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Heat tolerance of different genetic groups of sheep exposed to elevated temperature conditions

Published online by Cambridge University Press:  27 March 2009

M. Singh
Affiliation:
Central Sheep and Wool Research Institute, Avikanagar, India 304501
T. More
Affiliation:
Central Sheep and Wool Research Institute, Avikanagar, India 304501
A. K. Rai
Affiliation:
Central Sheep and Wool Research Institute, Avikanagar, India 304501

Summary

Indian Chokla and Malpura and their crosses with exotic Rambouillet and pure bred Rambouillet sheep were exposed to increasing temperature (20, 25, 30, 35 and 42 °C), or to 40 °C for 6 ha day for about a week, or suddenly to 40·4 or 44·2 °C to study their relative heat tolerance. Pronounced increase in the frequency of respiration under hot conditions together with increase in rectal temperature (under 44·2 °C) of Rambouillet contrasted with the physiological responses of the native breeds of sheep. Under thermal stress the Chokla and Malpura consumed more feed than the Rambouillet or the half breds. The Rambouillet × Chokla or the Rambouillet × Malpurahalf breds were apparently more heat tolerant than the Rambouillet sheep.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1980

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References

Blaxter, K.L. (1966). The Energy Metabolism of Ruminants. London: Hutchinson Scientific and Technical.Google Scholar
Diwivedi, I.S.D. (1976). Studies on the adaptability of exotic breeds of sheep and their crosses with indigenous breeds. I. Fluctuations in body temperature, pulse rate and respiration. Indian Veterinary Journal 53, 938942.Google Scholar
Eyai, E. (1963 a). Shorn and unshorn Awassi sheep. III. Respiration rate. Journal of Agricultural Science, Cambridge 60, 175181.Google Scholar
Eyal, E. (1963 b). Shorn and unshorn Awassi sheep. IV. Skin temperature and changes in temperature and humidity in the fleece and its surface. Journal of Agricultural Science, Cambridge 60, 183193.CrossRefGoogle Scholar
McDowell, R.E. (1972). Improvement of Livestock Production in Warm Climate. San Francisco: W. H. Freeman & Co.Google Scholar
MacFarlane, W.V., Morris, J.H. & Howard, B. (1958). Heat and water in tropical merino sheep. Australian Journal of Agricultural Research 9, 217228.CrossRefGoogle Scholar
Rai, A.K., Singh, M. & More, T. (1979). Cutaneous water loss and respiration rates of various breeds of sheep at high ambient temperatures. Tropical Animal Health and Production 11, 5156.CrossRefGoogle ScholarPubMed
Seth, o.N. & Roy, A. (1967). Physiological reactions of Romney Marsh, Corriedale and Bikaneri (Magra) rams under identical climatic conditions. Indian Journal of Veterinary Science and Animal Husbandry 37, 360364.Google Scholar
Singh, B. & Roy, A. (1963). Studies on certain aspects of sheep and goat husbandry. V. Effect of season on respiration and pulse rate of Corriedale and Bikaneri sheep and Jamnapari goat. Indian Journal of Veterinary Science 33, 128141.Google Scholar
Singh, M. & Acharya, R.M. (1977). A note on the mode of heat dissipation in different types of sheep. Indian Journal of Animal Science 47, 367368.Google Scholar
Taneja, G.C. (1966). Physiological responses of sheep to arid environment. I. Comparative responses of indigenous and exotic breed. Indian Journal of Physiology and Allied Sciences 20, 2429.Google Scholar