Genetic Correlations Across Ages for Greasy Fleece Weight and Fibre Diameter in Merino Sheep

Abstract

While adult wool production is a key determinant of profitability of Merino flocks, much of the on-farm recording through MERINOSELCT is focused on assessments at 12 or 18 months of age. While there have been numerous studies in research flocks examining these relationships these results have not been validated in industry flocks. The aim of this paper was to investigate the genetic correlations between multiple age expressions of fibre diameter and greasy fleece weight using the MERINOSELECT database. The results support earlier research in that, while the correlations across ages are generally very high they also suggest that at least one adult assessment of fleece weight and fibre diameter would be beneficial for the breeding program. As a result of this work the genetic evaluation for Sheep Genetics will be modified to include annual expressions of adult fleece traits.