Genetic parameters for subjectively scored traits in yearling and adult fine wool Merinos

Abstract

Genetic parameters were estimated for classer grade, handle, style, crimp definition, colour, neck wrinkle and body wrinkle scores in fine wool yearling wethers and yearling and adult ewes. Most traits had heritabilities of 20-40% and high genetic correlations (0.8 or more) between yearling and adult scores. The estimated genetic correlation between handle scores of independent assessors exceeded 0.99. Genetic correlations between subjective measurements and objectively measured traits were generally favourable. Softer handle was associated with lower fibre diameter (genetic correlations of 0.56 in yearlings, 0.57 in adults), increased yield (-0.55 and -0.39) and whiter colour (0.45 and 0.32). Better crimp definition was associated with lower variability of fibre diameter (0.45 and 0.46), whiter colour (0.31 and 0.51) and stronger staples (-0.24 and -0.37).