Abstract

Samples of wool from Perendale hoggets born at Whatawhata Research Centre in 1989 from ewes selected for and against loose wool bulk were tested for propensity to yellow. After storage in a laboratory for two years, wool from the high bulk line was significantly more yellow than wool from low bulk line. When the greasy wool was incubated at 40 degrees and 100% relative humidity, differences in all three tristimulus values between high and low bulk wool were significant. Tristimulus Y and Z decreased and Y minus Z increased when clean wool samples were subjected to more extreme challenges similar to those which may occur during processing. These changes did not affect the differences in colour between the selection lines. These results suggest that management changes may be required to restrict yellowing of high bulk wool during growth and storage. Simultaneous selection for reduced propensity to yellow and increased bulk may reduce the genetic progress attainable in either characteristic.

K, Stelwagen, JH Whyte, B Zavizon, CG Prosser, SR Davis, VC Farr, and I Politis

Proceedings of the New Zealand Society of Animal Production, Volume 55, , 7-8, 1995