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Báo cáo sinh học: " Accounting for genomic pre-selection in national BLUP evaluations in dairy cattle"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học quốc tế đề tài: Accounting for genomic pre-selection in national BLUP evaluations in dairy cattle | Patry and Ducrocq Genetics Selection Evolution 2011 43 30 http www.gsejournal.Org content 43 1 30 Ge n et i cs Selection Evolution RESEARCH Open Access Accounting for genomic pre-selection in national BLUP evaluations in dairy cattle Clotilde Patry1 2 and Vincent Ducrocq 1 Abstract Background In future Best Linear Unbiased Prediction BLUP evaluations of dairy cattle genomic selection of young sires will cause evaluation biases and loss of accuracy once the selected ones get progeny. Methods To avoid such bias in the estimation of breeding values we propose to include information on all genotyped bulls including the culled ones in BLUP evaluations. Estimated breeding values based on genomic information were converted into genomic pseudo-performances and then analyzed simultaneously with actual performances. Using simulations based on actual data from the French Holstein population bias and accuracy of BLUP evaluations were computed for young sires undergoing progeny testing or genomic pre-selection. For bulls pre-selected based on their genomic profile three different types of information can be included in the BLUP evaluations 1 data from pre-selected genotyped candidate bulls with actual performances on their daughters 2 data from bulls with both actual and genomic pseudo-performances or 3 data from all the genotyped candidates with genomic pseudo-performances. The effects of different levels of heritability genomic pre-selection intensity and accuracy of genomic evaluation were considered. Results Including information from all the genotyped candidates i.e. genomic pseudo-performances for both selected and culled candidates removed bias from genetic evaluation and increased accuracy. This approach was effective regardless of the magnitude of the initial bias and as long as the accuracy of the genomic evaluations was sufficiently high. Conclusions The proposed method can be easily and quickly implemented in BLUP evaluations at the national level although some .