Wool staple tenacity in New Zealand Romney sheep: heritability estimates, correlated traits, and direct response to selection
D. R. Scobie A E , A. R. Bray A , M. C. Smith B , J. L. Woods C , C. A. Morris D and S. M. Hickey DA AgResearch, Lincoln Research Centre, Private Bag 4749, Christchurch 8140, New Zealand.
B Faculty of Agriculture and Life Sciences, Field Service Centre, PO Box 84, Lincoln University, Lincoln 7647, New Zealand.
C 38A Yardley Street, Christchurch 8042, New Zealand.
D AgResearch, Ruakura Research Centre, Private Bag 3123, Hamilton 3240, New Zealand.
E Corresponding author. Email: scobie@agresearch.co.nz
Animal Production Science 52(7) 448-455 https://doi.org/10.1071/AN11243
Submitted: 19 October 2011 Accepted: 7 February 2012 Published: 3 April 2012
Abstract
A flock of New Zealand Romney sheep was established and selected as yearlings on the basis of fleece staple tenacity. The foundation flock was screened from contributing source flocks, with outliers of high or low staple tenacity as yearlings relative to the source flock mean contributing to a ‘high’ line and a ‘low’ line, respectively. A randomly selected control line was established because staple tenacity was known to be affected by yearly changes in feed supply. Staple tenacity of yearling fleeces was found to be heritable (0.41 ± 0.03). After 10 years of within-line selection, the line selected for increased staple tenacity had staples 53% stronger (33.9 N/mm2) than the control (22.1 N/mm2), while staples were 38% weaker in the line selected for decreased staple tenacity (13.8 N/mm2). Staple tenacity was genetically (0.67 ± 0.04) and phenotypically (0.44 ± 0.02) correlated with fibre diameter, and also with staple length (0.38 ± 0.07 and 0.32 ± 0.02, respectively). Longer, thicker fibres likely contributed to positive genetic (0.31 ± 0.07) and phenotypic (0.29 ± 0.02) correlations between staple tenacity and clean fleece weight. The indirect aim of selection was to improve fibre length after carding. Pooled wool samples were prepared from selection line groups of yearlings within sex each year, and a relationship between fibre length after carding measured on these samples and mean staple tenacity of the groups was observed (R2 = 0.514, P < 0.001). Within the tenth (last) year of selection, the high staple tenacity line produced the longest carded fibres (Hauteur: 103 mm) and the decreased staple tenacity line produced the shortest (87 mm), with the control line intermediate (96 mm).
References
Amer PR, McEwan JC, Dodds KG, Davis GH (1999) Economic values for ewe prolificacy and lamb survival in New Zealand sheep. Livestock Production Science 58, 78–90.Bigham ML, Sumner RMW, Hawker H, Fitzgerald JM (1983) Fleece tenderness: a review. Proceedings of the New Zealand Society of Animal Production 43, 73–78.
Bray AR, Scobie DR, Woods JL (1995) Genetic improvement in wool strength of Romney sheep. Proceedings of the 9th International Wool Textile Research Conference 2, 173–181.
Caffin RN (1976) A clamp for the tensile testing of fibre bundles. Journal of the Textile Institute 67, 33–34.
| A clamp for the tensile testing of fibre bundles.Crossref | GoogleScholarGoogle Scholar |
Craven AJ, Ashby MG, Scobie DR (2010) Wool characteristics in the Meat and Wool New Zealand central progeny test flocks. Proceedings of the New Zealand Society of Animal Production 70, 217–221.
Geenty KG, Orwin DFG, Woods JL, Young SR, Smith MC (1984) Seasonal wool production and staple strength of Romney ewes. Proceedings of the New Zealand Society of Animal Production 44, 57–59.
Gilmour AR, Gogel BJ, Cullis BR, Thompson R (2009) ‘ASReml user guide. Release 3.0.’ (VSN International Ltd: Hemel Hempstead, UK)
Hawker H, Crosbie SF (1985) Effects of level of nutrition in winter and summer on the wool growth of Romney and Perendale ewes with a history of high or low winter wool growth. Proceedings of the New Zealand Society of Animal Production 45, 225–228.
Hawker H, Littlejohn RP (1989) Relationships between staple strength and other wool characteristics of Romney ewes. New Zealand Journal of Agricultural Research 32, 305–310.
| Relationships between staple strength and other wool characteristics of Romney ewes.Crossref | GoogleScholarGoogle Scholar |
Kenyon PR, Morris ST, Revell DK, McCutcheon SM (2003) Shearing during pregnancy – review of a policy to increase birthweight and survival of lambs in New Zealand pastoral farming systems. New Zealand Veterinary Journal 51, 200–207.
| Shearing during pregnancy – review of a policy to increase birthweight and survival of lambs in New Zealand pastoral farming systems.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2MznsVantA%3D%3D&md5=35940e22fc406c73e53a8f3458e6facfCAS |
Kenyon PR, Revell DK, Morris ST (2006) Mid-pregnancy shearing can increase birthweight and survival to weaning of multiple-born lambs under commercial conditions. Australian Journal of Experimental Agriculture 46, 821–825.
| Mid-pregnancy shearing can increase birthweight and survival to weaning of multiple-born lambs under commercial conditions.Crossref | GoogleScholarGoogle Scholar |
Masters DG, Stewart CA, Connell PJ (1993) Changes in plasma amino acid patterns and wool growth during late pregnancy and early lactation in the ewe. Australian Journal of Agricultural Research 44, 945–957.
| Changes in plasma amino acid patterns and wool growth during late pregnancy and early lactation in the ewe.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2cXksl2gu7s%3D&md5=d304909aeeb812d0e1b9df883f40da47CAS |
McDermott AK, Sumner RMW (2009) Realities of clip preparation for strong wool from adult sheep. Proceedings of the New Zealand Society of Animal Production 69, 85–89.
Morris CA, Johnson DL, Sumner RMW, Hight GK, Dobbie JL, Jones KR, Wrigglesworth AL, Hickey SM (1996) Single trait selection for yearling fleece weight or liveweight in Romney sheep – correlated responses in liveweight, fleece traits, and ewe reproduction. New Zealand Journal of Agricultural Research 39, 95–106.
| Single trait selection for yearling fleece weight or liveweight in Romney sheep – correlated responses in liveweight, fleece traits, and ewe reproduction.Crossref | GoogleScholarGoogle Scholar |
NZS (1992) NZS 8719 : 1992 Method for the measurement of the fibre length after carding of scoured wool, UDC 677.314:677.017.2. (Standards New Zealand: Wellington)
Orwin DFG, Geenty KG (1986) Implications of objective measurement for fleece tenderness research. Proceedings of the New Zealand Society of Animal Production 46, 201–202.
Orwin DFG, Gourdie RG, Woods JL, Geenty KG (1987) Measuring the staple strength of New Zealand Romney and Corriedale wools. New Zealand Journal of Experimental Agriculture 15, 303–308.
Orwin DFG, Ranford SL, Geenty KG (1988) Relationship of staple strength and other fleece characteristics of Romney wool to fibre length after carding. New Zealand Journal of Agricultural Research 31, 409–414.
| Relationship of staple strength and other fleece characteristics of Romney wool to fibre length after carding.Crossref | GoogleScholarGoogle Scholar |
Robertson SM, Robards GE, Wolfe EC (2000) The timing of nutritional restriction during reproduction influences staple strength. Australian Journal of Agricultural Research 51, 125–132.
| The timing of nutritional restriction during reproduction influences staple strength.Crossref | GoogleScholarGoogle Scholar |
SAS (1995) ‘JMP version 3.’ (SAS Institute: Cary, NC)
Scobie DR, Maher AP, Bray AR, Smith MC, Merrick NC (1994) Staple strength in crossbred wool: the sensible solution. Proceedings of the Australian Society of Animal Production 20, 301–304.
Scobie DR, Merrick NC, Bray AR (1995) Staple tenacity versus staple strength. Proceedings of the New Zealand Society of Animal Production 55, 39–41.
Scobie DR, Walls RJ, Markham LJ, Woods JL, Bray AR (1996) Wool fibre tenacity of Romney sheep genetically different in staple tenacity. Australian Journal of Agricultural Research 47, 1203–1212.
| Wool fibre tenacity of Romney sheep genetically different in staple tenacity.Crossref | GoogleScholarGoogle Scholar |
Scobie DR, Bray AR, Merrick NC (1998) Medullation and average fibre diameter vary independently in the wool of Romney sheep. New Zealand Journal of Agricultural Research 41, 101–110.
| Medullation and average fibre diameter vary independently in the wool of Romney sheep.Crossref | GoogleScholarGoogle Scholar |
Scrivener CJ, Vizard AL (1997) The relationship between reproductive performance, time of lambing and the staple strength of wool from Merino ewes. Wool Technology and Sheep Breeding 45, 121–128.
Sumner RMW, McDermott AK, Cox NR (2008) Relative economic value of wool processing parameters for New Zealand strong wool between 2003 and 2007. Proceedings of the New Zealand Society of Animal Production 68, 53–56.
Vizard AL, Scrivener CJ, Anderson GA (1994) The agreement and repeatability of Atlas and Staplebreaker for estimating the staple strength of midside wool samples taken from Merino sheep. Wool Technology and Sheep Breeding 45, 121–128.
Wickham GA, McPherson AW (1985) A review of the importance of wool traits as genetic improvement objectives and selection criteria for New Zealand Romney sheep. Proceedings of the New Zealand Society of Animal Production 45, 203–208.
Woods JL, Orwin DFG (1988) Seasonal variations in the dimensions of individual Romney wool fibres determined by a rapid autoradiographic technique. New Zealand Journal of Agricultural Research 31, 311–323.
| Seasonal variations in the dimensions of individual Romney wool fibres determined by a rapid autoradiographic technique.Crossref | GoogleScholarGoogle Scholar |
Woods JL, Bray AR, Rogers GE, Smith MC (1995) Seasonal patterns of wool growth in Romney sheep selected for high and low staple tenacity. Proceedings of the New Zealand Society of Animal Production 55, 42–45.
Wuliji T, Dodds KG, Andrews RN, Turner PR (2011) Selection response to fleece weight, wool characteristics, and heritability estimates in yearling Romney sheep. Livestock Science 135, 26–31.
| Selection response to fleece weight, wool characteristics, and heritability estimates in yearling Romney sheep.Crossref | GoogleScholarGoogle Scholar |
