Selection for yearling fleece weight and its effect on fleece shedding in New Zealand Wiltshire sheep
D. O’Connell A , D. R. Scobie A D , S. M. Hickey B , R. M. W. Sumner B and A. J. Pearson CA AgResearch, Lincoln Research Centre, Private Bag 4749, Christchurch 8140, New Zealand.
B AgResearch, Ruakura Research Centre, Private Bag 3123, Hamilton 3240, New Zealand.
C 47a Balfour Crescent, Riverlea, Hamilton 3216, New Zealand.
D Corresponding author. Email: scobie@agresearch.co.nz
Animal Production Science 52(7) 456-462 https://doi.org/10.1071/AN11281
Submitted: 9 November 2011 Accepted: 5 March 2012 Published: 12 April 2012
Abstract
A flock of New Zealand Wiltshire sheep was divided into two lines and selected for increased greasy fleece weight or decreased greasy fleece weight as yearlings. Wiltshires shed their fleece annually, and although these yearlings may have expressed shedding as lambs in the preceding summer, they were shorn in autumn at 5 months and again in spring at 12 months of age to determine fleece weight before the subsequent shedding. A rapid separation in fleece weight was observed within 8 years, with ewe (0.89 kg) and ram yearlings (0.92 kg) selected for increased fleece weight producing significantly more wool (P < 0.001) than ewe (0.43 kg) or ram yearlings (0.39 kg) from the line selected for decreased fleece weight. There was no significant difference between sexes, and the sex × line interaction was not significant. Clearly this was very low wool production, but fleece weight was heritable (h2 = 0.57 ± 0.04).
Shedding was scored from 0 (not shed) to 5 (completely shed) for all animals (n = 2505 records) and was found to be heritable in December (h2 = 0.39 ± 0.04) and again in January (h2 = 0.52 ± 0.05), but less so in September at shearing (h2 = 0.24 ± 0.03). Fleece weight in spring was negatively correlated with shedding score in January, both phenotypically (–0.52 ± 0.02) and genetically (–0.81 ± 0.04). Selecting yearlings for low fleece weight developed a shedding sheep with negligible fleece, which may not require shearing. Selecting for shedding of lambs in January would likely achieve a similar outcome.
References
Andrewes WGK (1983) Performance of an autumn lambing Poll Dorset flock in Northland. Proceedings of the New Zealand Society of Animal Production 43, 49–51.Blair HT, Garrick DJ, Rae AL, Wickham GA (1985) Selection responses in New Zealand Romney sheep 2. Selection for yearling greasy fleeceweight. New Zealand Journal of Agricultural Research 28, 257–264.
| Selection responses in New Zealand Romney sheep 2. Selection for yearling greasy fleeceweight.Crossref | GoogleScholarGoogle Scholar |
Dolling CHS (2003) Classing lattice for Wiltipoll ewes and rams. Wool Technology and Sheep Breeding 51, 24–32.
Gilmour AR, Gogel BJ, Cullis BR, Thompson R (2009) ‘ASReml user guide. Release 3.0.’ (VSN International Ltd: Hemel Hempstead, UK) Available at http://www.vsni.co.uk [Verified 23 March 2012]
Johnson DL, Hight GK, Dobbie JL, Jones KR, Wrigglesworth AL (1995) Single trait selection for yearling fleeceweight or liveweight in Romney sheep – direct responses. New Zealand Journal of Agricultural Research 38, 115–122.
| Single trait selection for yearling fleeceweight or liveweight in Romney sheep – direct responses.Crossref | GoogleScholarGoogle Scholar |
Johnson PL, O’Connell D, Dodds KG, Sumner RMW, McEwan JC, Pearson AJ (2007) Wool shedding as a trait for genetic improvement using marker assisted selection? Proceedings of the Association for the Advancement of Animal Breeding and Genetics 17, 541–544.
Lincoln GA (1990) Correlation with changes in horns and pelage, but not reproduction, of seasonal cycles in the secretion of prolactin in rams of wild, feral and domesticated breeds of sheep. Journal of Reproduction and Fertility 90, 285–296.
| Correlation with changes in horns and pelage, but not reproduction, of seasonal cycles in the secretion of prolactin in rams of wild, feral and domesticated breeds of sheep.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3MXjs1ahtQ%3D%3D&md5=7261f7eda263b9c7808679ea9d664645CAS |
McQueen IPM, Reid TC (1988) The development of an autumn lambing flock of Dorset × Romney ewes without the use of hormones. Proceedings of the New Zealand Society of Animal Production 48, 87–90.
Merrick NC (2003) Assessment of fleece cover in crosses between Coopworth, Dorper, Damara, New Zealand Wiltshire, Poll Dorset and Suffolk sheep. Proceedings of the New Zealand Society of Animal Production 63, 160–163.
Morley FHW (1955) Selection for economic characters in Australian Merino sheep 5. Further estimates of phenotypic and genetic parameters. Australian Journal of Biological Sciences 6, 77–90.
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 |
Newton Turner H, Dolling CHS, Kennedy JF (1968) Response to selection in Australian Merino sheep 1. Selection for high clean wool weight, with a ceiling on fibre diameter and degree of skin wrinkle: response in wool and body characteristics. Australian Journal of Agricultural Research 19, 79–112.
Parry AL, Pearson AJ, Morris R, Still L-A (1991) An evaluation of the New Zealand Wiltshire sheep as a model for studies on the physiology of fibre growth. Proceedings of the New Zealand Society of Animal Production 51, 365–369.
Pearson AJ, Parry AL, Ashby MG, Choy VJ, Wildermoth JE (1996) Inhibitory effect of increased photoperiod on wool follicle growth. The Journal of Endocrinology 148, 157–166.
| Inhibitory effect of increased photoperiod on wool follicle growth.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK28XmtVyntg%3D%3D&md5=44b48deecf7adf361eb233a3e29a028fCAS |
Pollott GE (2011) A suggested mode of inheritance for wool shedding in sheep. Journal of Animal Science 89, 2316–2325.
| A suggested mode of inheritance for wool shedding in sheep.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXps1yqurw%3D&md5=74c99539e040d78e964b1ed9f55d62e9CAS |
Rathie KA, Tierney ML, Mulder JC (1994) Assessing Wiltshire Horn-Merino crosses 1. Wool shedding, blowfly strike and wool production traits. Australian Journal of Experimental Agriculture 34, 717–728.
| Assessing Wiltshire Horn-Merino crosses 1. Wool shedding, blowfly strike and wool production traits.Crossref | GoogleScholarGoogle Scholar |
Reid TC, Sumner RMW (1991) Wool growth in autumn and spring lambing ewes. Proceedings of the New Zealand Society of Animal Production 48, 87–90.
SAS (1995) ‘JMP version 3.’ (SAS Institute: Cary, NC)
Slee J (1959) Fleece shedding, staple length and fleece weight in experimental Wiltshire Horn-Scottish Blackface sheep crosses. The Journal of Agricultural Science 53, 209–223.
| Fleece shedding, staple length and fleece weight in experimental Wiltshire Horn-Scottish Blackface sheep crosses.Crossref | GoogleScholarGoogle Scholar |
Sumner RMW, Scobie DR, O’Connell D, Henderson HV (2012) Relative productivity of Wiltshire and Perendale sheep. Proceedings of the New Zealand Society of Animal Production 72, 28–34.
Thatcher LP, Pascoe HJ (1973) Whoever heard of sheep without wool? Journal of Agriculture, Victoria 71, 2–5.
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 |
