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Effect of light and temperature on wool growth

  • A. A. Elsherbiny (a1), H. A. Eloksh (a1), A. S. Elsheikh (a1) and M. H. Khalil (a1)


Wool samples were collected from 39 rams representing five breed groups of sheep: Merino (M), Ossimi (0), and the crosses between them, viz. ¾ Ossimi–¾ Merino (¾ O), ½ Ossimi–½ Merino (½ O) and ½ Ossimi–¾ Merino (¼ O) maintained at Sakha Experiment Station, Kafrelsheikh, Egypt, with the objectives of detecting the effect of the seasonal changes in normal light rhythm and temperature on wool fibre length and diameter. Animals were divided into two light treatments groups, the first consisting of four animals from each breed kept under continuous dim light conditions throughout the year and the second of three animals from Ossimi and four from each breed group kept inside an open pen free to sunlight and shade zones under daylight rhythm throughout the year. It was found that fibre length as well as fibre diameter in normal light exceeded that in dim light except in winter time. Breed groups showed different responses to the absence of light especially the Ossimi and the ¾ O whose fibre lengths were most affected. The breed groups had larger fibre diameters in normal light than in dim light except Merino and ¼ O. Seasonal changes in temperature had a highly significant effect on fibre length but not on fibre diameter. Higher temperature coincided with lower increases in fibre length. Season to season variation in wool growth seemed to suggest that the number of light hours per day and atmospheric temperature counteracted each other resulting in a non-significant seasonal pattern.



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Chapman, R. E. & Basset, J. M. (1970). The effect of prolonged administration of cortisol on the skin of sheep on different planes of nutrition. Journal of Endocrinology 48, 649–54.
Coop, I. E. (1953). Wool growth as affected by nutrition and by climatic factors. Journal of Agricultural Science, Cambridge 43, 456–72.
Coop, I. E. & Hart, D. S. (1953). Environmental factors affecting wool growth. Proceedings of the New Zealand Society of Animal Production 13, 113–22.
Doney, M. J. (1966). Breed differences in response of wool growth to annual nutritional and climatic cycles. Journal of Agricultural Science, Cambridge 67, 2530.
Downes, A. M. & Wallace, A. L. (1964). Local effects on wool growth of intradermal injections of hormones. In Biology of the skin and hair growth. Proceedings of a symposium held at Canberra, Australia, 22nd–28th of 08 1964, pp. 679702. Sydney: Angus & Robertson.
Ebling, F. J. & Johnson, E. (1964). The control of hair growth. In The Mammalian epidermis and its derivatives. Symposium of the Zoological Society, London, F. J. Ebling Edition, no. 12, pp. 97110.
Elsherbiny, A. & Markotić, B. (1974). Seasonality in wool growth under semi-arid conditions. Journal of Agricultural Science, Cambridge 83, 443–6.
Ferguson, K. A., Wallace, A. L. & Lindner, H. R. (1964). Hormonal regulation of wool growth. Biological Abstracts 47, 106762, 1966.
Godfrey, N. W. & Tribe, D. E. (1959). The effect of thyroxin implantation on wool growth. Journal of Agricultural Science, Cambridge 53, 369–73.
Henneman, H. A., Reineke, E. P. & Griffin, S. A. (1955). The thyroxin secretion rate of sheep as affected by season, age, breed, pregnancy and lactation. Journal of Animal Science 14, 419–34.
I.W.T.O. (1961). Method of determining wool fibre diameter by the projection microscope. International Wool Secretariat Research Department, Carlton Gardens, London, S.W.I.
Morris, L. R. (1961). Photoperiodicity of seasonal rhythm of wool growth in sheep. Nature, London 190, 102–8.
Nagarcenkar, R. (1963). Effect of climatic factors on wool production. International Abstracts of Biological Science 32, 6431.
Rougeot, J. (1957). The effect of seasonal variation in daily length of lighting on the moult of certain fibres in the fleece of Limousin sheep. Societé Biologique, Paris 151, 834–9.
Rougeot, J. (1961). Comparative effect of annual and semi-annual periodic variation in day length on the follicle cycles of the short kemp fibres of the fleece of Limousin sheep. Relationship with reproductive cycles. Annals of Animal Biology, Biochemistry and Biophysics 1, 385–97.
Rowell, J. G. & Waiters, D. E. (1976). Analysing data with repeated observations on each experimental unit. Journal of Agricultural Science, Cambridge 87, 423–32.
Ryder, M. L. & Slee, J. (1967). The effect of cold exposure on wool growth in Scottish Blackface sheep and Merino × Cheviot sheep. Journal of Agricultural Science, Cambridge 69, 449—53.
Slee, J. & Carter, H. B. (1961). A comparative study of fleece growth in Tasmanian Fine Merino and Wiltshire Horn ewes. Journal of Agricultural Science, Cambridge 57, 1119.
Snedecor, G. W. & Cochran, W. G. (1973). Statistical Methods, 6th ed. Ames, Iowa, U.S.A.: Iowa State University Press.
Thwaites, C. J. (1968). Heat stress and wool growth of sheep. Proceedings of the Australian Society of Animal Production 7, 259–67.
Thwaites, C. J. (1972). The effect of short term undernutrition and adrenocortical stimulation on wool growth. Journal of Animal Production 15, 3948.
Turner, C. D. & Bagnara, J. T. (1971). General Endocrinology. Philadelphia: Saunders Company.
Williams, A. J., Robards, J. E. & Saville, D. J. (1972). Metabolism of cystine by Merino sheep genetically different in wool production. II. The response in wool growth to abomasal infusion of L-cystine and DL-methionine. Australian Journal of Biological Science 25, 1269–78.
Zhilyakova, V. S. (1973). Inheritance, heritability and correlation of the light zone width with fibre length of Sure Karakul Peints. Ovtscvodstvo 19, 22–7.

Effect of light and temperature on wool growth

  • A. A. Elsherbiny (a1), H. A. Eloksh (a1), A. S. Elsheikh (a1) and M. H. Khalil (a1)


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