Live weights, fleece weights and wool characteristics of screened high fleece weight and randomly selected Romney ewe hoggets

H. Hawker and R.P. Littlejohn

Invermay Agricultural Centre, Ministry of Agriculture and Fisheries, Mosgiel

Proceedings of the New Zealand Society of Animal Production. 1986, 46: 219-224

Fleeces from 28 000 Romney ewe hoggets in 14 mobs on 7 farms were weighed. Within each mob the top 1% hogget fleece weight (High) and a random 1% (Random) were identified, midside sampled and weighed off-shears. Subsequently the top 0.6% on hogget fleece weight from each mob and a random 0.3% were transferred to Woodlands Research Station and managed as one flock for the next year.

At hogget shearing (9 months fleece) the 14 High sub-groups had an average 1.08 kg higher fleece weights (greasy) and 0.83 kg higher clean fleece weights than the Random sub-groups. There was a close between sub-group relationship between greasy fleece weight and live weight with the High hoggets having 0.78 kg heavier fleeces at the same live weight. The High hogget sub-groups had a higher mean live weight (+3.9kg), fibre diameter (+2.7 µm), staple length (+ 13mm) and staple strength (+ 0.343 g/tex). The High and Random hoggets did not differ in loose wool bulk or colour. Most of the variation between or within mobs in clean fleece weight was accounted for by variation in fibre volume.

During the 2-tooth year the differences in fleece weight and live weight persisted. At shearing in March (4 months fleece) and December (9 months fleece) the High ewes had a 0.38 and 0.62 kg higher mean greasy fleece weight respectively, than the Random ewes. The High ewes were 4 to 5 kg higher in live weight than the Random ewes at each weighing. The number of lambs born per ewe joined was higher for the High ewes (1.34 v 1.12), the advantage being largely attributable to these ewes' higher live weights.

Keywords: NZSAPAB; Romney; selection; high fleece weight; screening; live weight; fibre characteristics; staple strength

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Last Updated 18-03-1997