What is genomic prediction?
Genomic prediction is an advanced tool that can predict an animal's genetic merit or genetic potential based on analyzing DNA markers such as single nucleotide polymorphisms (SNP).
Using genomic prediction we can predict how an animal will perform before traits are measured, as early as right after the birth, based on DNA marker genotypes without any other information needed.
How does genomic prediction work?
Genomic prediction relies on having a reference population of animals with both DNA markers and performance records of their traits. Genomic Prediction analyzes the relationships between DNA markers and the traits in a reference animal population to generate a prediction equation.
Other animals can then have their DNA analyzed (genotyped) and the prediction equation can then be used to predict their molecular breeding value (MBV) without any other information. Subsequently, genetic merit or genetic potential such as genomic expected progeny difference (gEPD) is derived from the MBV (i.e. gEPD = half of the MBV).
How to genotype selection candidates?
Ear tissue, hair, blood or semen all contain DNA and can be sent to a DNA lab for DNA analysis/genotyping.
What is the accuracy of genomic prediction?
The accuracy of genomic prediction tells us how reliable the predicted genetic merit or gEPD is. Accuracy depends on multiple factors including how inheritable the trait is, DNA marker density, the size of the reference population, and how related the selection candidates are to the reference population.
What is the major advantage of genomic prediction?
Genomic prediction can predict the genetic merit of an animal as soon as its DNA is analyzed, so practically right after birth, without the need to measure the trait in that animal.
This is particularly useful for traits that that are difficult or expensive to measure such as feed efficiency and for traits that are measured relatively late in an animal's life and/or can only be measured by sacrificing potential breeding candidates, such as carcass merit traits.
How is genomic breed composition predicted?
The genomic breed composition (gBC) of an animal is predicted by comparing its genomic profile with the genomic profiles of several purebred reference populations.
The proportion of an animal's genomic profile that matches a pure breed is presented as a fraction, illustrating the breed composition of the animal tested.
The prediction of gBC can be considered as an extension of genomic prediction as it is predicted based solely on the DNA markers of selection candidates in comparison to that of a reference population of pure breeds.
What is genomic retained heterozygosity?
Genomic retained heterozygosity (gRH) is a measure of genome diversity of an individual, and gRH of crossbred animal is predicted based on the gBC of the animal. A larger value of gRH indicates that the animal have a potential to exhibit greater hybrid vigour or heterosis, i.e. an enhanced performance during to crossbreeding.