ABSTRACT
Meat quality can be defined in terms of composition, consumer appreciation, and safety. Each of these criteria are influenced by environmental and genetics factors. In recent years there have been major advances in knowledge about the organization of genomes of many species, including the major livestock species. This knowledge has provided methods and resources to investigate the genetic control of commercially important traits, including meat quality. In addition methods have been developed to
simultaneously explore the expression of large numbers of genes. Together these “genomics” approaches will provide information to assist the selection of animals with the best genotypes for particular production needs and help to develop diets best suited to producing meat with desired characteristics. At present the work is in its infancy. Although genome mapping approaches have localized some of the genes controlling important aspects of meat quality to regions on chromosomes-quantitative trait loci-few of the genes have themselves been identified. For those that have, there have been some unexpected findings such as variations in major genes responsible for large phenotypic differences in one breed being associated with little or no phenotype difference in another. Also, breeds with an extreme phenotype in a particular trait might carry less extreme alleles than a breed with a less extreme phenotype. At the level of the genome, functional polymorphisms might occur at considerable distances from the genes thought to control the phenotypic difference. The current explosion of information available on the genomes of many species, including livestock, arsing from genome sequencing projects will allow the functioning of the genome to be investigated in greater detail. In the short term this information will be used to enhance phenotypic selection programs, but will, in due course, allow selection strategies for the improvement of multiple difficult-to-measure traits to be developed.
