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Studies on the adaptability of three breeds of sheep to a tropical environment modified by altitude I. The annual fluctuation in body temperature and body temperature increase between 6.30 a.m. and 12.30 p.m.

Published online by Cambridge University Press:  27 March 2009

R. B. Symington
R. B. Symington
Affiliation:
Department of Agriculture, University College of Rhodesia and Nyasaland, Salisbury
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Extract

Early morning and midday body temperatures of rams and ewes of three breeds of sheep were measured once weekly for a period of 10 months in Northern Rhodesia and 12 months in Southern Rhodesia.

1. In all breeds seasonal fluctuations in body temperature were due to concurrent fluctuations in ambient air temperature.

2. Mean annual body temperatures were: Merino 102·2° F.; Persian 101·7° F. and Native 101·7° F. Wool and hair breeds differed considerably in their early morning temperatures and in their body temperature increases from 6.30 a.m. to 12.30 p.m. Mean annual values for these measurements were Merino 101·73 and 1·92° F.; Persian 100·81 and 1·83° F.; Native 100·73 and 1–92° F. At all times Merinos showed markedly greater uniformity of body temperature than either hair breed. There was no evidence to show that the thermoregulatory mechanisms of these animals had been stressed unduly.

3. Sex had no consistent effect on body temperature or on rise in body temperature.

In general, lactating ewes showed a significantly higher initial body temperature than either empty or pregnant ewes, but the respective heat tolerances as measured by body temperature increase did not differ appreciably. Body temperature differed little in empty and pregnant ewes.

4. Although the youngest group of ewes in each breed showed the highest early morning temperature, there was no evidence that heat tolerance was less in young than in old animals.

5. Black-coated Native ewes had higher initial body temperatures and a smaller body temperature increase during the summer months in Southern Rhodesia than brown or broken-coloured Native ewes. These effects were due to differences in coat density rather than to differences in coat colour or skin pigmentation.

6. In all breeds the magnitude of the diurnal and annual variation in body temperature was different in Northern and Southern Rhodesia. Differences were largely of climatic origin but low plane of nutrition in Southern Rhodesia possibly reduced critical body temperature and impaired thermoregulatory ability.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 55 , Issue 3 , December 1960 , pp. 287 - 294
Copyright
Copyright © Cambridge University Press 1960

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References

REFERENCES

Alexander, G. & McCance, I. (1958). Aust. J. Agric. Res. 9, 339.Google Scholar
Black, A. (1953). Veterinary Dictionary. London: A. and C. Black.Google Scholar
Bonsma, J. C. (1948). Fmg. In S. Afr. 23, 439.Google Scholar
Bramley, W. (1956). Fmrs' Weekly, S. Afr. 91, 16.Google Scholar
Dempsey, E. & Astwood, E. G. (1943). Endocrinology, 32, 809.Google Scholar
Duerden, J. E. & Boyd, E. (1930). Bull. Dep. Agric., S. Afr. no. 82.Google Scholar
Dukes, H. H. (1947). The Physiology of Domestic Animals. New York: Comstock.Google Scholar
Fesdlay, J. D. (1950). Bull. Hannah Dairy Res. Inst. no. 9.Google Scholar
Glover, J. (1952). East Afr. Agric. J. 17, 172.Google Scholar
Hafez, E. S. E., Badreldin, A. L. & Sharafeldin, H. A. (1956). J. Agric. Sci. 47, 280.Google Scholar
Kammlade, W. C. (1947). Sheep Science. Chicago: Lippincott.Google Scholar
Labuschagne, F. J. (1948). Fmg. In S. Afr. 23, 77.Google Scholar
Lee, D. H. K. (1950). Aust. J. Agric. Res. 1, 200.Google Scholar
McDowell, R. E., Matthews, C. A., Lee, D. K. H. & Fohrman, M. H. (1953). J. Anim. Sci. 12, 757.Google Scholar
Miller, J. C. & Monge, L. (1946). J. Anim. Sci. 5, 147.Google Scholar
Minett, F. C. (1955). J. Comp. Path. 65, 197.Google Scholar
Phillips, R. W. (1948). Breeding Livestock Adapted to Unfavourable Environments, F.A.O. Publication no. 1.Google Scholar
Quinlan, J. & Mare, G. S. (1931). D.V.S. Rep. S. Afr. no. 8.Google Scholar
Rhoad, A. O. (1944). Tropical Agric. 21, 162.Google Scholar
Rieck, R. F., Hardy, M. H., Lee, D. H. K. & Carter, H. B. (1950). Aust. J. Agric. Res. 1, 217.Google Scholar
Simkin, C. H. W. (1958). Handbook German Merino Assoc. S. Afr. p. 13.Google Scholar
Stewart, R. E. & Brody, S. (1954). Bull. Mo. Agric. Exp. Res. Sta., no. 561.Google Scholar
Wright, N. C. (1954). Progress in the Physiology of Farm Animals. London: Butterworth.Google Scholar
Yeates, N. T. M. (1953). J. Agric. Sci. 43, 199.CrossRefGoogle Scholar
Yeates, N. T. M. (1956). Aust. J. Agric. Res. 7, 635.Google Scholar