Effect of thermal stress on physiological and blood parameters in merino sheep

Open access

Abstract

Fifteen sheep where placed in climatic chamber and exposed to a high temperature (30°C). Then, the air movement was induced in order to examine its soothing effect on heat stress. The physiological reactions like respiratory and heart rates, as well as the morphologic, biochemical parameters and cortisol levels in blood were examined. It was found that under heat stress conditions, the respiratory rate increased up to 96.43 breaths/min, heart rate up to 107.79 beats/min, and white blood cells count decreased to 9.12 k/μL. The increased level of potassium, chlorine, and calcium was also observed. The increased air movement resulted in thermal stress soothing. A decrease in respiratory rate, heart rate, and cortisol concentration was observed. The study demonstrated that heat stress leads to serious changes in physiological and blood parameters in sheep but this effect can be minimised by air movement.

1. Alexiev J., Gudev D., Popova-Ralheva S., Moneva P.: Thermoregulation in sheep. IV. Effect of heat stress on heart rate dynamics in shorn and unshorned ewes from three breeds. Zhivotnov Dni-Nauki 2004, 41, 16-21.

2. Christison G.I., Johnson H.D.: Cortisol turnover in heat stressed cows. J Anim Sci 1972, 53, 1005-1010.

3. El-Sheikh A.S., Salem M.H., Ibrahim I.I., Mohamed A.A., El-Sherbini A.A., Yousef M.K.: Relative adaptability of some local and foreign breeds of sheep to Sahara desert. Egypt J Anim Prod 1981, 21, 109-120.

4. Gomes da Silva R., Paranhos da Costa M.J.R., Silva Sobrinho A.G.: Influence of hot environments on some blood variables of sheep. Int J Biometeorol 1992, 36, 223-225.

5. Haheeb A.A.M., Marai I.F.M., Kamal T.H.: Heat stress. In: Farm Animals and the Environment. Edited by Phillips C. and Pigginns D., CAB International, Wallingford, UK, 1992, pp. 27-47.

6. Hahn G.L.: Dynamic responses of cattle to thermal heat loads. J Anim Sci 1997, 77, 10-20.

7. Kolacz R., Dobrzański Z.: Hygiene and welfare of farm animals. Published by Agricultural University, Wroclaw 2006, pp. 31-38.

8. Marai I.F.M., Bahgat L.B., Shalaby T.H., Abdel-Hafez M.A.: Fattening performance, some behavioral traits and physiological reactions of male lambs fed concentrates mixture alone with or without natural clay, under hot summer of Egypt. Ann Arid Zone 2000, 39, 449-460.

9. Marai I.F.M., El-Darawany A.A., Fadiel A., Abdel-Hafez M.A.M.: Physiological traits as affected by heat stress in sheep- A review. Small Rum Res 2006, 71, 1-12.

10. Mittal J.P., Gosh P.K.: Body temperature, respiration and pulse rate in Corriedale, Marwari and Magra sheep in Rajasthan desert. J Agricult Sci (Cambridge), 1979, 93, 587-591.

11. Pereira A.M.F., Baccari F.Jr., Titto E.A.L., Almeida J.A.A.: Effect of thermal stress on physiological parameters, feed intake and plasma thyroid hormones concentration in Alentejana, Mertolenga, Frisian and Limousine cattle breeds. Int J Biometeorol 2008, 52, 199-208.

12. Sakurada S., Hales J.R.S.: A role for gastrointestinal endotoxins in enhancement of heat tolerance by physical fitness. J Appl Physiol 1998, 84, 207-214.

13. Schmidt Nielsen K.: Animal Physiology. Adaptation and environment. Press Syndicate of the University of Cambridge, U.K., 1997.

14. Silanikove N.: Effects of heat stress on the welfare of extensively managed domestic ruminants. Livestock Prod Sci, 2000, 67, 1-18.

15. Singh M., Rai A.K., More T., Dhaliwal J.S.: Note on comparative physiological response of sheep and goats to high ambient temperature. Indian J Anim Sci 1980, 50, 202-205.

16. Srikandakumar A., Johnson E.H., Mahgoub O.: Effect of heat stress on respiratory rate, rectal temperature and blood chemistry in Omani and Australian Merino sheep. Small Rum Res 2003, 49, 193-198.

17. Taylor R.E.: Adaptation to the environment. In: Scientific Farm Animal Production, Macmillan Publishing Company, New York, NY, 1992, pp. 326-332.

18. Uwayjan M., Bahattacharya A.N.: Effect of high ambient temperature and low humidity on nutrient utilization and on some physiological responses in Awasi sheep fed different levels of roughage. J Anim Sci 1975, 40, 320-328.

19. Winnicka A.: Reference values of basic laboratory tests in veterinary medicine. SGGW, Warszawa, 2011.

Bulletin of the Veterinary Institute in Pulawy

The Journal of National Veterinary Research Institute in Pulawy

Journal Information


IMPACT FACTOR 2018: 0,829
5-year IMPACT FACTOR: 0,938

CiteScore 2018: 0.68


SCImago Journal Rank (SJR) 2018: 0.291
Source Normalized Impact per Paper (SNIP) 2018: 0.501

Cited By

Metrics

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 510 351 32
PDF Downloads 309 244 25