Effect of a cashmere breeding program on fibre length traits

Abstract

Two cashmere goat breed lines were selected, over a 5-year period, for increased mean cashmere weight (Value line; V) or reduced mean cashmere diameter (Fine line; F) and were compared with a group bred randomly (Control; C). The mean staple length of V animals increased from 42.2 to 52.0 mm (P < 0.001) between Years 1 and 5 and by Year 5 it was longer than that of F (43.9; P < 0.001) and C animals (45.2; P < 0.05). Between Years 1 and 5, the mean maximum drawn length of the V and F cashmere increased, from 50.9 to 63.1 mm (P < 0.001) and from 45.0 to 52.8 mm (P < 0.001), respectively. The mean minimum length for the V line increased from 32.5 to 49.6 mm (P < 0.001). This was attributable to an increase in cashmere length in both males (P < 0.001) and females (P < 0.001). The mean minimum length for the F line increased (P < 0.001) primarily because of an increase in the mean minimum cashmere length of the females (P < 0.05). It is concluded that although the selection program resulted in an increase in cashmere production in the V line and no reduction in the F line animals, the associated increase in length and/or the changes in the relative length of the cashmere and guard hairs were likely to result in a reduction in fleece quality and value, particularly in the V animals.