Animal Science Department


Date of this Version

January 1982


Published in J Dairy Sci 1982, 65:164-167. Copyright © 1982 The American Dairy Science Association. Used by permission.


Theoretical weights for prediction of a son's genetic evaluation from genetic evaluations of his sire and dam are derived. Weights for sire and dam are equal and depend on number of daughters of the son when the bull evaluation is from his daughters alone and cow evaluation is from her records alone. Mixed model procedures which incorporate records of other relatives change theoretical weights. When records of daughters of both the son and his sire are used in evaluations of both, theoretical weights for the sire to predict the son's evaluation are about .50 for many combinations of daughter numbers of the bulls. Including the evaluation of the sire of the cow in her evaluation changes the theoretical weight to predict the son's evaluation from the dam's evaluation only slightly from the situation when only the dam's records are used. In addition, the theoretical weight for the maternal grandsire is nearly zero.