Studies in the wool production of grazing sheep. 2. Variation in wool characteristics with season and stocking rate

Abstract

A four-year study of the variation in wool characteristics of both periodic midside fleece samples and whole fleeces is reported. The wools are derived from an experiment (Arnold, McManus and Bush 1964) in which Merino wethers were continuously grazed on improved pastures at four widely different stocking rates. Despite very large differences in pasture availability and nutritional patterns between treatments the fleeces were essentially similar in staple length, fibre diameter, clean scoured yield, wax and suint content, in quality count and subjective characteristics of soundness, handle, colour, and character. The value of the fleeces was similar for all treatments. Staple length and fibre diameter were lowest in late summer and late winter, when feed quantity and quality, respectively, were also lowest. On all treatments over half the fleeces exhibited 'trade tenderness' attributable to undernutrition in summer. Winter shearing minimises the effects of undernutrition in winter on the soundness of the fleeces. The staple length on the tattoo midside was 21 per cent greater than annual growth on the alternate midside region. Possible reasons for this increase are discussed.