Abstract

Previous work estimating the impact of rearing lambs on wool growth and processing characteristics has been done primarily with single and twin-bearing ewes. The effect of bearing/rearing triplets on wool growth has been largely extrapolated from these data. The aim of this study was to compare the wool growth and quality of twin- and triplet- bearing/rearing ewes offered different sward height allowances. After pregnancy scanning, 94 Romney ewes (including 68 twin- and 26 triplet-bearing ewes) with 6 weeks wool growth, were randomly allocated to four different sward heights (2, 4, 6 and 8 cm). Within the first 24 hours of parturition ewes were transferred to one of two sward heights (4 and 8 cm). Ewes were shorn 87 days after parturition, the fleece was weighed and a sample was taken from the midside for measurement of fleece characteristics. There were no interactions between nutritional treatment and litter size for any wool measurements. Fleeces from twin-bearing/rearing ewes tended to be heavier (P<0.1 ; 2.0 kg vs 1.9 kg) than those from triplet-bearing/rearing ewes. There was no effect of litter size on any other wool characteristic. Ewes offered 2 cm during the last half of pregnancy had lighter (1.6 vs 2.2 kg, P<0.05) and finer (39.0 vs 41.8 µm, P<0.05) fleeces than those offered 4 cm but there was no increase in weight or fineness for those offered more than 4 cm. Nutritional treatments post parturition had no significant effects on wool characteristics. There seems to be little benefit, in terms of wool growth and wool processing characteristics, of offering twin- or triplet-bearing ewes a sward height of more than 4 cm.

RG, Sherlock, N Torbatinejad, PR Kenyon, and ST Morris

Proceedings of the New Zealand Society of Animal Production, Volume 64, Hamilton, 171-174, 2004