Expression of body weight, fleece weight and fibre diameter in across flock genetic evaluation

Abstract

Historically, estimated breeding values (EBVs) for body weight, fleece weight and fibre diameter of Australian sheep were produced using two different models. With the forming of the Sheep Genetics Australia (a national sheep genetic evaluation system) it was necessary to identify the most appropriate method. This paper compares the two most common methods: data analysed on the observed scale and percentage-transformed data. The results indicate that transforming observed data to a proportion of the contemporary group mean has beneficial outcomes for genetic evaluation. Transformed data have a slightly higher heritability and the resultant EBVs better reflect phenotypic differences in different production environments.