Genomic models account for genomic preselection by correctly estimating Mendelian sampling terms of preselected animals
It has been previously shown that in breeding programs that do not use external data, genomic models estimate breeding values of preselected animals without preselection bias and with minimal accuracy loss, as long as genotypes of preselected animals and of their parents are used in the evaluation. The objective of this paper was to show that genomic models account for genomic preselection (GPS) by correctly estimating the Mendelian sampling terms (MSTs) of preselected animals. We simulated a single-trait breeding goal with heritability of 0.1, and 15 recent generations undergoing selection. To select the parents of the next generation from the animals in the most recent generation, we genomically preselected 10% of males and 15% of females in generation 15. We then performed evaluations of the preselected animals with both genomic and pedigree models, both including and excluding records on the preselected animals. We also conducted another set of genomic and pedigree evaluations without preselection, to serve as control. Results showed that both the true and estimated MSTs in the control scenario were on average zero, regardless of whether they were estimated with genomic or pedigree models. With GPS, the average true MST was positive, was correctly estimated by genomic models, and hugely underestimated by pedigree models. Compared to the MSTs estimated by pedigree models, the MSTs estimated by genomic models in both GPS and control scenarios had variances that were closer to the variances of the corresponding true MSTs. We concluded that genomic models indeed correctly estimate Mendelian sampling terms of preselected animals, and that how they are able to account for GPS.
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).