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title: "4.15.3.1 Advantages of genomic selection (2024)"
canonical: "https://wiki.groenkennisnet.nl/space/TAB/288260372/4.15.3.1%20Advantages%20of%20genomic%20selection%20(2024)"
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Genomic selection makes it possible to select animals based on an estimated breeding value before they have reached the age to produce a phenotype themselves. The importance of this is that with traditional methods, with pedigree and performance data, the most accurate estimate of the breeding value of an individual without phenotype, or without descendants with phenotypes, comes from the average of the Estimated Breeding Values (EBV’s) of its own parents. This is regardless of the number of sibs and cousins with phenotypes as their relevant information flows through the sire and the dam. This estimate is *always* incomplete as it omits all the variation arising from the Mendelian sampling during the meiosis, which makes up half the total genetic variation.  With sufficient data on genetic markers, the Mendelian sampling from parent to offspring can be observed and used in evaluations to increase accuracy, approaching a high accuracy when sufficient data in the reference population are present. This advantage of genomics has greatest impact where information on Mendelian sampling terms limits the selection accuracy: age-limited traits, where phenotypes come later in life and later than desirable breeding ages; sex-limited traits such as egg production, where information only comes from female relatives; or destructive traits where a phenotype can only be obtained after slaughter, such as carcass traits. It has also impact on the genetic resistance against disease that can only measured after an (unwanted) infection or after a challenge test with the pathogen. In practical breeding programs where full sibs are born, genomic selection is applied to establish the differences between full sibs due to the Mendelian sampling phenomenon. The combination of advantages of genomic selection gives benefits which can result in increased accuracy, and/or increased intensity of selection, and/or decreased generation intervals, and each of these will result in a boost to genetic gain. This is summarized in the picture below:

![image](media://6ad6e687-c028-4405-b59a-2ff1ca1173aa)