Data is collected at the farm and transmitted to the main GIS office where a technician enters the data into a central database and interprets the scan data. The EBV program weights the individual EBVs by their appropriate economic value to generate an index that provides the best estimate of the economic value of the candidates. Individuals are ranked according to their potential economic value, but it is recognized that structural considerations of both replacement gilts and boars must be taken into consideration prior to their entrance into the breeding population. This is the compromise that breeders make in the realization that structure and visual perception are also economically important traits. GIS recognizes that durability and fitness are also required of its breeding populations to provide a profitable genetic resource.
Selection is practiced at the top tier of the hierarchical breeding pyramid.
Only purebred animals exist at this level the formulation of the actual breeding product begins at the F1 multiplier. The parent populations are derived from the nucleus production level. All of the M-Line gilts are performance tested using the same selection criteria as was used in the nucleus level. This selection reduces the genetic lag between the original source herds and the multiplication tier. The GIS Line-5 boar is derived from the nucleus tier.