Abstract

Commonly used cow evaluation methods apply principles of the selection index to herdmate deviations on the cow and close relatives. In contrast, best linear unbiased prediction adjusts records by best linear unbiased estimates of all fixed effects in the model and simultaneously weights those adjusted records by selection index principles. It would be advantageous to utilize all known relationships among animals in the herd in the latter method, but computations have been too laborious, requiring the inverse of the numerator relationship matrix. By a method of writing this inverse rapidly without computing the relationship matrix itself all relationships can now be used in intraherd cow evaluation. Further, tests of progeny by artificial insemination on sires used in the herd can be incorporated.