Research progress in Single step procedure theory and application in genomic selection

Genomic selection is an emerging technology of genetic evaluation in livestock and poultry. Studies have reported that genomic selection has more advantages than traditional methods，which make it a hot topic in the field of animal genetic evaluation. However，for species with lower economic importance such as poultry and swine，it is difficult to genotype all individuals. Single-step procedure integrates not only phenotypes and genetic markers of genotyped individuals into genomic evaluation，but also field records of non-genotyped individuals through the pedigree of the population，which is an ideal alternative for genomic evaluation. The application of single step procedure in pig（ or poultry） genomic selection has attracted much attention，but there are some key issues to be discussed in practical application. In this paper，the principle of single step procedure，the current status of implementation and related issues of single step method in livestock were reviewed.