the halothane and RN gent. It is most likely that further major genes or marker related to quantitative trait loci (QTL) will be detected. Meat quality traits should be incorporated into selection decisions in order to prevent further deterioration in these traits as a consequence of selection for higher lean meat growth.