Shearing Merino ewes at different stages of pregnancy: effects on fleece characteristics of progeny
E. H. van Reenen A , P. R. Kenyon B C , R. G. Sherlock B , R. E. Hickson B and S. T. Morris BA Ministry of Agriculture and Forestry, PO Box 2526, Wellington 6140, New Zealand.
B Sheep Research Centre, Massey University, PB 11-222, Palmerston North 4442, New Zealand.
C Corresponding author. Email: p.r.kenyon@massey.ac.nz
Animal Production Science 50(6) 603-607 https://doi.org/10.1071/AN09175
Submitted: 3 December 2009 Accepted: 14 April 2010 Published: 11 June 2010
Abstract
Shearing strong-wool ewes at different stages of pregnancy has been shown to influence the follicle population of the offspring which may result in a finer, heavier fleece. The aim of this study was to investigate the effect of shearing time of Merino ewes on the liveweight, fleece characteristics and follicle population of their progeny.
Pregnant Merino ewes were allocated to one of three shearing times; mid-pregnancy (d106; 106 days from the introduction of the ram), late-pregnancy (d141) and post-lambing (d191). A skin biopsy was taken from the mid-side of 128 lambs at d359 (~7 months of age) and analysed for primary and secondary follicle density. Mid-side wool samples were collected at d359, d499 and d716. Samples from d359 and d716 were analysed for washing yield, colour and fibre diameter. Greasy fleece weight was measured on d499 and a mid-side sample was taken to measure staple length and staple strength.
Shearing time of Merino ewes had no effect on lamb liveweight at any stage of the experiment. Lambs born to ewes shorn during pregnancy had a lesser (P < 0.05) follicle density, secondary follicle density, follicle number index (FNI) and secondary FNI than those born to ewes shorn post-lambing. However, there was no effect (P > 0.05) of dam shearing treatment on fleece characteristics of progeny. The results indicate that, under the conditions of this study shearing Merino ewes in mid-to-late pregnancy did not alter the fleece characteristics of their progeny.
Acknowledgements
We would like to acknowledge the financial support of the Vernon Willey Trust, the New Zealand Merino Co. Ltd, the Sinclair Cummings Trust and the Institute of Veterinary, Animal and Biomedical Sciences, Massey University and the on-farm support of Evan Gibson and Gus McAllister, Mt Grand, Wanaka.
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