Epsilon Archive for Student Projects

Abstract

International genomic evaluation for Brown Swiss population known as InterGenomics, was officially launched in 2011 by Interbull Center in Uppsala, Sweden. The routine evaluation is currently carried out using a single-trait approach where estimated breeding value from multi-trait across countries evaluation (MACE EBV) are used as a dependent variable and genetic corre-lations are assumed to be equal to one between countries. The current study is exploring a multi-trait approach as an alternative to the routine one. This approach uses the estimated breeding value (EBV) from the national genetic evaluations as a dependent variable and make use of the genetic correlations estimated between countries as well. In this study, we compared reliability from both approaches for Brown Swiss (BSW) and Holstein (HOL) dairy cat-tle in traits with different heritabilities. Findings show that single-trait ap-proach resulted in higher reliability than multi-trait approach. There were some cases where multi-trait approach showed a small gain in evaluations variance for traits where heritability and genetic correlations were low. Fur-ther work may be required to check the extent of bias that could exist in both approaches.