Application of genomics to identify genes influencing economicallyimportant traits in livestock.

The objective of this paper was to review the current status of the tools used to identify genes influencing economically important traits in livestock, and give an example using markers developed for meat tenderness. The current linkage maps comprise 4,000 microsatellites and 1,000 single nucleotide polymorphisms. The complete bovine genome sequence is now available. This information will be useful to identify genes affecting production traits. It will also enable identify causative mutations of the traits of interest. There are different methods to identifying causitive mutations in the genes of the with quantitative trait loci (QTL); maximum likelihood and mean squares are the most commonly used. Quantitative trait loci have been detected in several bovine chromosomes. The ì-calpain gene has beenidentified and associated with meat tenderness. Marker information can be now incorporated in animal breeding programs and will improve their overall effectiveness