Abstract

Fleece tenderness is a serious fault of New Zealand crossbred wool costing the sheep industry between $50 and $100 million annually. Wool fibres break at the point where fibre diameter is at its minimum and factors which influence minimum fibre diameter will influence the incidence of fleece tenderness, e.g. breed and strain of sheep, age of ewe, level of feeding and reproductive status. Tender fleeces are on average lighter than sound fleeces and often have other associated faults such as cotting and yellow discolouration. Variation in minimum winter fibre diameter accounts for only about 40% of the variation in staple strength within a flock suggesting that factors other than fibre diameter may be involved. There are fibre structural and compositional differences between sound and tender wools of the same diameter and these may be associated with fleece tenderness. The wool producer can influence the incidence of fleece tenderness by the level of feeding during mid pregnancy but it may not always be economic to feed better. Choice of shearing time will also influence the level of fleece tenderness. A preliminary estimate of the heritability of fleece tenderness of 0.58

AWF, Davey, C Grainger, DDS MacKenzie, DS Flux, GF Wilson, IM Brookes, and CW Holmes

Proceedings of the New Zealand Society of Animal Production, Volume 43, , 67-70, 1983