EFFECTS OF GLUCOSE IN DRINKING-WATER ON THE CHANGES IN WHOLE-BLOOD VISCOSITY AND PLASMA OSMOLALITY OF BROILER-CHICKENS DURING HIGH-TEMPERATURE EXPOSURE

This study was conducted to elucidate the influence of glucose in drin king water on whole blood viscosity and Plasma osmolality of broilers during high temperature exposure. TWO groups Of birds, which had ad li bitum access to either a 4% glucose-water solution (Group G) or tap wa ter (Group W), were exposed simultaneously to 30 C from 0300 h for 12 h each day for 3 d. During the experimental period, Group G birds had greater metabolic energy intake and body weight gain than Group W. Hem atocrit and whole blood viscosity decreased significantly at 30 C comp ared to controls at 20 C in Group W, whereas, in Group G, no changes w ere found for these two variables. Plasma osmolality also decreased at 30 C compared to 20 C in Group W, whereas no change was noted in this variable in Group G. However, at 20 C, plasma osmolality was signific antly higher in Group Mi than in Group G, but no difference was observ ed between the two groups at 30 C. Plasma protein concentration decrea sed during exposure to 30 C in both groups, but the decrease tended to be greater in Group W than in Group G. These results suggest that glu cose intake may alleviate the influence of heat stress on whole blood viscosity and plasma osmolality.