THERMOREGULATION IN THE ONE-HUMPED SHE CAMEL (Camelus dromedarius): DIURNAL AND SEASONAL EFFECTS ON CORE AND SURFACE TEMPERATURES | ||||
| Journal of Animal and Poultry Production | ||||
| Article 5, Volume 2, Issue 10, October 2011, Page 427-437 PDF (362.05 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jappmu.2011.83406 | ||||
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| Authors | ||||
| Afaf A. Abdel-Hameed1; Wissam T. El-Zeiny2; S. A. Zaakoug2 | ||||
| 1Animal Physiology Dept,, Desert Research Center, Al Matareya, Cairo, Egypt | ||||
| 2Zoology Dept., Fac. of Sci., Al-Azhar Univ., Nasr City, Cairo, Egypt | ||||
| Abstract | ||||
| The study was carried out at Maryout Research Station, 35 km to Southwest of Alexandria that belongs to the Desert Research Center (DRC), Egypt. The study was performed to evaluate the thermoregulatory ability of one-humped she camel (Camelus dromedarius) during summer and winter seasons. Five adult healthy she-camels aged 6-8 years with initial body weight recorded 522.00±3.52 and 613.00±6.63 kg for summer and winter seasons, respectively, were used. The animals were kept in outdoor pen (un-shaded). Rectal (RT), skin surface (SST), surface coat (SCT) and mid-coat (MCT) temperatures were measured 3 times daily (6:00 am; 12:00 pm and 6:00 pm) during the ten middle days of each month during both summer (from June till August) and winter (from December till February). Ambient temperature and relative humidity were recorded at 06:00, 12:00 and 18:00 hr during summer and winter seasons. Regarding the effect of season on RT, the results indicated that there were significant differences (P<0.01) between seasons. Average RT was 38.6 and 37.45 ºC during summer and winter seasons, respectively. In general, seasonal and diurnal variations in rectal temperature followed closely observed changes in the temperature-humidity index (THI). Skin surface temperature(SST)varied between the selected sites over the animal’s body and between seasons. The changes in SST at the selected sites were higher (P<0.01) under cold climatic conditions (winter) than warm climatic conditions (summer). These results indicated that SSTwas dependent on climatic conditions. The results revealed that SSTrecorded highly (P<0.01) significant differences between hump (represent site exposed to sun) and abdomen (represent site not exposed to sun). The hump site was the warmest during summer (35.5 and 33.27 ºC) and winter (16.23 and 20.17 ºC) for SCT and MCT, respectively, whereas AB site recorded the lowest readings during summer (30.30 and 28.57 ºC) and winter (10.70 and 13.07 ºC) for SCT and MCT, respectively. The mid-coat temperature is less than surface-coat temperature in summer in order to decrease the transfer of heat from air to the skin. Meanwhile, the mid-coat temperature is more than surface-coat temperature in winter to minimize or prevent the dissipation of heat from the skin to the environment and preserve skin temperature as much as possible. The camels' coats, which are hairy rather than wooly in nature, create a favorable microclimatic buffer zone that separate the body surface from the surrounding harsh climatic conditions. | ||||
| Keywords | ||||
| She camel; dromedary; thermoregulation; diurnal rhythms; diurnal season effects | ||||
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