Animal model evaluation within herd linked to national evaluations
1990
Wiggans, G.R. | Vanraden, P.M.
Computer programs with modest computational requirements were developed to calculate animal model evaluations on a herd basis. Evaluations are connected to the national system through parents with national evaluations and parents assigned to unknown-parent groups. The programs can be used to compute evaluations of animals in herds not included in national evaluations or to update evaluations between semiannual national evaluations for herds that are included. Computer memory requirements are reduced dramatically from those of the national system, because only data for animals with records or progeny in the herd are in memory at any time. Computational requirements also are reduced by processing only lactation records initiated after an adjustable date; earlier lactation records are replaced by management group deviations. For older animals, processing is reduced further by not updating the animals's evaluation. When progeny evaluations no longer are updated, the animal's evaluation no longer is required. Solutions for management group, permanent environmental, and herd-sire effects are by Gauss-Seidel iteration and for animal effects by approximate successive overrelaxation.
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