THE CONTRIBUTION OF PROGENY OF UNCERTAIN PATERNITY TO THE ACCURACY OFSIRE EVALUATION

Recent advances in statistical methodology now permit the genetic eval uation of animals with uncertain pedigrees. Although widescale practic e of these techniques is not likely, implementation will never occur u ntil we characterize the effect of uncertain pedigrees on the accuracy of animal evaluation. This work develops the framework for such a cha racterization, illustrating the contribution of uncertainly identified records to accuracy of evaluation through a hypothetical example. The effect of including records of uncertain paternity is greatest for si res with few certainly identified progeny. Thus, young sires stand to benefit the most from the inclusion of progeny records with uncertain paternity. In general, as the level of uncertainty in the data is repl aced by the inclusion of progeny with certain paternity, the accuracy of evaluation increases. However, situations do arise in which the acc uracy unexpectedly declines with the addition of progeny records with certain paternity.