An analysis of wool fibres from different strains of Merinos: A dissertation submitted to the faculty of Lincoln University in partial fulfilment of the requirements for the degree of Bachelor of Agricultural Science (Honours)

Abstract

A comparison of Merino wool fibre from a Saxon strain and Merryville strain was made from measurements generated by an optical fibre diameter analyser (OFDA) and fibre cross sectional analysis for shape and dimension. From 58 Saxon strain and 44 Merryville strain mid-side samples, sub samples were taken and each sample split in half; one half was analysed by Mr Peter Baxter of SGS (Wellington) in conjunction with a fibre differentiation trial using the OFDA, and the other half measured for cross-sectional characteristics at Lincoln University using image analysis. There was no significant difference in the mean fibre diameter of the two strains, however there was a significant difference between strains in both the mean coefficient of variation of fibre diameter ( <. 01) within animals and the variance of the fibre diameter between animals (p<.05). The Saxon strain was more uniform in both the mean coefficient of variation and the variance of the mean, which was possibly a genetic effect. The Saxon strain had a mean fibre curvature of 117.5°/mm, significantly greater (<.01) than that of the Merryville strain which was 104.3°/mm. There was however, no difference in mean fibre ellipticity between the two flocks and no correlation was found between fibre ellipticity and fibre curvature. There were however, large variations in fibre ellipticity between animals within each strain ranging from 1.0 to 2.2. The Saxon strain had a greater fraction of "small blobs" occurring on the fibre (p<0.05) than did the Merryville strain, measurements being .84 and .81 respectively. The "small blob" measurement is a recently developed parameter generated by OFDA and at this stage it is unclear what the "small blob" fraction actually measures. Differentiating fibres from different fine wool strains is difficult due to the fact that most fine wool strains have used Saxon genetics at some point in their development.