Application Evaluation Of Single Step Procedure In Genome Selection

Using the high density single nucleotide polymorphism(SNP) markers covering the whole genome, genomic selection(GS) can increase the accuracy of estimated breeding values(EBV) by mapping all the genes or QTL affecting the traits under consideration.GS has the advantages of increasing the accuracy of EBVs estimationand decreasing the generation interval by selecting individuals at the early stage of life. Implementationof genomic selection need for individual genotyping. However, for some of the smaller value of economic species(pig or poultry), in practical breeding program were all individual genotyping is not realistic.Single step method allows part of the individual genotyping can carry out genomic selection, and overcome these problemeffectivelyin genomic selection.1In this study,we developed thesingle stepprocedure genome selection calculation and evaluation software base on R language.The developed program is rubust, and flexible with matrix construction. It can be confidencially used in further investagations and applied to the genomic prediction of livestock.2 The results indicated that single step procedure could greatly improve the accuracy and unbiasedness of genomic prediction for feeding traits(0.2%~10.7%), carcass traits(3%~10.1%) and growth traits(5.4%~13.9%) of broiler chicken compared with BLUP and GBLUP.3 The resultsfrom simulationshow thatthe accuracy of single step procedure is better than the traditional BLUP and GBLUP method.The genetic gain of single step procedure can be increased by ~25%(BLUP) and ~4%(GBLUP), and even larger for traits with low heritability or individuals without phenotypes before selection.4 The simulation of pig breeding process and the implementation of genome selection through single step procedure study show that, parent average breeding values used to selecting genotyped individual based on parent average, and genotyping 40% of candidate population is enough for obtaining the maximum potentially genetic progress through single step procedure.As the reference population continues to expand, the accuracy of genetic evaluation and the genetic progress of each generation are improved obviously.