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Performance and heat tolerance of Awassi lambs as affected by early shearing

Published online by Cambridge University Press:  27 March 2009

A. A. Younis
Affiliation:
Department of Animal Production, College of Agriculture, University of Baghdad, Abu-Ghraib, Iraq
F. Al-Mahmoud
Affiliation:
Department of Animal Production, College of Agriculture, University of Baghdad, Abu-Ghraib, Iraq
E. A. El-Tawil
Affiliation:
Department of Animal Production, College of Agriculture, University of Baghdad, Abu-Ghraib, Iraq
A. S. El-Shobokshy
Affiliation:
Department of Animal Production, College of Agriculture, University of Baghdad, Abu-Ghraib, Iraq

Summary

Forty-two Awassi lambs, 21 males and 21 females, were used to investigate the effect of early shearing, before the hottest months, on their performance and heat tolerance as indicated by rectal temperature and respiration rate.

Within each sex, half the number of lambs were sheared and the rest were left unshorn. All lambs were fed for 132 days, covering the hottest period of the year, on a concentrate mixture at the daily rate of 2% of their average live weight plus green roughage offered ad libitum. Rectal temperatures and respiration rates were recorded 1 day of each week on three occasions each day.

Shorn lambs of both sexes had significantly (P < 0·01) higher values for body gain and final body weight than the unshorn ones. Average total digestible nutrients intake was slightly higher for shorn lambs. However, average dry-matter intake as a percentage of body weight was almost the same for shorn and unshorn lambs. Shorn lambs of both sexes were more efficient than the unshorn ones in converting food to body gain.

Shorn lambs were more heat-tolerant than the unshorn ones as indicated by their significantly (P < 0·01) lower rectal temperature and respiration rate.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1977

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References

Bhattacharya, A. N. & Uwayjan, M. (1975). Effect of high ambient temperature and low humidity on nutrient utilization and on some physiological responses in Awassi sheep fed different levels of roughage. Journal of Animal Science 40, 320–8.CrossRefGoogle Scholar
Blaxter, K. L. (1969). The Energy Metabolism of Ruminants. 3rd impression. London: Hutchinson Scientific and Technical.Google Scholar
Elvidge, D. G. & Coop, I. E. (1974). Effect of shearing on feed requirements of sheep. New Zealand Journal Experimental Agriculture 2, 397402.CrossRefGoogle Scholar
Eyal, E. (1963 a). Shorn and unshorn Awassi sheep. I. Body temperature. Journal of Agricultural Science, Cambridge 60, 159–68.CrossRefGoogle Scholar
Eyal, E. (1963 b). Shorn and unshorn Awassi sheep. II. Pulse rate. Journal of Agricultural Science, Cambridge 60, 169–74.CrossRefGoogle Scholar
Eyal, E. (1963 c). Shorn and unshorn sheep. III. Respiration rate. Journal of Agricultural Science, Cambridge 60, 175–82.CrossRefGoogle Scholar
Eyal, E. (1963 d). Shorn and unshorn sheep. IV. Skin temperature and changes in temperature and humidity in fleece and its surface. Journal of Agricultural Science, Cambridge 60, 183–93.CrossRefGoogle Scholar
Farhan, S. A., Rollinson, D. H. L., Al-Rawi, A. R. & Sorensen, J. B. (1970). Studies on the effect of climate on livestock production in Iraq. II. The relationship of climate to roughage and water intake of calves. International Journal of Biometeorology 14, 167–85.CrossRefGoogle Scholar
Juma, K. H., Gharib, F. H. & Eliya, J. (1971). A note on studies on heat tolerance in Awassi sheep. Animal Production 13, 369–70.Google Scholar
Khawaja, A. K., Matti, S. A., Asadi, R. F., Mokhtar, K. M. & Aboona, S. H. (1971). The Composition and Nutritive Value of Iraqi Feed Stuffs. Ministry of Agriculture, Directorate-general of Animal Resources, Nutrition Division.Google Scholar
Koes, R. M. & Pfander, W. H. (1975). Heat load and supplement effects on performance and nutrient utilization by lambs fed orchard-grass hay. Journal of Animal Science 40, 313–19.CrossRefGoogle Scholar
Minson, D. J. & Ternouth, J. H. (1971). The expected and observed changes in the intake of three hays by sheep after shearing. British Journal of Nutrition 26, 31–9.CrossRefGoogle ScholarPubMed
Pani, S. N. (1966). Effect of solar radiation on rectal temperature, pulse rate and respiratory of shorn and unshorn sheep. Indian Veterinary Journal 43, 800–5.Google ScholarPubMed
Parer, J. T. (1963). Wool length and radiant heating effects in sheep. Journal of Agricultural Science, Cambridge 60, 141–4.CrossRefGoogle Scholar
Ramadan, M. Y. (1974). A note on the effect of shearing, shade and water spraying on the heat tolerance of Najdi sheep. Publication, Joint Agricultural Research and Development Project, University College of North Wales, Bangor, Ministry of Agriculture and Water, Saudi Arabia, no. 28, p. 8.Google Scholar
Rea, J. C, Ross, C. V. & Pfander, W. H. (1963). Studies of factors affecting performance of growingfinishing lambs. Missouri Agricultural Research Bulletin, no. 827, 05 1963, p. 65.Google Scholar
Robinson, D. W. (1969). Preliminary observations on the heat tolerance of shorn and nutritionally depleted sheep in a tropical environment. British Veterinary Journal 125, 112–20.CrossRefGoogle Scholar
Rollinson, D. H. J., Injidi, M., Kassab, A., Obaidi, K. & Koster, K. (1969). Studies on the effect of climate on domestic animals in Iraq. III. Effect of climate stress on the body temperature and respiration rate of Awassi sheep. Technical Report, no. 33 UNDP/SE/FAO. Animal Research and Training Project, Baghdad.Google Scholar
Rowell, J. G. & Walters, D. E. (1976). Analysing data with repeated observations on each experimental unit. Journal of Agricultural Science, Cambridge 87, 423–32.CrossRefGoogle Scholar
Snedecor, G. W. & Cochran, W. G. (1970). Statistical Methods, 5th ed.Ames, Iowa: Iowa State University Press.Google Scholar
Spedding, C. R. W. (1970). Sheep Production and Grazing Management, 2nd ed.London: Baillière, Tindall and Cassell.Google Scholar
Ternouth, J. H. & Beattie, A. W. (1970). A note on the voluntary food consumption and the sodiumpotassium ratio of sheep after shearing. Animal Production 12, 343–6.Google Scholar
Wheeler, J. L., Reardon, T. F. & Lambourne, L. J. (1963). The effect of pasture availability and shearing stress on herbage intake of grazing sheep. Australian Journal of Agricultural Research 14, 364–72.CrossRefGoogle Scholar
Williams, G. L. & Andrews, R. (1966). Fattening store lambs on hill farms. Agriculture, London 73, 387–90.Google Scholar
Wodzicka-Tomaszewska, M. (1963). The effect of shearing on the appetite of sheep. New Zealand Journal of Agricultural Research 6, 440–7.CrossRefGoogle Scholar
Youths, A. A., Seoudy, A. M., Galal, E., Salah, E., Ghanem, Y. S. & Khishtn, S. S. (1975). Effect of plane of nutrition on feedlot performance and carcass traits of desert sheep. Tropical Agriculture 52, 233–42.Google Scholar