Effect of heat stress and drinking water salt supplements on plasma electrolytes and aldosterone concentration in broiler chickens.

An experiment was conducted to evaluate the effects of supplementing drinking water with isomolar (0.067 mol/l) KCl or NaCl on mass gain, food and water consumption, rectal temperature, and plasma concentrations of aldosterone, Na+, and K+ in broiler chickens reared in thermoneutral and cycling heat stressing environments. Heat stress decreased (P > or = 0.05) mass gain, food consumption, and plasma concentrations of Na+ and K+, while increases (P < or = 0.05) in plasma concentrations of aldosterone, rectal temperature, and water consumption were observed. Drinking water supplemented with either KCl or NaCl increased (P < or = 0.05) broiler mass gain and water consumption, but had no effect (P > 0.1) on the other variables evaluated. The results of this study indicate that broiler chickens in a heat stress environment are under osmotic stress and supplementing drinking water with 0.067 mol/l KCl or NaCl does not lessen this stress.