These sires have all gone through the rigorous performance testing station.
 To enter a calf for the trial, breeders send in the stud book paper on each calf they want to enter to the breeding advisory committee for them to consider which are most interesting. On the paper the birth weight is stated as well as the birth weights, weanling weights and yearling weights of the dam and granddams offspring. The calves epd are on the paper to, as well as pedigree etc. There are a lot of criteria the calves must fill.
Upon being accepted, they are sent to the performance testing station in August. They are weighed every two weeks and health checked. Their adjusted weanling weight is registered and later on yearling weight. The trial ends in March, and towards the end the calves are scored for conformation, foot health (before trimming) size of testicles, and since 2013, scanned for marbling. Even if the calves average daily gain is higher than average, minimum scores for conformation and size of testicles must be met if the calf is to be eligible for the sale and as a potential AI sire. VikingGenetics chooses two Hereford bulls per year at the moment, due to the demand for Hereford semen.