New Zealand Journal of Agricultural Research abstracts
Skin wrinkles affect wool characteristics and the time taken to
harvest wool from Merino and Halfbred sheep
D. R. Scobie
S. R. Young
D. O’Connell
S. Gurteen
AgResearch Limited
Canterbury Agriculture and Science Centre
P.O. Box 60, Lincoln
Canterbury, New Zealand
Abstract A flock of New Zealand Halfbred hoggets
and three flocks of Merino hoggets were shorn and wrinkle score
determined. There was a small (0.2 µm) decrease in fibre
diameter with each unit of increase in wrinkle score (P = 0.003)
in one Merino flock (Flock C), but this trend was not significant in
the other three flocks. The coefficient of variation of fibre diameter
increased with wrinkle score (0.9% per unit increase) in the Halfbred
flock (Flock A, P < 0.001) and two of the Merino flocks (P
= 0.004 in Flock C, P = 0.005 in Flock D) but the trend
was not significant in Flock B. Greasy fleece weight increased
significantly with increasing wrinkle score in all four flocks (P = 0.012,
< 0.001, < 0.001, and < 0.013 for Flocks A, B, C, and D
respectively). Yield was not measured for Flock B, did not change with
wrinkle score in the Halfbreds (Flock A), and tended to decrease with
wrinkle score in the other two flocks (by 0.4% per unit increase),
although the relationship was significant in Flock C only (P =
0.040). The proportional change in yield was small, so the estimated
clean fleece weight increased with wrinkle score in the Halfbreds (P
= 0.011) and Flock C (P < 0.001) but not Flock D (P =
0.076). Staple length was measured in the Halfbreds, where it did not
change with wrinkle score (P = 0.476), and in one flock of
Merinos (Flock C) where it decreased by 3.4 mm per unit increase
in wrinkle score (P < 0.001). In a second experiment, a flock
of adult Merino ewes (n = 296) were shorn and scored for
wrinkles. The time taken and the number of blows required to shear each
sheep were strongly correlated (R = 0.801), and both increased
with wrinkle score, so that the wrinkliest ewes required about
16 more blows (P < 0.001) and 15 more seconds (P
< 0.001) to shear than the least wrinkly ewes. In contrast to the
hoggets, the adult ewes produced wool that increased in fibre diameter (P
= 0.048) by 0.15 µm with each wrinkle score, but was not
different in staple length or coefficient of variation of fibre
diameter. Greasy fleece weight of these ewes increased (P <
0.001) but yield decreased (P = 0.017) with increasing wrinkle
score such that estimated clean fleece weight increased by 288 g (P
= 0.004) between the least and most wrinkly ewes. This work suggests
that Merino sheep with fewer wrinkles exhibit a slight reduction in
fleece weight and little or no change in wool characteristics, but
potential improvements in labour costs and animal welfare.
Keywords ribby pelts; fleece weight; yield; fibre
diameter; staple length; shearing
A03053; Received 2 October 2003; accepted 5 January 2005; Online
publication date 30 May 2005
New Zealand Journal of Agricultural Research, 2005, Vol. 48:
177–185
0028–8233/05/4802–0177 © The Royal Society of New Zealand 2005
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