Genetics and breeding: Approaches Investigated to Correct for Preferential Treatment

摘要

Simulated data were used to investigate the effec- tiveness of three approaches to correct for preferential treatment in the genetic evaluation of US dairy cat- tle. The methods tested included power transforma- tions applied to the phenotypic records, fitting a ran- dom preferential treatment effect to suspect records that were defined according to magnitude of residual, and a two-group mixture model. Transformation of records with a power of 0.1 reduced bias to zero, but had a very adverse effect on ranking.