Effect of ammonium chloride on the bicarbonate buffer system in heat-stressed broilers

1. The effects of ammonium chloride (NH4Cl) on the bicarbonate buffer system and plasma lactate in heat-stressed broilers were investigated. 2. The infusion of a 10 g/l solution of NH4Cl into the crop during a 90 min thermoneutral period produced a metabolic acidosis resulting from a reduction in blood bicarbonate concentration. Blood bicarbonate continued to decrease in NH4Cl-treated birds and reached values which were 30% of controls by the end of a 90 min heat stress period. 3. By the end of heat stress, plasma lactate concentrations were lower in NH4Cl-infused birds than in controls.