Distribution of body fluid and change of blood viscosity in broilers (Gallus domesticus) under high temperature exposure

This study was to observe the distribution of body fluid by measuring blood volume, extracellular and intracellular fluid volumes and total body water under heat exposure. in order to clarify the mechanism of decrease in whole blood viscosity of the heat-exposed broilers. Whole blood viscosity, haematocrit, plasma protein concentration, plasma osmolality and extracellular fluid volume decreased during high temperature exposure, while plasma and blood volumes increased. No significant changes were found in both intracellular fluid volume and total body water between thermoneutral and high temperature exposure. These results indicate the decreased whole blood viscosity is induced by a plasma volume expansion, in which water may come from the interstitial space and alimentary tract, under heat exposure. (C) 1999 Elsevier Science Ltd. All rights reserved.