Animal Science Department


Date of this Version

January 1983


Published in J Dairy Sci 1983, 66:927-934. Copyright © 1983 The American Dairy Science Association. Used by permission.


The frequently arbitrary application and definition of genetic groups makes sire grouping the “weak link” of the sire evaluation process. A selection model for records not in the model for observations is similar in form to the genetic groups model. Implications of this correspondence are discussed and illustrated through a small example. Guidelines for possible grouping strategies also are discussed.