Chronic heat stress has an effect on glucose, ATP levels, and G6PDH activity. (A) Blood glucose level was decreased in the LT group. (B) G6PDH activity was higher in the liver of broilers in the ST and LT groups under heat stress than in that of Ctrl group. (C) The ATP level was remarkably lower in the liver of broilers in the LT group under chronic heat stress than in that of Ctrl and ST groups. a-c Values with different superscripts within the same column are significantly different (P < 0.05). Abbreviations: ATP, adenosine triphosphate; Ctrl, Control; G6PDH, glucose-6-phosphate dehydrogenase.