Genomic estimated breeding values (GEBVs) are used for computing additive or dominant SNP effect, the first column should be the sample id, and the rest columns are the additive or dominant GEBVs, an example with three individuals is as follows:
id add Ind1 -1.1345 Ind2 0.3245 Ind3 0.0234
The file should be assigned to parametric option --gebv.
NOTE
If --add is specified, additive breeding value should be provided, so does the flag --dom. If both --add and --dom are specified, the breeding values of additive and dominance should be provided in file, the column of additive breeding values should be at the front of dominant breeding values.