Temperature and water deprivation and their effect on ... - Nwrc.gov.sa

37 the difference was only O.8°C.Thus, the animals didnot allow for much decrease in <strong>their</strong> body temperature,although the air temperature was low. This isprobably because the animals tend to take more food(while dehydration), in addition to using <strong>their</strong> ownbody fat to produce excess heat energy to counter thedrop of the air temperature <strong>and</strong> succeed to keep asteady body temperature (Tietz, 1987).The opposite situation was seen when the animalswere dehydrated in summer as they allowed for greatervariation in <strong>their</strong> body temperature (2.1°C) during theday.A directly proportional relationship has beennoticed between the air temperature <strong>and</strong> the animalbody temperature during the last periods ofdehydration.This was seen when the lowest animalbody temperature was 39.5°C when the air. temperaturewas 28°C, <strong>and</strong> the highest recorded animal bodytemperature was 41.6°C when the air temperature was41°C at 4-6 pm. It could be explained that thisvariation was accomplished in <strong>their</strong> attempt to reduceevaporation through respiration <strong>and</strong> sweating duringhigh body <strong>and</strong> air temperature in the day. Similarresults were obtained by Ghobrial(1970b) on Afrigazelle <strong>and</strong> Taylor (1970b) on Thompson's <strong>and</strong> Grant'sgazelles. When the air temperature starts to drop inIthe afternoon <strong>and</strong> night, the animals dissipate <strong>their</strong>body heat to the environment to reach the lbwest~ : . i :' ."' t ;.,.• ' ~ j •