Fleece characters and their influence on wool production per unit area of skin in Merino sheep

Abstract

The variations in fleece characters and the dependence of wool production per unit area of skin on these characters were studied with 15 sheep in both a medium and a strong-wool strain of Merino. Small but significant differences in staple length and fibre diameter were found between regions on the body, whereas differences in density were large. The variation in density was about three times as large as those in staple length and fibre diameter. Distinct dorsoventral and anteroposterior gradients over the body existed for fibre density, but not for staple length and fibre diameter. The influences of the fleece characters on wool production per unit area were somewhat different in the two strains, and changed with level of production. Among the medium-wool sheep, fibre density had the largest effect on production, with staple length less and mean fibre cross-sectional area least. Among the strong-wool sheep, length was more important than density, which in turn was more important than fibre cross-sectional area. The combined data indicated that as mean wool weight per unit area increased, the influence of density rose to a maximum and then diminished, whereupon mean fibre volume became the main contributor to wool weight. For different positions on the body of individual sheep, the dependence of wool production per unit area on the fleece characters was found to be similar in the two strains. Fibre density had the major effect in determining the level of production, whereas the influences of staple length and fibre area were negligible.

The study of variability in some wool traits in a coarse wool breed of sheep

“…Doney (1959) suggested that within a sheep, variation in the mean length and mean diameter is influenced by the local density of follicle population. Earlier, Young & Chapman (1958) defined the role of density in determining the level of production; in fine wool breeds density plays the major role in wool production whereas in strong wool breeds the length and diameter assume the major importance.…”

The Administration of Flumethasone, by Three Different Routes, its Measurement in the Plasma and Some Effects on Wool Growth in Merino Wethers

“…It is of interest that the anterior or first-formed follicle groups (Carter and Hardy 1947) and the relatively denser dorsal follicle groups (Young and Chapman 1958) were .most resistant to the effects of flumethasone .. .ltis a matter of speculation whether the treatment was reversing the original orderof follicle group development, and although the possibility exists that the greater density of fibres along the dorsum, relative to the somewhat sparser follicle populations ventrally and cervically, may reduce the quantity of hormone available to each fibre target, this explanation appears to be remote when the response of cervical follicles is taken into account. Another related question which needs' additional research is whether the unbroken fibres represented a random sample of the fibre population in any region.…”

Nutrition during fetal life alters annual wool production and quality in young Merino sheep

“…Young and Chapman (1958) recorded variation in wool production and quality over 11 body sites in 2 strains of 3.5-to 4.5-year-old Merino ewes, and found that staple length was greatest in the midbody region, while fibre diameter increased and fibre density decreased from anterior to posterior regions. In the vertical plane, both staple length and fibre diameter tended to decrease away from the midbody region, while fibre density decreased from the dorsal to ventral sites.…”