Effect of nutrition, body condition and liveweight change on efficacy of biological wool harvesting with epidermal growth factor (Bioclip)
Clare Ward A , Tim Watts B , David Miller A and Caroline Jacobson A CA School of Veterinary and Biomedical Science, Murdoch University, Murdoch, WA 6150, Australia.
B Anagen Pty Ltd, Bibra Lake, WA 6163, Australia.
C Corresponding author. Email: C.Jacobson@murdoch.edu.au
Animal Production Science 53(6) 487-494 https://doi.org/10.1071/AN12143
Submitted: 24 April 2012 Accepted: 27 November 2012 Published: 3 April 2013
Abstract
This study investigated the effect of nutrition on wool harvesting efficiency of a biological wool harvesting system (Bioclip) utilising epidermal growth factor (EGF) to induce shedding of the fleece. The experiment had nine groups, each representing a different growth path based on a 3 by 3 design with three levels of nutrition (low, medium and high) fed during two periods, specifically the pre-injection period (4-weeks leading up to EGF injection) and post-injection period (4 weeks between EGF injection and wool harvesting). Sheep weight and body condition score were measured at the start and end of each period. Wool harvesting efficiency, fleece weight and body wrinkle were assessed at wool harvesting. Continuous data were analysed using general linear models and linear regression. Bivariate categorical data were analysed using Chi-squared tests and odds ratios. Wool harvesting efficiency was reduced in sheep with greater skin wrinkle (P < 0.001), poorer body condition (P < 0.001) and poorer nutrition in both pre- and post-injection periods (P < 0.001). Sheep that gained 1 kg bodyweight or 0.5 body condition score either pre- or post-injection had improved wool harvestability (P < 0.05). Sheep that lost weight post-injection were 10.2 (95% confidence interval 4.0, 25.5) times and 4 times (2.4, 6.7) more likely to have very poor harvestability compared with sheep that gained or maintained weight respectively (P < 0.001). Sheep with greater body wrinkle were 6.6 (4.1, 10.7) times more likely to have very poor harvestability than plain-bodied sheep (P < 0.001). Nutrition that ensures modest weight gain during the pre- and post-injection periods can partially overcome poorer harvestability in wrinkly sheep.
Additional keywords: biological shearing, sheep, wrinkle.
References
Adamson ED, Rees AR (1981) Epidermal growth factor receptors. Molecular and Cellular Biochemistry 34, 129–152.| Epidermal growth factor receptors.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL3MXhtVSgs7g%3D&md5=bdcaabd978b9ceb8512f5443e246c3a2CAS |
Australian Bureau of Meteorology (2010) Graphical climate statistics for Australian locations. Available at http://www.bom.gov.au/jsp/ncc/cdio/cvg/av [Verified 10 October 2012]
Australian Wool Innovation and Meat and Livestock Australia (2007) Visual sheep score. Genetic research and enhanced breeding for flystrike resistance. Available at http://www.wool.com/Grow_Animal-Health_Flystrike-prevention_Genetic-and-breeding.htm [Verified 7 October 2012]
Belschner HG, Carter HB, Newton Turner H (1937) Fleece characteristics of stud Merino sheep in relation to the degree of wrinkliness of the skin of the breech III. Australian Veterinary Journal 13, 16–28.
| Fleece characteristics of stud Merino sheep in relation to the degree of wrinkliness of the skin of the breech III.Crossref | GoogleScholarGoogle Scholar |
Brinsfield TH, Clark MV, Dolnick EH, Reynolds PJ (1972) Cytoplasmic degeneration in the wool follicle bulb following administration of cyclophosphamide. Journal of Animal Science 34, 273–277.
Chapman RE, Bassett JM (1970) The effects of prolonged administration of cortisol on the skin of sheep on different planes of nutrition. The Journal of Endocrinology 48, 649–663.
| The effects of prolonged administration of cortisol on the skin of sheep on different planes of nutrition.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE3MXhtVSmsQ%3D%3D&md5=59aab62ee0df60fe6acb6427695596b1CAS |
Chapman RE, Hardy MH (1988) Effects of intradermally injected and topically applied mouse Epidermal Growth Factor on wool growth, skin and wool follicles of Merino sheep. Australian Journal of Biological Sciences 41, 261–268.
Cohen S (1972) Epidermal Growth Factor. The Journal of Investigative Dermatology 59, 13–16.
| Epidermal Growth Factor.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaE383isFeqsQ%3D%3D&md5=ddfffbf5d128ce82523cbc157bbb8356CAS |
Dolnick EH, Lindahl IL, Terrill CE, Reynolds PJ (1969) Cyclophosphamide as a chemical ‘defleecing’ agent for sheep. Nature 221, 467–468.
| Cyclophosphamide as a chemical ‘defleecing’ agent for sheep.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaF1MXms1Kmsg%3D%3D&md5=ec237e5a90c9d8d5da12a7e36eaba212CAS |
Hollis DE, Chapman RE, Panaretto BA, Moore GPM (1983) Morphological changes in the skin and wool fibres of Merino sheep infused with mouse Epidermal Growth Factor. Australian Journal of Biological Sciences 36, 419–434.
Hourihan ME, Terrill CE, Wilson RL (1970) Effects of chemical shearing on wool fleeces. Journal of Animal Science 31, 356–357.
Lyne AG (1964) Effect of adverse nutrition on the skin and wool follicles in Merino sheep. Australian Journal of Agricultural Research 15, 788–801.
| Effect of adverse nutrition on the skin and wool follicles in Merino sheep.Crossref | GoogleScholarGoogle Scholar |
Moore GPM, Panaretto BA, Carter NB (1985) Epidermal hyperplasia and wool follicle regression in sheep infused with Epidermal Growth Factor. The Journal of Investigative Dermatology 84, 172–175.
| Epidermal hyperplasia and wool follicle regression in sheep infused with Epidermal Growth Factor.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL2MXhtVOjtL0%3D&md5=cafa7ec374ece557cc6d4649119b182eCAS |
National Health and Medical Research Council (2004) ‘Australian code of practice for the care and use of animals for scientific purposes.’ 7th edn. (Australian Government: Canberra)
Panaretto BA, Leish Z, Moore GPM, Robertson DM (1984) Inhibition of DNA synthesis in dermal tissue of Merino sheep treated with depilatory doses of mouse epidermal growth factor. The Journal of Endocrinology 100, 25–31.
| Inhibition of DNA synthesis in dermal tissue of Merino sheep treated with depilatory doses of mouse epidermal growth factor.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL2cXksF2rsQ%3D%3D&md5=1412eecd334313300328655f6775f9caCAS |
Reis PJ, Tunks DA, Munro SG (1992) Effects of abomasal protein and energy supply on wool growth in Merino sheep. Australian Journal of Agricultural Research 43, 1353–1366.
| Effects of abomasal protein and energy supply on wool growth in Merino sheep.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3sXlvVGqug%3D%3D&md5=dedc151d9511aa03172cb2b2909eb699CAS |
Reynolds PJ, Dolnick EH, Sidwell GM, Terrill CE (1972) Effects of cyclophosphamide dosage on the rate of wool loosening. Journal of Animal Science 34, 246–249.
Russel AJF, Doney JM, Gunn RG (1969) Subjective assessment of body fat in live sheep. The Journal of Agricultural Science 72, 451–454.
| Subjective assessment of body fat in live sheep.Crossref | GoogleScholarGoogle Scholar |
Scobie DR, Young SR, O’Connell D, Gurteen S (2005) Skin wrinkles affect wool characteristics and the time taken to harvest wool from Merino and Halfbreed sheep. New Zealand Journal of Agriculture 48, 177–185.
| Skin wrinkles affect wool characteristics and the time taken to harvest wool from Merino and Halfbreed sheep.Crossref | GoogleScholarGoogle Scholar |
Senate Select Committee on Animal Welfare (1989) ‘Sheep husbandry.’ Parliament of Australia Senate Committee Report, Canberra. (Australian Government Publishing Service: Canberra)
Thompson AN, Schlink AC, Peterson AD, Hynd PI (1998) Follicle abnormalities and fibre shedding in Merino weaners fed different levels of nutrition. Australian Journal of Agricultural Research 49, 1173–1179.
| Follicle abnormalities and fibre shedding in Merino weaners fed different levels of nutrition.Crossref | GoogleScholarGoogle Scholar |
Thwaites CJ (1972) The effects of short-term under nutrition and edrenocortical stimulation on wool growth. Animal Production 15, 39–46.
| The effects of short-term under nutrition and edrenocortical stimulation on wool growth.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE3sXjtFWn&md5=3d28b23d0ff793972f44bea610503ea4CAS |
van Burgel AJ, Oldham CM, Behrendt R, Curnow M, Gordon DJ, Thompson AN (2011) The merit of condition score and fat score as an alternative to liveweight for managing the nutrition of ewes. Animal Production Science 51, 834–841.
| The merit of condition score and fat score as an alternative to liveweight for managing the nutrition of ewes.Crossref | GoogleScholarGoogle Scholar |
