The Impact of Daughter Misidentification on the Genetic Evaluation of Dairy Sires

Abstract Text:   A study was undertaken to quantify the effect of daughter misidentification on the bias of genetic evaluation of sires.  Breeding values (BVs) were estimated using data on 479,421 cows that were DNA-verified to sire.  The BVs were used to calculate a breeding worth (BW) index of seven traits (BW_DNA).  Sire selection was done within breed and year of birth on either the national BW (BW_NAT), based on data in which paternity is primarily determined through mating records, or BW_DNA. The correlations between BW_NAT and BW_DNA were close to the expectation of 0.85.  Selection of the top 10 sires resulted in a difference in BW_DNA of 15 to 21 BW.  When there is a substantial increase in the number of DNA-verified cows, evaluating sires based on this data will result in improved genetic evaluations and rates of genetic gain.

Keywords:

DNA-verified

Sire evaluation

Within-herd heritabilities