Effect of carbonated water on arterial pH, PCO2 and plasma lactate in heat-stressed broilers

1. The effects of tap (TW) or carbonated (CW) water on arterial pH, partial pressure of carbon dioxide (PCO2) and plasma lactate were determined in heat-stressed broilers. Water treatments were infused directly into the crop at a rate of 0.4 ml/min kg BW. 2. Heat stress increased body temperature (Tb) and respiration rate (RR) but both were higher in birds given CW after 4 and 5 h than in TW-infused controls. However, PCO2 was lower and arterial pH and plasma lactate were higher in TW-infused birds after 4 and 5 h of heat stress than in CW-infused birds. Hematocrit was also higher in CW-treated birds after 4 and 5 h of heat stress than in TW controls. 3. The results indicate that CW is capable of attenuating changes in blood pH and PCO2 in heat-stressed domestic fowl. The lower pH in CW birds after 4 and 5 h of heat stress may have suppressed plasma lactate concentrations in these birds.