Effect of misidentification on genetic gain and estimation of breeding value in dairy cattle populations

The effect of pedigree errors on estimated breeding value and genetic gain for a sex-limited trait with heritability of 0.25 was evaluated. Ten popula tions of 100,000 milking cows were simulated with correct paternity identif ication for all animals, and 10 populations were simulated with 10% incorre ct paternal identification. The initial populations consisted of 100,000 un related individuals, and simulations were continued for 20 yr. The BLUP gen etic evaluations were computed every year by an animal model analysis for e ach complete population. Estimated breeding values for the populations with 10% incorrect paternity were biased, especially in the later generations. Genetic gains were 4.3% higher with correct paternity identification. Reduc tion of pedigree errors by paternity confirmation of daughters of test sire s by DNA microsatellites may result in considerable economic benefits, depe nding on the cost of testing in each country.