Abstract

The Meat and Wool New Zealand Central Progeny Test programme (CPT) was established to demonstrate the relative breeding merit of leading sires in the New Zealand sheep industry. Here we describe the wool grown over the summer by the 2007 born one-year-old ewes within the CPT. Within fleeces, staple strength varied between farms as shown by the mean difference of 23 N/ktex in offspring of the link sire. Staple strength correlated positively with midside fibre diameter (r = 0.26), medullation (r = 0.23) and negatively with fibre curvature (r = -0.61). Staple strength was similar on anterior (74 ± 24 N/ktex) and midside (75 ± 24 N/ktex) body-sites, but was weaker on the hindleg (64 ± 21 N/ktex; P <0.001). Overall mean staple strength was 72 ± 20 N/ktex, while individual fleeces ranged from 19 to 121 N/ktex. Ten percent of fleeces measured below 45 N/ktex leaving them prone to excessive fibre breakage during processing. Some fleeces varied up to 40 N/ktex across body-sites. Even within one flock, offspring of individual sires differed by a mean of 29 N/ktex, suggesting a consistent weakness of wool in the progeny of some highly ranked sires which will negatively affect processing and end-product performance.

AJ, Craven, MG Ashby, and DR Scobie

Proceedings of the New Zealand Society of Animal Production, Volume 70, Palmerston North, 217-221, 2010