Sheep coats can economically improve the style of western fine wools

Wethers from a mixed bloodline flock in western New South Wales were coated for 12 months between August 1998 and August 1999. The coated and a similar number of uncoated control wethers from each of the 11 bloodlines (2 medium, 3 fine and 6 superfine) were grazed together as part of a larger mob. Dye bands were placed in the fleeces of each wether before fitting of the coats and were removed before shearing when a mid-side sample was taken and a number of subjective assessments made of each fleece. The major effect of the sheep coats was to improve the style of the coated wool by about 1 style grade. This was largely the result of the coated fleeces being whiter, with less tip weathering and lower levels of dust and vegetable mater. There was no significant difference between the 2 treatment groups in wool production, fibre diameter, staple strength or resistance to compression. A partial budgeting approach was used to evaluate the economic returns from using sheep coats based on the observed differences in wool quality. Clean prices and wool values per head for the coated and uncoated sheep from each of the 11 bloodlines were calculated using NSW Agriculture's wether trial software and the flock least squares means for each wool trait. The analysis established it would be economically viable to coat all the sheep except the medium-wool sheep. Even allowing for 20% improvement in the price differential for medium wool, coating them was not economically viable.