Whole Genome Selection (WGS) is a term often used in conjunction with SNP chips. It is the industry application of the SNP chip technology.
Most traits that breeders are interested in are caused by lots of small effects that are spread throughout the whole genome (DNA) of an individual. The new SNP technology will offer more bang for your buck by examining a large portion of the genome - not just a small part.
Instead of current genetic markers that occur on one point in the genome (e.g. muscling with the MyoMAXTM gene) WGS offers the power derived from a 50 thousand marker screen throughout the genome of an animal.
Through using SNP chips which contain 50,000 DNA markers, the "Whole Genome" can be investigated to search for multiple genetic markers associated with a variety of traits at one time.
The R&D process is to collect DNA samples and performance data from an extensive and representative set of animals (thousands spread across the industry and the country). DNA samples from these animals are run across the SNP chip and the data analysed to select SNPs that are most predictive for a particular trait, with weightings determined for each SNP. The resulting "SNP Key" consists of 30 to 300 SNPs per trait which account for most of the trait variation and industry animals can then be tested using the SNP Key. Results from the SNP Key can be summed to obtain an estimate of the genetic merit of an individual.
This is similar to a breeding value, but instead of an estimated breeding value predicted from animal measurements and pedigree you will get a Molecular Breeding Value (MBV). If you have both a traditional and a molecular breeding value, these can be combined to give you an even more powerful estimate of breeding merit - a so called genomic breeding value (GBV). This information can be used to make predictions about an animals genetic merit as a parent, even if it has not been measured directly for all of the traits.
Whole Genome Selection marks a point where genomics will move from the laboratory into the paddock and consequently the marketplace.
The benefits of using this technology as a selection tool is that it can result in faster gains through a reduction in the interval from testing to selection and it reduces the need to measure difficult to measure traits such as meat quality or disease resistance.