Estimating Son's Progeny Test from His Pedigree Information

Abstract

United States Department of Agricul- ture Dairy Herd Improvement files were used to assemble pedigrees on 705 artifi- cial insemination and 2293 nonartificial Holstein bulls. Each pedigree contained estimates of breeding values (twice Pre- dicted Differences) for son, sire, and ma- ternal grandsire based on proofs of first lactation daughters versus herdmates with all lactations, and various estimates of breeding value of the dam from devia- tions of her individual lactations from herdmates. Pedigrees on 340 sons enter- ing artificial insemination as young bulls gave correlations of .47 between son and son's pedigree index, .43 between son and sire, .24 between son and maternal grand- sire, and .21, .16, .16, .08, and .08 between son and dam's lactations one through five. With the exception of the correlations of son with dam's lactations four and five, values are close to ex- pected. Young bull indexes based on United States Department of Agriculture Predicted Differences and Cow Indexes can provide an effective tool for screening applicants for a young sire sampling program. Possible refinements would be to give the dam's first lactation more weight than later lactations or to use only the first three lactations in computing her Cow Index.