title: An indirect method of forming expressions for the inverses of genetic variance-covariance matrices for two traits.
abstract: Pratical application of best linear unbiased prediction procedures to large data sets requires efficient use of computer time and storage. One way to increase effiency of computer use is to eliminate extraneous equations, i.e., equations for genetic predictions that are of no or little practical value. Rules are derived for obtaining, by inspection of the pedigree, a matrix representing the inverse of the genetic variance-convariance matrix for two traits in which all genetic values are not represented. The need to form the genetic variance-covariance matrix itself is eliminated. The condition in which the expression is the exact inverse is specified. An illustration is provided. Inbreeding is not considered.
mesh_terms: D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle / Q000235:genetics*; D003201:Computers; D005260:Female; D007774:Lactation; D008433:Mathematics; D010375:Pedigree; D011247:Pregnancy